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CONTENTS1. INDIA - LOCATION ............................................................................................................ 1

Structure and Physiography......................................................................................................... 2The Peninsular Block ................................................................................................................... 2The Himalayas and other Peninsular Mountains ........................................................................... 2Indo-Ganga-Brahmaputra Plain ..................................................................................................... 2Physiography .............................................................................................................................. 3North and North Eastern Himalaya: .............................................................................................. 3The Himalayan Mountains ........................................................................................................... 3Karewas ...................................................................................................................................... 4Longitudinal division ................................................................................................................... 4Kashmir or Northwestern Himalayas ............................................................................................. 4The Himachal and Uttaranchal Himalays ....................................................................................... 5The Darjeeling and Sikkim Himalayas ............................................................................................ 5The Arunachal Himalayas ............................................................................................................ 6The Eastern Hills and Mountains ................................................................................................. 6The Northern Plains ..................................................................................................................... 6The Peninsular Plateau ................................................................................................................. 7The Deccan Plateau ..................................................................................................................... 8The Central Highlands ................................................................................................................. 8The Northeastern Plateau ............................................................................................................. 9The Indian Desert ........................................................................................................................ 9The Coastal Plains ....................................................................................................................... 9The Islands ............................................................................................................................... 10

2. DDRAINAGE SYSTEM ....................................................................................................... 11Drainage systems of India .......................................................................................................... 12Important Drainage Patterns ....................................................................................................... 12The Himalayan Drainage ............................................................................................................ 12Evolution of the Himalayan Drainage.......................................................................................... 12The river Systems of the Himalayan Drainage ............................................................................. 13The Indus system ...................................................................................................................... 13The Ganga System ..................................................................................................................... 14The Brahmaputra System ........................................................................................................... 15The peninsular drainage system ................................................................................................. 16The Evolution of Peninsular Drainage System ............................................................................ 16River systems of the peninsular drainage .................................................................................... 16Smallar Rivers flowing towards the West .................................................................................... 17

3. CLIMATE ....................................................................................................................... 19Factors determining the climate of India ...................................................................................... 19

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II Contents

Mechanism of Weather in the Winter Season .............................................................................. 20Inter Tropical Convergence Zone (ITCZ) .................................................................................... 21Mechanism of Weather in the Summer Season ............................................................................ 21The Nature of Indian Monsoon .................................................................................................. 22Onset of the Monsoon ............................................................................................................... 22Rain-bearing Systems and Rainfall Distribution ........................................................................... 23EI-Nino and the Indian Monsoon ............................................................................................... 23Break in the Monsoon ................................................................................................................ 24The Rhythm of Seasons ............................................................................................................. 24Some Famous Local Storms of Hot Weather Season .................................................................... 24The Cold Weather Season .......................................................................................................... 24Role of Westerly Jet Stream ........................................................................................................ 25The Hot Weather Season ........................................................................................................... 26The Southwest Monsoon Season .............................................................................................. 27Monsoon Winds of the Arabian Sea ........................................................................................... 27Monsoon Winds of the Bay of Bengal ........................................................................................ 28Characteristics of Monsoonal Rainfall ........................................................................................ 28Season of Retreating Monsoon .................................................................................................. 29Distribution of Rainfall ............................................................................................................... 29Types of Forests ........................................................................................................................ 31Tropical Evergreen and Semi Evergreen Forests .......................................................................... 31

4. NATURAL VEGETATION .................................................................................................... 31Tropical Deciduous Forests ....................................................................................................... 32Tropical Thorn Forests .............................................................................................................. 32Montane Forests ....................................................................................................................... 32Littoral and Swamp Forests ........................................................................................................ 33Forest cover in India .................................................................................................................. 34Forest Conservation .................................................................................................................. 34Social Forestry........................................................................................................................... 35Farm Forestry ............................................................................................................................ 35Wildlife ...................................................................................................................................... 35Wildlife Conservation in India .................................................................................................... 36Biosphere Reserves ................................................................................................................... 37Nilgiri Biosphere Reserve ........................................................................................................... 37Nanda Devi Biosphere Reserve .................................................................................................. 37Sunderbans Biosphere Reserve .................................................................................................. 38Gulf of Mannar Biosphere Reserve ............................................................................................. 38

5. SOILS ............................................................................................................................ 39Classification of Soils ................................................................................................................. 39Alluvial Soils ............................................................................................................................. 40Black Soil ................................................................................................................................... 40Red and Yellow Soil ................................................................................................................... 40Laterite Soil ............................................................................................................................... 41


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Contents III

Arid Soils .................................................................................................................................. 41Saline Soils ................................................................................................................................ 41Peaty Soils ................................................................................................................................. 41Forest Soils ............................................................................................................................... 42Soil Degradation ........................................................................................................................ 42Soil Erosion ............................................................................................................................... 42Soil Conservation ...................................................................................................................... 43Water Resources ....................................................................................................................... 43Water Resources of India ........................................................................................................... 43Surface Water Resources ........................................................................................................... 44Groundwater Resources ............................................................................................................. 44Demand of Water for Irrigation ................................................................................................... 45Prevention of Water Pollution .................................................................................................... 46Watershed Management ............................................................................................................ 46Rainwater Harvesting ................................................................................................................. 47Highlights of India’s National Water Policy, 2002 ........................................................................ 47

6. LAND USE AND AGRICULTURE ........................................................................................... 49Land-use Changes in India ......................................................................................................... 50Agricultural Land Use in India .................................................................................................... 51Primitive Subsistence Farming .................................................................................................... 52Intensive Substance Farming ..................................................................................................... 52Commercial Farming ................................................................................................................... 53Types of Farming ....................................................................................................................... 53Cropping Pattern ....................................................................................................................... 53Growth of Agricultural Output and Technology .......................................................................... 59

7. MINERAL AND ENERGY RESOURCES ................................................................................... 61Mode of Occurrence of Minerals ................................................................................................ 61Agencies Involved in the exploration of minerals ........................................................................ 62Distribution of Minerals in India ................................................................................................. 62Major Industries ........................................................................................................................ 67The Iron and Steel Industry........................................................................................................ 67Integrated Steel Plants ............................................................................................................... 68Visvesvaraiya Iron and Steel Works Ltd. (VISL) .......................................................................... 68Rourkela Steel Plant ................................................................................................................... 68Bhilai Steel Plant ........................................................................................................................ 69The Cotton Textile Industry........................................................................................................ 69

8. SUGAR INDUSTRY ............................................................................................................ 72Location of the Sugar Industry................................................................................................... 72Petrochemical Industries ............................................................................................................ 73Knowledge based Industries ...................................................................................................... 74Liberalization, Privatization, Globalization (LPG) and Industrial Development in India ................... 74Industrial Region and Districts ................................................................................................... 75


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IV Contents

Industrial Regions in India ......................................................................................................... 76Mumbai-Pune Industrial Region ................................................................................................. 76Hugli Industrial Region .............................................................................................................. 77Bangalore-Chennai Industrial Region ......................................................................................... 77Gujarat Industrial Region ............................................................................................................ 78Chotanagpur Region .................................................................................................................. 78Vishakhapatnam-Guntur Region ................................................................................................. 78Gurgaon-Delhi-Merrut Region .................................................................................................... 79Kollam-Tiruvanantapuram Region .............................................................................................. 79

9. TRANSPORT AND COMMUNICATION ...................................................................................... 80Land Transport .......................................................................................................................... 80Indian Road Network (2005) ....................................................................................................... 80Rural Roads ............................................................................................................................... 81Other Roads .............................................................................................................................. 81National Highways Development Projects .................................................................................. 81Rail Transport ............................................................................................................................ 82Water Transport ........................................................................................................................ 83Inland Waterways ...................................................................................................................... 83Oceanic Routes ......................................................................................................................... 83Air Transportation ..................................................................................................................... 83History of Indian Airlines ........................................................................................................... 84Mass Communication System .................................................................................................... 85International Trade .................................................................................................................... 86Direction of Trade ...................................................................................................................... 87Ports ......................................................................................................................................... 87Tourism as a Trade..................................................................................................................... 89

11. OUR SOLAR SYSTEM ........................................................................................................ 90The Moon ................................................................................................................................. 91Development of Lithosphere ...................................................................................................... 91Minerals & Rocks ...................................................................................................................... 92Metallic Minerals ....................................................................................................................... 92Non-Metallic Minerals ............................................................................................................... 93Rocks ........................................................................................................................................ 93Igneous Rocks ........................................................................................................................... 93Sedimentary Rocks .................................................................................................................... 93Metamorphic Rocks ................................................................................................................... 94Interior of the Earth .................................................................................................................... 94Direct Sources ........................................................................................................................... 94Indirect Sources ......................................................................................................................... 94Earthquake ................................................................................................................................ 94Why does the earth shake? ........................................................................................................ 94Earthquake Waves ..................................................................................................................... 95Propagation of Earthquake Waves .............................................................................................. 95


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Contents V

Emergence of Shadow Zone ....................................................................................................... 95Measuring Earthquakes ............................................................................................................. 96Structure of the Earth ................................................................................................................. 96

12. LAND FORMS .................................................................................................................. 99Running Water .......................................................................................................................... 99Youth ........................................................................................................................................ 99Mature ...................................................................................................................................... 99Old ........................................................................................................................................... 100Erosional landforms .................................................................................................................. 100Vallyes...................................................................................................................................... 100Potholes and Pluge Pools .......................................................................................................... 100Incised or Entrenched Meanders ............................................................................................... 100River Terraces ........................................................................................................................... 100Depositional Landforms ............................................................................................................ 100Alluvial Fans ............................................................................................................................ 100Deltas ....................................................................................................................................... 100Floodplains, Natural Levees and Point Bars ............................................................................... 100Meanders ................................................................................................................................. 101Groundwater ............................................................................................................................. 101Erosional Landforms ................................................................................................................. 102Pools, Sinkholes, Lapies and Limestone Pavements ................................................................... 102Glaciers .................................................................................................................................... 102Erosional Landforms ................................................................................................................. 103Horns and Serrated Ridges ........................................................................................................ 103Glacial Valleys/Troughs............................................................................................................. 103Depositional Landforms ............................................................................................................ 103Eskers ...................................................................................................................................... 103Outwash Plains ......................................................................................................................... 104Drumlins ................................................................................................................................... 104Waves and Currents ................................................................................................................. 104High Rocky Coasts ................................................................................................................... 104Low sedimentary coasts ............................................................................................................ 105Erosional Landforms ................................................................................................................. 105Depositional landforms ............................................................................................................. 105Erosional Landforms ................................................................................................................. 106

14. COMPOSITION AND STRUCTURE OF ATMOSPHERE .............................................................. 109Composition and Structure of Atmosphere ................................................................................ 109Composition of the Atmosphere ................................................................................................ 109Structure of the Atmosphere ..................................................................................................... 110Evaporation and Condensation ................................................................................................. 111


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Geography 1

The mainland of India, extends fromKashmir in the north to Kanniyakumari inthe south and Arunachal Pradesh in the eastto Gujarat in the west. India’s territorial limitfurther extends towards the sea upto 12nautical miles (about 21.9 km) from the coast.(See the box for conversion).

Statute mile= 63,360 inchesNautical mile= 72,960 inches1 Statute mile= about 1.6 km (1.584 km)1 Nautical mile= about 1.8 km (1.852 km)Our southern boundary extends upto

6º45 N latitude in the Bay of Bengal. If youwork out the latitudinal and longitudinalextent of India, they are roughly about 30degrees, whereas the actual distancemeasured from north to south extremity is3,214 km, and that from east to west is only2,933 km. What is the reason for thisdifference?

This difference is based on the fact thatthe distance between two longitudesdecreases towards the poles whereas thedistance between two latitudes remains thesame everywhere.

From the values of latitude, it isunderstood that the southern part of thecountry lies within the tropics and thenorthern part lies in the sub-tropical zone orthe warm temperate zone. This location isresponsible for large variations in land forms,

climate, soil types and natural vegetation inthe country.

There is a general understanding amongthe countries of the world to select thestandard meridian in multiples of 7º30 oflongitude. That is why 82º30 E has beenselected as the ‘standard meridian’ of India.Indian Standard Time is ahead of GreenwichMean Time by 5 hours and 30 minutes.

There are some countries where thereare more than one standard meridian due totheir vast east-to-west extent. For example,the USA has seven time zones.

Now, let us observe the extent and itsimplications on the Indian people. From thevalues of longitude, it is quite discernible thatthere is a variation of nearly 30 degrees, whichcauses a time difference of nearly two hoursbetween the easternmost and thewesternmost parts of our country. What isthe use of the standard meridian? While thesun rises in the northeastern states about twohours earlier as compared to Jaisalmer, thewatches in Dibrugarh, Imphal in the east andJaisalmer, Bhopal or Chennai in the otherparts of India show the same time. Why doesthis happen?

Name a few place in India throughwhich the standard meridian passes?

India with its area of 3.28 million sq. kmaccounts for 2.4 per cent of the world’s land

INDIA - LOCATION

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2 Gist of NCERT (Geography)

surface area and stands as the seventh largestcountry in the world.Structure and Physiography

Current estimation shows that the earthis approximately 4600 million years old.

Based on the variations in its geologicalstructure and formations, Indian can bedivided into three geological divisions. Thesegeological regions broadly follow the physicalfeatures:

(i) The Peninsular Block(ii) The Himalayas and other Peninsular

Mountains(iii) Indo-Ganga-Brahmaputra Plain

The Peninsular Block

The northern boundary of thePeninsular Block may be taken as an irregularthe running from Kachchh along the westernflank of the Aravali Range near Delhi andthen roughly parallel to the Yamuna and theGanga as far as the Rajmahal Hills and theGanga delta. Apart from these, the KarbiAnglong and the Meghalaya Plateau the thenortheast and Rajasthan in the west are alsoextensions of this block. The northeasternparts are separated by the Media fault inWest Bengal from the Chotanagpur plateau.In Rajasthan, the desert and other desert-likefeatures overlay this block.

The Peninsula is formed essentially bya great complex of very ancient gneisses andgranites, which constitutes as major part ofit. Since the Cambrian period, the Peninsulahas been standing like a rigid block with theexception of some of its western coast whichis submerged beneath the sea and some otherparts changed due to tectonic activity withoutaffecting the original basement. As a part ofthe Indo-Australian Plate, it has been

subjected to various vertical movements andblock faulting. The rift valleys of theNarmada, the Tapi and the Mahanadi andthe Satpura block mountains are someexamples of it. The Peninsula mostly consistsof relict and residual mountains like theAravali hills, the Nallamala hills, the Javadihills, the Veliconds hills, the Palkonda rangeand the Mahendragiri hills, etc. The rivervalleys here are shallow with low gradients.

Most of the east flowing rivers formdeltas before entering into the Bay of Bengal.The deltas formed by the Mahanadi, theKrishna, the Kaveri and the Godavari areimportant examples.The Himalayas andother Peninsular Mountains

The Himalayas along with otherpeninsular mountains are young, weak andflexible in their geological structure unlike therigid and stable peninsular Block,Consequently, they are still subjected to theinterplay of exogenic and endogenic forces,resulting in the development of faults, foldsand thrust plains. These mountains aretectonic in origin, dissected by fast-flowingrivers which are in their youthful stage.Various landforms like gorges, V-shapedvalleys, rapids, waterfalls, etc. are indicativeof this stage.Indo-Ganga-Brahmaputra Plain

The third geological division of Indiacomprises the plains form by the river Indus,the Ganga and the Brahmaputra. Originally,it was a geo-synclinal depression whichattained its maximum development duringthe third phase of the Himalayan during thethird phase of the Himalayan mountainformation approximately about 64 millionyears ago. Since then, it has been gradually


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India - Location 3

filled by the sediments brought by theHimalayan and Peninsular rivers. Averagedepth of alluvial deposits in these plainsranges from 1,000-2,000 m.Physiography

‘Physiography’ of an area is the outcomeof structure, process and the stage ofdevelopment.

Based on these macro variations, Indiacan be divided into the follow physiographicdivisions:

(i) The Northern and NortheasternMountains

(ii) The Northern Plain(iii) The Peninsular Plateau(iv) The Indian Desert(v) The Coastal Plains(vi) The Islands.

North and North Eastern Himalaya:

Formation of Physical features of northand north-eastern Himalay is a result of“Plate tectonics” According to Plate Tectonictheory earth is divided into several plateau.The formation of Himalaya & north easternmountain is due to convergent of two platesEurasia (North of Himalaya) and Gondwana(Indian subcontinents Australia, South Africa,South America). Both the plates came closeto each other and tethys sediment calledgeosynclines was pressed from two sidesgave birth to current Himalaya mountains.

The Himalayan uplift out of the Tethyssea and subsidence of the northern flank ofthe peninsular plateau resulted in theformation of a large basin. In due course oftime this depression, gradually got filled withdeposition of sediments by the rivers flowingfrom the mountains in the north and thepeninsular plateau in the south. A flat land

of extensive alluvial deposits led to theformation of the northern plains of India.

The land of India displays great physicalvariation. Geologically, the Peninsular Plateauconstitutes one of the ancient landmasses onthe earth’s surface. It was supposed to be oneof the most stable land blocks. TheHimalayans and the Northern Plains are themost recent landforms. From the view pointof geology, Himalayan Mountains form anunstable zone. The whole mountain systemof Himalaya represents a very youthfultopography with high peaks, deep valleysand fast flowing rivers. The northern plainsare formed of alluvial deposits. Thepeninsular plateau is composed of igneousand metamorphic rocks with gently risinghills and wide valleys.The Himalayan Mountains

The Himalayas, geologically young andstructurally fold mountains stretch over thenorthern borders of India. These mountainranges run in a west-east direction from theIndus to the Brahmaputra. The Himalayasrepresent the loftiest and one of the mostrugged mountain barriers of the world. Theyform an arc, which covers a distance of about2,400 Km.

Their width varies from 400 Km inKashmir to 150 Km in Arunachal Pradesh.The altitudinal variations are greater in theeastern half than those in the western half.The Himalaya consists of three parallel rangesin its longitudinal extent. A number of valleyslie between these ranges. The northern mostrange is known as the Great or InnerHimalayas of the ‘Himadri’. It is the mostcontinuous range consisting of the loftiestpeaks with an average height of 6,000 metres.It contains all the prominent Himalayan


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peaks. The folds of Great Himalayas areasymmetrical in nature. The core of this partof Himalayas is composed of granite. It isperennially snow bound, and a number ofglaciers descend from this range.

The range lying to the south of theHimadri forms the most rugged mountainsystem and is known as Himachal or lesserHimalaya. The ranges are mainly composedof highly compressed and altered rocks. Thealtitude varies between 3,700 and 4,500 metresand the average width is of 50 Km. Whilethe Pir Panjal range forms the longest andthe most important rage, the Dhaula Dharand the Mahabharat ranges are alsoprominent ones. This range consists of thefamous valley of Kashmir, the Kangra andKullu Valley in Himachal Pradesh. This regionis well known for its hill stations.Karewas

Karewas are the thick deposits of glacialclay and other materials embedded withmoraines. The outer most range of theHimalayas is called the Shiwaliks. Theyextend over a width of 10.50 Km and havean altitude varying between 900 and 1100metres. These ranges are composed ofunconsolidated sediment brought down byrivers from the main Himalayans rangeslocated farther north. These valleys arecovered with thick gravel and alluvium. Thelongitudinal valley lying between lesserHimalaya and the Shiwaliks are known asDuns. Dehra Dun, Kotli Dun and Patli Dunare some of the well-known Duns.

An Interesting Fact in Kashmir Valley,the meanders in Jhelum river are caused bythe local base level provided by the erstwhilelarger lake of which the present Dal lake is asmall part.

There are large-scale regional variationswithin the Himalayas. On the basis of relief,alignment of ranges and othergeomorphological features the Himalayas canbe divided into the following sub-divisions:Longitudinal division

(i) Kashmir or NorthwesternHimalayas

(ii) Himachal and UttaranchalHimalayas

(iii) Darjeeling and Sikkim Himalayas(iv) Arunachal Himalayas(v) Eastern Hills and Mountains

Kashmir or Northwestern Himalayas

It comprise a series of ranges such asthe Karakoram. Ladakh. Zaskar and PirPanjal. The northeastern part of the KashmirHimalayas is a cold desert, which liesbetween the Greater Himalayas and theKarakoram ranges. Between the GreatHimalayas and the Pir Panjal range, lies theworld famous valley of Kashmir and thefamous Dal Lake. Important glaciers of SouthAsia such as the Baltoro and Siachen are alsofound in this region. The Kashmir Himalayasare also famous for Karewa formations, whichare useful for the cultivation of Zafran, a localvariety of saffron. Some of the importantpasses of the region are Zoji La on the GreatHimalayas. Banihal on the Panjal, Photu Laon the Zaskar and Khardung La on theLadakh range. Some of the important freshlakes such as Dal and Wular and salt waterlakes such as Pangong Tso and Moriri are alsoin this region. This region is drained by theriver Indus, and its tributaries such as theJhelum and the Chenab. The Kashmir andnorthwestern Himalayas are well-known fortheir scenic beauty and picturesque


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India - Location 5

landscape. The landscape of Himalayas is amajor source of attraction for adventuretourists. Some famous places of pilgrimagesuch as Vaishno Devi, Amarnath Cave,Charar -e-Shariff, etc. are also located hereand large number of pilgrims visits theseplaces every year.

Srinagar, capital city of the Jammu andKashmir is located on the banks of Jhelumriver. Dal Lake in Srinagar presents aninteresting physical feature. Jhelum in thevalley of Kashmir is still in its youth stageand yet forms meanders- a typical featureassociated with the mature stage in theevolution of fluvial land form.

The southernmost part of this regionconsists of longitudinal valleys known as‘duns’. Jammu dun and Pathankot dun areimportant examples.The Himachal and Uttaranchal Himalays

This part lies approximately between theRavi in the west and the Kali (a tributary ofGhaghara) in the east. It is drained by twomajor river systems of India, i.e. the Indusand the Ganga. Tributaries of the Indusinclude the river Ravi, the Beas and the Satluj,and the tributaries of Ganga flowing throughthis region include the Yamuna and theGhaghara. The northernmost part of theHimachal Himalayas is an extension of theLadakh cold desert, which lies in the Spitisubdivision of district Lahul and Spiti. All thethree ranges of Himalayas are prominent inthis section also. These are the GreatHimalayan range, the Lesser Himalayas(which is locally known as Dhaoladhar inHimachal Pradesh and Nagtibha inUttaranchal) and the Shiwalik range from theNorth to the South. In this section of LesserHimalayas, the altitude between 1,000-2,000

m specially attracted to the British colonialadministration, and subsequently, some of theimportant hill stations such as Dharamshala,Mussoorie, Shimla Kaosani and thecantonment towns and health resorts such asShimla, Mussoorie, Kasauli, Almora,Lansdowne and Ranikhet, etc. weredeveloped in this region.

The two distinguishing features of thisregion from the point of view ofphysiography are the ‘Shiwalik’ and ‘Dunformations’. Some important duns located inthis region are the Chandigarh- Kalka dun,Nalagarh dun, Dehra Dun, Harike dun andthe Kota dun, etc. Dehra Dun is the largestof all the duns with an approximate lengthof 35-45 km and a width of 22-25 km. In theGreat Himalayan range, the valleys aremostly inhabited by the Bhotia’s. These arenomadic groups who migrate to ‘Bugyals’(the summer grasslands in the higher reaches)during summer months and return to thevalleys during winters. The famous ‘Valleyof flowers’ is also situated in this region. Theplaces of pilgrimage such as the Gangotri,Yamunotri, Kedarnath, Badrinath andHemkund Sahib are also situated in this part.The region is also known to have five famousPrayags (river confluences). Can you namesome other famous prayags in other parts ofthe country?The Darjeeling and Sikkim Himalayas

They are flanked by Nepal Himalayasin the west and Bhutan Himalayas in the east.It is relatively small but is a most significantpart of the Himalayas. Known for its fast-flowing rivers such as Tista, it is a region ofhigh mountain peaks like Kanchenjunga(Kanchengiri), and deep valleys. The higherreaches of this region are inhabited by


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Lepcha tribes while the southern part,particularly the Darjeeling Himalayas, has amixed population of Nepalis, Bengalis andtribals from Central India. The British, takingadvantage of the physical conditions such asmoderate slope, thick soil cover with highorganic content, well distributed rainfallthroughout the year and mild winters,introduced tea plantations in this region. Ascompared to the other sections of theHimalayas, these along with the ArunachalHimalayas are conspicuous by the absence ofthe Shiwalik formations. In place of Shiwalikshere, the ‘duar formations’ are important,which have also been used for thedevelopment of tea gardens. Sikkim andDarjeeling Himalayas are also known fortheir scenic beauty and rich flora and fauna,particularly various types of orchids.The Arunachal Himalayas

These extend from the east of the BhutanHimalayas upto the Diphu pass in the east.The general direction of the mountain rangeis from southwest to northeast. Some of theimportant mountain peaks of the region areKangtu and Namcha Barwa. These rangersare dissected by fast-flowing rivers from thenorth to the south, forming deep gorges.Brahmaputra flows through a deep gorgeafter crossing Namcha Barwa. Some of theimportant rivers are the Kameng, theSubansiri, the Dihang and the Lohit.

These are perennial with the high rateof fall, thus, having the highest hydro-electricpower potential in the country. An importantaspect of the Arunachal Himalayas is thenumerous ethnic tribal community inhabitingin these areas. Some of the prominent onesfrom west to east are the Monpa, Daffla,Abor, Mishmi, Nishi and the Nagas. Most of

these communities practice Jhumming. It isalso known as shifting or slash and Figure:Eastern Himalayas communities. Due torugged topography, the inter-valleytransportation linkages are nominal. Hence,most of the interactions are carried throughthe duar region along the Arunachal-Assamborder.The Eastern Hills and Mountains

These are part of the Himalayanmountain system having their generalalignment from the north to the southdirection. They are known by different localnames. In the north, they are known as PatkaiBum, Naga hills, the Manipur hills and in thesouth as Mizo or Lushai hills. These are lowhills, inhabited by numerous tribal groupspracticing Jhum cultivation.

Most of these ranges are separated fromeach other by numerous small rivers. TheBarak is an important river in Manipur andMizoram. The physiography of Manipur isunique by the presence of a large lake knownas ‘Loktak’ lake at the centre, surrounded bymountains from all sides. Mzoram which isalso known as the ‘Molassis basin’ which ismade up of soft unconsolidated deposits.Most of the rivers in Nagaland form thetributary of the Brahmaputra. While tworivers of Mizoram and Manipur are thetributaries of Barak river, which in turn isthe tributary of Meghna; the rivers in theeastern part of Manipur are the tributariesof Chindwin, which in turn is a tributary ofthe Irrawaddy of Myanmar.The Northern Plains

The northern plains are formed by thealluvial deposits brought by the rivers- theIndus, the Ganga and the Brahmaputra.These plain extend approximately 3,200 km


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India - Location 7

from the east to the west. The average widthof these plains varies between 150-300 km.The maximum depth of alluvium depositsvaries between 1,000-2,000 m. From the northto the south, these can be divided into threemajor zones: the Bhabar, the Tarai and thealluvial plains. The alluvial plains can befurther divided into the Khadar and theBhangar.

Bhabar is a narrow belt ranging between8-10 km parallel to the Shiwalik foothills atthe break-up of the slope. As a result of this,the streams and rivers coming from themountain deposit heavy materials of rocksand boulders, and at times, disappear in thiszone. South of the Bhabar is the Tarai belt,with an approximate width of 10-20 kmwhere most of the streams and rivers re-emerge without having any properlydemarcated channel, thereby, creatingmarshy and swampy conditions known as theTarai. This has a luxurious growth of naturalvegetation and houses a varied wild life.

The south of Tarai is a belt consisting ofold and new alluvial deposits known as theBhangar and Khadar respectively. Theseplains have characteristic features of maturestage of fluvial erosional and depositionallandforms such as sand bars, meanders,oxbow lakes and braided channels. TheBrahmaputra plains are known for theirriverine islands and sand bars. Most of theseareas are subjected to periodic floods andshifting river courses forming braidedstreams.

The mouths of these mighty rivers alsoform some of the largest deltas of the world,for example, the famous Sunderbans delta.Otherwise, this is a featureless plain with ageneral elevation of 50-150 m above the mean

sea level. The states of Haryana and Delhiform a water divide between the Indus andthe Ganga river systems. As opposed to this,the Brahmaputra river flows from thenortheast to the southwest direction beforeit takes an almost 90º southward turn atDhubri before it enters into Bangladesh.These river valley plains have a fertile alluvialsoil cover which supports a variety of cropslike wheat, rice, sugarcane and jute, andhence, supports a large population.The Peninsular Plateau

Rising from the height of 150 m abovethe river plains up to an elevation of 600-900m is the irregular triangle known as thepeninsular plateau. Delhi ridge in thenorthwest, (extension of Aravalis), theRajmahal hills in the east, Gir range in thewest and the Cardamom hills in the southconstitute the outer extent of the peninsularplateau. However, an extension of this is alsoseen in the northeast, in the form of ShillongKarbi-Anglong plateau. The peninsular Indiais made up of a series of patland plateaus suchas the Hazaribagh plateau, the Palamuplateau, the Ranchi plateau, the Malwaplateau, the Coimbatore plateau and theKarnataka plateau, etc. This is one of theoldest and the most stable landmass of India.The general elevation of the plateau is fromthe west to the east, which s also proved bythe pattern of the flow of rivers. Name somerivers of the peninsular plateau which havetheir confluence in the Bay of Bengal and theArabian sea and mention some landformswhich are typical to the east flowing riversbut are absent in the west flowing rivers.Some of the important physiographic featuresof this region are tors, block mountains, riftvalleys, spurs, bare rocky structures, series


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of hummocky hills and wall-like quartzitedykes offering natural sites for water storage.The western and northwestern part of theplateau has an emphatic presence of blacksoil. This peninsular plateau has undergonerecurrent phases of upliftment andsubmergence accompanied by crustal faultingand fractures. (The Bhima fault needs specialmention, because of its recurrent seismicactivities). These spatial variations havebrought in elements of diversity in the reliefof the peninsular plateau. The northwesternpart of the plateau has a complex relief ofravines and gorges. The ravines of Chambal,Bhind and Morena are some of the well-known examples.

On the basis of the prominent relieffeatures, the peninsular plateau can bedivided into three broad groups: (i) TheDeccan Plateau (ii) The Central Highlands (iii)The Northeastern Plateau.The Deccan Plateau

This is bordered by the Western Ghatsin the west, Eastern Ghats in the east andthe Satpura, Maikal range and Mahadeo hillsin the north. Western Ghats are locallyknown by different names such as Sahyadriin Maharashtra, Nilgiri hills in Karnataka andTamil Nadu and Anaimalai hills andCardamom hills in Kerala. Western Ghats arecomparatively higher in elevation and morecontinuous than the Eastern Ghats. Theiraverage elevation is about 1,500 m with theheight increasing from north to south.‘Anaimudi’ (2,695 m), the highest peak ofPeninsular plateaus is located on theAnaimalai hills of the Western Ghatsfollowed by Dodabetta (2,670 m) on theNilgiri hills. Most of the Peninsular rivershave their origin in the Western Ghats.

Eastern Ghats comprising the discontinuousand low hills are highly eroded by the riverssuch as the Mahanadi, the Godavari, theKrishna, the Kaveri, etc. Some of theimportant ranges include the Javadi hills, thePalconda range, the Nallamala hills, theMahendragiri hills, etc. The Eastern and theWestern Ghats meet each other at the Nilgirihills.The Central Highlands

They are bounded to the west by theAravali range. The Satpura range is formedby a series of scarped plateaus on the south,generally at an elevation varying between600-900 m above the mean sea level. Thisforms the northernmost boundary of theDeccan plateau. It is a classic example of therelict mountains which are highly denudedand form discontinuous ranges. The extensionof the Peninsular plateau can be seen as faras Jaisalmer in the West, where it has beencovered by the longitudinal sand ridges andcrescent-shaped sand dunes called barchans.This region has undergone metamorphicprocesses in its geological history, which canbe corroborated by the presence ofmetamorphic rocks such as marble, slate,gneiss, etc.

The general elevation of the CentralHighlands ranges between 700-1,000 m abovethe mean sea level and it slopes towards thenorth and northeastern directions. Most ofthe tributaries of the river Yamuna have theirorigin in the Vindhyan and Kaimur ranges.Banas is the only significant tributary of theriver Chambal that originates from theAravalli in the west. An eastern extension ofthe Central Highland is formed by theRajmahal hills, to the south of which lies alarge reserve of mineral resources in the


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India - Location 9

Chotanagpur plateau.The Northeastern Plateau

In fact it is an extension of the mainpeninsular plateau, it is believed that due tothe force exerted by the northeastwardmovement of the Indian plate at the time ofthe Himalayan origin, a huge fault was createdbetween the Rajmahal hills and theMeghalaya plateau. Later, this depression gotfilled up by the deposition activity of thenumerous rivers. Today, the Meghalaya andKarbi Anglong plateau stand detached fromthe main peninsular Block. The meghalayaplateau is further sub-divided into three: (i)The Garo Hills; (ii) The Khasi Hills; (ii) TheJaintia Hills, named after the tribal groupsinhabiting this region. An extension of this isalso seen in the Karbi Anglong hills of Assam.Similar to the Chotanagpur plateau, theMeghalaya plateau is also rich in mineralresources like coal, iron ore, sillimanite,limestone and uranium. This area receivesmaximum rainfall from the south westmonsoon. As a result, the Meghalaya plateauhas a highly eroded surface. Cherrapunjidisplays a bare rocky surface devoid of anypermanent vegetation cover.The Indian Desert

To the northwest of the Aravali hills liesthe Great Indian desert. It is a land ofundulating topography dotted withlongitudinal dunes and barchans. This regionreceives low rainfall below 150 mm per year;hence, it has arid climate with low vegetationcover. It is because of these characteristicfeatures that this is also known as Marusthali.It is believed that during the Mesozoic era,this region was under the sea. This can becorroborated by the evidence available at

wood fossils park at Aakal and marinedeposits around Brahmsar, near Jaisalmer(The approximate age of the wood fossils isestimated to be 180 million years).

Though the underlying rock structureof the desert is an extension of the peninsularplateau, yet, due to extreme arid conditions,its surface features have been carved byphysical weathering and wind actions. Someof the well pronounced desert land featurespresent here are mushroom rocks, shiftingdunes and oasis (mostly in its southern part).On the basis of the orientation, the desertcan be divided into two parts: the northernpart is sloping towards Sindh and thesouthern towards the Rann of Kachchh. Mostof the rivers in this region are ephemeral. TheLuni river flowing in the southern part of thedesert is of some significance. Lowprecipitation and high evaporation makes ita water deficit region. There are some streamswhich disappear after flowing for somedistance and present a typical case of inlanddrainage by joining a lake or playa. The lakesand the playas have brackish water which isthe main source of obtaining salt.The Coastal Plains

India has a long coastline. On the basisof the location and active geomorphologicalprocesses, it can be divided into two: (i) thewestern coastal plains; (ii) the eastern coastalplains.

The western coastal plains are anexample of submerged coastal plain. It isbelieved that the city of Dwaraka which wasonce a part of the Indian mainland situatedalong the west coast is submerged underwater. Because of this submergence it is anarrow belt and provides natural conditionsfor the development of ports and harbours.


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Kandla, Mazagaon, JLN port Navha Sheva,Marmagao. Mangalore, Cochin, etc. are someof the important natural ports located alongthe west coast. Extending from the Gujaratcoast in the north to the Kerala coast in thesouth, the western coast may be divided intofollowing divisions- the Kachchh andKathiawar coast in Gujarat, Konkan coast inMaharashtra. Goa coast and Malabar coastin Karnataka and Kerala respectively. Thewestern coastal plains are narrow in themiddle and get broader towards north andsouth. The rivers flowing through this coastalplain do not form any delta. The Malabarcoast has got certain distinguishing featuresin the form of ‘Kayals’ (backwaters), whichare used for fishing, inland navigation andalso due to its special attraction for tourists.Every year the famous Nehru TrophyVallamkali (boat race) is held in PunnamadaKayal in Kerala.

Some important mountain peaks inAndaman and Nicobar islands are Saddlepeak (North Andaman- 738 m), MountDiavolo (Middle Andaman- 515 m), MountKoyob (South Andaman- 460 m) and MountThuiller (Great Nicobar- 642 m).

As compared to the western coastalplain, the eastern coastal plain is broader andis an example of an emergent coast. Thereare well developed deltas here, formed bythe rivers flowing eastward in to the Bay ofBengal. These include the deltas of theMahanadi, the Godavari, the Krishna and theKaveri. Because of its emergent nature, it hasless number of ports and harbours. Thecontinental shelf extends up to 500 km intothe sea, which makes it difficult for thedevelopment of good ports and harbours.Name some ports on the eastern coast.

The Islands

There are two major island groups inIndia- one in the Bay of Bengal and the otherin the Arabian. The Bay of Bengal Islandgroups consist of about 572 islands/islets.These are situated roughly between 6ºN –14ºN and 92ºE-94ºE. The two principal groupsof islets include the Ritchie’s archipelago andthe Labrynth island. The entire group ofisland is divided into two broad categories-the Andaman in the north and the Nicobarin the south. They are separated by a waterbody which is called the Ten degree channel.It s believed that these islands are an elevatedportion of submarine mountains. However,some smaller islands are volcanic in origin.Barren island, the only active volcano in Indiais also situated in the Nicobar islands.

The coastal line has some coral deposits,and beautiful beaches. These islands receiveconventional rainfall and have an equatorialtype of vegetation.

The islands of the Arabian sea includeLakshadweep and Minicoy. These arescattered between 8ºN and 71ºE- 74ºElongitude. These islands are located at adistance of 280 km- 480 km off the Keralacoast. The entire island group is built of coraldeposits. There are approximately 36 islandsof which 11 are inhabited. Minicoy is thelargest island with an area of 453 sq. km. Theentire group of islands is broadly divided bythe Eleventh degree channel, north of whichis the Amini Island and to the south of theCanannore Island. The islands of thisarchipelago have storm beaches consisting ofunconsolidated pebbles, shingles, cobbles andboulders on the eastern seaboard.


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Geography 11

DRAINAGE SYSTEM

A river drains the water collected froma specific area, which is called its ‘catchmentarea’.

The flow of water through well-definedchannels is known as ‘drainage’ and thenetwork of such channels is called a ‘drainagesystem’. The drainage pattern of an area isthe outcome of the geological time period,nature and structure of rocks, topography,slope, amount of water flowing and theperiodically of the flow.

An area drained by a river and itstributaries is called a drainage basin. Theboundary line separating one drainage basinfrom the other is known as the watershed.The catchments of large rivers are called riverbasins while those of small rivulets and rillsare often referred to as watersheds. There ishowever, a slight difference between a riverbasin and a watershed. Watersheds are smallin area while the basins cover larger areas.

Indian drainage system may be dividedon various bases. On the basis of dischargeof water (orientations to the sea), it may begrouped into: (i) the Arabian Sea drainage;and (ii) the Bay of Bengal drainage. They areseparated from each other through the Delhiridge, the Aravalis and the Sahyadris (waterdivide is shown by a line in Figure. Nearly77 per cent of the drainage area consisting ofthe Ganga, the Brahmaputra, the Mahanadi,

the Krishna, etc. is oriented towards the Bayof Bengal while 23 per cent comprising theIndus, the Narmada, the Tapi, the Mahi andthe Periyar systems discharge their watersin the Arabian Sea.

On the basis of the size of thewatershed, the drainage basins of India aregrouped into three categories: (i) Major riverbasins with more than 20,000 sq. km. ofcatchment area. It includes 14 drainage basinssuch as the Ganga, the Brahmaputra, theKrishna, the Tapi, the Narmada, the Mahi,the Pennar, the Sabarmati, the Barak, etc. (ii)Medium river basins with catchment areabetween 2,000- 20,000 sq. km. incorporating44 river basins such as the Kalindi, thePeriyar, the Meghna, etc. (iii) Minor riverbasins with catchment area of less than 2,000sq. km. include fairly good number of riversflowing in the area of low rainfall.

The Narmada and Tapi are two largerivers which are exceptions. They along withmany small rivers discharge their waters inthe Arabian Sea.

On the basis of the mode of origin,nature and characteristics, the Indiandrainage may also be classified into theHimalayan drainage and the peninsulardrainage. Although it has the problem ofincluding the Chambal, the Betwa, the Son,etc. which are much older in age and origin


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than other rivers that have their origin in theHimalayas, it is the most accepted basis ofclassification.Drainage systems of India

Indian drainage system consists of alarge number of small and big rivers. It isthe outcome of the evolutionary process ofthe three major physiographic units and thenature and characteristics of precipitation.Important Drainage Patterns

(i) The drainage pattern resembling thebranches of a tree is known as“dendritic” the examples of whichare the rivers of northern plain.

(ii) When the rivers originate from a hilland flow in all directions, thedrainage pattern is known as ‘radial’.The rivers originating from theAmarkantak range present a goodexample of it.

(iii) When the primary tributaries ofrivers flow parallel to each other andsecondary tributaries join them atright angles, the pattern is knownas ‘trellis’.

(iv) When the rivers discharge theirwaters from all directions in a lakeor depression, the pattern is knowas ‘centripetal’.

The Himalayan Drainage

The Himalayan drainage system hasevolved through a long geological history. Itmainly includes the Ganga, the Indus and theBrahmaputra rivers basins. Since these are fedboth by melting of snow and precipitation,rivers of this system are perennial. These riv-ers pass through the giant gorges carved outby the erosional activity carried on simulta-neously with the uplift of the Himalayas.

Besides deep gorges, these rivers also formV-shaped valleys, rapids and waterfalls intheir mountainous course. While entering theplains, they form depositional features likeflat valleys, ox-bow, lakes, flood plains,braided channels, and deltas near the rivermouth. In the Himalayan reaches, the courseof these rivers is highly tortuous, but overthe plains they display a strong meanderingtendency and shift their courses frequently.River Kosi, also know as the ‘sorrow ofBihar’, has been notorious for frequentlychanging its course. The Kosi brings hugequantity of sediments from its upper reachesand deposits in the plains. The course getsblocked, and consequently the river changesits course.Evolution of the Himalayan Drainage

There are difference of opinion aboutthe evolution of the Himalayan rivers.However, geologists believe that a mightyriver called Shiwalik or Indo-Brahmatraversed the entire longitudinal extent of theHimalaya from Assam to Punjab and onwardsto Sind, and finally discharge into the Gulfof Sind near lower Punjab during theMiocene period some 5-24 million years ago.The remarkable continuity of the Shiwalikand its lacustrine origin and alluvial depositsconsisting of sands, silt, clay, boulders andconglomerates support this viewpoints.

It is opined that in due course of timeIndo-Brahma river was dismembered intothree main drainage systems: (i) the Indusand its five tributaries in the western part;(ii) the Ganga and its Himalayan tributariesin the central part: and (iii) the stretch of theBrahmaputra in Assam and its Himalayantributaries in the eastern part. Thedismemberment was probably due to the


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Drainage System 13

Pleistocene upheaval in the westernHimalayan, including the uplift of the PotwarPlateau (Delhi Ridge), which acted as thewater divide between the Indus and Gangadrainage systems. Likewise, the downthrusting of the Malda gap area between theRajmahal hills and the Meghalaya plateauduring the mid-Pleistocene period, period,diverted the Ganga and the Brahmaputrasystems to flow towards the Bay of Bengal.The riverSystems of the Himalayan Drainage

The Himalayan drainage consists ofseveral river systems but the following arethe major river systems:The Indus system

It is one of the largest river basins ofthe world, covering an area of 11,65,000 sq.km (in India it is 321, 289 sq. km and a totallength of 2,880 km (in India 1,114 km). TheIndus also known as the Sindhu, is thewesternmost of the Himalayan rivers in India.It originates from a glacier near Bokhar Chu(31º 15’ N latitude and 81º40’ E longitude) inthe Tibetan region at an altitude of 4,164 min the Kailash Mountain range. In Tibet, it isknown as ‘Singi Khamban; or Lion’s mouth.After flowing in the northwest directionbetween the Ladakh and Zaskar ranges, itpasses through Ladakh and Baltistan. It cutsacross the ladakh range, forming aspectacular gorge near Gilgit in Jammu andKashmir. It enters into Pakistan near Chillarin the Dardistan region.

The Indus receives a number ofHimalayan tributaries such as the Shyok, theGilgit, the Zaskar, the Hunza, the Nubra, theShigar, the Gasting and the Dras. It finallyemerges out of the hills near Attock where itreceives the Kabul river on its right bank. The

other important tributaries joining the rightbank of the Indus are the Khurram, the Tochi,the Gomal. The Viboa and the Sangar. Theyall originate in the Sulaiman ranges. The riverflows southward and receives Panjnad’ a littleabove Mithankot. The Panjnad is the namegiven to the five rivers of Punjab, namely theSatluj, the Beas, the Ravi, the Chenab and theJhelum. It finally discharges into the ArabianSea, east of Karachi. The Indus flows in Indiaonly through the Leh district in Jammu andKashmir.

The Jhelum an important tributary of theIndus, rises from a spring at Verinag situatedat the foot of the Pir Panjal in the south-eastern part of the valley of Kashmir. It flowsthrough Srinagar and the Wular lake beforeentering Pakistan through a deep narrowgorge. It joins the Chenab near Jhang inPakistan. The Chenab is the largest tributaryof the Indus. It is formed by two streams,the Chandra and the Bhaga, which join atTandi near Keylong in Himachal Pradesh.Hence, it is also known as Chandrabhaga.The river flows for 1,180 km before enteringinto Pakistan.

The Ravi is another important tributaryof the Indus it rises west of the Rohtang passin the Kullu hills of Himachal Pradesh andflows through the Chamba valley of the state.Before entering Pakistan and joining theChenab near Sarai Sidhu, it drains the arealying between the southeastern part of thePir Panjal and the Dhauladhar ranges.

The Beas is another important tributaryof the Indus, originating from the Beas Kundnear the Rohtang Pass at an elevation of 4,000m above the mean sea level. The river flowsthrough the Kullu valley and forms gorgesat Kati and Largi in the Dhaoladhar range. It


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enters the Punjab plains where it meets theSatluj near Harike.

The Satluj originates in the Rakas lakenear Mansarovar at an altitude of 4,555 m inTibet where it is known as LangchenKhambab. It flows almost parallel to the Indusfor about 400 km before entering India, andcomes out of a gorge at Rupar. It passesthrough the Shipki La on the Himalayanranges and enters the Punjab plains. It is anantecedent river. It is a very importanttributary as it feeds the canal system of theBhakra Nangal project.The Ganga System

The Ganga is the most important riverof India both from the point of view of itsbasin and cultural significance. It rises in theGangotri glacier near Gaumukh (3,900 m) inthe Uttarkashi district of Uttarankhand. Here,it is known as the Bhagirathi. It cuts throughthe Central and the Lesser Himalayas innarrow gorges. At Devprayag, the Bhagirathimeets the Alaknanda; hereafter, it is knownas the Ganga. The Alaknanda has its sourcein the Satopanth glacier above Badrinath. TheAlaknanda consists of the Dhaul and theVishnu Ganga which meet at Joshimath orVishnu Prayag. The other tributaries ofAlaknanda such as the Pindar join it at KarnaPrayag while Mandakini or Kali Ganga meetsit at Rudra Prayag. The Ganga enters theplains at Haridwar. From here, it flows firstto the south, then to the south-east and eastbefore splitting into two distributaries,namely the Bhagirathi and the Hugli. Theriver has a length of 2,525 km. It is shared byUttarakhand (110 km) and Uttar Pradesh(1,450 km), Bihar (445 km) and West Bengal(520 km). The Ganga basin covers about 8.6lakh sq. km area in India alone. The Ganga

river system is the largest in India having anumber of perennial and non-perennial riversoriginating in the Himalayas in the north andthe Peninsula in the south, respectively. TheSon is its major right bank tributary. Theimportant left bank tributaries are theRamganga, the Gomati, the Ghaghara, theGandak, the Kosi and the Mahananda. Theriver finally discharges itself into the Bay ofBengal near the Sagar Island.

The Yamuna, the western most and thelongest tributary of the Ganga, has its sourcein the Yamunotri glacier on the westernslopes of Banderpunch range (6,316 km). Itjoins the Ganga at Prayag (Allahabad). It isjoined by the Chambal, the Sind, the Betwaand the Ken on its right bank which originatesfrom the Peninsular plateau while theHindan, the Rind, the Sengar, the Varuna,etc. join it on its left water feeds the westernand eastern Yamuna and the Agra canals forirrigation purposes.

The Chambal rises near Mhow in theMalwa plateau of Madhya Pradeshnorthwards through a gorge up wards ofKota in Rajasthan, where the Gandhisagardam has been constructed. From Kota, ittraverses down to Bundi, Sawai Madhopurand Dholpur, and finally joins the Yamuna.The Chambal is famous for its badlandtopography called the Chambal ravines.

The Gandak comprises two streams,namely Kaligandak and Trishulganga. It risesin the Nepal Himalayas between theDhaulagiri and Mount Everest and drains thecentral part of Nepal. It enters the Gangaplain in Champaran district of Bihar and joinsthe Ganga at Sonpur near Patna.

The Ghaghara originates in the glaciersof Mapchachungo. After collecting the waters


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Drainage System 15

of its tributaries- Tila, Seti and Beri, it comesout of the mountain, cutting a deep gorge atShishapani. The river Sarda (Kali or KaliGanga) joins it in the plain before it finallymeets the Ganga at Chhapra.

The Kosi is an antecedent river with itssource to the north of Mount Everest in Ti-bet, where its main stream Arun rises. Aftercrossing the Central Himalayas in Nepal, itis joined by the Son Kosi from the West andthe Tamur Kosi from the east. It forms SaptKosi after uniting with the river Arun.

The Ramganga is comparatively a smallriver rising in the Garhwal hills near Gairsain.It changes its course to the southwestdirection after crossing the Shiwalik andenters into the plains of Uttar Pradesh nearNajibabad. Finally, it joins the Ganga nearKannauj. The Damodar occupies the easternmargins of the Chotanagpur Plateau whereit flows through a rift valley and finally joinsthe Hugli. The Barakar is its main tributary.Once known as the ‘sorrow of Bengal’, theDamodar has been now tamed by theDamodar Valley corporation, multipurposeproject.

The Sarda or Saryu river rises in theMilan glacier in the Nepal Himalayas whereit is known as the Goriganga. Along the Indo-Nepal border, it is called Kali or Chauk,where it joins the Ghaghara.

The Mahananda is another importanttributary of the Ganga rising in theDarjeeling hills. It joins the Ganga as its lastleft bank tributary in West Bengal.

The Son is a large south bank tributaryof the Ganga, originating in the Amarkantakplateau. After forming a series of waterfallsat the edge of the plateau, it reaches Arrah,west of Patna, to join the Ganga.

The Brahmaputra System

The Brahmaputra, one of the largestrivers of the world, has its origin in theChemayungdung glacier of the Kailash rangenear the Mansarovar lake. From here, ittraverses eastward longitudinally for adistance of nearly 1,200 km in a dry and flatregion of southern Tibet, where it is knownas the Tsangpo, which means ‘the purifier’.The Rango Tsangpo is the major right banktributary of this river in Tibet. It emerges asa turbulent and dynamic river after carvingout a deep gorge in the Central Himalayasnear Namcha Barwa (7,755 m). The riveremerges from the foothills under the nameof Siang or Dihang. It enters India west ofSadiya town in Arunachal Pradesh. Flowingsouthwest, it receives its main left banktributaries, viz., Dibang or Sikang and Lohit;thereafter; it is known as the Brahmaputra.

The Brahmaputra receives numeroustributaries in its 750 km long journey throughthe Assam valley. Its major left banktributaries are the Burhi Dihing, Dhansari(South) and Kalang whereas the importantright bank tributaries are the Subansiri,Kameng, Manas and sankosh. The Subansiriwhich has its origin in Tibet, is an antecedentriver. The Brahmaputra enters intoBangladesh near Dhubri and flowssouthward. In Bangladesh, the Tista joins iton its right bank from where the river isknown as the Yamuna. It finally merges withthe river Padma, which falls in the Bay ofBengal. The Brahmaputra is well-known forfloods, channel shifting and bank erosion.This is due to the fact that most of itstributaries are large, and bring large quantityof sediments owing to heavy rainfall in itscatchment area.


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The peninsular drainage system

The peninsular drainage system is olderthan the Himalayan one. This is evident fromthe broad, largely-graded shallow valleys,and the maturity of the rivers. The WesternGhats running close to the western coast actas the water divide between the majorpeninsular rivers, discharging their water inthe Bay of Bengal and as small rivulets joiningthe Arabian Sea. Most of the major peninsularrivers except Narmada and Tapi flow fromwest to east. The Chambal, the Sind, theBetwa, the Ken, the Son, originating in thenorthern part of the peninsular belong to theGanga river system. The other major riversystems of the peninsular drainage are- theMahanadi the Godavari, the Krishna and theKaveri, Peninsular rivers are characterized byfixed course, absence of meanders and noperennial flow of water. The Narmada andthe Tapi which flow through the rift valleyare, however, exceptions. They meet inArabian sea.The Evolution ofPeninsular Drainage System

Three major geological events in thedistant past have shaped the presentdrainage systems of peninsular India: (i)Subsidence of the western flank of thepeninsula leading to its submergence belowthe sea during the early tertiary period.Generally, it has disturbed the symmetricalplan of the river on either side of the originalwatershed. (ii) Upheavel of the Himalayaswhen the northern flank of the peninsularblock was subjected to subsidence and theconsequent trough faulting. The Narmadaand The Tapi flow in trough faults and fillthe original cracks with their detritusmaterials. Hence, there is a lack of alluvial

and deltaic deposits in these rivers, (iii) Slighttilting of the peninsular block from northwestto the southeastern direction gave orientationto the entire drainage system towards theBay of Bengal during the same period.River systems of the peninsular drainage

There are a large number of riversystems in the peninsular drainage. A briefaccount of the major peninsular river systemsis given below:

The Mahanadi rises near Sihawa inRaipur district of Chhattisgarh and runsthrough Orissa to discharge its water intothe Bay of Bengal. It is 851 km long and itscatchment area spreads over 1.42 lakhs sq.km. Some navigation is carried on in the lowercourse of this river. Fifty three per cent ofthe drainage basin of this rivers lies in MadhyaPradesh and Chhattisgarh, while 47 per centlies in Orissa.

The Godavari is the largest peninsularriver system. It is also called the DakshinGanga. It rises in the Nasik district ofMaharashtra and discharges its water into theBay of Bengal. Its tributaries run through thestates of Maharashtra, Madhya Pradesh,Chhattisgarh, Orissa and Andhra Pradesh. Itis 1,465 km long with a catchment areaspreading over 3.13 lakh sq. km 49 per centof this, lies in Maharashtra, 20 per cent inMadhya Pradesh and Chhattisgarh, and therest in Andhra Pradesh. The Penganga, theIndravati, the Pranhita, and the Manjra areits principal tributaries. The Godavari issubjected to heavy floods in its lower reachesto the south of Polavaram, where it forms apicturesque gorge. It is navigable only in thedeltaic stretch. The river after Rajamundrisplits into several branches forming a largedelta.


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Drainage System 17

The Krishna is the second largest eastflowing peninsular river which rises nearMahabaleshwar in Sahyadri. Its total lengthis 1,401 km. The Koyna, the Tungbhadra andthe Bhima are its major tributaries. Of thetotal catchment area of the Krishna, 27 percent lies in Maharashyra, 44 per cent inKarnataka and 29 per cent in Andhra Pradesh.

The Kaveri rises in Brahmagiri hills1,341m of Kogadu district in Karnataka. Itslength is 800 km and it drains an area of 81,155sq. km. Since the upper catchment areareceives rainfall during the southwestmonsoon season (summer) and the lowerpart during the northeast monsoon season(winter), the river carries water throughoutthe year with comparatively less fluctuationthan the other peninsular rivers. About 3 percent of the Kaveri basin falls in Kerala, 41per cent in Karnataka and 56 per cent in TamilNadu. Its important tributaries are theKabini, the Bhavani and the Amravati.

The Narmada originates on the westernflank of the Amarkantak plateau at a heightof about 1,057 m. Flowing in a rift valleybetween the Satpura in the south and theVindhyan range in the north. It forms apicturesque gorge in marble rocks andDhuandhar waterfall near Jabalpur. Afterflowing a distance of about 1,312 km, it meetsthe Arabian sea south of Bharuch, forming abroad 27 km long estuary. Its catchment areais about 98,796 sq. km. The Sardar SarovarProject has been constructed on this river.

The Tapi is the other importantwestward flowing river. It originates fromMultai in the Betul district of MadhyaPradesh. It is 724 km long and drains an areaof 65,145 sq. km. Nearly 79 per cent of itsbasin lies in Maharashtra, 15 per cent in

Madhya Pradesh and the remaining 6 per centin Gujarat.

Luni is the largest river system ofRajasthan, west of Aravali. It originates nearPushkar in two branches. i.e. the Saraswatiand the Sabarmati, which join with each otherat Govindgarh. From here, the river comesout of Aravali and is known as Luni. It flowstowards the west till Telwara and then takesa southwest direction to join the Rann ofKuchchh. The entire river system isephemeral.

River Catchment area sq. kmSabarmati 21,674Mahi 34,842Dhandhar 2,770Kalinadi 5,179Sharavati 2,029Bharathapuzha 5,397Periyar 5,243

Smallar Rivers flowing towards the West

The rivers flowing towards the Arabiansea have short courses. Find out the smallerrivers of Gujarat. The Shetruniji is one suchriver which rises near Dalkahwa in Amrelidistrict. The Bhadra, originates near Anialivillage in Rajkot district. The Dhadhar risesnear Ghantar village in Panchmahal district.Sabarmati and Mahi are the two famousrivers of Gujarat.

The Vaitarna rises from the Trimbakhills in Nasik district at an elevation of 670m. The Kalinadi rises from Belgaum districtand falls in the Karwar Bay. The source ofBedti river lies in Hubli Dharwar andtraverses a course of 161 km. The Sharavatiis another important river in Karnatakaflowing towards the west. The Sharavatioriginates in Shimoga district of Karnataka


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and drains a catchment area of 2,209 sq. km.Goa has two important rivers which can bementioned here. One is Mandovi and theother is Juari.

River Catchment area sq. km

Subarnarekha 19.296Baitarni 12.789Brahmani 39.033Penner 55.213Palar 17.870

Kerala has a narrow coastline. The

longest river of Kerala, Bharathapuzha risesnear Annamalai hills. It is also known asPonnani. It drains an area of 5,397 sq. kmCompare its catchment area with that of theSharavati river of Karnataka.

The Periyar is the second largest riverof Kerala. Its catchment area is 5,243 sq. km.You can see that there is a marginal differencein the catchment area of the Bhartapuzha andthe Periyar rivers.

Another river of Kerala worthmentioning is the Pamba river which falls inthe Vemobanad lake after traversing a courseof 177 km.

Gist of NCERT

Indian PolityISBN: 9789351720249

Book Code: F21


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Geography 19

CLIMATE

3

Climate refers to the sum total ofweather conditions and variations over alarge area for a long period of time (morethan thirty years). Weather refers to the stateof the atmosphere over an area at any pointof time.

The elements of weather and climate arethe same, i.e. temperature, atmosphericpressure, wind, humidity and precipitation.You may have observed that the weatherconditions fluctuate very often even withina day. But there is some common pattern overa few weeks or months, i.e. days are cool orhot, windy or calm, cloudy or bright, andwet or dry. On the basis of the generalizedmonthly atmospheric conditions, the year isdivided into seasons such as winter, summeror rainy seasons.

During the summer season the desertarea of Rajasthan witnesses 50º temperaturewhereas Pahalgam sector of Jammu andKashmir has 20ºC temperature. Duringwinter nights Dras sector of Jammu andKashmir witnesses– 45ºC temperature whereas Thiruvananthpuram has 20ºC.

Rainfall also varies in terms of quantityand distribution in the regions of Himalayarainfall is in the from of snowy balls whereas in the rest of part of India it is a generalrain. Again annual rainfall varies from 400ºCin the Meghalya to 10ºc in Ladakh and West

Rajasthan. In the coastal area the variation ofrainfall is less. Whereas in the inner part ofcountry the seasonal variation is more. Ac-cordingly the Indians show their unity in di-versity in terms of food, clothing, housingand culture.Factors determining the climate of India

India’s climate is controlled by a numberof factors which can be broadly divided intotwo groups- (a) factors related to location andrelief, and (b) factors related to air pressureand winds.(a) Factors related to Location and Relief

Latitude: You know that the Tropic ofCancer passes through the central part ofIndia in east-west direction. This, northernpart of the India lies in sub-tropical andtemperate zone and the part lying south ofthe Tropic of Cancer falls in the tropical zone.The tropical zone being nearer to the equator,experiences high temperatures throughoutthe year with small daily and annual range.Area north of the Tropic of Cancer beingaway from the equator, experiences extremeclimate with high daily and annual range oftemperature.

The Himalayan Mountains: Thetowering mountain chain provides aninvincible shield to protect the subcontinentfrom the cold northern winds. The Himalayasalso trap the monsoon winds, forcing them


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to shed their moisture within thesubcontinent. Distribution of Land andWater: India is flanked by the India Oceanon three sides in the south and girdled by ahigh and continuous mountain-wall in thenorth. As compared to the landmass, waterheats up or cools down slowly. Thisdifferential heating of land and sea createsdifferent air pressure zones in differentseasons in and around the Indiansubcontinent. Difference in air pressurecauses reversal in the direction of monsoonwinds.

Distance from the Sea: With a longcoastline, large coastal areas have an equableclimate. Areas in the interior of India are faraway from the moderating influence of thesea. Such areas have extremes of climate. Thatis why, the people of Mumbai and the Konkancoast have hardly any idea of extremes oftemperature and the seasonal rhythm ofweather. On the other hand, the seasonalcontrasts in weather at places in the interiorof the country such as Delhi, Kanpur andAmritsar affect the entire sphere of life.

Altitude : Temperature decreases withheight. Due to thin air, places in themountains are cooler than places on theplains. For example, Agra and Darjeeling arelocated on the same latitude, but temperatureof January in Agra is 16ºC whereas it is only4ºC in Darjeeling.

Relief: The physiography or relief ofIndia also affects the temperature, airpressure, direction and speed of wind andthe amount and distribution of rainfall. Thewindward sides of Western Ghats and Assamreceive high rainfall during June-Septemberwhereas the southern plateau remains dry toits leeward situation along the Western

Ghats.(b) FactorsRelated to Air Pressure and Wind

To understand the differences in localclimates of India, we need to understand themechanism of the following three factors:

(i) Distribution of air pressure andwinds on the surface of the earth.

(ii) Upper air circulation caused byfactors controlling global weatherand the inflow of different airmasses and jet streams.

(iii) Inflow of western cyclones generallyknown as disturbances during thewinter season and tropicaldepressions during the south-westmonsoon period into India, creatingweather conditions favourable torainfall.

The mechanism of these three factors canbe understood with reference to winter andsummer seasons of the year separately.Mechanism ofWeather in the Winter Season

Surface pressure and winds: In wintermonths, the weather conditions over Indiaare generally influenced by the distributionof pressure in Central and Western Asia. Ahigh pressure centre in the region lying tothe north of the Himalayas during winter.This centre of high pressure gives rise to theflow of air at the low level from the northtowards the Indian subcontinent, south of themountain range. The surface winds blowingout of the high pressure centre over CentralAsia reach India in the form of a drycontinental air mass. These continental windscome in contact with trade winds overnorthwestern India. The position of this


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Climate 21

contact zone is not, however, stable.Occasionally, it may shift its position as fareast as the middle Ganga valley with theresult that whole of northwestern andnorthern India up to the middle Ganga valleycomes under the influence of drynorthwestern winds.

Jet Stream and Upper Air Circulation:The pattern of air circulation discussed aboveis witnessed only at the lower level of theatmosphere near the surface of the earth.Higher up in the lower troposphere, aboutthree km above the surface of the earth, adifferent pattern of air circulation isobserved. The variations in the atmosphericpressure closer to the surface of the earth haveno role to play in the making of upper aircirculation. All of Western and Central Asiaremains under the influence of westerlywinds along the altitude of 9-13 km fromwest to east. These winds blow across theAsian continent at latitudes north of theHimalayas roughly parallel to the Tibetanhighlands. These are known as jet streams.Tibetan highlands act as a barrier in the pathof these jet streams. As a result, jet streamsget bifurcated. On of its branches blows tothe north of the Tibetan highlands, while thesouthern branch blows in an eastwarddirection, south of the Himalayas. It has itsmean position at 25ºN in February at 200-300mb level. It is believed that this southernbranch of the jet stream exercise an importantinfluence on the winter weather in India.

Western Cyclonic Disturbance andTropical Cyclones: The western cyclonedisturbances which enter the Indiansubcontinent from the west and thenorthwest during the winter monthsoriginate over the Mediterranean Sea and are

brought into India by the westerly jet stream.An increase in the prevailing nighttemperature generally indicates an advancein the arrival of these cyclones disturbances.

Tropical cyclones originate over the Bayof Bengal and the Indian Ocean. Thesetropical cyclones have very high windvelocity and heavy rainfall and hit the TamilNadu, Andhra Pradesh and Orissa coast.Most of these cyclones are very destructivedue to high wind velocity and torrential rainthat accompanies it.Inter Tropical Convergence Zone (ITCZ)

The Inter Tropical Convergence Zone(ITCZ) is a low pressure zone located at theequator where trade winds converge, and so,it is a zone where air tends to ascend. In July,the ITCZ is located around 20ºN latitudes(over the Gangetic plain), sometimes calledthe monsoon trough. This monsoon troughencourages the development of thermal lowover north and northwest India. Due to theshift of ITCZ, the trade winds of the south-ern hemisphere cross the equator between40ºE and 60ºE longitudes and start blowingfrom southwest to northeast due to theCoriolis force. It becomes southwestmonsoon. In winter, the ITCZ moves south-ward, and so the reversal of winds fromnortheast to south and southwest, takesplace. They are called northeast monsoons.Mechanism ofWeather in the Summer Season

Surface Pressure and Winds: As thesummer sets in and the sun shifts northwards,the wind circulation over the subcontinentundergoes a complete reversal at both, thelower as well as the upper levels. By themiddle of July, the low pressure belt nearerthe surface (termed as Inter Tropical


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Convergence Zone (ITCZ) shifts northwards,roughly parallel to the Himalayas between20ºN and 25ºN. By this time, the westerly jetstream withdraws from the Indian region.In fact, meteorologists have found aninterrelationship between the northwardshift of the equatorial trough (ITCZ) and thewithdrawal of the westerly jet stream fromover the North Indian Plain. It is generallybelieved that there is a cause and effectrelationship between the two. The ITCZ beinga zone of low pressure attracts inflow ofwinds from different directions. Themaritime tropical air mass (mT) from thesouthern hemisphere, after crossing theequator, rushes to the low pressure area inthe general southwesterly direction. It is thismoist air current which is popularly knownas the southwest monsoon.

Jet Streams and Upper Air Circulation:The pattern of pressure and winds asmentioned above is formed only at the levelof the troposphere. An easterly jet streamflows over the southern part of the Peninsulain June, and has a maximum speed of 90 kmper hour. In August, it is confined to 15ºNlatitude, and in September up to 22ºNlatitudes. The easterlies normally do notextend to the north of 30ºN latitude in theupper atmosphere.

Easterly Jet Stream and TropicalCyclones: The easterly jet stream steers thetropical depressions into India. Thesedepressions play a significant role in thedistribution of monsoon rainfall over theIndian subcontinent. The tracks of thesedepressions are the areas of highest rainfallin India. The frequency at which thesedepressions visit India, their direction andintensity, all go a long way in determining

the rainfall pattern during the southwestmonsoon period.The Nature of Indian Monsoon

Monsoon is a familiar, though a littleknown climatic phenomenon. Despite theobservations spread over centuries, themonsoon continues to puzzle the scientists.Many attempts have been made to discoverthe exact nature and causation of monsoon,but so far, no single theory has been able toexplain the monsoon fully. A realbreakthrough has come recently when it wasstudied at the global rather than at regionallevel.

Systematic studies of the causes ofrainfall in the South Asian region help tounderstand the causes and salient featuresof the monsoon, particularly some of itsimportant aspects, such as:

(i) The onset of the monsoon.(ii) Rain-bearing systems (e.g. tropical

cyclones) and the relationshipbetween their frequency anddistribution of monsoon rainfall.

(iii) Break in the monsoon.Onset of the Monsoon

Towards the end of the nineteenthcentury, it was believed that the differentialheating of land and sea during the summermonths is the mechanism which sets the stagefor the monsoon winds of drift towards thesubcontinent. During April and May whenthe sun shines vertically over the Tropic ofCancer, the large landmass in the north ofIndian Ocean gets intensely heated. Thiscauses the formation of an intense lowpressure in the northwestern part of thesubcontinent. Since the pressure in the IndianOcean in the south of the landmass is high as


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Climate 23

water gets heated slowly, the low attractsthe southeast trades across the Equator.These conditions help in the northward shiftin the position of the ITCZ. The southwestmonsoon may thus, be seen as a continuationof the southeast trades deflected towards theIndian subcontinent after crossing theEquator. These winds cross the Equatorbetween 40ºE and 60ºE longitudes.

The shift in the position of the ITCZ isalso related to the phenomenon of thewithdrawal of the westerly jet stream fromits position over the north Indian plain, southof the Himalayas. The easterly jet stream setsin along 15ºN latitude only after the westernjet stream has withdrawn itself from theregion. This easterly jet stream is heldresponsible for the burst of the monsoon inIndia. Entry of Monsoon into India: Thesouthwest monsoon sets in over the Keralacoast by 1st June and moves swiftly to reachMumbai and Kolkata between 10th and 13thJune. By mid- July, southwest monsoonengulfs the entire subcontinent.Rain-bearingSystems and Rainfall Distribution

There seem to be two rain-bearingsystems in India. First originate in the Bay ofBengal causing rainfall over the plains ofnorth India. Second is the Arabian Sea currentof the southwest monsoon which brings rainto the west coast of India. Much of therainfall along the Western Ghats is orographicas the moist air is obstructed and forced torise along the Ghats. The intensity of rainfallover the west coast of India is, however,related to two factors:

(i) The offshore meteorologicalconditions.

(ii) The position of the equatorial jet

stream along the eastern coast ofAfrica.

The frequency of the tropicaldepressions originating from the Bay ofBengal varies from year to year. Their pathsover India are mainly determined by theposition of ITCZ which is generally termedas the monsoon trough. As the axis of themonsoon trough oscillates, there arefluctuations in the track and direction of thesedepressions, and the intensity and theamount of rainfall vary from year to year.The rain which comes in spells, displays adeclining trend from west to east over thewest coast, and from the southeast towardsthe northwest over the North Indian Plainand the northern part of the Peninsula.EI-Nino and the Indian Monsoon

EI-Nino is a complex weather systemthat appears once every three to seven yearsbringing drought, floods and other weatherextremes to different parts of the world.

The system involves oceanic and atmos-pheric phenomena with the appearance ofwarm currents off the coast of peru in theEastern Pacific and affects weather in manyplaces including India. EI-Nino is merely anextension of the warm equatorial currentwhich gets replaced temporarily by cold Pe-ruvian current or Humbolt current. This cur-rent increases the temperature of water onthe Peruvian coast by 10ºC. This results in:

(i) The distortion of equatorialatmospheric circulation;

(ii) Irregularities in the evaporation ofsea water;

(iii) Reduction in the amount ofplanktons which further reduces thenumber of fish in the sea.

The word EI-Nino means ‘Child Christ’


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because this current appears aroundChristmas in December. December is asummer month in Peru (SouthernHemisphere).

EI-Nino is used in India for forecastinglong range monsoon rainfall. In 1990-91, therewas a wild EI-Nino even and the onset ofsouthwest monsoon was delayed over mostparts of the country ranging from five totwelve days.Break in the Monsoon

During the south-west, monsoon periodafter having rains for a few days, it rain failsto occur for one or more weeks, it is knownas break in the monsoon. These dry spellsare quite common during the rainy season.These breaks in the different regions are dueto different reasons:

(i) In northern India rains are likely tofail if the rain-bearing storms are notvery frequent along the monsoontrough or the ITCZ over this region.

(ii) Over the west coast the dry spellsare associated with days whenwinds blow parallel to the coast.

The Rhythm of Seasons

The climatic conditions of India can bestbe described in terms of an annual cycle ofseasons. The meteorologists recognize thefollowing four seasons:

(i) The cold weather season(ii) The hot weather season(iii) The southwest monsoon season(iv) The retreating monsoon season.

Some Famous LocalStorms of Hot Weather Season

(i) Mango Shower: Towards the endof summer. There are pre-monsoon

showers which are a commonphenomena in Kerala and coastalareas of Karnataka. Locally, they areknown as mango showers since theyhelp in the early ripening ofmangoes.

(ii) Blossom Shower: With this shower,coffee flowers blossom in Keralaand nearby areas.

(iii) Nor Westers: These are dreadedevening thunderstorms in Bengaland Assam. Their notorious naturecan be understood from the localnomenclature of ‘Kalbaisakhi’, acalamity of the month of Baisakh.These showers are useful for tea, Juteand rice cultivation. In Assam, thesestorms are known as “Bordoiseela”.

(iv) Loo: Hot, dry and oppressing windsblowing in the Northern plains fromPunjab to Bihar with higher intensitybetween Delhi and Patna.

The Cold Weather Season

Temperature: Usually, the cold weatherseason sets in by mid-November in northernIndia. December and January are the coldestmonths in the northern plain. The mean dailytemperature remains below 21ºC over mostparts of northern India. The nighttemperature may be quite low, sometimesgoing below freezing point in Punjab andRajasthan. There are three main reasons forthe excessive cold in north India during thisseason:

(i) States like Punjab, Haryana andRajasthan being far away from themoderating influenced of seaexperience continental climate.

(ii) The snowfall in the nearby


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Climate 25

Himalayan ranges creates cold wavesituation; and

(iii) Around February, the cold windscoming from the Caspian Sea andTurkmenistan bring cold wave alongwith frost and fog over thenorthwestern parts of India.

The Peninsular region of India,however, does not have any well-definedcold weather season. There is hardly anyseasonal change in the distribution patternof the temperature in coastal areas becauseof moderating influence of the sea and theproximity to equator. For example, the meanmaximum temperature for January atThiruvanantapuram is as high as 31ºC, andfor June, it is 29.5ºC. Temperatures at the hillsof Western Ghats remain comparatively low.

Pressure and Winds: By the end ofDecember (22nd December), the sun shinesvertically over the Tropic of Capricorn in thesouthern hemisphere. The weather in thisseason is characterized by feeble highpressure conditions over the northern plain.In south India, the air pressure is slightlylower. The isobars of 1019 mb and 1013 mbpass through northwest India and far south,respectively.

As a result, winds start blowing fromnorthwestern high pressure zone to the lowair pressure zone over the Indian Ocean inthe south.

Due to low pressure gradient, the lightwinds with a low velocity of about 3-5 kmper hour begin to blow outwards. By andlarge, the topography of the region influencesthe wind direction. They are westerly ornorthwesterly down the Ganga Valley. Theybecome northerly in the Ganga-Brahamputradelta. Free from the influence of topography,

they are clearly northeasterly over the Bayof Bengal.

During the winters, the weather in Indiais pleasant. The pleasant weather conditions,however, at intervals, get disturbed byshallow cyclonic depressions originating overthe east Medirranean Sea and travellingeastwards across West Asia, Iran,Afghanistan and Pakistan before the reachthe northwestern parts of India. On theirway, the moisture content gets augmentedfrom the Caspian Sea in the north and thePersian Gulf in the south.Role of Westerly Jet Stream

Rainfall: Winter monsoons do not causerainfall as they move from land to the sea. Itis because firstly, they have little humidity;and secondly, due to anti cyclonic circulationon land, the possibility of rainfall from themreduces. So, most parts of India do not haverainfall in the winter season. However, thereare some exceptions to it:

(i) In northwestern India, some weaktemperate cyclones from theMediterranean sea cause rainfall inPunjab, Haryana, Delhi and westernUttar Pradesh. Although the amountis meager, it is highly beneficial forrabi crops. The precipitation is in theform of snowfall in the lowerHimalayas. It is this snow thatsustains the flow of water in theHimalayan Rivers during thesummer months. The precipitationgoes on decreasing from west to eastin the plains and from north to southin the mountains. The averagewinter rainfall in Delhi is around 53mm. In Punjab and Bihar, rainfallremains between 25 mm and 18 mm


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respectively.(ii) Central parts of India and northern

parts of southern Peninsula also getwinter rainfall occasionally.

(iii) Arunachal Pradesh and Assam in thenortheastern parts of India also haverains between 25 mm and 50 mmduring these winter months.

(iv) During October and November,northeast monsoon while crossingover the Bay of Bengal, pick upmoisture and causes torrentialrainfall over the Tamil Nadu coast,southern Andhra Pradesh, southeastKarnataka and southeast Kerala.

The Hot Weather Season

Temperature: With the apparentnorthward movement of the sun towards theTropic of Cancer in March, temperatures startrising in north India. April, May and Juneare the months of summer in north India. Inmost parts of India, temperatures recordedare between 30º-32ºC. In March, the highestday temperature of about 38ºC occurs in theDeccan Plateau while in April, temperatureranging between 38ºC and 43ºC are found inGujarat and Madhya Pradesh. In May, theheat belt moves further north, and in thenorth-western part of India, temperaturesaround 48ºC are not uncommon.

The hot weather season in south Indiais mild and not so intense as found in northIndia. The Peninsular situation of south Indiawith moderating effect of the oceans keepsthe temperatures lower than that prevailingin north India. So, temperatures remainbetween 26ºC and 32ºC. Due to altitude, thetemperatures in the hills of Western Ghatsremain below 25ºC. In the coastal regions,the north-south extent of isotherms parallel

to the coast confirms that temperature doesnot decrease from north to south rather itincreases from the coast to the interior. Themean daily minimum temperature during thesummer months also remains quite high andrarely goes below 26ºC.

Pressure and Winds: The summermonths are a period of excessive heat andfalling air pressure in the northern half of thecountry. Because of the heating of thesubcontinent, the ITCZ moves northwardsoccupying a position centred at 25ºN in July.Roughly, this elongated low pressuremonsoon trough extends over the Thardesert in the north-west to Patna andChotanagpur plateau in the east-southeast.The location of the ITCZ attracts a surfacecirculation of the winds which aresouthwesterly on the west coast as well asalong the coast of West Bengal andBangladesh. They are easterly orsoutheasterly over north Bengal and Bihar.It has been discussed earlier that thesecurrents of southwesterly monsoon are inreality ‘displaced’ equatorial westerlies. Theinflux of these winds by mid-June bringsabout a change in the weather towards therainy season.

In the heart of the ITCZ in the north-west, the dry and hot winds known as ‘Loo’,blow in the afternoon, and very often, theycontinue to well into midnight. Dust stormsin the evening are very common during Mayin Punjab, Haryana, Eastern Rajasthan andUttar Pradesh. These temporary storms bringa welcome respite from the oppressing heatsince they bring with them light rains and apleasant cool breeze. Occasionally, The mois-ture-laden winds are attracted towards theperiphery of the trough. A sudden contactbetween dry and moist air masses gives rise


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Climate 27

to local storms of great intensity. These localstorms are associated with violent winds,torrential rains and even hailstorms.The Southwest Monsoon Season

As a result of rapid increase oftemperature in May over the northwesternplains, the low pressure conditions over thereget further intensified. By early June, theyare powerful enough to attract the tradewinds of Southern Hemisphere coming fromthe Indian Ocean.

These southeast trade winds cross theequator and enter the Bay of Bengal and theArabian Sea, only to be caught up in the aircirculation over India. Passing over theequatorial warm currents, they bring withthem moisture in abundance. After crossingthe equator, they follow a southwesterlydirection. That is why they are known assouthwest monsoons.

The rain in the southwest monsoonseason begins rather abruptly. One result ofthe first rain is that it brings down thetemperature substantially. This sudden onsetof the moisture-laden winds associated withviolent thunder and lightening, is oftentermed as the “break” or “burst” of themonsoons.

The monsoon may burst in the first weekof June in the coastal areas of Kerala,Karnataka, Goa and Maharashtra while in theinterior parts of the country; it may bedelayed to the first week of July. The daytemperature registers a decline of 5ºC to 8ºCbetween mid-June and mid-July.

As these winds approach the land, theirsouthwesterly direction is modified by therelief and thermal low pressure over thenorthwest India. The monsoon approachesthe landmass in two branches:

(i) The Arabian Sea branch(ii) The Bay of Bengal branch.

Monsoon Winds of the Arabian Sea

The monsoon winds originating overthe Arabian Sea further split into threebranches:

(i) Its one branch is obstructed by theWestern Ghats. These winds climbthe slopes of the Western Ghats from900-1200 m. Soon, they become cool,and as a result, the windward sideof the Sahyadris and WesternCoastal Plain receive very heavyrainfall ranging between 250 cm and400 cm. After crossing the WesternGhats, these winds descend and getheated up. This reduces humidity inthe winds. As a result, these windscause little rainfall east of theWestern Ghats. This region of lowrainfall is known as the rain-shadowarea.(ii) Another branch of theArabian sea monsoon strikes thecoast north of Mumbai. Movingalong the Narmada and Tapi rivervalleys, these winds cause rainfall inextensive areas of central India. TheChotanagpur plateau gets 15 cmrainfall from this part of the branch.Thereafter, they enter the Gangaplains and mingle with the Bay ofBengal branch.

(iii) A third branch of this monsoonwind strikes the SaurashtraPeninsula and the Kachchh. It thenpasses over west Rajasthan andalong the Aravallis, causing only ascanty rainfall. In Punjab andHaryana, it too jokns the Bay of


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Bengal branch. These two branches,reinforced by each other, cause rainsin the western Himalayas.

Monsoon Winds of the Bay of Bengal

The Bay of Bengal branch strikes thecoast of Myanmar and part of southeastBangladesh. But the Arakan Hills along thecoast of Myanmar deflect a big portion of thisbranch towards the Indian subcontinent. Themonsoon, therefore, enters West Bengal andBangladesh from south and southeast insteadof from the south-westerly direction. Fromhere, this branch splits into two under theinfluence of the Himalayas and the thermallow is northwest India. Its one branch moveswestward along the Ganga plains reachingas far as the Punjab plains. The other branchmoves up the Brahmaputra valley in the northand the northeast, causing widespread rains.Its sub-branch strikes the Garo and Khasi hillsof Meghalya. Mawsynram, located on thecrest of Khasi hills, receives the highestaverage annual rainfall in the world.

Here it is important to know why theTamil Nadu coast remains dry during thisseason. There are two factors responsible forit:

(i) The Tamil Nadu coast is situatedparallel to the Bay of Bengal branchof southwest monsoon.

(ii) It lies in the rain shadow area of theArabian Sea branch of the south-west monsoon.

Characteristics of Monsoonal Rainfall

(i) Rainfall received from the southwestmonsoons is seasonal in character,which occurs between June andSeptember.

(ii) Monsoonal rainfall is largely

governed by relief or topography.For instance the windward side ofthe Western Ghats register a rainfallof over 250 cm. Again, the heavyrainfall in the northeastern states canbe attributed to their hill ranges andthe Eastern Himalayas.

(iii) The monsoon rainfall has a decliningtrend with increasing distance fromthe sea. Kolkata receives 119 cmduring the southwest monsoonperiod, Patna 105 cm, Allahabad 76cm and Delhi 56 cm.

(iv) The monsoon rains occur in wetspells of few days, duration at a time.The wet spells are interspersed withrainless interval known as ‘breaks’.These breaks in rainfall are relatedto the cyclonic depressions mainlyformed at the head of the Bay ofBengal, and their crossing into themainland. Besides the frequency andintensity of these depressions, thepassage followed by themdetermines the spatial distributionof rainfall.

(v) The summer rainfall comes in aheavy downpour leading toconsiderable run off and soilerosion.

(vi) Monsoons play a pivotal role in theagrarian economy of India becauseover three-fourths of the total rainin the country is received during thesouthwest monsoon season.

(vii) Its spatial distribution is also unevenwhich ranges from 12 cm to morethan 250 cm.

(viii)The beginning of the rains


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Climate 29

sometimes is considerably delayedover the whole or a part of thecountry.

(ix) The rains sometimes endconsiderably earlier than usual,causing great damage to standingcrops and making the sowing ofwinter crops difficult.

Season of Retreating Monsoon

The months of October and Novemberare known for retreating monsoons. By theend of September, the southwest monsoonbecomes weak as the low pressure trough ofthe Ganga plain starts moving southward inresponse to the southward march of the sun.The monsoon retreats from the westernRajasthan by the first week of September. Itwithdraws from Rajasthan, Gujarat, WesternGanga plain and the Central Highlands bythe end of the month. By the beginning ofOctober, the low pressures covers northernparts of the Bay of Bengal and by earlyNovember, it moves over Karnataka andTamil Nadu. By the middle of December, thecentre of low pressure is completely removedfrom the Peninsula.

The retreating southwest monsoonseason is marked by clear skies and rise intemperature. The land is still moist. Owingto the conditions of high temperature andhumidity, the weather becomes ratheroppressive. This is commonly known as the‘October heat’. In the second half of October,the mercury begins to fall rapidly, particularlyin northern India. The weather in theretreating monsoon is dry in north India butit is associated with rain in the eastern partof the Peninsula. Here, October andNovember are the rainiest months of theyear. The widespread rain in this season isassociated with the passage of cyclonic

depressions which originate over theAndaman Sea and manage to cross theeastern coast of the southern Peninsula. Thesetropical cyclones are very destructive. Thethickly populated deltas of the Godavari,Krishna and Kaveri are their preferredtargets. Every year cyclones bring disasterhere. A few cyclonic storms also strike thecoast of West Bengal, Bangladesh andMyanmar. A bulk of the rainfall of theCoromondal coast is derived from thesedepressions and cyclones. Such cyclonicstorms are less frequent in the Arabian Sea.Distribution of Rainfall

The average annual rainfall in India isabout 125 cm, but it has great spatial varia-tions. Areas of High Rainfall: The highestrainfall occurs along the west coast, on theWestern Ghats, as well as in the sub-Himalayan areas is the northeast and the hillsof Meghalaya. Here the rainfall exceeds 200cm. In some parts of Khasi and Jaintia hills,the rainfall exceeds 1,000 cm. In theBrahmaputra valley and the adjoining hills.The rainfall is less then 200 cm. Areas of Me-dium Rainfall: Rainfall between 100-200 cmis received in the southern parts of Gujarat,east Tamil Nadu, northeastern Peninsula cov-ering Orissa, Jharkhand, Bihar, easternMadhya Pradesh, northern Ganga plain alongthe sub-Himalayas and the Cachar Valley andManipur.

Seasons Months Months(According to the (According to theIndia Calendar) Indian Calendar)

Vasanta Chaitra-Vaisakha March-AprilGrishma Jyaistha-Asadha May-JuneVarsha Sravana-Bhadra July-AugustSharada Asvina-Kartika September-OctoberHemanta Margashirsa-Pausa November-

DecemberShishira Magha-Phalguna January-February


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Areas of Low Rainfall: Western UttarPradesh, Delhi, Haryana. Punjab, Jammu andKashmir, eastern Rajasthan, Gujarat andDeccan Plateau receive rainfall between50-100 cm.

Areas of Inadequate Rainfall: Parts ofthe Peninsula, especially in Andhra Pradesh,Karnataka and Maharashtra, Ladakh andmost of western Rajasthan receive rainfallbelow 50 cm. Snowfall is restricted to theHimalayan region.

Gist of NCERT

Indian HistoryISBN: 9789382732785

Book Code: F16


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Geography 31

NATURAL VEGETATION

4

Natural vegetation refers to a plantcommunity that has been left undisturbedover a long time. So as to allow its individualspecies to adjust themselves to climate andsoil conditions as fully as possible.

India is a land of great variety of naturalvegetation. Himalayan heights are markedwith temperate vegetation; the WesternGhats and the Andaman Nicobar Islandshave tropical rain forests, the deltaic regionshave tropical forests and mangroves; thedesert and semi desert areas of Rajasthan areknown for cacti, a wide variety of bushes andthorny vegetation. Depending upon thevariations in the climate and the soil, thevegetation of India changes from one regionto another.

On the basis of certain common featuressuch as predominant vegetation type andclimatic regions, Indian forests can bedivided into the following groups:Types of Forests

(i) Tropical Evergreen and SemiEvergreen forests

(ii) Tropical Deciduous forests(iii) Tropical Thorn forests(iv) Montane forests(v) Littoral and Swamp forests.

TropicalEvergreen and Semi Evergreen Forests

These forests are found in the westernslope of the Western Ghats, hills of thenortheastern region and the Andaman andNicobar Islands. They are found in warm andhumid areas with an annual precipitation ofover 200 cm and mean annual temperatureabove 220C. Tropical evergreen forests arewell stratified, with layers closer to theground and are covered with shrubs andcreepers, with short structured treesfollowed by tall variety of trees. In theseforests, trees reach great heights up to 60 mor above. There is no definite time for treesto shed their leaves, flowering and fruition.As such these forests appear green all the yearround. Species found in these forests includerosewood, mahogany, aini, ebony, etc.

The semi evergreen forests are foundin the less rainy parts of these regions. Suchforests have a mixture of evergreen andmoist deciduous trees. The under growingclimbers provide an evergreen character tothese forests. Main species are white cedar,hillock and kail.

The British were aware of the economicvalue of the forests in India, hence, large scaleexploitation of these forests was started. Thestructure of forests was also changed. Theoak forests in Garhwal and Kumaon werereplaced by pine (chirs) which was neededto lay railway lines. Forests were also clearedfor introducing plantations of tea, rubber and


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coffee. The British also used timber ofconstruction activities as it acts as an insulatorof heat. The protectional use of forests was,thus, replaced by commercial use.Tropical Deciduous Forests

These are the most widespread forestsin India. They are also called the monsoonforests. They spread over regions whichreceive rainfall between 70-200 cm. On thebasis of the availability of water, these forestsare further divided into moist and drydeciduous.

The Moist deciduous forests are morepronounced in the regions which recordrainfall between 100-200 cm. These forests arefound in the northeastern states along thefoothills of Himalayas, eastern slopes of theWestern Ghats and Odissa. Teak, sal,shisham, hurra, mahua, amla, semul, kusumand sandalwood etc. are the main species ofthese forests.

Dry deciduous forest covers vast areasof the country, where rainfall ranges between70-100 cm. On the wetter margins, it has atransition to the moist deciduous, while onthe drier margins to thorn forests. Theseforests are found in rainier areas of thePeninsula and the plains of Uttar Pradesh andBihar. In the higher rainfall regions of thePeninsular plateau and the northern Indianplain, these forests have a parkland landscapewith open stretches in which teak and othertrees interspersed with patches of grass arecommon.

As the dry season begins, the trees shedtheir leaves completely and the forest appearslike a vast grassland with naked trees allaround Tendu, palas, amaltas, bel, khair,axlewood, etc. are the common trees of theseforests. In the western and southern part of

Rajasthan, vegetation cover is very scantydue to low rainfall and overgrazing.Tropical Thorn Forests

Tropical thorn forests occur in the areaswhich receive rainfall less than 50 cm. Theseconsist of a variety of grasses and shrubs. Itincludes semi-arid areas of south west Punjab,Haryana, Rajasthan, Gujarat, Madhya Pradeshand Uttar Pradesh. In these forests, plantsremain leafless for most part of the year andgive an expression of scrub vegetation.Important species found are babool, ber, andwild date palm, khair, neem, khejri, palas,etc. Tussocky grass grows upto a height of 2m as the under growth.Montane Forests

In mountainous areas, the decrease intemperature with increasing altitude leads toa corresponding change in natural vegetation.Mountain forests can be classified into twotypes, the northern mountain forests and thesouthern mountain forests.

The Himalayan ranges show asuccession of vegetation from the tropical tothe tundra, which change in with the altitude.Deciduous forests are found in the foothillsof the Himalayas. It is succeeded by the wettemperate type of forests between analtitudes of 1,000-2,000 m.

In the higher hill ranges of northeasternIndia, hilly areas of West Bengal andUttaranchal, evergreen broad leaf trees suchas oak and chestnut are predominant.Between 1,500-1,750 m, pine forests are alsowell-developed in this zone, with Chir Pineas a very useful commercial tree. Deodar, ahighly valued endemic species grows mainlyin the western part of the Himalayan range.Deodar is a durable wood mainly used inconstruction activity. Similarly, the chinar


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Natural Vegetation 33

and the walnut, which sustain the famousKashmir handicrafts, belong to this zone.Blue pine and spruce appear at altitudes of2,225-3,048 m. At many places in this zone,temperate grasslands are also found.

But in the higher reaches there is atransition to Alpine forests and pastures.Silver firs, junipers, pines, birch andrhododendrons, etc. occur between 3,000-4,000 m. However, these pastures are usedextensively for transhumance by tribes likethe Gujjars, the Bakarwals, the Bhotiyas andthe Gaddis. The southern slopes of theHimalayas carry a thicker vegetation coverbecause of relatively higher precipitation thanthe drier north-facing slopes. At higheraltitudes, mosses and lichens form part of thetundra vegetation.

The southern mountain forests includethe forests found in three distinct areas ofPeninsular India viz; the Western Ghats, theVindhyas and the Nilgiris. As they are closerto the tropics, and only 1,500 m above thesea level, vegetation is temperate in thehigher regions, and subtropical on the lowerregions of the Western Ghats, especially inKerala, Tamil Nadu and Karnataka. Thetemperate forests are called Sholas in theNilgiris, Anaimalai and Palani hills. Some ofthe other trees of this forest of economicsignificance include magnolia, laurel,cinchona and wattle. Such forests are alsofound in the Satpura and the Maikal ranges.

The Region PercentageCover of the

Forest

(i) The region of high concentration > 40(ii) The region of medium concentration 20-40(iii) The region of low concentration 10-20

(iv) The region of very low concentration < 10

Littoral and Swamp Forests

India has a rich variety of wetlandhabitats. About 70 per cent of this comprisesareas under paddy cultivation. The total areaof wetland is 3.9 million hectares. Two sites-Chilika Lake (Odissa) and Keoladeo NationalPark (Bharatpur) are protected as water-fowlhabitats under the Convention of Wetlandsof International Importance (RamsarConvention).

The country’s wetlands have beengrouped into eight categories, viz. (i) thereservoirs of the Deccan Plateau in the southtogether with the lagoons and other wetlandsof the southern west coast; (ii) the vast salineexpanses of Rajasthan, Gujarat and the Gulfof Kachchh; (iii) freshwater lakes andreservoirs from Gujarats through Rajasthan(Keoladeo National Park) and MadhyaPradesh; (iv) the delta wetlands and lagoonsof India’s east coast (Chilika Lake); (v) thefreshwater marshes of the Gangetic Plain; (vi)the floodplains of the Brahmaputra; themarshes and swamps in the hills of northeastIndia and the Himalayan foothills; (vii) thelakes and rivers of the montane region ofKashmir and Ladakh; and (viii) the mangroveforest and other wetlands of the island arcsof the Andaman and Nicobar IslandsMangroves grow along the coasts in the saltmarshes, tidal creeks, mud flats andestuaries.

They consist of a number of salt-tolerant species of plants. Crisscrossed bycreeks of stagnant water and tidal flows,these forests give shelter to a wide varietyof birds.

In India, the mangrove forests spreadover 6,740 sq. km which is 7 per cent of the


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world’s mangrove forests. They are highlydeveloped in the Andaman and NicobarIslands and the Sunderbans of West Bengal.Other areas of significance are the Mahanadi,the Godavari and the Krishna deltas. Theseforests too, are being encroached upon, andhence, need conservation.Forest cover in India

According to state records, the forestarea covers 23.28 per cent of the total landarea of the country. The forest area is thearea notified and recorded as the forest landirrespective of the existence of trees, whilethe actual forest cover is the area occupiedby forests with canopy.

The former is based on the records ofthe State Revenue Department, while thelatter is based on aerial photographs andsatellite imageries. In 2001, the actual forestcover was only 20.55 per cent. Of the forestcover, the share of dense and open forestswas 12.60 per cent and 7.87 per centrespectively.

Both forest area and forest covers varyfrom state to state. Lakshadweep has zeropercent forest area; Andaman and NicobarIslands have 86.93 per cent. Most of the stateswith less than 10 per cent of the forest arealie in the north and northwestern part of thecountry. These are Rajasthan, Gujarat, Punjab,Haryana and Delhi.

Most of the forests in Punjab andHaryana have been cleared for cultivation.States with 10-20 per cent forest area areTamil Nadu and West Bengal. In PeninsularIndia, excluding Tamil Nadu, Dadra andNagar Haveli and Goa, the area under forestcover is 20-30 per cent. The northeastern stateshave more than 30 per cent of the land underforest. Hilly topography and heavy rainfall

are good for forest growth.There is a lot of variation in actual forest

cover, which ranges from 9.56 per cent inJammu and Kashmir to 84.01 per cent inAndaman and Nicobar Islands. From thetable showing the distribution of forests inIndia, it is clear that there are 15 states wherethe forest cover is more than one-third of thetotal area, which is the basic requirement formaintaining the ecological balance.

On the basis of the percentage of theactual forest cover, the states have beengrouped into four regions.Forest Conservation

Forests have an intricateinterrelationship with life and environment.These provide numerous direct and indirectadvantages to our economy and society.Hence, conservation of forest is of vitalimportance to the survival and prosperity ofman kind.

Accordingly, the Government of Indiaproposed to have a nation-wide forestconservation policy, and adopted a forestpolicy in 1952, which was further modifiedin 1988. According to the new forest policy,the Government will emphasis sustainableforest management in order to conserve andexpand forest reserve on the one hand, andto meet the needs of local people on theother.

The forest policy aimed at:(i) bringing 33 per cent of the

geographical areas under forestcover;

(ii) maintaining environmental stabilityand to restore forests whereecological balance was disturbed;

(iii) conserving the natural heritage of


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the country, its biological diversityand genetic pool;

(iv) checks soil erosion, extension of thedesert lands and reduction of floodsand droughts;

(v) increasing the forest cover throughsocial forestry and afforestation ondegraded land;

(vi) increasing the productivity of foreststo make timber, fuel, fodder andfood available to rural populationdependant on forests, andencourage the substitution of wood;

(vii)creating of a massive peoplesmovement involving women toencourage planting of trees, stopfelling of trees, and thus, reducepressure on the existing forest.

Based on the forest conservation policythe following steps were initiated:Social Forestry

Social forestry means the managementand protection of forests and afforestationon barren lands with the purpose of helpingin the environmental, social and ruraldevelopment.

The National Commission onAgriculture (1976) has classified socialforestry into three categories. These areUrban forestry, Rural forestry and Farmforestry.

Urban forestry pertains to the raisingand management of trees on public andprivately owned lands in and around urbancentres such as green belts, parks, roadsideavenues, industrial and commercial greenbelts, parks, roadside avenues, industrial andcommercial green belts, etc.

Rural forestry lays emphasis on

promotion of agro-forestry and community-forestry. Agro-forestry is the raising of treesand agriculture crops on the same landinclusive of the waste patches. It combinesforestry with agriculture, thus, altering thesimultaneous production of food, fodder,fuel, timber and fruit.

Community forestry involves the raisingof trees on public or community land such asthe village pasture and temple land, roadside,canal bank, strips along railway lines, andschools etc.

Community forestry programme aimsat providing benefits to the community as awhole. Community forestry provides ameans under which the people of landlessclasses can associate themselves in treeraising and thus, get those benefits whichotherwise are restricted for landowners.Farm Forestry

Farm forestry is a term applied to theprocess under which farmers grow trees forcommercial and non-commercial purposes ontheir farm lands.Wildlife

Wildlife of India is a great naturalheritage. It is estimated that about 4-5 percent of all known plant and animal specieson the earth are found in India. There arecertain species that are at the brink ofextinction.

Some estimates suggest that at least 10per cent of India’s recorded wild flora and20 per cent of its mammals are on thethreatened list.

Let us now understand the differentcategories of existing plants and animalspecies. Based on the International Union forConservation of Nature and Natural


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Resources (IUCN), we can classify as follows-Normal Species: Species whose

population levels are considered to be normalfor their survival, such as cattle, sal, pine,rodents, etc.

Endangered Species: These are specieswhich are in danger of extinction. Thesurvival of such species is difficult if thenegative factors that have led to a decline intheir population continue to operate. Theexamples of such species are black buck,crocodile, Indian wild ass, Indian rhino, liontailed macaque, sangai (brow anter deer inManipur), etc. Vulnerable Species: These arespecies whose population has declined tolevels from where it is likely to move intothe endangered category in the near futureif the negative factors continue to operate.The examples of such species are blue sheep,Asiatic elephant, Gangetic dolphin etc. RareSpecies:

Species with small population may moveinto the endangered for vulnerable categoryif the negative factors affecting them continueto operate. The examples of such species arethe Himalayan brown bear, wild Asiaticbuffalo, desert fox and hornbill, etc.

Endemic Species: These are specieswhich are only found in some particular areasusually isolated by natural or geographicalbarriers. Examples of such species are theAndaman teal, Nicobar pigeon, Andamanwild pig, mithun in Arunachal Pradesh.Extinct Species: These are species which arenot found after searches of known or likelyareas where they may occur. A species maybe extinct from a local area, region, country,continent or the entire earth. Examples ofsuch species are the Asiatic cheetah, pinkhead duck.

Wildlife Conservation in India

The protection of wildlife has a longtradition in India. Many stories ofPanchtantra and Jungle Books, etc. havestood the test of time relating to the love forwildlife. These have a profound impact onyoung minds. In 1972, a comprehensiveWildlife Act was enacted, which provides themain legal framework for conservation andprotection of wildlife in India. The two mainobjectives of the Act are; to provideprotection to the endangered species listedin the schedule of the Act and to provide legalsupport to the conservation areas of thecountry classified as National parks,sanctuaries and closed areas.

This Act has been comprehensivelyamended in 1991, making punishments morestringent and has also made provisions forthe protection of specified plant species andconservation of endangered species of wildanimals. There are 92 National parks and 492wildlife sanctuaries covering an area of 15.67million hectares in the country. Wildlifeconservation has a very large ambit withunbounded potential for the wellbeing ofmankind. However, this can be achieved onlywhen every individual understands itssignificance and contributes his bit.

For the purpose of effective conservationof flora and fauna, special steps have beeninitiated by the Government of India incollaboration with UNESCO’s ‘Man andBiosphere Programme’. Special schemes likeProject Tiger (1973) and Project Elephant(1992) have been launched to conserve thesespecies and their habitat in a sustainablemanner.

Project Tiger has been implementedsince 1973. The main objective of the scheme


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is to ensure maintenance of viable populationof tigers in India for scientific, aesthetic,cultural and ecological values, and to preserveareas of biological importance as naturalheritage for the benefit, education andenjoyment of the people. Initially, the ProjectTiger was launched in nine tiger reserves,covering an area of 16,339 sq. km, which hasnow increased to 27 tiger reserves,encompassing 37,761 sq. km of tiger habitatsdistributed in 17 states. The tiger populationin the country has registered an increase from1,827 in 1972 to 3,642 in 2001-2002.

Project Elephant was launched in 1992to assist states having free ranging popula-tion of wild elephants. It was aimed at en-suring long-term survival of identified viablepopulation of elephants in their natural habi-tat. The project is being implemented in 13states. Apart from this, some other projectssuch as Crocodile Breeding Project, ProjectHangul and conservation of Himalayan Muskdeer have also been launched by the Gov-ernment of India.Biosphere Reserves

A Biosphere Reserve is a unique andrepresentative ecosystem of terrestrial andcoastal areas which are internationallyrecognized within the framework ofUNESCO’s Man and Biosphere (MAB)Programme. The Biosphere Reserve aims atachieving the three objective as depicted inFigure. There are 16 Biosphere Reserves inIndia. Four Biosphere Reserves. Namely (i)Nilgiri; (ii) Nanda Devi: (iii) Sunderbans; and(iv) Gulf of Mannar have been recognized bythe UNESCO on World Network ofBiosphere Reserves.Nilgiri Biosphere Reserve

The Nilgiri Biosphere Reserve (NBR),

the first of the fourteen biosphere reservesof India, was established in September 1986.It embraces the sanctuary complex ofWyanad, Nagarhole, Bandipur andMudumalai, the entire forested hill slopes ofNilambur, the Upper Nilgiri plateau, SilentValley and the Siruvani hills. The total areaof the biosphere reserve is around 5,520 sq.km. The Nilgiri Biosphere Reserve possessesdifferent habitat types, unspoilt areas ofnatural vegetation types with several dryscrubs, dry and moist deciduous, semievergreen and wet evergreen forests,evergreen shoals, grasslands and swamps. Itincludes the largest known population of twoendangered animal species, namely theNilgiri Tahr and the Lion-tailed macaque.The largest south Indian population ofelephant, tiger, gaur, sambar and chital aswell as a good number of endemic andendangered plants are also found in thisreserve. The habitat of a number of tribalgroups remarkable for the traditional modesof harmonious use of the environment arealso found here. The topography of the NBRis extremely varied, ranging from an altitudeof 250 m to 2,650 m. About 80 per cent of theflowering plants reported from the WesternGhats occur in the Nilgiri Biosphere Reserve.Nanda Devi Biosphere Reserve

The Nanda Devi Biosphere Reservesituated in Uttarakhand includes parts ofChamoli, Almora, Pithoragarh andBageshwar districts. The major forest typesof the reserve are temperate. A few importantspecies are silver weed and orchids likelatifolie and rhododendron. The biospherereserve has a rich fauna, for example the snowleopard, black bear, brown bear, musk deer,snowcock, golden eagle and black eagle.


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Major threats to the ecosystem are the collection of endangered plants for medicinal use,forest fires and poaching.

List of Biosphere Reserves

Sl.No. Name of the Biosphere TotalReserve Geographical Location (States)

Area (km2)

1. Nilgiri 5,520 Part of Wynad, Nagarhole, Bandipur and Mudumalai, Nilambur, Silent Valleyand Struvant Hills (Tamil Nadu, Kerala and Karnataka)

2. Nanda Devi 2,236.74 Part of Chamoli, Pithoragarh and Almora districts (Uttar Pradesh) and part ofGaro Hills (Meghalaya)

3. Nokrek 820 Part of Garo Hills (Meghalaya)4. Manas 2,837 Part of Kokrajhar, Bongaigaon, Barpeta, Nalbari, Kamrup and Darrang districts

(Assam)5. Sunderbans 9,630 Part of delta of Ganges and Brahmaputra river system (West Bengal)6. Gulf of Mannar 10,500 Indian part of Gulf of Mannar between India and Sri Lanka (Tamil Nadu)7. Great Nicobar 885 Southernmost Islands of the Andaman and Nicobar (A&N Islands)8. Similipal 4,374 Part of Mayurbhanj district (Orissa)9. Dibru Saikhowa 765 Part of Dibrugarh and Tinsukia districts (Assam)10. Dihang Dibang 5,111.5 Part of Siang and Debang valley in Arunachal Pradesh11. Kanchenjunga 2,619.92 Parts of North and West Sikkim12. Pachman 4,926.28 Parts of Betul. Hoshangabad and Chindwara districts of Madhya Pradesh.13. Agasthya-malai 1,701 Agasthyamalai Hills in Kerala14. Achanakmar- 3,835.51 Parts of Anupur and Dindori district of MP and parts of Bilaspur district of

Amarkantak Chhatisgarh

Sunderbans Biosphere Reserve

It is located in the swampy delta of theriver Ganga in West Bengal. It extends overa vast area of 9,630 sq. km. and consists ofmangrove forests, swamps and forestedislands. Sundarbans is the home of nearly 200Royal Bengal tigers.The tangled mass of rootsof mangrove trees provide safe homes for alarge number of species, from fish to shrimp.More than 170 birds species are known toinhabit these mangrove forests.Adaptingitself to the saline and fresh waterenvironment, the tigers at the park are goodswimmers, and they hunt scarce preys suchas chital deer, barking deer, wild pig andeven macaques. In the Sunderbans, themangrove forests are characterized by

Heritiera fomes, a species valued for itstimber.Gulf of Mannar Biosphere Reserve

The Gulf of Mannar Biosphere Reservecovers an area of 105,000 hectares on thesoutheast coast of India. It is one of theworld’s richest regions from a marinebiodiversity perspective. The biospherereserve comprises 21 islands with estuaries,beaches, forests of the near shoreenvironment, sea grasses, coral reefs, saltmarshes and mangroves. Among the Gulf’s3,600 plant and animal species are the globallyendangered sea cow (Dugong / dugon) andsix mangrove species, endemic to PeninsularIndia.


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Geography 39

SOILS

5

Soil is the most important layer of theearth’s crust. It is a valuable resource.

Soil is the mixture of rock debris andorganic materials which develop on theearth’s surface. The major factors affectingthe formation of soil are relief, parent mate-rial, climate, vegetation and other life-formsand time. Besides these, human activities alsoinfluence it to a large extent. Components ofthe soil are mineral particles, humus, waterand air. The actual amount of each of thesedepend upon the type of soil. Some soils aredeficient in one or more of these, while thereare some others that have varied combina-tions.

If we dig a pit on land and look at thesoil, we find that it consists of three layerswhich are called horizons. ‘Horizon A’ is thetopmost zone, where organic materials havegot incorporated with the mineral matter,nutrients and water, which are necessary forthe growth of plants. ‘Horizon B’ is atransition zone between the ‘horizon A’ and‘horizon C’, and contains matter derivedfrom below as well as from above. It has someorganic matter in it, although the mineralmatter is noticeably weathered. ‘Horizon C’is composed of the loose parent material. Thislayer is the first stage in the soil formationprocess and eventually forms the above twolayers. This arrangement of layers is knownas the soil profile. Underneath these three

horizons is the rock which is also known asthe parent rock or the bedrock. Soil, which isa complex and varied entity, has alwaysdrawn the attention of the scientists.Classification of Soils

India has varied relief features,landforms, climatic realms and vegetationtypes. These have contributed in thedevelopment of various types of soils inIndia.

On the basis of genesis, colour,composition and location, the soils of Indiahave been classified into: (i) Alluvial soils,(ii) Black soils, (iii) Red and Yellow soils, (iv)Laterite soils, (v) arid soils, (vi) Saline soils,(vii) Peaty soils, (viii) Forest soils.ICAR has classified the soils of India intothe following order as per the USDA soiltaxonomy

Sl.No. Order Area Percentage(In Thousand

Hectares)

(i) Inceptisols 130372.90 39.74(ii) Entisols 92131.71 28.08(iii) Alfisols 44448.68 13.55(iv) Vertisols 27960.00 8.52(v) Aridisols 14069.00 4.28(vi) Ultisols 8250.00 2.51(vii) Mollisols 1320.00 0.40(viii) Others 9503.10 2.92

Total 100


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Source: Soils of India. National Bureauof Soil Survey and Land Use Planning.Publication Number 94Alluvial Soils

Alluvial soils are widespread in thenorthern plains and the river valleys. Thesesoils cover about 40 per cent of the total areaof the country. They are depositional soils,transported and deposited by rivers andstreams. Through a narrow corridor inRajasthan, They extend into the plains ofGujarat. In the Peninsular region, they arefound in deltas of the east coast and in theriver valleys.

The alluvial soils vary in nature fromsandy loam to clay. They are generally richin potash but poor in phosphorous. In theUpper and Middle Ganga plain, two differenttypes of alluvial soils have developed, viz.Khadar and Bhangar. Khadar is the newalluvium and is deposited by floods annually,which enriches the soil by depositing finesilts. Bhangar represents a system of olderalluvium, deposited away from the floodplains. Both the Khadar and Bhangar soilscontain calcareous concretions (Kankars).These soils are more loamy and clayey in thelower and middle Ganga plain and theBrahamputra valley. The sand contentdecreases from the west to east.

The colour of the alluvial soils variesfrom the light grey to ash grey. Its shadesdepend on the depth of the deposition, thetexture of the materials, and the time takenfor attaining maturity. Alluvial soils areintensively cultivated.Black Soil

Black soil covers most of the DeccanPlateau which includes parts of Maharashtra,

Madhya Pradesh, Gujarat, Andhra Pradeshand some parts of Tamil Nadu. In the upperreaches of the Godavari and the Krishna, andthe north western part of the Deccan Plateau,the black soil is very deep. These soils arealso known as the ‘Regur Soil’ or the ‘BlackCotton Soil’. The black soils are generallyclayey, deep and impermeable. They swelland become sticky when wet and shrinkwhen dried. So, during the dry season, thesesoils develop wide cracks. Thus, there occursa kind of ‘self ploughing’. Because of thischaracter of slow absorption and loss ofmoisture, the black soil retains the moisturefor a very long time, which helps the crops,especially; the rain fed ones, to sustain evenduring the dry season.

Chemically, the black soils are rich inlime, iron, magnesia and alumina. They alsocontain potash. But they lack in phosphorous,nitrogen and organic matter. The colour ofthe soil ranges from deep black to grey.Red and Yellow Soil

Red Soil develops on crystalline igneousrocks in areas of low rainfall in the easternand southern part of the Deccan Plateau.Along the piedmont zone of the WesternGhat, long stretch of area is occupied by redloamy soil. Yellow and red soils are alsofound in parts of Odissa and Chattisgarh andin the southern parts of the middle Gangaplain. The soil develops a reddish colour dueto a wide diffusion of iron in crystalline andmetamorphic rocks. It looks yellow when itoccurs in a hydrated form. The fine-grainedred and yellow soils are normally fertile,whereas coarse-grained soils found in dryupland areas are poor in fertility. They aregenerally poor in nitrogen, phosphorous andhumus.


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Soils 41

Laterite Soil

Laterite has been derived from the Latinword ‘Later’ which means brick. The lateritesoils develop in areas with high temperatureand high rainfall. These are the result ofintense leaching due to tropical rains. Withrain, lime and silica are leached away, andsoils rich in iron oxide and aluminumcompound are left behind. Humus contentof the soil is removed fast by bacteria thatthrives well in high temperature. These soilsare poor in organic matter, nitrogen,phosphate and calcium, while iron oxide andpotash are in excess. Hence, laterites are notsuitable for cultivation; however, applicationof manures and fertilizers are required formaking the soils fertile for cultivation.

Red laterite soils in Tamil Nadu, AndhraPradesh and Kerala are more suitable for treecrops like cashew nut.

Laterite soils are widely cut as bricksfor use in house construction. These soilshave mainly developed in the higher areasof the Peninsular plateau. The laterite soilsare commonly found in Karnataka, Kerala,Tamil Nadu, Madhya Pradesh and the hillyareas of Odissa and Assam.Arid Soils

Arid soils range from red to brown incolour. They are generally sandy in structureand saline in nature. In some areas, the saltcontent is so high that common salt is obtainedby evaporating the saline water. Due to thedry climate, high temperature andaccelerated evaporation, they lack moistureand humus. Nitrogen is insufficient and thephosphate content is normal. Lower horizonsof the soil are occupied by ‘kankar’ layersbecause of the increasing calcium contentdownwards. The ‘Kankar’ layer formation in

the bottom horizons restricts the infiltrationof water, and as such when irrigation is madeavailable, the soil moisture is readily availablefor a sustainable plant growth. Arid soils arecharacteristically developed in westernRajasthan, which exhibit characteristic andtopography. These soils are poor and containlittle humus and organic matter.Saline Soils

They are also known as Usara soils.Saline soils contain a larger proportion ofsodium, potassium and magnesium, andthus, they are infertile, and do not supportany vegetative growth. They have moresalts, largely because of dry climate and poordrainage. They occur in arid and semi aridregions, and in waterlogged and swampyareas. Their structure ranges from sandy toloamy. They lack in nitrogen and calcium.Saline soils are more widespread in westernGujarat, deltas of the eastern coast and inSunderban areas of West Bengal. In the Rannof Kuchchh, the Southwest Monsoon bringssalt particles and deposits there as a crust.Seawater intrusions in the deltas promote theoccurrence of saline soils. In the areas ofintensive cultivation with excessive use ofirrigation, especially in areas of greenrevolution, the fertile alluvial soils arebecoming saline. Excessive irrigation withdry climatic conditions promotes capillaryaction, which results in the deposition of salton the top layer of the soil. In such areas,especially in Punjab and Haryana, farmers areadvised to add gypsum to solve the problemof salinity in the soil.Peaty Soils

They are found in the areas of heavyrainfall and high humidity, where there is agood growth of vegetation. Thus, large


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quantity of dead organic matter accumulatesin these areas, and this gives a rich humusand organic content to the soil. Organicmatter in these soils may go even up to 40-50per cent. These soils are normally heavy andblack in colour. At many places, they arealkaline also. It occurs widely in the northernpart of Bihar, southern part of Uttaranchaland the coastal areas of West Bengal, Orissaand Tamil Nadu.Forest Soils

As the name suggests, forest soils areformed in the forest areas where sufficientrainfall is available. The soils vary in structureand texture depending on the mountainenvironment where they are formed. Theyare loamy and silty on valley sides andcoarse-grained in the upper slopes. In thesnow-bound areas of the Himalayas, theyexperience denudation, and are acidic withlow humus content. The soils found in thelower valleys are fertile.Soil Degradation

In a broad sense, soil degradation canbe defined as the decline in soil fertility, whenthe nutritional status declines and depth ofthe soil goes down the erosion and misuse.Soil degradation is the main factor leadingto the depleting soil resource base in India.The degree of soil degradation varies fromplace to place according to the topography,wind velocity and amount of the rainfall.Soil Erosion

The destruction of the soil cover isdescribed as soil erosion. The soil formingprocesses and the erosional processes ofrunning water and wind go onsimultaneously. But generally, there is abalance between these two processes. The

rate of removal of fine particles from thesurface is the same as the rate of addition ofparticles to the soil layer. Sometimes, such abalance is disturbed by natural or humanfactors, leading to a greater rate of removalof soil. Human activities too are responsiblefor soil erosion to a great extent. As thehuman population increases, the demand onthe land also increases. Forest and othernatural vegetation is removed for humansettlement, for cultivation, for grazing animaland for various other needs.

Wind and water are powerful agents ofsoil erosion because of their ability to removesoil and transport it. Wind erosion issignificant in arid and semi-arid regions. Inregions with heavy rainfall and steep slopes,erosion by running water is more significant.Water erosion which is more serious andoccurs extensively in different parts of India,takes place mainly in the form of sheet andgully erosion. Sheet erosion takes place onlevel lands after a heavy shower and the soilremoval is not easily noticeable. But it isharmful since it removes the finer and morefertile top soil. Gully erosion is common steepslopes. Gullies deepen with rainfall, cut theagricultural lands into small fragments andmake from them unfit for cultivation. Aregion with a large number of deep gulliesor ravines is called a badland topography.Ravines are widespread, in the Chambalbasin. Besides this, they are also found inTamil Nadu and West Bengal. The countryis losing about 8,000 hectare of land toravines every year.

Deforestation is one of the major causesof soil erosion. Plants keep soils bound inlocks of roots, and thus, prevent erosion.They also add humus to the soil by shedding


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Soils 43

leaves and twigs. Forests have been denudedpractically in most parts of India but theireffect on soil erosion are more in hilly partsof the country.

A fairly large area of arable land in theirrigated zones of India is becoming salinebecause of over irrigation. The salt lodgedin the lower profiles of the soil comes up tothe surface and destroys its fertility. Chemicalfertilizers in the absence of organic manuresare also harmful to the soil. Unless the soilgets enough humus, chemicals harden it andreduce its fertility in the long run. Thisproblem is common in all the command areasof the river valley projects, which were thefirst beneficiaries of the Green Revolution.According to estimates, about half of the totalland of India is under some degree ofdegradation. Every year, India loses millionsof tones of soil and its nutrients to the agentsof its degradation, which adversely affectsour national productivity. So, it is imperativeto initiate immediate steps to reclaim andconserve soils.Soil Conservation

Contour bunding, Contour terracing,regulated forestry, controlled grazing, covercropping, mixed farming and crop rotationare some of the remedial measures which areoften adopted to reduce soil erosion.

Efforts should be made to prevent gullyerosion and control their formation. Fingergullies can be eliminated by terracing. Inbigger gullies, the erosive velocity of watermay be reduced by constructing a series ofcheck dams. Specially attention should bemade to control headward extension ofgullies. This can be done by gully plugging,terracing or by planting cover vegetation.

In arid and semi-arid areas, efforts

should be made to protect cultivable landsfrom encroachment by sand dunes throughdeveloping shelter belts of trees and agro-forestry. Lands not suitable for cultivationshould be converted into pastures forgrazing. Experiments have been made tostabilize sand dunes in western Rajasthan bythe Central Arid Zone Research Institute(CAZRI). The Central Soil ConservationBoard, set up by the Government of India,has prepared a number of plans for soilconservation in different parts of the country.These plans are based on the climaticconditions, configuration of land and thesocial behavior of people. Even these plansare fragmental in nature. Integrated land useplanning, therefore, seems to be the besttechnique for proper soil conservation.Water Resources

Water is a cyclic resource with abundantsupplies on the globe. Approximately, 71 percent of the earth’s surface is covered with itbut fresh water constitutes only about 3 percent of the total water. In fact, a very smallproportion of fresh water is effectivelyavailable for human use. The availability offresh water varies over space and time.Water Resources of India

India accounts for about 2.45 per centof world’s surface areas, 4 per cent of theworld’s water resources and about 16 per centof world’s population. The total wateravailable from precipitation in the country ina year is about 4,000 cubic km. The availabilityfrom surface water and replenishablegroundwater is 1,869 cubic km. Out of thisonly 60 per cent can be put to beneficial uses.Thus, the total utilizable water resource inthe country is only 1,122 cubic km.


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Surface Water Resources

There are four major sources of surfacewater. These are rivers, lakes, ponds, andtanks. In the country, there are about 10,360rivers and their tributaries longer than 1.6km each. The mean annual flow in all theriver basins in India is estimated to be 1,869cubic km. However, due to topographical,hydrological and other constraints, onlyabout 690 cubic km (32 per cent) of the avail-able surface water can be utilized. Water flowin a river depends on size of its catchmentarea or river basin and rainfall within itscatchment area. Given that precipitation isrelatively high in the catchment areas of theGanga, the Brahmaputra and the Barak riv-ers, these rivers, although account for only

about one-third of the total area in the coun-try, have 60 per cent of the total surface wa-ter resource. Much of the annual water flowin south Indian rivers like the Godavari, theKrishna, and the Kaveri has been harnessed,but it is yet to be done in the Brahmaputraand the Ganga basins.Groundwater Resources

The total replenishable groundwaterresources in the country are about 432 km.Table shows that the Ganga and theBrahmaputra basins, have about 46 per centof the total replenishable groundwater re-sources. The level of groundwater utilizationis relatively high in the river basins lying innorth-western region and parts of south In-dia.

Basinwise Ground water Potential and Utilization in India (Cubic Km/Year)

S.No. Name of Basin Total Replenishable Level ofGround water Resources Utilization (%) Groundwater

1. Brahmani with Baltarni 4.05 8.452. Brahmaputra 26.55 3.373. Chambal Composite 7.19 40.094. Kaveri 12.3 55.335. Ganga 170.99 33.526. Godavari 40.65 19.537. Indus 26.49 77.718. Krishna 26.41 30.399. Kuchchh and Saurashtra Including Luni 11.23 51.1410. Chennai and South Tamil Nadu 18.22 57.6811. Mahanadi 16.46 6.9512. Meghna (Barak & Others) 8.52 3.9413. Narmada 10.83 21.7414. Northeast Composite 18.84 17.215. Pennar 4.93 36.616. Subarnarekha 1.82 9.5717. Tapi 8.27 33.0518. Western Ghat 17.69 22.88

Total 431.42 31.97


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Soils 45

The groundwater utilization is very highin the states of Punjab, Haryana, Rajasthan,and Tamil Nadu. However, there are Stateslike Chhatisgarh, Orissa, Kerala, etc., whichutilize only a small proportion of theirgroundwater potentials. States like Gujarat,Uttar Pradesh, Bihar, Tripura andMaharashtra are utilizing their ground waterresources at a moderate rate. If the presenttrend continues, the demands for waterwould need the supplies. And such situation,will be detrimental to development, and cancause social upheaval and disruptions.

Water Demand and Utilization India hastraditionally been an agrarian economy, andabout two-third of its population have beendependent on agriculture. Hence,development of irrigation to increaseagricultural production has been assigned avery high priority in the Five Year Plans, andmultipurpose river valleys projects like theBhakra-Nangal, Hirakund, Damodar, Valley,Nagarjuna Sagar, Indira Gandhi CanalProject, etc. have been taken up. In fact, India’swater demand at present is dominated byirrigational needs.

Agriculture accounts for most the sur-face and ground water utilization, it accountsfor 89 per cent of the surface water and 92per cent of the groundwater utilization. Whilethe share of industrial sector is limited to 2per cent of the surface water utilization and5 per cent of the ground-water, the share ofdomestic sector is higher (9 per cent) in sur-face water utilization as compared togroundwater. The share of agricultural sec-tor in total water utilization is much higherthan other sectors. However, is future, withdevelopment, the shares of industrial anddomestic sectors in the country are likely toincrease.

Demand of Water for Irrigation

In agriculture, water is mainly used forirrigation. Irrigation is needed because ofspatiotemporal variability in rainfall in thecountry. The large tracts of the country aredeficient in rainfall and are drought prone.North-Western India and Deccan plateauconstitute such areas. Winter and summerseasons are more or less dry in most part ofthe country. Provisions of irrigation makesmultiple cropping possible. It has also beenfound that irrigated lands have higheragricultural productivity than un-irrigatedland. Further, the high yielding varieties ofcrops need regular moisture supply, whichis made possible only by a developedirrigation systems. In fact, this is why thatgreen revolution strategy of agriculturedevelopment in the country has largely beensuccessful in Punjab, Haryana and westernUttar Pradesh.

In Punjab, Haryana and Western UttarPradesh more than 85 per cent of their netsown area is under irrigation. Wheat and riceare grown mainly with the help of irrigationin these states. Of the total net irrigated area76.1 per cent in Punjab and 51.3 per cent inHaryana are irrigated through wells and tubewells. This shows that these states utilizelarge proportion of their ground waterpotential which has resulted in ground waterdepletion in these states. The share of areairrigated through wells and tube wells is alsovery high in the states given in table.

The over-use of ground water resourceshas led to decline in ground water table inthese states. In fact, over withdrawals insome states like Rajasthan, and Maharashtrahas increased fluoride concentration inground-water, and this practice has led toincrease in concentration of arsenic in parts


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of West Bengal and Bihar.Prevention of Water Pollution

Available water resources aredegrading rapidly. The major rivers of thecountry generally retain better water qualityin less densely populated upper stretches inhilly areas. In plans, river water is usedintensively for irrigation, drinking, domesticand industrial purposes. The drains carryingagricultural (fertilizers and insecticides),domestic (solid and liquid wastes), andindustrial effluents join the rivers. Theconcentration of pollutants in rivers,especially remains very high during thesummer season when flow of water is low.

The Central Pollution Control Board(CPCB) in collaboration with State PollutionControl Boards has been monitoring waterquality of national aquatic resources at 507stations. The data obtained from thesestations show that organic and bacterialcontamination continues to be the main sourceof pollution in rivers. The Yamuna river isthe most polluted river in the countrybetween Delhi and Etawah.

Other severely polluted rivers are: theSabarmati at Ahmedabad, the Gomti atLucknow, the Kali, the Adyar, the Cooum(entire stretches), the Vaigai at Madurai andthe Musi of Hyderabad and the Ganga atKanpur and Varanasi. Groundwaterpollution has occurred due to highconcentrations of heavy/toxic metals,fluoride and nitrates at different parts of thecountry.

The legislative provisions such as theWater (Prevention and Control of Pollution)Act 1974, and Environment Protection Act1986 have not been implemented effectively.

The result is that in 1997, 251 pollutingindustries were located along the rivers andlakes.

The Water Cess Act, 1977, meant toreduce pollution has also made marginalimpacts. There is a strong need to generatepublic awareness about importance of waterand impacts of water pollution. The publicawareness and action can be very effectivein reducing the pollutants from agriculturalactivities, domestic and industrial discharges.Watershed Management

Watershed management basically refersto efficient management and conservation ofsurface and groundwater resources. It in-volves prevention of runoff and storage andrecharge of groundwater through variousmethods like percolation tanks, rechargewells, etc. However, in broad sense water-shed management includes conservation, re-generation and judicious use of all resources-natural (like land, water, plants and animals)and human with in a watershed. Watershedmanagement aims at bringing about balancebetween natural resources on the one handand society on the other. The success of wa-tershed development largely depends uponcommunity participation.

The Central and State Governmentshave initiated many watershed developmentand management programmes in the coun-try. Some of these are being implemented bynongovernmental organizations also. Haryaliis a watershed development project spon-sored by the Central Government which aimsat enabling the rural population to conservewater for drinking, irrigation, fisheries andafforestation. The Project is being executedby Gram Panchayats with people’s participa-tion.

Neeru-Meeru (Water and You)


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Soils 47

programme (in Andhra Pradesh) and ArvaryPani Sansad (in Alwar, Rajasthan) have takenup constructions of various water harvestingstructures such as percolation tanks, dug outponds (Johad), check dams, etc. throughpeople’s participation. Tamil Nadu has madewater harvesting structures in the housescompulsory. No building can be constructedwithout making structures for waterharvesting.

Watershed development projects insome areas have been successful inrejuvenating environment and economy.However, are only a few success stories. Inmajority of cases, the programme is still inits nascent stage. There is a need to generateawareness regarding benefits of watersheddevelopment and management among peoplein the country, and through this integratedwater resource management approach wateravailability can be ensured on sustainablebasis.Rainwater Harvesting

Rain water harvesting is a method tocapture and store rainwater for various uses.It is also used to recharge groundwater aq-uifers. It is a low cost and eco-friendly tech-nique for preserving every drop of water byguiding the rain water to bore well, pits andwells. Rainwater harvesting increases wateravailability, checks the declining ground wa-ter table, improves the quality ofgroundwater through dilution of contami-nants like fluoride and nitrates, prevents soilerosion, and flooding and arrests salt waterintrusion in coastal areas if used to rechargeaquifers.

Rainwater harvesting has been practicedthrough various methods by differentcommunities in the country for a long time.

Traditional rain water harvesting in ruralareas is done by using surface storage bodieslike lakes, ponds, irrigation tanks, etc. InRajasthan, rainwater harvesting structureslocally known as Kund or Tanka (a coveredunderground tank) are constructed near orin the house or village to store harvestedrainwater.

There is a wide scope to use rainwaterharvesting technique to conserve waterresource. It can be done by harvestingrainwater on rooftops and open spaces.

Harvesting rainwater also decreases thecommunity dependence on groundwater fordomestic use. Besides bridging the demandsupply gap, it can also save energy to pumpgroundwater as recharge leads to rise ingroundwater. These days rainwaterharvesting is being taken up on massive scalein many states in the country. Urban areascan specially benefit from rainwaterharvesting as water demand has alreadyoutstripped supply in most of the cities andtowns.

Apart from the above mentionedfactors, the issue desalinization of waterparticularly in coastal areas and brackishwater in arid and semi-arid areas, transferof water from water surplus areas to waterdeficit areas through inter linking of riverscan be important remedies for solving waterproblem in India (read more about interlinking of rivers). However, the mostimportant issue from the point of view ofindividual users, household and communitiesis pricing of water.Highlights ofIndia’s National Water Policy, 2002

The National Water Policy 2002stipulates water allocation priorities broadly


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in the following order: drinking water;irrigation, hydro-power, navigation,industrial and other uses. The policystipulates progressive new approaches towater management. Key features include:

• Irrigation and multi-purpose projectsshould invariably include drinkingwater component, wherever there isno alternative source of drinkingwater.

• Providing drinking water to allhuman beings and animals should bethe first priority.

• Measures should be taken to limitand regulate the exploitation of

groundwater.• Both surface and groundwater

should be regularly monitored forquality. A phased programmeshould be undertaken for improvingwater quality.

• The efficiency of utilization in all thediverse uses of water should beimproved.

• Awareness of water as a scarceresource should be fostered.

• Conservation consciousness shouldbe promoted through education,regulation, incentives anddisincentives.

Gist of NCERT

Indian Economy

ISBN: 9789351720256Book Code: F22


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Geography 49

LAND USE AND AGRICULTURE

Different types of lands are suited todifferent uses. Human beings thus, use landas a resource for production as well asresidence and recreation.

Land-use records maintained by landrevenue department. The land use categoriesadd up to reporting area, which is somewhatdifferent from the geographical area. TheSurvey of India is responsible for measuringgeographical area of administrative units inIndia. The difference between the twoconcepts are that while the former changessomewhat depending on the estimates of theland revenue records, the latter does notchange and stays fixed as per Survey of Indiameasurements.

The land-use categories as maintainedin the Land Revenue are as follows:

(i) Forests: It is important to note thatarea under actual forest cover isdifferent from area classified asforest. The latter is the area whichthe Government has identified anddemarcated for forest growth. Theland revenue records are consistentwith the latter definition. Thus, theremay be an increase in this categorywithout any increase in the actualforest cover.

(ii) Land put to Non-agricultural Uses:Land under settlements (rural and

urban), infrastructure (roads, canals,etc.), industries, shops, etc. areincluded in this category. Anexpansion in the secondary andtertiary activities would lead to anincrease in this category of land-use.

(iii) Barren and Wastelands: The landwhich may be classified as awasteland such as barren hillyterrains, desert lands, ravines, etc.normally cannot be brought undercultivation with the availabletechnology.

(iv) Area under Permanent pastures andGrazing Lands: Most of this typeland is owned by the village‘Panchayat’ or the Government.Only a small proportion of this landis privately owned. The land ownedby the village panchayat comesunder ‘Common PropertyResources’.

(v) Area under Miscellaneous TreeCrops and Goves (Not included isNet sown Area): The land underorchards and fruit trees are includedin this category. Much of this land isprivately owned.

(vi) Culturable Waste-Land: Any landwhich is left fallow (uncultivated) formore than five years is included in


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this category. It can be broughtunder cultivation after improving itthrough reclamation practices.

(vii) Current Fallow: This is the landwhich is left without cultivation forone or less than one agricultural year,Fallowing is a cultural practiceadopted for giving the land rest. Theland recoups the lost fertilitythrough natural processes.

(viii) Fallow other than CurrentFallow: This is also a cultivable landwhich is left uncultivated for morethan five years, it would becategorized as culturable wasteland.

(ix) Net Area Sown: The physical extentof land on which crops are sown andharvested is known as net sownarea.

Land-use Changes in India

Land-use in a region, to a large extent,is influenced by the nature of economicactivities carried out in the region. However,while economic activities change over time,land, like many other natural resources, isfixed in terms of its area. At this stage, oneneeds to appreciate three types of changesthat an economy undergoes, which affectland-use.

India has undergone major changeswithin the economy over the past four or fivedecades, and this has influenced the land-usechanges in the country, These changesbetween 1960-61 and 2002-03 have beenshown in Fig. There are two points that youneed to remember before you derive somemeaning from this figure. Firstly, thepercentage shown in the figure have beenderived with respect to the reporting area.

Secondly, since even the reporting area hasbeen relatively constant over the years, adecline in one category usually leads to anincrease in some other category.

Three categories have undergoneincreases, while four have registereddeclines. Share of area under forest, are undernonagricultural uses and current fallow landshave shown an increase. The followingobservations can be made about theseincreases:

(i) The rate of increase is the highest incase of area under non-agriculturaluses. This is due to the changingstructure of Indian economy, whichis increasingly depending on thecontribution from industrial andservices sectors and expansion ofrelated infrastructural facilities.Also, an expansion of area underboth urban and rural settlements hasadded to the increase. Thus, the areaunder non-agricultural uses isincreasing at the expense ofwastelands and agricultural land.

(ii) The increase in the share underforest, as explained before, can beaccounted for by increase in thedemarcated area under forest ratherthan an actual increase in the forestcover in the country.

(iii) The increase in the current fallowcannot be explained frominformation pertaining to only twopoints. The trend of current fallowfluctuates a great deal over years,depending on the variability ofrainfall and cropping cycles.

The four categories that have registereda decline are barren and wasteland, culturable


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Land use and Agriculture 51

wasteland, area under pastures and treecrops and net area sown.

The following explanations can be givenfor the declining trends:

(i) As the pressure on land increased,both from the agricultural andnonagricultural sectors, thewastelands and culturablewastelands have witnessed declineover time.

(ii) The decline in net area sown is arecent phenomenon that started inthe late nineties, before which it wasregistering a slow increase. There areindications that most of the declinehas occurred due to the increases inarea under nonagricultural use.(Note: the expansion of buildingactivity on agricultural land in yourvillage and city).

(iii) The decline in land under pasturesand grazing lands can be explainedby pressure from agricultural land.Illegal encroachment due toexpansion of cultivation on commonpasture lands is largely responsiblefor this decline.

Agricultural Land Use in India

Land resource is more crucial to thelivelihood of the people depending on

agriculture:(i) Agriculture is a purely land based

activity unlike secondary andtertiary activities. In other words,contribution of land in agriculturaloutput is more compared to itscontribution in the outputs in theother sectors. Thus, lack of access toland is directly correlated withincidence of poverty in rural areas.

(ii) Quality of land has a direct bearingon the productivity of agriculture,which is not true for other activities.

(iii) In rural areas, aside from its valueas a productive factor, landownership has a social value andserves as a security for credit,natural hazards or life contingencies,and also adds to the social status.

An estimation of the total stock of agri-cultural land resources (i.e. total cultivableland can be arrived at by adding up net sownarea, all fallow lands and culturable waste-land. It may be observed from Table that overthe years, there has been a marginal declinein the available total stock of cultivable landas a percentage to total reporting area. Therehas been a greater decline of cultivated land,in spite of a corresponding decline of culti-vable wasteland.

Agricultural land-Use As a percentage of As a percentage to TotalReporting Area Cultivated land

Categories 1960-61 2002-03 1960-61 2002-03Culturable Wasteland 6.23 4.41 10.61 7.52Fallow other than current fallow3.5 3.82 5.96 6.51Current Fallow 3.73 7.03 6.35 11.98Net Area Sown 45.26 43.41 77.08 73.99Total Cultivable Land 58.72 58.67 100.00 100.00


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Cropping Seasons in India: There arethree distinct crop seasons in the northernand interior parts of country, namely kharif,rabi and zaid. The kharif season largelycoincides with Southwest Monsoon underwhich the cultivation of tropical crops suchas rice, cotton, jute, jowar, bajra and tur ispossible. The rabi season begin with the onsetof winter in October-November and ends inMarch-April. The low temperatureconditions during this season facilitate thecultivation of temperate and subtropical cropssuch as wheat, gram and mustard. Zaid is ashort duration summer cropping seasonbeginning after harvesting of rabi crops. Thecultivation of watermelons, cucumbers,vegetables and fodder crops during thisseason is done on irrigated lands. However,this type of distinction in the cropping seasondoes not exist in southern parts of thecountry. Here, the temperature is high enoughto grow tropical crops during any period inthe year provided the soil moisture isavailable. Therefore, in this region same cropscan be grown thrice in an agricultural yearprovided there is sufficient soil moisture.Primitive Subsistence Farming

Based upon the characteristics ofphysical environment technology and socio-cultural practices following farming systemcan be identified.

This type of farming is still practiced infew pockets of India. Primitive subsistenceagriculture is practiced on small patches ofland with the help of primitive tools like hoe,dao and digging sticks, and family/community labour. This type of farmingdepends upon monsoon, natural fertility ofthe soil and suitability of other environmentconditions to the crops grown.

It is a ‘slash and burn’ agriculture.Farmers clear a patch of land and producecereals and other food crops to sustain theirfamily. When the soil fertility decreases, thefarmers shift and clear a fresh patch of landfor cultivation. This type of shifting allowsNature to replenish the fertility of the soilthrough natural processes; land productivityin this type of agriculture is low as the farmerdoes not use fertilizers or other moderninputs. It is known by different names indifferent parts of the country. It is jhummingin north-eastern states like Assam,Meghalaya, Mizoram and Nagaland; Pamlouin Manipur, Dipa in Bastar district ofChattishgarh, and in Andaman and NicobarIslands.

Jhumming: The ‘slash and burn’agriculture is known as ‘Milpa’ in Mexico andCentral America, ‘Conuco’ in Venzuela, ‘Roca’in Brazil, ‘Masole’ in Central Africa, ‘Ladang’in Indonesia, ‘Ray’ in Vietnam.

In India, this primitive form ofcultivation is called ‘Betwar’ or ‘Dahiya’ inMadhya Pradesh, ‘Podu’ or ‘Penda’ inAndhra Pradesh, ‘Pama Dabi’ or ‘Koman’ or‘Bringa’ in Orissa, ‘Kumari’ in Western Ghats,‘Valre’ in South-Eastern Rajasthan, ‘Khil’ inthe Himalayan belt, ‘Kuruwa’ in Jharkhand,and ‘Jhumming’ in the North-Eastern region.Intensive Substance Farming

This type of farming is practiced in areasof high population pressure on land. It islabour intensive farming, where high dosesof biochemical inputs and irrigation are usedfor obtaining higher production.

Though the ‘right of inheritance’ leadingto the divion of land among successivegenerations has rendered land-holding sizeuneconomical, the farmers continue to take


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maximum output from the limited land in theabsence of alternative source of livelihood.Thus, there is enormous pressure onagricultural land.Commercial Farming

The main characteristic of this type offarming is the use of higher doses of moderninputs, e.g. high yielding variety (HYV)seeds, chemical fertilizers, insecticides andpesticides in order to obtain higherproductivity. The degree ofcommercialization of agriculture varies fromone region to another. For example, rice is acommercial crop in Haryana and Punjab, butin Orissa, it is a subsistence crop. Plantationis also a type of commercial farming. In thistype of farming, a single crop is grown on alarge area. The plantation has an interface ofagriculture and industry. Plantations coverlarge tracts of land, using capital intensiveinputs, with the help of migrant laboures. Allthe produce is used as raw material inrespective industries.Types of Farming

On the basis of main source of moisturefor crops, the farming can be classified asirrigated and rainfed (barani). There isdifference in the nature of irrigated farmingas well based on objective of irrigation, i.e.protective or productive. The objective ofprotective irrigation is to protect the cropsfrom adverse of soil moisture deficiencywhich often means that irrigation acts as asupplementary source of water over andabove the rainfall. The strategy of this kindof irrigation is to provide soil moisture tomaximum possible area. Productive irrigationis meant to provide sufficient soil moisturein the cropping season to achieve highproductivity. In such irrigation the water

input per unit area of cultivated land is higherthan protective irrigation. Rainfed farmingis further classified on the basis of adequacyof soil moisture during cropping season intodry land and wetland farming. In India, thedry land farming is largely confined to theregions having annual rainfall less than 75 cm.These regions grow hardy and droughtresistant crops such as ragi, bajra, moong,gram and guar (fodder crops) and practicevarious measures of soil moistureconservation and rain water harvesting. Inwetland farming, the rainfall is in excess ofsoil moisture requirement of plants duringrainy season. Such regions may face flood andsoil erosion hazards. These areas growvarious water intensive crops such as rice,jute and sugarcane and practice aquaculturein the fresh water bodies.Cropping Pattern

Food grains: The importance of foodgrains in Indian agricultural economy maybe gauged from the fact these crops occupyabout two-third of total cropped area in thecountry. Food grains are dominant crops inall parts of the country whether they havesubsistence or commercial agriculturaleconomy. On the basis of the structure ofgrain the food grains are classified as cerealsand pulses.

Cereals: The cereals occupy about 54 percent of total cropped area in India. Thecountry produces about 11 per cent cerealsof the world and ranks third in productionafter China and U.S.A. India produces avariety of cereals, which are classified as finegrains (rice, wheat) and coarse grains (jowar,maize, ragi) etc. Account of important cerealshas been given in the following paragraphs.

Rice: Rice is a staple food for the


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overwhelming majority of population inIndia. Though, it is considered to be a cropof tropical humid areas, it has about 3,000varieties which are grown in different agro-climatic regions. These are successfully grownfrom sea level to about 2,000 m altitude andfrom humid areas in eastern India to dry butirrigated areas of Punjab, Haryana, westernU.P. and northern Rajasthan. In southernstates and West Bengal the climaticconditions allow the cultivation of two orthree crops of rice in an agricultural year. InWest Bengal farmers grow three crops of ricecalled ‘aus’, ‘aman’ and ‘boro’. But inHimalayas and northwestern parts of thecountry, it is grown as a Kharif crop duringsouthwest Monsoon season.

India contributes 22 per cent of riceproduction in the world and ranks secondafter China. About one-fourth of the totalcropped area in the country is under ricecultivation. West Bengal, Punjab, UttarPradesh, Andhra Pradesh and Tamil Naduwere five leading rice producing states in thecountry in 2002-03. The yield level of rice ishigh in Punjab, Tamil Nadu. Andhra Pradesh,West Bengal and Kerala. In the first four ofthese states almost the entire land under ricecultivation is irrigated. Punjab and Haryanaare not traditional rice growing areas. Ricecultivation in the irrigated areas of Punjaband Haryana was introduced in 1970sfollowing the Green Revolution. Generallyimproved varieties of seed, relatively highusage of fertilizers and pesticides and lowerlevels of susceptibility of the crop to pestsdue to dry climatic conditions are responsiblefor higher yield of rice in this region. Theyield of this crop is very low in rainfed areasof Madhya Pradesh, Chhattisgarh and Orissa.

Wheat: Wheat is the second mostimportant cereal crop in India after rice. Indiaproduces about 12 per cent of total wheatproduction of world. It is primarily a crop oftemperate zone. Hence, its cultivation in Indiais done during winter i.e. rabi season. About85 per cent of total area under this crop isconcentrated in north and central regions ofthe country i.e. Indo-Gangetic Plain, MalwaPlateau and Himalayas up to 2,700 m altitude.Being a rabi crop, it is mostly grown underirrigated conditions. But it is rainfed crop inHimalayan highlands and parts of Malwaplateau in Madhya Pradesh. About 14 percent of the total cropped area in the countryis under wheat cultivation. Uttar Pradesh,Punjab, Haryana, Rajasthan and MadhyaPradesh are five leading wheat producingstates. The yield level of wheat is very high(above 4,000 k.g. per ha) in Punjab andHaryana whereas, Uttar Pradesh, Rajasthanand Bihar have moderate yields. The stateslike Madhya Pradesh, Himachal Pradesh andJammu and Kashmir growing wheat underrainfed conditions have low yield.

Jowar: The coarse cereals togetheroccupy about 16.50 per cent of total croppedarea in the country. Among these, jowar orsorghum alone accounts for about 5.3 per centof total cropped area. It is main food crop insemi-arid areas of central and southern India.Maharashtra alone produces more than halfof the total jowar production of the country.Other leading producer states of jowar areKarnataka, Madhya Pradesh and AndhraPradesh. It is sown in both Kharif and rabiseasons in southern states. But it is a Kharifcrop in northern India where it is mostlygrown as a fodder crop. South of Vindhyachalit is a rainfed crop and its yield level is verylow in this region.


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Bajra: Bajra is sown in hot and dryclimatic conditions in northwestern andwestern parts of the country. It is a hardycrop which resists frequent dry spells anddrought in this region. It is cultivated aloneas well as part of mixed cropping. This coarsecereal occupies about 5.2 per cent of totalcropped area in the country. Leadingproducers of bajra are the states ofMaharashtra, Gujarat, Uttar Pradesh,Rajasthan and Haryana. Being a rainfed crop,the yield level of this crop is low in Rajasthanand fluctuates a lot from year to year. Yieldof this crop has increased during recent yearsin Haryana and Gujarat due to introductionof drought resistant varieties and expansionof irrigation under it.

Maize: Maize is a food as well as foddercrop grown under semi-arid climaticconditions and over inferior soils. This cropoccupies only about 3.6 per cent of totalcropped area. Maize cultivation is notconcentrated in any specific region. It is sownall over India except eastern and north-eastern regions. The leading producers ofmaize are the states of Madhya Pradesh,Andhra Pradesh, Karnataka, Rajasthan andUttar Pradesh. Yield level of maize is higherthan other coarse cereals. It is high insouthern states and declines towards centralparts.

Pulses: Pulses are a very importantingredient of vegetarian food as these are richsources of proteins. These are legume cropswhich increase the natural fertility of soilsthrough nitrogen fixation. India is a leadingproducer of pulses and accounts for aboutone-fifth of the total production of pulses inthe world. The cultivation of pulses in thecountry is largely concentrated in the dry

lands of Deccan and central plateaus andnorthwestern parts of the country. Pulsesoccupy about 11 per cent of the total croppedarea in the country. Being the rainfed cropsof dry lands, the yields of pulses are low andfluctuate from year to year. Grain and turare the main pulses cultivated in India.

Grain: Grain is cultivated in subtropicalareas. It is mostly a rainfed crop cultivatedduring rabi season in central, western andnorthwestern parts of the country. Just oneor two light showers or irrigations arerequired to grow this crop successfully. It hasbeen displaced from the cropping pattern bywheat in Haryana, Punjab and northernRajasthan following the green revolution. Atpresent, grain covers only about 2.8 per centof the total cropped area in the country.Madhya Pradesh, Uttar Pradesh,Maharashtra, Andhra Pradesh and Rajasthanare the main producers of this pulse crop. Theyield of this crop continues to be low andfluctuates from year to year even in irrigatedareas.

Tur (Arhar): Tus is the second importantpulse crop in the country. It is also known asred grain or pigeon pea. It is cultivated overmarginal lands and under rainfed conditionsin the dry areas of central and southern statesof the country. This crop occupies only about2 per cent of total cropped area of India.Maharashtra alone contributed about one-third of the total production of tur. Otherleading producer states are Uttar Pradesh,Karnataka, Gujarat and Madhya Pradesh. Perhectare output of this crop is very low andits performance is inconsistent.

Oilseeds: The oilseeds are produced forextracting edible oils. Dry lands of Malwaplateau, Marathwada, Gujarat, Rajasthan,


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Telangana and Rayalseema region of AndhraPradesh and Karnataka plateau are oilseedsgrowing regions of India. These cropstogether occupy about 14 per cent of totalcropped area in the country. Groundnut,rapeseed and mustard, soyabean andsunflower are the main oilseed crops grownin India.

Groundnut: India produces about 17per cent the total of groundnut productionin the world. It is largely a rainfed kharif cropof dry lands. But in southern India, it iscultivated during rabi season as well. Itcovers about 3.6 per cent of total croppedarea in the country. Gujarat, Tamil Nadu,Andhra Pradesh, Karnataka and Maharashtraare the leading producers. Yield ofgroundnut is comparatively high in TamilNadu where it is partly irrigated. But its yieldis low in Andhra Pradesh and Karnataka.

Rapeseed and Mustard: Rapeseed andmustard comprise several oilseeds as rai,sarson, toria and taramira. These aresubtropical crops cultivated during rabiseason in north-western and central parts ofIndia. These are frost sensitive crops andtheir yields fluctuate from year to year. Butwith the expansion of irrigation andimprovement in seed technology; their yieldshave improved and stabilized to some extend.About two-third of the cultivated area underthese crops is irrigated. These oilseedstogether occupy only 2.5 per cent of totalcropped area in the country. Rajasthancontributes about one-third production whileother leading producers are Uttar Pradesh,Haryana, West Bengal and Madhya Pradesh.Yields of these crops are comparatively highin Haryana and Rajasthan.

Other Oilseeds: Soyabean and

sunflowere are other important oilseedsgrown in India. Soyabean is mostly grownin Madhya Pradesh and Maharashtra. Thesetwo states together produce about 90 per centof total output of soyabean in the country.Sunflower cultivation is concentrated inKarnataka, Andhra Pradesh and adjoiningareas of Maharashtra. It is a minor crop innorthern parts of the country where its yieldis high due to irrigation.

Fibre Crops: These crops provide usfibre for preparing cloth, bags, sacks and anumber of other items. Cotton and jute aretwo main fibre crops grown in India.

Cotton: Cotton is a tropical crop grownin kharif season in semi-arid areas of thecountry. India lost a large proportion ofcotton growing area to Pakistan duringpartition. However, its acreage has increasedconsiderably during the last 50 years. Indiagrows both short staple (Indian) cotton aswell as long staple (American) cotton called‘narma’ in north-western parts of thecountry. Cotton requires clear sky duringflowering stage.

India ranks fourth in the world in theproduction of cotton after China. U.S.A. andPakistan and accounts for about 8.3 per centof production of cotton in the world. Cottonoccupies about 4.7 per cent of total croppedarea in the country. There are three cottongrowing areas, i.e. parts of Punjab, Haryanaand northern Rajasthan in north-west,Gujarat and Maharashtra in the west andplateaus of Andhra Pradesh, Karnataka andTamil Nadu in South. Leading producers ofthis crop are Maharashtra, Gujarat, AndhraPradesh, Punjab and Haryana. Per hectareoutput of cotton is high under irrigatedconditions in north-western region of the


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country. Its yield is very low in Maharashtrawhere it is grown under rainfed conditions.

Jute: Jute is used for making coarsecloth, bags, sacks and decorative items. It isa cash crop in West Bengal and adjoiningeastern parts of the country. India lost largejute growing areas to East Pakistan(Bangladesh) during partition. At present,India produces about three-fifth of juteproduction of the world. West Bengalaccounts for about three-fourth of theproduction in the country. Bihar and Assamare other jute growing areas. Beingconcentrated only in a few states, this cropaccounts for only about 0.5 per cent totalcropped area in the country.

Other Crops: Sugarcane, tea and coffeeare other important crops grown in India.

Sugarcane: Sugarcane is a crop oftropical areas. Under rainfed conditions, itis cultivated in sub-humid and humidclimates. But it is largely an irrigated crop inIndia. In Indo-Gangetic plain, its cultivationis largely concentrated in Uttar Pradesh.Sugarcane growing area in western India isspread over Maharashtra and Gujarat. Insouthern India, it is cultivated in irrigatedtracts of Karnataka, Tamil Nadu and AndhraPradesh.

India is the second largest producer ofsugarcane after Brazil. It accounts for about23 per cent of the world production ofsugarcane. But it occupies only 2.4 per centof total cropped are in the country. UttarPradesh produces about two-fifth ofsugarcane of the country. Maharashtra,Karnataka, Tamil Nadu and Andhra Pradeshare other leading producers of this cropwhere yield level of sugarcane is high. Itsyield is low in northern India.

Tea: Tea is a plantation crop used asbeverage. Black tea leaves are fermentedwhereas green tea leaves are unfermented.Tea leaves are fermented whereas green tealeaves are unfermented. Tea leaves have richcontent of caffeine and tannin. It is anindigenous crop of hills in northern China. Itis grown over undulating topography of hillyareas and well drained soils in humid andsub-humid tropics and sub-tropics. In India,tea plantation started in 1840s in Brahmaputravalley of Assam which still is a major teagrowing area in the country. Later on, itsplantation was introduced in the sub-Himalayan region of West Bengal (Darjeeling,Jalpaiguri and Cooch districts). Tea is alsocultivated on the lower slopes of Nilgiri andCardamom hills in Western Ghats. India is aleading producer of tea and accounts forabout 28 per cent of total production in theworld. India’s share in the internationalmarket of tea has declined substantially. Atpresent, it ranks third among tea exportingcountries in the world after Sri Lanka andChina. Assam accounts for about 53.2 per centof the total cropped area and contributesmore than half of total production of tea inthe country. West Bengal and Tamil Naduare the other leading producers of tea.

Coffee: Coffee is a tropical plantationcrop. Its seeds are roasted, ground and areused for preparing a beverage. There arethree varieties of coffee i.e. Arabica, robustaand liberica. India mostly grows superiorquality coffee, Arabica, which is in greatdemand in great demand in Internationalmarket. But India produces only about 4.3per cent coffee of the world and ranks sixthafter Brazil, Vietnam, Colombia, Indonesiaand Mexico. Coffee is cultivated in the


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highlands of Western Ghats in Karnataka,Kerala and Tamil Nadu. Karnataka aloneaccounts for more than two third of totalproduction of coffee in the country.

Agricultural Development in India:Agriculture continues to be an importantsector Indian economy. In 2001 about 53 percent population of the country was dependenton it. The importance of agricultural sectorin India can be gauged from the fact thatabout 57 per cent of its land is devoted tocrop cultivation, whereas, in the world, thecorresponding share is only about 12 per cent.In spite of this, there is tremendous pressureon agricultural land in India, which isreflected from the fact that the land-humanratio in the country is only 0.31 ha which isalmost of that of the world as a whole (0.59ha). Despite various constrains, Indianagriculture has marched a long way sinceIndependence.

Strategy of Development: Indianagricultural economy was largely subsistencein nature before Independence It had dismalperformance in the first half of twentiethcentury. This period witnessed severedroughts and famines. During portion aboutone-third of the irrigated land in undividedIndia went to Pakistan. This reduced theproportion of irrigated area in IndependentIndia. After Independence, the immediategoal of the Government was to increase foodgrains production by (i) switching over fromcash crops to food crops; (ii) intensificationof cropping over already cultivated land; and(iii) increasing cultivated area by bringingcultivable and fallow land under plough.Initially, this strategy helped in increasingfood grains production. But agriculturalproduction stagnated during late 1950s. To

overcome this problem, IntensiveAgricultural District Programme (IADP) andIntensive Agricultural Area Programme(IAAP) were launched. But two consecutivedroughts during mid-1960s resulted in foodcrisis in the country. Consequently, the foodgrains were imported from other countries.

New seed varieties of wheat (Mexico)and rice (Philippines) known as high yieldingvarieties (HYVs) were available forcultivation by mid-1960s. India tookadvantage of this and introduced packagetechnology comprising HYVs, along withchemical fertilizers in irrigated areas ofPunjab, Haryana, Western Uttar Pradesh,Andhra Pradesh and Gujarat. Assured supplyof soil moisture through irrigation was abasic pre-requisite for the success of this newagricultural technology. This strategy ofagricultural development paid dividendsinstantly and increased the food grainsproduction at very fast rate. This spurt ofagricultural growth came to be known as‘Green Revolution’.

This also gave fillip to the developmentof a large number of agro-inputs, agro-processing industries and small-scale indus-tries. This strategy of agricultural develop-ment made the country self-reliant in foodgrain production. But green revolution wasinitially confined to irrigated areas only. Thisled to regional disparities in agricultural de-velopment in the country till the seventies,after which the technology spread to the East-ern and Central parts of the country.

The Planning Commission of Indiafocused its attention on the problems ofagriculture in rainfed areas in 1980s. Itinitiated agro-climatic planning in 1988 toinduce regionally balanced agriculturaldevelopment in the country. It also


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emphasized the need for diversification ofagriculture and harnessing of resources fordevelopment of dairy farming, poultry,horticulture, livestock rearing andaquaculture.

Initiation of the policy of liberalizationand free market economy in 1990s is likelyto influence the course of development ofIndian agriculture. Lack of development ofrural infrastructure, withdrawal of subsidiesand price support, and impediments inavailing of the rural credits may lead to inter-regional and inter-personal disparities inrural areas.Growth ofAgricultural Output and Technology

There has been a significant increase inagricultural output and improvement intechnology during the last fifty years.

• Production and yield of many cropssuch as rice and wheat has increasedat an impressive rate. Among theother crops, the production ofsugarcane, oilseeds and cotton hasalso increased appreciably. Indiaranks first in the production ofpulses, tea, jute, cattle and milk. It isthe second largest producer of rice,wheat, groundnut, sugarcane andvegetables.

• Expansion of irrigation has played avery crucial role in enhancingagricultural output in the country. Itprovided basis for introduction ofmodern agricultural technology suchas high yielding varieties of seeds,chemical fertilizers, pesticides andfarm machinery. The net irrigatedarea in the country has increasedfrom 20.85 million ha over the period

1950-51 to 2000-01. Over these 50years, are irrigated more than oncein an agricultural year has increasedfrom 1.71 to 20.46 million ha.

• Modern agricultural technology hasdiffused very fast in various areasof the country. Consumption ofchemical fertilizers has increased by15 times since mid-sixties. In 2001-02, per hectare consumption ofchemical fertilizers in India was 91kg which was equal to its averageconsumption in the world (90 kg).But in the irrigated areas of Punjaband Haryana, the consumption ofchemical fertilizers per unit area isthree to four times higher than thatof the national average. Since thehigh yielding varieties are highlysusceptible to pests and diseases, theuse of pesticides has increasedsignificantly since 1960s.

Problems of Indian Agriculture: Yet,there are some problems which are commonand range from physical constraints toinstitutional hindrances. A detaileddiscussion on these problems follows:

Dependence on Erratic Monsoon:Irrigation covers and about 33 per cent of thecultivated area in India. The crop productionin rest of the cultivated land directly dependson rainfall.

Low productivity: The yield of thecrops in the country is low in comparison tothe international level. The vast rainfed areasof the country, particularly drylands whichmostly grow coarse cereals, pulses andoilseeds have very low yields.

Constraints of Financial Resources andIndebtedness: The inputs of modern


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agriculture are very expensive. Crop failuresand low returns from agriculture have forcedthem to fall in the trap of indebtedness.

Lack of Land Reforms: Afterindependence, land reforms were accordedpriority, but these reforms were notimplemented effectively due to lack of strongpolitical will.

Small Farm Size and Fragmentation ofLandholding: There are a large number ofmarginal and small farmers in the country.More than 60 per cent of the ownershipholdings have a size smaller than one (ha).Furthermore, about 40 per cent of the farmershave operational holding size smaller than0.5 hectare (ha). The average size of landholding is shrinking further under increasingpopulation pressure.

Lack of Commercialization: Most of thesmall and marginal farmers grow food grains,which are meant for their own familyconsumption. Modernization andcommercialization of agriculture havehowever, taken place in the irrigated areas.

Vast Under-employment: In theseareas, there is a seasonal unemploymentranging from 4 to 8 months. Even in thecropping season work is not availablethroughout, as agricultural operations are notlabour intensive.

Degradation of Cultivable Land: Oneof the serious problems that arises out offaulty strategy of irrigation and agriculturaldevelopment is degradation of landresources.

Gist of NCERT

General Science

ISBN: 9789351720188Book Code: F20


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Geography 61

MINERAL AND ENERGY RESOURCES

7

India is endowed with a rich variety ofmineral resources due to its varied geologicalstructure. Bulk of the valuable minerals areproducts of pre-Paleozoic age mainlyassociated with metamorphic and igneousrocks of the peninsular India. The vast alluvialplain tract of north India is devoid of mineralsof economic use.

The mineral resources provide the coun-try with the necessary base for industrialdevelopment. The availability of varioustypes of mineral and energy resources in thecountry.Mode of Occurrence of Minerals

Minerals generally occur in these forms:(i) In igneous and metamorphic rocks

minerals may occur in the cracks,crevices, faults or joints. The smalleroccurrences are called veins and thelarger are called lodes. In mostcases, they are formed whenminerals in liquid/molten andgaseous forms are forced upwardthrough cavities towards the earth’ssurface. They cool and solidify asthey rise. Major metallic mineralslike tin, copper, zinc and lead etc.are obtained from veins and lodes.

(ii) In sedimentary rocks a number ofminerals occur in beds or layers.They have been formed as a result

of deposition, accumulation andconcentration in horizontal strata.Coal and some forms of iron orehave been concentrated as a resultof long periods under great heatand pressure. Another group ofsedimentary minerals includegypsum. Potash salt and sodium salt.These are formed as a reulst ofevaporation especially in aridregions.

(iii) Another mode of formationinvolves the decomposition ofsurface rocks, and the removal ofsoluble constituents, leaving aresidual mass of weathered materialcontaining ores. Bauxite is formedthis way.

(iv) Certain minerals may occur asalluvial deposits in sands of valleyfloors and the base of hills. Thesedeposits are called ‘placer deposits’and generally contain minerals,which are not corroded by water.Gold, silver, tin and platinum aremost important among suchminerals.

(v) The ocean waters contain vastquantities of minerals, but most ofthese are too widely diffused to beof economic significance. However,


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common salt, magnesium andbromine are largely derived fromocean waters. The ocean beds, too,are rich in manganese nodules.

Rat-Hole Mining. Do you know that most of theminerals in India are nationalized and theirextraction is possible only after obtaining duepermission from the government? But in most ofthe tribal areas of the north-east India, minerals areowned by individuals or communities. InMeghalaya, there are large deposits of coal, ironore, limestone and dolomite etc. Coal mining inJowai and Cherapunjee is done by family memberin the form of a long narrow tunnel, known as ‘Rathole’ mining.

AgenciesInvolved in the exploration of minerals

In India, systematic surveying,prospecting and exploration for minerals isundertaken by the Geological Survey of India(GSI), Oil and Natural Gas Commission(ONGC), Mineral Exploration CorporationLtd. (MECL), National Mineral DevelopmentCorporation (NMDC), Indian Bureau ofMines (IBM), Bharat Gold Mines Ltd.(BGML), Hindustan Copper Ltd. (HCL),National Aluminum Company Ltd. (NALCO)and the Departments of Mining and Geologyin various states.Distribution of Minerals in India

Most of the metallic minerals in Indiaoccur in the peninsular plateau region in theold crystalline rocks. Over 97 percent of coalreserves occur in the valleys of Damodar,Sone, Mahanadi and Godavari. Petroleumreserves are located in the sedimentary basinsof Assam, Gujarat and Mumbai High i.e. off-shore region in the Arabian. New reserveshave been located in the Krishna-Goadavariand Kaveri basins. Most of the major mineral

resources occur to the east of a line linkingMangalore and Kanpur.

Minerals are generally concentrated inthree broad belts in India. There may besome sporadic occurrence here and there inisolated pockets. These belts are:

The North-Eastern Plateau Region. Thisbelt covers Chotanagpur (Jharkhand), OrissaPlateau, West Bengal and parts ofChhattsgarh.

The South-Western Plateau Region:This belt extends over Karnataka, Goa andcontiguous Tamil Nadu uplands and Kerala.This belt is rich in ferrous metals and bauxite.It also contains high grade iron ore,manganese and limestone. This belt packs incoal deposits except naively lignite.

This belt does not have as diversifiedmineral deposits as the north-eastern belt.Kerala has deposits of monazite and thorium,bauxite clay. Goa has iron ore deposits.

The North-Western Region: This beltextends along Aravali in Rajasthan and partof Gujarat and minerals are associated withDharwar system of rocks. Copper, zinc havebeen major minerals. Rajasthan is rich inbuilding stones i.e. sandstone, granite,marble. Gypsum and Fuller’s earth depositsare also extensive. Dolomite and limestoneprovide raw materials for cement industry.Gujarat is known for its petroleum deposits.Gujarat and Rajasthan both have rich sourcesof salt.

The Himalayan belt is another mineralbelt where copper, lead, zinc, cobalt andtungsten are known to occur. They occur onboth the eastern and western parts. Assamvalley has mineral oil deposits. Besides oilresources are also found in off-shore-areasnear Mumbai Coast (Mumbai High).


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Mineral and Energy Resources 63

Ferrous Mineral: Ferrous minerals suchas iron ore, manganese, chromite, etc.,provide a strong base for the developmentof metallurgical industries. Our country iswell-placed in respect of ferrous mineralsboth in reserves and production.

Iron Ore: India is endowed with fairlyabundant resources of iron ore. It has thelargest reserve of iron ore in Asia. The twomain types of ore found in our country arehematite and magnetite. It has great demandin international market due to its superiorquality. The iron ore mines occur in closeproximity to the coal fields in the north-eastern plateau region of the country whichadds to their advantage.

The total reserves of iron ore in thecountry were about 20 billion tones in theyear 2004-05. About 95 per cent of totalreserves of iron ore is located in the States ofOrissa, Jharkhand, Chhattisgarh, KarnatakaGoa, Andhra Pradesh and Tamil Nadu. InOrissa, iron ore occurs in a series of hill rangesin Sundergarh, Mayurbhanj and Jhar. Theimportant mines are Gurumahisani, Sulaipet,Badampahar (Mayurbhaj), Kiruburu(Kendujhar) and Bonai (Sundergarh). Similarhill ranges, Jharkhand has some of the oldestiron ore mines and most of the iron and steelplants are located around them. Most of theimportant mines such as Noamundi and Guaare located in Poorbi and PashchimiSinghbhum districts. This belt further extendsto Durg, Dantewara and Bailadila. Dalli,Rajhara in Durg are the important mines ofiron ore in the country. In Karnataka, ironore deposits occur in Sandur-Hospet area ofBellary district, Baba Budan hills andKudremukh in Chikmagalur district and partsof Shimoga, Chitradurg and Tumkur

districts. The districts of Chandrapur,Bhandara and Ratnagiri in Maharashtra,Karimnagar, Warangal, Kurnool, Cuddapahand Anantapur districts of Andhra Pradesh,Salem and Nilgiris- districts of Tamil Naduare other iron mining regions. Goa has alsoemerged as an important producer of ironore.

Manganese: Manganese is an importantraw material for smelting of iron ore and alsoused for manufacturing Ferro alloys.Manganese deposits are found in almost allgeological formations; however, it is mainlyassociated with Dharwar system.

Orissa is the leading producer ofManganese. Major mines in Orissa are locatedin the central part of the iron ore belt of India,particularly in Bonai, Keudujhar, Sundergarh,Gangpur, Koraput, Kalahandi and Bolangir.

Karnataka is another major producerand here the mines are located in Dharwar,Bellary, Belgaum, North Canara,Chikmagalur, Shimoga, Chitradurg andTumkur. Maharashtra is also an importantproducer of manganese which is mined inNagpur Bhandara and Ratnagiri districts. Thedisadvantage to these mines is that they arelocated far from steel plants. The manganesebelt of Madhya Pradesh extends in a belt inBalaghat-Chhindwara-Nimar-Mandla andJhabua districts districts. Andhra Pradesh,Goa, and Jharkhand are other minorproducers of manganese.

Non-Ferrous Minerals: India is poorlywith non-ferrous metallic minerals exceptbauxite.

Bauxite: Bauxite is the ore which is usedin manufacturing of aluminum. Bauxite isfound mainly in tertiary deposits and isassociated with laterite rocks occurring


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extensively either on the plateau or hill rangesof peninsular India and also in the coastaltracts of the country.

Orissa happens to be the largestproducer of Bauxite. Kalahandi andSambalpur are the leading producers. Theother two areas which have been increasingtheir production are Bolangir and Koraput.The patlands of Jharkhand in Lohardaga haverich deposits. Gujarat, Chhattisgarh, MadhyaPradesh and Maharashtra are other majorproducers. Bhavnagar, Jamnagar in Gujarathave the major deposits. Chhattisgarh hasbauxite deposits in Amarkantak plateau whileKatni-Jabalpur area and Balaghat in M.P. haveimportant deposits of bauxite. Kolaba, Thane,Ratnagiri, Satara, Pune and Kolhapur inMaharashtra are important producers. TamilNadu. Karanataka and Goa are minorproducers of bauxite.

Copper: Copper is an indispensablemetal in the electrical industry for makingwires, electric motors, transformers andgenerators. It is alloyable. Malleable andductile. It is also mixed with gold to providestrength to jewellery.

The Copper deposits mainly occur inSinghbhum district in Jharkhand, Balaghatdistrict in Madhya Pradesh and Jhunjhunuand Alwar districts in Rajasthan.

Minor producers of Copper areAgnigundala in Guntur District (AndhraPradesh), Chitradurg and hasan districts(Karnataka) and South Arcot district (TamilNadu).

Non-metallic Minerals: Among thenon-metallic minerals produced in India, micais the important one. The other mineralsextracted for local consumption are limestone,dolomite and phosphate.

Mica: Mica is mainly used in theelectrical and electronic industries. It can besplit into very thin sheets which are toughand flexible. Mica in India is produced inJharkhand, Andhra Pradesh and Rajasthanfollowed by Tamil Nadu, West Bengal andMadhya Pradesh. In Jharkhand high qualitymica is obtained in a belt extending over adistance of about 150 km, in length and about22 km, in width in lower Hazaribagh plateau.In Andhra Pradesh. Nellore district producesthe best quality mica. In Rajasthan mica beltextends for about 320 kms from Jaipur toBhilwara and around Udaipur. Mica depositsalso occur in Mysore and Hassan districts ofKarnataka, Coimbatore. Tiruchirapalli,Madurai and Kanniyakumari in Tamil Nadu,Alleppey in Kerala, Ratnagiri in Maharashtra,Purulia and Bankura in West Bengal.

Energy Resources: Mineral fuels areessential for generation of power, requiredby agriculture, industry, transport and othersectors of the economy. Mineral fuels likecoal, petroleum and natural gas (known asfossil fuels), nuclear energy minerals, are theconventional sources of energy. Theseconventional sources are exhaustibleresources.

Coal: Coal is a one of the importantminerals which is mainly used in thegeneration of thermal power and smeltingof iron ore. Coal occurs in rock sequencesmainly of two geological ages, namelyGondwana and tertiary deposits.

Lignite is a low grade brown coal,which is soft with high moisture content. Theprincipal lignite reserves are in Neyveli inTamil Nadu and are used for generation ofelectricity. Coal that has been buried deepand subjected to increased temperatures is


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bituminous coal. It is the most popular coalin commercial use. Metallurgical coal is highgrade bituminous coal which has a specialvalue for smelting iron in blast furnaces.

Anthracite is the highest quality hardcoal. About 80 per cent of the coal depositsin India is of bituminous type and is of non-coking grade. The most importantGondwana coal fields of India are located inDamodar Valley.

They lie in Jharkhand-Bengal coal beltand the important coal fields in this regionare Raniganj, Jharia, Bokaro, Giridih,Karanpura.

Jharia is the largest coal field followedby Raniganj. The other river valleysassociated with coal are Godavari, Mahanadiand Sone. The most important coal miningcentres are Singrauli in Madhya Pradesh (partof Singrauli coal field lies in Uttar Pradesh),Korba in Chhattisgarh, Talcher and Rampurin Orissa, Chanda-Wardha, Kamptee andBander in Maharashtra and Singareni andPandur in Andhra Pradesh.

Tertiary coals occur in Assam, ArunachalPradesh, Meghalaya and Nagaland. It isextracted from Darangiri, Cherrapunji,Mewlong and Langrin (Meghalaya); Makum,Jaipur and Nazira in upper Assam, Namchik-Namphuk (Arunachal Pradesh) and Kalakot(Jammu and Kashmir). Besides, the browncoal or lignite occur in the coastal areas ofTamil Nadu, Pondicherry, Gujarat andJammu and Kashmir.

Petroleum: Crude petroleum consists ofhydrocarbons of liquid and gaseous statesvarying in chemical composition, colour andspecific gravity. It is an essential source ofenergy for all internal combustion engines inautomobiles, railways and aircraft. Its

numerous by-products are processed inpetrochemical industries such as fertilizer,synthetic fibre, medicines, Vaseline,lubricants, wax, soap and cosmetics.

Most of the petroleum occurrences inIndia are associated with anticlines and faulttraps in the rock formations of the tertiaryage. In regions of folding, anticlines ordomes, it occurs where oil is trapped in thecrest of the up fold. The oil bearing layer is aporous limestone or sandstone throughwhich oil may flow. The oil is prevented fromrising or sinking by intervening non-porouslayers.

Petroleum is also found in fault trapsbetween porous and non-porous rocks. Gas,being lighter usually occurs above the oil.

About 63 per cent of India’s petroleumproduction is from Mumbai High, 18 per centfrom Gujarat and 16 per cent from Assam.

Crude petroleum occurs in sedimentaryrocks of the tertiary period. Oil explorationand production was systematically taken upafter the Oil and Natural Gas Commissionwas set up in 1956. Till then, the Digboi inAssam was the only oil producing region butthe scenario has changed after 1956. In recentyears, new oil deposits have been found atthe extreme western and eastern parts of thecountry. In Assam, Digboi, Naharkatiya andMoran are important oil producing areas. Themajor oil fields of Gujarat are Ankaleshwar,Kalol, Mehsana, Nawagam, Kosamba andLunej. Mumbai High which lies 160 km offMumbai was discovered in 1973 andproduction commenced in 1976. Oil andnatural gas have been found in exploratorywells in Krishna-Godavari and Kaveri basinon the east coast.

Oil extracted from the well is crude oil


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and contains many impurities. It cannot beused directly. It needs to be refined. Thereare two types of refineries in India: (a) fieldbased and (b) market based. Digboi is anexample of field based and Barauni is anexample of market based refinery.

Natural Gas: The Gas Authority of IndiaLimited was set up in 1984 as a public sectorundertaking to transport and market naturalgas. It is obtained alongwith oil in all the oilfields but exclusive reserves have beenlocated along the eastern coast as well as(Tamil Nadu, Orissa and Andhra Pradesh),Tripura, Rajasthan and off-shore wells inGujarat and Maharashtra.

Nuclear Energy Resources: Nuclearenergy as a viable source in recent times.Important minerals used for the generationof nuclear energy are uranium and thorium.Uranium deposits occur in the Dharwarrocks. Geographically, uranium ores areknown to occur in several locations along theSingbhum Copper belt. It is also found inUdaipur, Alwar and Jhunjhunu districts ofRajasthan, Durg district of Chhattisgarh,Bhandara district of Maharashtra and Kulludistrict of Himachal Pradesh. Thorium ismainly obtained from monazite and ilmenitein the beach sands along the coast of Keralaand Tamil Nadu. World’s richest monazitedeposits occur in Palakkad and Kollamdistricts of Kerala, near Vishakhapatnam inAndhra Pradesh and Mahanadi river deltain Orissa.

Atomic Energy Commission wasestablished in 1948, progress could be madeonly after the establishment of the AtomicEnergy Institute at Trombay in 1954 whichwas renamed as the Bhabha Atomic ResearchCentre in 1967. The important nuclear power

projects are Tarapur (Maharashtra),Rawatbhata near Kota (Rajasthan),Kalpakkam (Tamil Nadu), Narora (UttarPradesh), Kaiga (Karnataka) and Kakarapara(Gujarat).

Non-Conventional Energy Sources:Fossil fuel sources, such as coal, petroleum,natural gas and nuclear energy useexhaustible raw materials. Sustainable energyresources are only the renewable energysources like solar, wind, hydro-geothermaland biomass. These energy sources are moreequitably distributed and environmentalfriendly. The non-conventional energysources will provide more sustained, eco-friendly cheaper energy after the initial costis taken care of.

Solar Energy: Sun rays tapped inphotovoltaic cells can be converted intoenergy, known as solar energy. The twoeffective processes considered to be veryeffective to tap solar energy are photovoltaicsand solar thermal technology. Solar thermaltechnology has some relative advantages overall other non-renewable energy sources. It iscost competitive, environment friendly andeasy to construct. Solar energy is 7 per centmore effective than coal or oil based plantsand 10 per cent more effective than nuclearplants. It is generally used more in applianceslike heaters, crop dryers, cookers, etc. Thewestern part of India has greater potentialfor the development of solar energy inGujarat and Rajasthan.

Wind Energy: Wind energy isabsolutely pollution free, inexhaustible sourceof energy. The mechanism of energyconversion from blowing wind is simple. Thekinetic energy of wind, through turbines isconverted into electrical energy. The


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permanent wind systems such the tradewinds, westerly’s and seasonal wind likemonsoon have been used as source ofenergy. Besides these, local winds, land andsea breezes can also be used to produceelectricity.

India, already has started generatingwind energy. It has an ambitious programmeto install 250 wind-driven turbines with atotal capacity of 45 megawatts, spread over12 suitable locations, specially in coastal ar-eas. According to the estimation by Ministryof Power, India will be able to produce 3,000megawatts of electric from this source. TheMinistry of non-conventional sources of en-ergy is developing wind energy in India tolessen the burden of oil import bill. The coun-try’s potential of wind power generation ex-ceeds 50,000 megawatts; of which one fourthcan be easily harnessed. In Rajasthan, Gujarat,Maharashtra and Karnataka, favourable con-ditions for wind energy exist. Wind powerplant at Lamba in Gujarat in Kachchh is thelargest in Asia. Another, wind power plantis located at Tuticorin in Tamil Nadu.

Tidal and Wave Energy: Ocean currentsare the store-house of infinite energy. Sincethe beginning of seventeenth and eighteenthcentury, persistent efforts were made tocreate a more efficient energy system fromthe ceaseless tidal waves and ocean current.

Large tidal waves are known to occuralong the west coast of India. Hence, Indiahas great potential for the development oftidal energy along the coasts but so far thesehave not yet been utilized.

In India, the Gulf of Kuchchh, providesideal conditions for utilizing tidal energy. A900 mw tidal energy power plant is set uphere by the National HydropowerCorporation.

Geothermal Energy: When the magmafrom the interior of earth, comes out on thesurface, tremendous heat is released. Thisheat energy can successfully be tapped andconverted to electrical energy. Apart fromthis, the hot water that gushes out throughthe gyser well is also used in the generationof thermal energy. It is popularly known asGeothermal energy. This energy is nowconsidered to be one of the key energysources which can be developed as analternate source. The hot springs and geysersare being used since medieval period.

The first successful (1890) attempt to tapthe underground heat was made in the cityof Boise, Idaho (U.S.A.), where a hot waterpipe network was built to give heat to thesurrounding buildings. This plant is stillworking.

Bio-energy: Bio-energy refers to energyderived from biological products whichincludes agricultural residues, municipal,industrial and other wastes.

Establishment of iron and steel industryin Bhilai and Rourkela were based ondecision to develop backward tribal areas ofthe country. At present, government of Indiaprovides lots of incentives to industrieslocating in backward area.Major Industries

The iron and steel industry is basic tothe industrial development of any country.The cotton textile Industry is one of ourtraditional industries. The sugar Industry isbased on local raw materials which prosperedeven in the British period.The Iron and Steel Industry

The development of the iron and steelindustry opened the doors to rapid industrial


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development in India. Almost all sectors ofthe Indian industry depend heavily on theiron and steel industry for their basicinfrastructure.

The other raw materials besides iron oreand coking coal, essential for iron and steelindustry are limestone, dolomite, manganeseand fire clay. All these raw materials are gross(weight losing), therefore, the best locationfor the iron and steel plants is near the sourceof raw materials. In India, there is a crescentshaped region comprising parts ofChhattisgarh, Northern Orissa, Jharkhandand western West Bengal, which is extremelyrich in high grade iron ore, good qualitycoking coal and other supplementing rawmaterials.

The Indian iron and steel industryconsists of large integrated steel plants as wellas mini steel mills. It also includes secondaryproducers, rolling mills and ancillaryindustries.Integrated Steel Plants

TISCO: The Tata Iron and Steel plantlies very close to the Mumbai-Kolkata railwayline and about 240 km away from Kolkata,which is the nearest port for the export ofsteel. The rivers Subarnarekha and Kharkaiprovide water to the plant. The iron ore forthe plant is obtained from Noamundi andBadam Pahar and coal is brought from Jodamines in Orissa. Coking coal comes fromJharia and West Bokaro coalfields.

IISCO: The Indian Iron and SteelCompany (IISCO) set up its first factory atHirapur and later on another at Kulti. In 1937,the Steel corporation of Bengal wasconstituted in association with IISCO and setup another iron and steel producing unit atBurnpur (West Bengal). All the three plants

under IISCO are located very close toDamodar valley coal fields (Raniganj), Jharia,and Ramgarh. Iron ore comes fromSinghbhum in Jharkhand. Water is obtainedfrom the Barakar River, a tributary of theDamodar. All the plants are located along theKolkata-Asansol railway line. Unfortunately,steel production from IISCO fell considerablyin 1972-73 and the plants were taken over bythe government.VisvesvaraiyaIron and Steel Works Ltd. (VISL)

The third integrated steel plant, theVisvesvaraiya Iron and Steel Works, initiallycalled the Mysore Iron and Steel Works, islocated close to an iron ore producing areaof Kemangundi in the Bababudan hills.Limestone and manganese are also locallyavailable. But this region has no coal. At thebeginning, charcoal obtained by burningwood from nearby forests was used as fueltill 1951. Afterwards, electric furnaces wereinstalled which use hydroelectricity from theJog Falls-hydel power project. The Bhadravatiriver supplies water to the plant. This plantproduces specialized steels and alloys.

After independence, during the SecondFive Year Plan (1956-61), three new inte-grated steel plants were set up with foreigncollaboration: Rourkela in Orissa, Bhilai inChhattisgarh and Durgapur in West Bengal.These were public sector plants underHindustan Steel Limited (HSL). In 1973, theSteel Authority of India Limited (SAIL) wascreated to manage these plants.Rourkela Steel Plant

The Rourkela Steel plant was set up in1959 in the Sundargarh district of Orissa incollaboration with Germany. The plant waslocated on the basis of proximity to raw


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materials, thus, minimizing the cost oftransporting weight losing raw material. Thisplant has a unique locational advantage, as itreceives coal from Jharia (Jharkhand) and ironore from Sundargarh and Kendujhar. TheHirakud project supplies power for theelectric furnaces and water is obtained fromthe Koel and Sankh rivers.Bhilai Steel Plant

The Bhilai Steel Plant was establishedwith Russian collaboration in Durg Districtof Chhattisgarh and started production in1959. The iron ore comes from Dalli-Rajharamine, coal comes from Korba and Kargali coalfields. The water comes from theTanduladam and the power from the KorbaThermal Power Station. This plant also lieson the Kolkata-Mumbai railway route. Thebulk of the steel produced goes to theHindustan Shipyard at Vishakhapatnam.

Durgapur Steel Plant: Durgapur SteelPlant, in West Bengal, was set up incollaboration with the government of theUnited Kingdom and started production in1962. This plant lies in Raniganj and Jhariacoal belt and gets iron ore from Noamundi.Durgapur lies on the main Kolkata-Delhirailway route. Hydel power and water isobtained from the Damodar ValleyCorporation (DVC).

Bokaro Steel Plant: This steel plant wasset up in 1964 at Bokaro with Russiancollaboration. This plant was set up on theprinciple of transportation cost minimizationby creating Bokaro-Rourkela combine. Itreceives iron ore from the Rourkela regionand the wagons on return take coal toRourkela. Other raw materials come toBokaro from within a radius of about 350 km.Water and Hydel power is supplied by the

Damodar Valley Corporation.Other Steel Plants: New steel plants

which were set up in the Fourth Plan periodare away from the main raw material sources.All the three plants are located in South India.The Vizag Steel Plant, in Vishakhapatnam inAndhra Pradesh is the first port based plantwhich started operating in 1992. Its portlocation is of advantage.

The Vijaynagar Steel Plant at Hospet inKarnataka was developed using indigenoustechnology. This uses local iron ore andlimestone. The Salem Steel Plant in TamilNadu was commissioned in 1982.

Apart from these major steel plants,there are more than 206 units located indifferent parts of country. Most of these usescrap iron as their main raw material, andprocess it in electric furnaces.The Cotton Textile Industry

In 1854, the first modern cotton mill wasestablished in Mumbai. This city had severaladvantages as a cotton textile manufacturingcentre. It was very close to the cottonproducing areas of Gujarat and Maharashtra.Raw cotton used to be brought to Mumbaiport to be transported to England. Therefore,cotton was available in Mumbai city itself,Moreover, Mumbai even then was thefinancial centre and the capital needed tostart an industry was available there. As alarge town, providing employmentopportunities attracted labour in largenumbers. Hence, cheap and abundant labourtoo was available locally. The machineryrequired for a cotton textile mill could bedirectly imported from England.Subsequently, two more mills, the ShahpurMill and the Calico Mill were established inAhmedabad. By 1947, the number of mills in


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India went up to 423 but the scenario changedafter partition, and this industry suffered amajor recession. This was due to the fact thatthe most of the good quality cotton growingareas had gone to West Pakistan and Indiawas left with 409 mills and only 29 per centof the cotton producing area.

After Independence, this industrygradually recovered and eventuallyflourished. In 1998, India had 1782 mills; ofwhich, 192 mills were in the public sector and151 mills in the cooperative sector. The largestnumber, that is, 1,439 mills were in the privatesector.

The cotton textile industry in India canbe broadly divided into two sectors, theorganized sector and the decentralizedsector. The decentralized sector includescloth produced in handlooms (includingKhadi) and power looms. The production ofthe organized sector has drastically fallenfrom 81 per cent in the mid-twentieth centuryto only about 6 per cent in 2000. At present,the power looms on the decentralized sectorproduce more than 59 per cent and the handloom sector produces about 19 per cent of allcotton cloth produced in the country.

Cotton is a “pure” raw material whichdoes not lose weight in the manufacturingprocess, so other factors, like, power to drivethe looms, labour, capital or market maydetermine the location of the industry. Atpresent the trend is to locate the industry ator close to markets, as it is the market thatdecides what kind of cloth is to be produced.Also the market for the finished produces isextremely variable, therefore, it becomesimportant to locate the mills close to themarket.

After the first mills were set up in

Mumbai and Ahmedabad in the second halfof the nineteenth century, the cotton textileindustry expanded very rapidly. The numberof units increased dramatically. The Swadeshimovement gave a major impetus to theindustry as there was a call for boycottingall British made goods in favour of Indiangoods. After 1921, with the development ofthe railway network other cotton textilecentres expanded rapidly. In southern India,mills were set up at Coimbatore, Maduraiand Bangalore. In central India, Nagpur,Indore, Solapur and Vadodra became cottontextile centres. Cotton textile mills were setup at Kanpur based on local investment. Millswere also set up at Kolkata due to its portfacilities. The development of hydro-electricity also favoured the location of thecotton textile mills away from the cottonproducing areas. The rapid development ofthis industry in Tamil Nadu is the result ofthe abundant availability of hydel power forthe mills. Lower labour costs at centres likeUjjain, Bharuch, Agra, Hathras, Coimbatoreand Tirunelveli also caused industries to belocated away from cotton producing areas.

Thus, the cotton textile industry islocated in almost every state in India, whereone or more of the locational factors havebeen favourable. The importance of rawmaterials has given way to market or to acheaper local labour force or it may be theavailability of power.

Presently, the major centres of the cottontextile industry are Ahmedabad, Bhiwandi,Solapur, Kolhapur, Nagpur, Indore andUjjain. All these centres are the traditionalcentres and are located close to the cottonproducing regions. Maharashtra, Gujarat andTamil Nadu are the leading cotton producing


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states. West Bengal, Uttar Pradesh,Karnataka, and Punjab are the otherimportant cotton textile producers.

Tamil Nadu has the largest number ofmills and most of them produce yarn ratherthan cloth. Coimbatore has emerged as themost important centre with nearly half themills located there. Chennai, Madurai,Tirunelveli, Tuticorin, Thanjavur,Ramanathapuram and Salem are the otherimportant centres. In Karnataka, the cottontextile industry has developed in the cottonproducing areas in the north-eastern part ofthe state. Davangere, Hubli, Bellary, Mysoreand Bangalore are important centres. InAndhra Pradesh, the cotton textile industry

is located in the cotton producing Telenganaregion, where most of the mills are spinningmills producing yarn. The important centresare Hyderabad, Secundrabad, Warangal andGuntur.

In Uttar Pradesh, Kanpur is the largestcentre. Some of the other important centresare Modinagar, Hathras, Saharanpur, Agraand Lucknow. In West Bengal, the cottonmills are located in the Hugli region. Howrah,Serampur, Kolkata and Shyamnagar are theimportant centres. Production of cotton clothincreased almost five times from 1950-51 to1999-2000. Cotton textile has been facingtough competition from synthetic cloth.

INDIAN POLITYForCivil Services

Preliminary Examinations

ISBN: 9789381362310Book Code: A14, 350`


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72 Gist of NCERT

SUGAR INDUSTRY

8

The sugar industry is the second mostimportant agro-based industry in thecountry. India is the largest producer of bothsugarcane and cane sugar and contributesabout 8 per cent of the total sugar productionin the world. Besides, khandasari and gur orjaggery are also prepared from sugarcane.This industry provides employment for morethan 4 lakh persons directly and a largenumber of farmers indirectly. Sugar industryis a seasonal industry because of theseasonality of raw materials.

Development of the industry on mod-ern lines dates back to 1903, when a sugarmill was started in Bihar. Subsequently, sugarmills were started in other parts of Bihar andUttar Pradesh. In 1950-51, 139 factories werein operation producing 11.34 lakh tones ofsugar. The number of sugar factories rose to506 and production to 176,99 lakh tones in2000-01.Location of the Sugar Industry

Sugarcane is a weight-losing crop. Theratio of sugar to sugarcane varies between 9to 12 per cent depending on its variety. Itssucrose content begins to dry during haulageafter it has been harvested from the field.Better recovery of sugar is dependent uponits being crushed within 24 hours of itsharvesting. Sugar factories hence, are locatedwithin the cane producing regions.

Maharashtra has emerged as a leadingsugar producer in the country and producesmore than one-third of the total productionof the sugar in the country. There are 119sugar mills in the state in a narrow beltextending from Manmad in the north toKolhapur in the south. There are 87 mills inthe cooperative sector.

Uttar Pradesh is the second largestproducer of sugar. The sugar factories areconcentrated in two belts- the Ganga-Yamunadoab and the taria region. The major sugarproducing centres in the Ganga- Yamunadoab are Saharanpur, Muzaffarnagar, Meerut,Ghaziabad, Baghpat and Bulandshehrdistricts; while Kheri Lakhimpur, Basti,Gonda, Gorakhpur, Bahraich are importantsugar producing districts in the Tarai region.

In Tamil Nadu, sugar factories arelocated in Coimbatore, Vellore,Tiruvanamalai, Villupuram andTiruchchirappalli districts. Belgaum, Bellary,Mandya, Shimoga, Bijapur, and Chitradurgdistricts are the major producers inKarnataka. The industry is distributed in thecoastal regions i.e. East Godawari, WestGodavari, Vishakhapatnam districts andNizamabad, and Medak districts ofTelangana alongwith Chittoor district ofRayalseema.

The other States which produce sugar


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Sugar Industry 73

are Bihar, Punjab, Haryana, Madhya Pradeshand Gujarat. Saran, Champaran,Muzaffarnagar, Siwan, Darbhanga, and Gayaare the important sugarcane producing dis-tricts in Bihar. The relative significance ofPunjab has declined, although Gurdaspur,Jalandhar, Sangarur, Patiala and Amrtisar aremajor sugar producers. In Haryana, sugarfactories are located in Yamuna Nagar,Rohtak, Hissar and Faridabad districts. Sugarindustry is comparatively new in Gujarat.Sugar mills are located in the cane growingtracts of Surat, Junagarh, Rajkot, Amreli,Valsad and Bhavnagar districts.Petrochemical Industries

This group of industries has beengrowing very fast in India. A variety ofproducts come under this category ofindustries. In 1960s, demand for organicchemicals increased so fast that it becamedifficult to meet this demand. At that time.Petroleum refining industry expandedrapidly. Many items are derived from crudepetroleum, which provide raw materials formany new industries; these are collectivelyknown as petrochemical industries. Thisgroup of industries is divided into four sub-groups; (i) polymers, (ii) synthetic fibres, (iii)elastomers, and (iv) surfactant intermediate.Mumbai is the hub of the petrochemicalindustries. Cracker units are also located inAuraiya (Uttar Pradesh), Jamnagar,Gandhinagar, and Hajira (Gujarat),Nagothane, Ratnagiri (Maharashtra), Haldia(West Bengal) and Vishakhapatnam (AndhaPradesh).

Three organizations are working in thepetrochemical sector under the administrativecontrol of the Department of Chemicals andPetrochemicals. First is the Indian

Petrochemical Corporation Limited (IPCL),a public sector undertaking. It is responsiblefor the manufacture and distribution of thevarious petrochemicals like polymers,chemicals, fibres and fibre intermediates.Second is the Petrofils Cooperative Limited(PCL), a joint venture of the Government ofIndia and Weaver’s Cooperative Societies. Itproduces polyester filament yarn and nylonchips at its two plants located at Vadodaraand Naldhari in Gujarat. Third is the CentralInstitute of Plastic Engineering andTechnology (CIPET), involved in impartingtraining in petrochemical industry.

Polymers are made from ethylene andpropylene. These materials are obtained inthe process of refining crude oil. Polymersare used as raw materials in the plasticindustry. Among polymers, polyethylene isa widely used thermoplastic. Plastic is firstcovered into sheets, power, resin and pellets,and then used in manufacturing plasticproducts. Plastic products are preferredbecause of their strength, water and chemicalresistance and low prices. Production ofplastic polymers started in India in the latefifties and the early sixties using other organicchemicals. The National Organic ChemicalsIndustries Limited (NOCIL), established inprivate sector in 1961, started the firstnaphtha based chemical industry in Mumbai.Later, several other companies were formed.The plants located at Mumbai, Barauni,Mettur, Pimpri and Rishra are majorproducers of plastic materials.

About 75 per cent of these units are insmall scale sector. The industry also usesrecycled plastics, which constitutes about 30per cent of the total production.

Synthetic fibres are widely used in the


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manufacturing of fabrics because of theirinherent strength, durability, wash ability,and resistance to shrinkage. Industriesmanufacturing nylon and polyester yarns arelocated at Kota, Pimpri, Mumbai, Modinagar,Pune, Ujjain, Nagpur and Udhna. Acrylicstaple fibre is manufactured at Kota andVadodara.

Though plastics have becomesinseparable items in our daily use and theyhave affected our life style. But due to itsnon-biodegradable quality it has emerged asthe greatest threat to our environment.Hence, use of plastic is being discouraged indifferent states of India.Knowledge based Industries

The advancement in informationtechnology has had a profound influence onthe country’s economy. The InformationTechnology (IT) revolution opened up newpossibilities of economic and socialtransformation. The IT and IT enabledbusiness process outsourcing (ITESBPO)services continue to be on a robust growthpath. Indian software industry has emergedas one of the fastest growing sectors in theeconomy. Exports of the Indian software andservices sector were Rs. 78,230 crore in 2004-05 which is approximately 30-32 per centincrease from the previous year. The softwareindustry has surpassed electronic hardwareproduction. The Indian government hascreated a number of software parks in thecountry.

The IT software and services industryaccount for almost 2 per cent of India’s GDP.India’s software industry has achieved aremarkable distinction for providing qualityproducts. A large number of Indian softwarecompanies have acquired international

quality certification. A majority of themultinational companies operating in the areaof information technology have eithersoftware development centres or researchdevelopment centres in India. However, inthe hardware development sector, India isyet to make any remarkable achievements.

A major impact of this growth has beenon employment creation, which is almostdoubled every year.Liberalization, Privatization, Globalization(LPG) and Industrial Development in India

The new Industrial Policy wasannounced in 1991. The major objectives ofthis policy were to build on the gains alreadymade, correct the distortions or weaknessesthat have crept in, maintain a sustainedgrowth in productivity and gainfulemployment and attain internationalcompetitiveness.

Within this policy, measures initiatedare: (1) abolition of industrial licensing, (2)free entry to foreign (technology, (3) foreigninvestment policy, (4) access to capitalmarket, (5) open trade, (6) abolition ofphased manufacturing programme, and (7)liberalized industrial location programme.The policy has three main dimensions:privatization and globalization.

The industrial licensing system has beenabolished for all except six industries relatedto security, strategic or environmentalconcerns. At the same time, the number ofindustries reserved for public sector since1956 have been reduced from 17 to 4.Industries related to atomic energysubstances specified in the schedule of theDepartment of Atomic Energy as well asRailways have remained under the publicsector. The government also have decided


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Sugar Industry 75

to offer a part of the shareholdings in thepublic enterprises to financial institutions,general public and workers. The thresholdlimits of assets have been scrapped and noindustry required prior approval forinvesting in the delicensed sector. They onlyneed to submit a memorandum in theprescribed format.

In the new industrial policy, ForeignDirect Investment (FDI) has been seen as asupplement to the domestic investment forachieving a higher level of economicdevelopment. FDI benefits the domesticindustry as well as the consumers byproviding technological upgradation, accessto global managerial skills and practices,optimum use of natural and humanresources, etc. Keeping all this in mind,foreign investment has been liberalized andthe government has permitted access to anautomic route for Foreign Direct Investment.The government has also announced changesin the industrial location policies. Industriesare discouraged in or very close to large citiesdue to environmental reasons.

The industrial policy has beenliberalized to attract private investor bothdomestic and multinationals. New sectorslike, mining, telecommunication, highwayconstruction and management have beenthrown open to private companies. In spiteof all these concessions, Foreign DirectInvestment has not been up to the expectation.There has been a big gap between approvedand actual foreign direct investment, eventhough the numbers of foreign collaborationsare increasing. Larger parts of this investmenthave gone to domestic appliances, finance,services, electronics and electrical equipment,and food and dairy products.

Globalization means integrating theeconomy of the country with the worldeconomy. Under this process, goods andservices along with capital, labour andresources can move freely from one nationto another. The thrust of globalization hasbeen to increase the domestic and externalcompetition through extensive application ofmarket mechanism and facilitating dynamicrelationship with the foreign investors andsuppliers of technology. In Indian context,this implies: (1) opening of the economy toforeign direct investment by providingfacilities to foreign companies to invest indifferent fields of economies activity in India;(2) removing restrictions and obstacles to theentry of multinational companies in India; (3)allowing Indian companies to enter intoforeign collaboration in India and alsoencouraging them to set up joint venturesabroad; (4) carrying out massive importliberalization programs by switching overfrom quantitative restrictions to tariffs in thefirst place and then bringing down the levelof import duties considerably; and (5) insteadof a set of export in incentives, opting forexchange rate adjustments for promotingexport.Industrial Region and Districts

Major Industrial Regions (8)

1. Mumbai-Pune Region,2. Hugli Region,3. Bangalore-Tamil Nadu Region,4. Gujarat Region,5. Chotanagpur Region,6. Vishakhapatnam-Guntur Region,7. Gurgaon-Delhi-Meerut Region and8. Kollam-Tiruvantapuram Region.


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Minor Industrial Regions (13)

1. Ambala-Amritsar,2. Saharanpur-Muzaffarnagar-Bijnor,3. Indore-Dewas-Ujjain,4. Jaipur-Ajmer,5. Molhapur-South Kannada,6. Northern Malabar,7. Middle Malabar,8. Adilabad-Nizamabad,9. Allahabad-Varanasi-Mirzapur,10. Bhojpur-Munger,11. Durg-Raipur,12. Bilaspur-Korba, and13. Brahmaputra valley.

Industrial Districts (15)

1. Kanpur,2. Hyderabad,3. Agra,4. Nagpur,5. Gwalior,6. Bhopal,7. Lucknow,8. Jalpaiguri,9. Cuttak,10. Gorakhpur,11. Aligarh,12. Kota,13. Purnia,14. Jabalpur, and15. Bareilly.

A breakup of foreign collaborationapproval reveals that the major share wentto core, priority sectors while infrastructuralsector was untouched. Further, gap betweendeveloped and developing states has become

wider. Major share of both domesticinvestment as well as foreign directinvestment went to already developed states.For example, out of the total proposedinvestment by the industrial entrepreneursduring 1991-2000 nearly one fourth (23 percent) was for industrially developedMaharashtra, 17 per cent for Gujarat, 7 percent for Andhra Pradesh, and about 6 percent for Tamil Nadu while Uttar Pradesh, thestate with the largest population has only 8per cent. In spite of several concessions, sevennorth-eastern states could get less than 1 percent of the proposed investment. In fact,economically weaker states could notcompete with the developed states in openmarket in attracting industrial investmentproposals and hence they are likely to sufferfrom these processes.Industrial Regions in India

Industries are not evenly distributed inthe country. They tend to concentrate oncertain locations because of the favourablelocations factors.

Several indices are used to identify theclustering of industries, important amongthem are: (i) the number of industrial units,(ii) number of industrial workers, (iii)quantum of power used for industrialpurposes, (iv) total industrial output, and (v)value added by manufacturing etc.

Major industrial regions of the countryare given below in some details.Mumbai-Pune Industrial Region

It extends from Mumbai-Thane to Puneand in adjoining districts of Nasik andSolapur. Besides, industrial development hasbeen rapid in Kolaba, Ahmednagar, Satara,Sangli and Jalgaon districts. Development ofthis region started with the location of cotton


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Sugar Industry 77

textile industry in Mumbai. Mumbai, withcotton hinterland and moist climate favouredthe location of cotton textile industry.Opening of the Suez Canal in 1869 providedimpetus to the growth of Mumbai port.Machineries were imported through this port.Hydro-electricity was developed in theWestern Ghat region to meet requirementsof this industry.

With the development of cotton textileindustry, chemical industry also developed.Opening of the Mumbai High petroleum fieldand erection of nuclear energy plants addedadditional pull to this region.

Besides, engineering goods, petroleumrefining, petrochemicals, leather, syntheticand plastic goods, drugs, fertilizers, electrical,shipbuilding, electronics, software, transportequipments and food industries alsodeveloped. Important industrial centres areMumbai, Kolaba, Kalyan, Thane, Trombay,Pune, Pimpri, Nasik, Manmad, Solapur,Kolhapur, Ahmednagar, Satara and Sangli.Hugli Industrial Region

Located along the Hugli river, thisregion extends from Bansberia in the northto Birlanagar in the south for a distance ofabout 100 km. Industries also have developedin Mednipur in the west. Kolkata- Howrahfrom the nucleus of this industrial region.Historical, geographical, economic andpolitical factor have contributed much to itsdevelopment. It developed with the openingof river port on Hugli. Kolkata, emerged asa leading centre of the country, Later, Kolkatawas connected with interior parts by railwaylines and road routes. Development of teaplantations in Assam and northern hills ofWest Bengal, the processing of indigo earlierand jute later coupled with the opening of

coalfields of the Damodar Valley and ironore deposits of the Chotanagpur plateau,contributed to the industrial development ofthe region. Cheap labour available fromthickly populated part of Bihar, eastern UttarPradesh and Orissa also contributed to itsdevelopment. Kolkata, being the capital cityof British India (1773-1911), attracted theBritish capital. The establishment of first jutemill at Rishra in 1855 ushered in the era ofmodern industrial clustering in this region.

The major concentration of jute industryis at Howrah and Bhatapara. The partitionof the country in 1947 adversely affected thisindustrial region. Cotton textile industry alsogrew along with jute industry, paper,engineering, textile machinery, electrical,chemical, pharmaceuticals, fertilizer andpetrochemical industries have also developedwithin this region. Factory of the HindustanMotors Limited at Konnagar and dieselengine factory at Chittaranjan are landmarksof this region. Location of petroleum refineryat Haldia has facilitated the development ofa variety of industries. Important, industrialcentres of this region are Kolkata, Haora,Haldia, Serampur, Rishra, Shibpur, Nahati,Kakinara, Shamnagar, Titagarh, Sodepur,Budge Budge, Birlanagar, Bansberia,Belgurriah, Triveni, Hugli, Belur, etc.However, industrial growth of this regionhas slowed down in comparison to otherregions. Decline of the jute industry is one ofthe reasons.Bangalore-Chennai Industrial Region

This region witnessed most rapidindustrial growth in post-Independenceperiod. Till 1960, industries were confinedto Bangalore, Salem and Madurai districts butnow they have spread over all the districts


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of Tamil Nadu except Viluppuram. Since, thisregion is away from the coalfields, itsdevelopment is dependent on the Pykarahydroelectric plant, which was built in 1932.Cotton textile industry was the first to takeroots due to the presence of cotton growingareas. Along with cotton mills, loom industryspread very rapidly. Several heavyengineering industries converged atBangalore. Aircraft (HAL), machine tools,telephone (HTL) and Bharat Electronics areindustrial landmarks of this region. Importantindustries are textiles rail wagons, dieselengines, radio, light engineering goods,rubber goods, medicines, aluminum, sugar,cement, glass, paper, chemicals, film,cigarette, match box, leather goods, etc.Petroleum refinery at Chennai, iron and steelplant at Salem and fertilizer plants are recentdevelopments.Gujarat Industrial Region

The nucleus of this region lies betweenAhmedabad and Vadodara but this regionextends upto Valsad and Surat in the southand to Jamnagar in the west. Developmentof this region is also associated with thelocation of the cotton textile industry since1860s. This region became an important textileregion with the decline of the cotton textileindustry at Mumbai.

Located in cotton growing area, thisregion has double advantage of the proximityof raw materials as well as of market. Thediscovery of oil fields led to the establishmentof petrochemical industries aroundAnkleshwar, Vadodara and Jamnagar. Theport at Kandla helped in the rapid growth ofthis region. Petroleum refinery at Koyaliprovided raw materials to a host ofpetrochemical industries.

The industrial structure is nowdiversified. Besides, textiles (cotton, silk andsynthetic fabrics) and petrochemicalindustries, other industries are heavy andbasic chemicals, motor, tractor, dieselengines, textile machinery, engineering,pharmaceuticals. Dyes, pesticides, sugar,dairy products and food processing. Recently,largest petroleum refinery has been set up atJamnagar. Important industrial centres of thisregion are Ahmedabad, Vadodara, Bharuch,Koyali, Anand, Khera, Surendranagar,Rajkot, Valsad and Jamnagar.Chotanagpur Region

This region extends over Jharkhand,northern Orissa and western West Bengaland is known for the heavy metallurgicalindustries. This region owes its developmentto the discovery of coal in the DamodarValley and metallic and non-metallic inJharkhand and northern Orissa. Proximity ofcoal, iron ore and other minerals facilitatedthe location of heavy industries in this region.Six large integrated iron and steel plants atJamshedpur, Burnpur-Kulti, Durgapur,Bokaro and Rourkela are located within thisregion. To meet the power requirement,thermal and hydroelectric plants have beenconstructed in the Damodar Valley. Denselypopulated surrounding regions providecheap labour and Hugli region provides vastmarket for its industries. Heavy engineering,machine tools, fertilizers, cement, paper,locomotives and heavy electrical are some ofthe important industries in this region.Important centres are Ranchi, Dhanbad,Chaibasa, Sindri, Hazaribag, Jamshedpur,Bokaro, Rourkela, Durgapur, Asansol andDalmianagar.


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Sugar Industry 79

Vishakhapatnam-Guntur Region

This industrial region extends fromVishakhapatnam district to Kurnool andPrakasam districts in the south. Industrialdevelopment of this region hinges uponVishakhapatnam and districts in the south.Industrial development of this region hingesupon Vishakhapatnam and Machilipatnamports and developed agriculture and richreserves of minerals in their inter lands.Coalfields of the Godavari basin provideenergy. Ship building industry was startedat Vishakhapatnam in 1941. Petroleumrefinery based on imported petroleumfacilitated the growth of severalpetrochemical industries. Sugar, textile, jute,paper, fertilizer, cement, aluminum and lightengineering are principal industries of thisregion. One lead-zinc smelter is functioningin Guntur district. Iron and steel plant atVishakhapatnam uses the Bailadila iron ore.Vishakhapatnam, Vijayawada, Vijaynagar,Rajahmundry, Guntur, Eluru and Kurnool areimportant industrial centres.Gurgaon-Delhi-Merrut Region

Industries located in this region haveshown very fast growth in the recent past.This region is located far away from the min-eral and power resources, and therefore, theindustries are light and market-oriented.Electronics, light engineering and electricalgoods are major industries of this region.

Besides, there are cotton, woolen and syn-thetic fabrics, hosiery, sugar, cement, machinetools, tractor, cycle, agricultural implements,chemical and vanaspati industries which havedeveloped on large scale. Software industryis a recent addition. To the south lies theAgra-Mathura industrial area whichspecializes in glass leather goods. Mathurawith an oil refinery is a petrochemicalcomplex. Among industrial centres, mentionbe made Gurgaon, Delhi, Shahdara,Faridabad, Meerut, Modinagar, Ghaziabad,Ambala, Agra and Mathura.Kollam-Tiruvanantapuram Region

The industrial region is spread overTiruvanantapuram, Kollam, Alwaye,Ernakulam and Alappuzha districts. Planta-tion agriculture and hydropower provideindustrial base to this region. Located faraway from the mineral belt of the country,agricultural products processing and marketoriented light industries predominate theregion.

Among them, cotton textile, sugar, rub-ber, matchbox, glass, chemical fertilizer andfish-based industries are important. Foodprocessing, paper, coconut coir products,aluminum and cement industries are also sig-nificant. Location of petroleum refinery atKochi has added a vista of new industries tothis region. Important of petroleum centresare Kollam, Tiruvanantapuram, Alluva,Kochi, Alappuzha, and Punalur.


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80 Gist of NCERT

TRANSPORT AND COMMUNICATION

9

The use of transport and communicationdepends upon our need to move things fromplace of their availability to the place of theiruse.Land Transport

Road Transport: India has one of thelargest road networks in the world with atotal length of 33.1 lakh km (2005). About 85per cent of passenger and 70 per cent offreight traffic are carried by roads everyyear. Road transport is relatively suitable forshorter distance travel.

Road transport in modern sense wasvery limited in India before World War-II.The first serious attempt was made in 1943when ‘Nagpur Plan’ was drawn. This plancould not be implemented due to lack ofcoordination among the princely states andBritish India. After Independence, twenty-year road plan (1961) was introduced toimprove the conditions of roads in India.However, roads continue to concentrate inand around urban centres. Rural and remoteareas had the least connectivity by road.

For the purpose of construction andmaintenance, roads are classified as NationalHighways (NH), State Highways (SH), MajorDistrict Roads and Rural Roads.

National Highways: The main roadswhich are constructed and maintained by the

Central Government are known as theNational Highways. These roads are meantfor inter-state transport and movement ofdefence men and material in strategic areas.These also connect the state capitals, majorcities, important ports, railway junctions, etc.The length of the National Highways hasincreased from 19,700 km in 1951 to 65,769km in 2005. The National Highwaysconstitute only two per cent of the total roadlength but carry 40 per cent of the road traffic.

The National Highways Authority ofIndia (NHAI) was operationalized in 1995.It is an autonomous body under the Ministryof Surface Transport. It is entrusted with theresponsibility of development, maintenanceand operation of National Highways. This isalso the apex body to improve the quality ofthe roads designated as National Highways.Indian Road Network (2005)

Sl. Road Length in %ofNo. Category Km

totalroad

length

1. National Highways 65,769 22. State Highways 1,28,000 43. Major District Roads 4,70,000 144. Rural Rods 2,65,000 80

Total 33,13,769 100


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Transport and Communication 81

State Highways: These are constructedand maintained by state governments. Theyjoin the state capitals with districtheadquarters and other important towns.These roads are connected to the NationalHighways. These constitute 4 per cent of totalroad length in the country.

In order to consolidate his empireShershah Suri built the road from Indus Valley(Pakistan) to Soner Valley in Bangal. This wascoordinating Kolkata to Peshawar later onnamed as Grand Trunk Road during theBritish period. In the present time it has beendivided into two part between Amritsar toKolkata. (a) National Highway (NH-I) fromDelhi to Amritsar. (b) National Highway(NH-2) Delhi to Kolkata.

District Roads: These roads are theconnecting link between DistrictHeadquarters and the other important nodesin the district. They account for 14 per centof the total road length of the country.Rural Roads

These roads are vital for providing linksin the rural areas. About 80 per cent of thetotal road length in India are categorized asrural roads. There is regional variation in thedensity of rural because these are influencedby the nature of the terrain.Other Roads

Other roads include Border Roads andInternational Highways. The Border RoadOrganization (BRO) was established in May1960 for accelerating economic developmentand strengthening defence preparednessthrough rapid and coordinated improvementof strategically important roads along thenorthern and north-eastern boundary of thecountry. It is a premier multifacetedconstruction agency. It has constructed roads

in high altitude mountainous terrain joiningChandigarh with Manali (Himachal Pradesh)and Leh (Ladakh). This road runs at anaverage altitude of 4,270 metres above themean sea level.

This organization has completed over40,450 km of roads by March 2005. Apartfrom the construction and maintenance ofroads in strategically sensitive areas, the BROalso undertakes snow clearance in highaltitude areas. The international highways aremeant to promote the harmoniousrelationship with the neighbouring countriesby providing effective links with India.

The distribution of roads is not uniformin the country. Density of roads (length ofroads per 100 square km of area) varies fromonly 10.48 km in Jammu and Kashmir to387.24 km in Kerala with a national averageof 75.42 km. The density of road is high inmost of the northern states and majorsouthern states. It is low in the Himalayanregion, Madhya Pradesh and Rajasthan. Whydoes this variation occur? Nature of terrainand the level of economic development arethe main determinants of density of roads.Construction of roads is easy and cheaper inthe plain areas while it is difficult and costlyin hilly and plateau areas. Therefore, not onlythe density but also the quality of roads isrelatively better in plains as compared toroads in high altitude areas, rainy andforested regions.National Highways Development Projects

NHAI has taken up some major projectsin the country under different phases:

Golden Quadrilateral: It comprisesconstruction of 5,846 km long 4/6 lane, highdensity traffic corridor, to connect India’sfour big metro cities of Delhi-Mumbai-


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Chennai-Kolkata. With the construction ofGolden Quadrilateral, the time-distance andcost of movement among the mega cities ofIndia will be considerably minimized.

North-South and East-West Corridors:North-South corridor aims at connectingSrinagar in Jammu and Kashmir andKaniyakumari in Tamil Nadu (includingKochi-Salempur) with 4,076 km long road.The East-West Corridor has been planned toconnect Silchar in Assam with the port townof Porbandar in Gujarat with 3,640 km ofroad length.Rail Transport

Indian Railway was introduced in 1853,when a line was constructed from Bombayto Thane covering a distance of 34 km.

Indian Railways is the largestgovernment undertaking in the country. Thelength of Indian Railways network is 63,221km. Its very large size puts lots of pressureon a centralized railway management system.Thus, in India, the railway system has beendivided into sixteen zones. Table shows thezone-wise performance of Indian Railways.

Areas around towns, raw materialproducing areas and of plantations and othercommercial crops, hill stations andcantonment towns were well-connected byrailways from the British colonial era. Thesewere mostly developed for the exploitationof resources. After the Independence of thecountry, railway routes have been extendedto other areas too. The most significantdevelopment has been the development ofKonkan Railway along the western coastproviding a direct link between Mumbai andMangalore. Railway continuous to remain themain means of transport for the masses.Railway network is relatively less dense in

the hill states, north eastern states, centralparts of India and Rajasthan.

Rural Roads:These roads receivedspecial impetus under the Pradhan MantriGrameen Sadak Yojana. Under this schemespecial provisions are made so that everyvillage in the country is linked to a majortown in the country by an all seasonmotorable road.

Konkan Railway:Konkan Railway wasa great achievement of Indian railway in1998. It is 760 km long track extending fromRoha in Karnataka to Mangalore. Thisrailway crosses 146 rivers, 2000 bridges and91 tunnels, has longest tunnels of the Asiahaving 6.5 km in length. It is joint enterpriseof Karnataka, Goa and Maharashtragovernment.

Indian Railways Zone

Railway Zone Headquarters

Central Mumbai CSTEastern KolkataEast Central HajipurEast Coast BhubaneshwarNorthern New DelhiNorth Central AllahabadNorth Eastern GorakhpurNorth East Frontier Maligaon

(Guwahati)North Western JaipurSouthern ChennaiSouth Central SecundrabadSouth Eastern KolkataSouth East Central BilaspurSouth Western HubliWestern Mumbai

(Church Gate)West Central Jabalpur


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Water Transport

Waterways is an important mode oftransport for both passenger and cargo trafficin India. It is the cheapest means of transportand is most suitable for carrying heavy andbulky material. It is a fuel-efficient and eco-friendly mode of transport. The watertransport is of two types-(a) inlandwaterways, and (b) oceanic waterways.Inland Waterways

It was the chief mode of transportbefore the advent of railways. It, however,faced tough competition from road andrailway transport. Moreover, diversion ofriver water for irrigation purposes madethem non navigable in large parts of theircourses. India has 14,500 km of navigablewaterways, contributing about 1% to thecountry’s transportation. It comprises rivers,canals, backwaters, creeks, etc. At present,3,700 km of major rivers are navigable bymechanized flat bottom vessels, out of whichonly 2,000 km are actually used. Similarly,out of 4,300 km of the network of navigablecanal, only 900 km is navigable by mechanizedvessels.

For the development, maintenance andregulation of national waterways in thecountry, the Inland Waterways Authoritywas set up in 1986. The authority has declaredthree inland waterways as NationalWaterways as given in the table.

Inland Waterways Authority has alsoidentified ten other inland waterways, whichcould be upgraded. The backwaters (Kadal)of Kerala has special significance in InlandWaterway. Apart from providing cheapmeans of transport, they are also attractinglarge number of tourists in Kerala. The

famous Nehru Trophy Boat Race(VALLANKALI) is also held in thebackwaters.

National Highway-7 is the longest andtraverses 2,369 km between Varanasi andKanyakumari via Jabalpur, Nagpur,Hyderabad, Bangalore and Madurai. Delhiand Mumbai are connected by NationalHighway-8, while National Highway-15covers most of Rajasthan.Oceanic Routes

India has a vast coastline of approximate7,517 km, including islands. Twelve major and185 minor ports provide infrastructuralsupport to these routes. Oceanic routes playan important role in the transport sector ofIndia’s economy. Approximately 95 per centof India’s foreign trade by volume and 70per cent by value moves through oceanroutes. Apart from international trade, thesealso used for the purpose of transportationbetween the islands and the rest of thecountry.Air Transportation

Air Transport is the fastest means ofmovement from one place to the other. It hasreduced distances by minimizing the traveltime. It is very essential for a vast countrylike India, where distances are large and theterrain and climatic conditions are diverse.

Air transport in India made a beginningin 1911 when airmail operation commencedover a little distance of 10 km betweenAllahabad and Naini. But its real developmenttook place in post-Independent period. TheAirport Authority of India is responsible forproviding safe, efficient air traffic andaeronautical communication services in theIndian Air Space. The authority manages 126


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airports including 11 international, 86domestic and 29 civil enclaves at defence airfields.

The air transport in India is managedby two corporations, Air India and IndianAirlines after nationalization. Now manyprivate companies have also startedpassenger services.History of Indian Airlines

1911 - Air transport in India waslaunched between Allahabad andNaini.

1947 - Air transport was provided byfour major companies namelyIndian National Airways. TataSons Limited, Air Services ofIndia and Deccan Airways.

1951 - Four more companies joined theservices, Bharat Airways,Himalayan Aviation Limited,Airways India and KalingaAirlines.

1953 - Air transport was nationalizedand two Corporations. Air IndiaInternational and Indian Airlineswere formed. Now IndianAirlines is known as ‘Indian’.

Air India: Air India providesInternational Air Services for both passengersand cargo traffic. It connects all the continentsof the world through its services. In 2005, itcarried 12.2 million passengers and 4.8 lakhmetric tonnes of cargo. About 52 per cent ofthe total air traffic was handled only atMumbai and Delhi airports. In 2005, domesticmovement involved 24.3 million passengersand 20 lakh metric tonnes of cargo. PawanHans is the helicopter service operating inhilly areas and is widely used by tourists innorth-eastern sector.

In addition, Pawan Hans Limited mainlyprovides helicopter services to petroleumsector and for tourism.

Oil and Gas Pipelines: Pipelines are themost convenient and efficient mode oftransporting liquids and gasses over longdistances. Even solids can also be transportedby pipelines after converting them intoslurry. Oil India Limited (OIL) under theadministrative set up of the Ministry ofPetroleum and Natural Gas is engaged in theexploration, production and transportationof crude oil and natural gas. It wasincorporated in 1959 as a company. Asia’sfirst cross country pipeline covering adistance of 1,157 km was constructed by OILfrom Naharkatiya oilfield in Assam toBarauni refinery to Bihar. It was furtherextended up to Kanpur in 1966. Anotherextensive network of pipeline has beenconstructed in the western region of India ofwhich Ankleshwar-Koyali, Mumbai High-Koyali and Hazira-Vijapur-Jagdishpur (HVJ)are most important. Recently, a 1256 km longpipeline connecting Salaya (Gujarat) withMathura (U.P.) has been constructed. Itsupplies crude oil from Gujarat to Punjab(Jalandhar) via Mathura. OIL is in the processof constructing of 660 km long pipeline fromNumaligarh to Siliguri.

Communication Networks: Humanbeings have evolved different methods ofcommunication over time. In earlier times,the messages were delivered by beating thedrum or hollow tree trunks, givingindications through smoke or fire or with thehelp of fast runners. Horses, camels, dogs,birds and other animals were also used tosend messages. Initially, the means ofcommunication were also the means of


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transportation. Invention of post office,telegraph, printing press, telephone, satellite,etc. has made the communication much fasterand easier. Development in the field of scienceand technology has significantly contributedin bringing about revolution in the field ofcommunication.

People use different modes ofcommunication to convey the messages. Onthe basis of scale and quality, the mode ofcommunication can be divided into followingcategories:

Personal Communication System:Among all the personal communication sys-tem internet is the most effective and ad-vanced one. It is widely used in urban areas.It enables the user to establish direct contactthrough e-mail to get access to the world ofknowledge and information. It is increasinglyused for e-commerce and carrying out moneytransactions. The internet is like a huge cen-tral warehouse of data, with detailed infor-mation on various items. The networkthrough internet and e-mail provides an ef-ficient access to information at a compara-tively low cost. It enables us with the basicfacilities of direct communication.

Three types of Indian Railway on thebasis of breadth of Rails

1. Broad guage- distance --- two rails1.616 mts total length of Broadguage in India.

2. Meter guage- Distance between tworail in one meter. Total length ofmeter ganage in India is 13,290 km,account 21.02% of total length ofcountry.

3. Narrow gauge- Distance betweentwo rail is 0.762 mts/0.610 mts. Totallength is 3,124 km, accounts 4,49%of total length.

Mass Communication System

Radio: Radio broadcasting started inIndia in 1923 by the Radio Club of Bombay.Since then, it gained immense popularity andchanged the socio cultural the life of people.Within no time, it made a place in everyhousehold of the country. Government tookthis opportunity and brought this popularmode of communication under its control in1930 under the Indian Broadcasting System.It was changed to All India Radio in 1936 andto Akashwani in 1957.

All India Radio broadcasts a variety ofprogrammes related to information,education and entertainment. Special newsbulletins are also broadcast at specificoccasions like session of parliament and statelegislatures.

Television (T.V.): Televisionbroadcasting has emerged as the mosteffective audio-visual medium fordisseminating information and educatingmasses. Initially, the T.V. services werelimited only to the National Capital where itbegan in 1959. After 1972, several othercentres became operational. In 1976, TV wasdelinked from All India Radio (AIR) and gota separate identity as Doordarshan (DD).After INSAT-IA (National Television- DD1)became operational, Common NationalProgrammes (CNP) were started for theentire network and its services wereextended to the backward and remote ruralareas.

Satellite Communication: Satellites aremode of communication in themselves as wellas they regulate the use of other means ofcommunication. However, use of satellite ingetting a continuous and synoptic view oflarger area has made satellite communication


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very vital for the country, due to theeconomic and strategic reasons. Satelliteimages can be used for the weather forecast,monitoring of natural calamities, surveillanceof border areas, etc. On the basis ofconfiguration and purposes, satellite systemin India can be grouped into two: IndianNational Satellite System (INSAT) and IndianRemote Sensing Satellite System (IRS).

The INSAT, which was established in1983, is a multipurpose satellite system fortelecommunication, meteorologicalobservation and for various other data andprogrammes.

The IRS satellite system becameoperational with the launching of IRS-IA inMarch 1988 from Vaikanour in Russia. Indiahas also developed her own LaunchingVehicle PSLV (Polar Satellite Launch Vehicle).These satellites collect data in several spectralbands and transmit them to the groundstations for various uses. The NationalRemote Sensing Agency (NRSA) atHyderabad provides facilities for acquisitionof data and its processing. These are veryuseful in the management of naturalresources.

Region Imports2003-04 2004-05

West Europe 85,88 1,08,71East Europe 43 85CIS and Baltic states 5,79 8,32Asia and Oceania 1,24,76 1,70,28Africa 14,69 16,80America 31,82 40,20Latin American Countries 5,35 8,55

Source : India 2006

International Trade

The exchange of goods among people,states and countries is referred to as trade.The market is the place where such exchangestake place. Trade between two countries iscalled international trade. It may take placethrough sea, air or land routes. While localtrade is carried in cities, towns and villages,state level trade is carried between two ormore states. Advancement of internationaltrade of a country is an index to its economicprosperity. It is, therefore, considered theeconomic barometer for a country.

As the resources are space bound, nocountry can survive without internationaltrade. Export and import are the componentsof trade. The balance of trade of a country isthe difference between its export and import.When the value of export exceeds the valueof imports, it is called a favourable balanceof trade. On the contrary, if the value ofimports exceeds the value of exports, it istermed as unvfavourable balance of trade.

India has trade relations with all themajor trading blocks and all geographicalregions of the world. Among thecommodities of export, whose share has beenincreasing over the last few year till 2004-05are agriculture and allied products (2.53 percent), ores and minerals (9.12 per cent), gemsand jewellery (26.75 per cent) and chemicaland allied products (24.45 per cent),engineering goods (35.63 per cent) andpetroleum products (86.12 per cent).

Table: India’sMajor Trading Partner’sPercentage share in total trade

(Export + Import)

Country 2000-01 2003-04

U.S.A. 13.0 10.3U.K. 5.7 3.7


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Belgium 4.6 3.7Germany 3.9 3.5Japan 3.8 2.7Switzerland 3.8 3.3Hong Kong 3.7 2.8U.A.E. 3.4 6.2China 2.5 6.4Singapore 2.5 3.4Malaysia 1.9 1.7Total 48.6 47.7Source : Economic Survey 2005-06

The commodities imported to Indiainclude petroleum and petroleum products(41.87 per cent), pearls and precious stones(29.26 per cent), inorganic chemicals (29.39per cent), coal, coke and briquettes (94.17 percent), machinery (12.56 per cent). Bulkimports as a group registered a growthaccounting for 39.09 per cent of total imports.This group includes fertilizers (67.01 percent), cereals (25.23 per cent), edible oils (7.94per cent) and newsprint (5.51 per cent).International trade has under gone a seachange in the last fifteen years. Exchange ofcommodities and goods have beensuperseded by the exchange of informationand knowledge. India has emerged as asoftware giant at the international level andit is earning large foreign exchange throughthe export of information technology.Direction of Trade

India has trade relations with most ofthe countries and major trading blocks of theworld.

India aims to double its share in theinternational trade within the next five years.It has already started adopting suitablemeasures such as import liberalization,

reduction in import duties, de-licensing andchange from process to product patents.

Asia and Oceania accounted for 47.41per cent of India’s export followed by WestEurope (23.80 per cent) and America (20.42).Similarly, India’s imports were highest fromAsia and Oceania (35.40 per cent) followedby West Europe (22.60 per cent) and America(8.36 per cent) in 2004-05.

The U.S.A. is India’s largest tradingpartner and the most trading partner and themost important destination of India’s export.Other countries in order of significanceinclude the U.K., Belgium, Germany, Japan,Switzerland, Hong Kong, the U.A.E., China,Singapore and Malaysia.

Most of India’s foreign trade is carriedthrough sea and air routes. However, a smallportion is also carried through land route toneighbouring countries like Nepal, Bhutan,Bangladesh and Pakistan.Ports

Today Indian ports are handling largevolumes of domestic as well as overseastrade. Most of the ports are equipped withmodern infrastructure. Previously thedevelopment and modernization was theresponsibility of the government agencies,but considering the increase in function andneed to bring these ports at par with theinternational ports, private entrepreneurshave been invited for the modernization ofports in India. The capacity of Indian portsincreased from 20 million tonnes of cargohandling in 1951 to more than 500 milliontonnes at present.

Kandla Port situated at the head of Gulfof Kuchchh has been developed as a majorport to cater to the needs of western andnorth western parts of the country and also


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to reduce the pressure at Mumbai port. Theport is specially designed to receive largequantities of petroleum and petroleumproducts and fertilizer. The offshore terminalat Vadinar has been developed to reduce thepressure at Kandla port.

Demarcation of the boundary of thehinterland would be difficult as it is not fixedover space. In most of the cases, hinterlandof one port may overlap with that of theother.

Mumbai is a natural harbor and thebiggest port of the country. The port issituated closer to the general routes from thecountries of Middle East, Mediterraneancountries, North Africa, North America andEurope where the major share of country’soverseas trade is carried out. The port is 20km long and 6-10 km wide with 54 berthsand has the country’s largest oil terminal.M.P., Maharashtra, Gujarat, U.P. and partsof Rajasthan constitute the main hinterlandsof Mumbai ports.

Jawaharlal Nehru Port at Nhava Shevawas developed as a satellite port to relievethe pressure at the Mumbai port. It is thelargest container port in India.

Marmagao Port, situated at the entranceof the Zuari estuary, is a natural harbor inGoa. It gained significance after itsremodeling in 1961 to handle iron-ore exportsto Japan. Construction of Konkan railway hasconsiderably extended the hinterland of thisport. Karnataka, Goa, Southern Maharashtraconstitutes its hinterland.

New Mangalore Port is located in thestate of Karnataka and caters to the needs ofthe export of iron-ore and iron-concentrates.It also handles fertilizers, petroleumproducts, edible oils, coffee, tea, wood pulp,

yarn, granite stone, molasses, etc. Karnatakais the major hinterland for this port.

Kochchi Port situated at the head ofVembanad Kayal, popularly known as the“Queen of the Arabian Sea,” is also a naturalharbor. This port has an advantageouslocation being close to the Suez-Colomboroute. It caters to the needs of Kerala,southern- Karnataka and south western TamilNadu.

Kolkata Port is located on the Hulgiriver, 128 km inland from the Bay of Bengal.Like the Mumbai port, this port was alsodeveloped by the British. Kolkata had theinitial advantage of being the capital of BritishIndia. The port has lost its significanceconsiderably on account of the diversion ofexports to the other ports such asVishakhapatnam, Paradwip and its satelliteport, Haldia.

Kolkata port is also confronted with theproblem of silt accumulation in the Hugliriver which provides a link to the sea. Itshinterland covers U.P, Bihar, Jharkhand,West Bengal, Sikkim and the north-easternstates. Apart from this, it also extends portsfacilities to our neighbouring land-lockedcountries such as Nepal and Bhutan.

Haldia Port is located 105 kmdownstream from Kolkata. It has beenconstructed to reduce the congestion atKolkata port. It handles bulk cargo like ironore, coal, petroleum, petroleum products andfertilizers, jute, jute products, cotton andcotton yarn, etc.

Paradwip Port is situated in theMahanadi delta, about 100 km from Cuttack.It has the deepest harbor specially suited tohandle very large vessels. It has beendeveloped mainly to handle large-scale


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export of iron-ore. Orissa, Chhattisgarh andJharkhand are the parts of its hinterland.

Visakhapatnam Port in Andhra Pradeshis a land-locked harbor, connected to the seaby a channel cut through solid rock and sand.An outer harbor has been developed forhandling iron-ore, petroleum and generalcargo. Andhra Pradesh is the main hinterlandfor this port.

Chennai Port is one of the oldest portson the eastern coast. It is an artificial harborbuilt in 1859. It is not much suitable for largeships because of the shallow waters near thecoast. Tamil Nadu and Pondicherry are itshinterland. Ennore, a newly developed portin Tamil Nadu, has been constructed 25 kmnorth of Chennai to relieve the pressure atChennai port. Tuticorin Port was alsodeveloped to relieve the pressure of Chennaiport. It deals with a variety of cargo includingcoal, salt, food grains, edible oils, sugar,chemical and petroleum products.Tourism as a Trade

Tourism in India has grownsubstantially over the last three decades.

Foreign tourist’s arrivals in the countrywitnessed an increase of 23.5 per cent duringthe year 2004 as against the year 2003, thuscontributing Rs. 21,828 crore of foreignexchange. Over 2.6 million foreign touristsvisit India every year. More than 15 millionpeople are directly engaged in the tourismindustry. Tourism also promotes nationalintegration, provides support to localhandicrafts and cultural pursuits. It also helpsin the development of internationalunderstanding about our culture andheritage. Foreign tourists visit India forheritage tourism, eco tourism, adventuretourism, cultural tourism, medical tourismand business tourism.

Rajasthan, Goa, Jammu and Kashmir andtemple towns of south India are importantdestinations of foreign tourists in India.There is vast potential of tourismdevelopment in the north-eastern states andthe interior parts of Himalayas, but due tostrategic reasons these have not beenencouraged so far. However, there lies abright future ahead for this upcomingindustry.

GEOGRAPHYForCivil Services


ISBN: 9789381362303Book Code: A15, 315`


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90 Gist of NCERT

OUR SOLAR SYSTEM

10

Our Solar system consists of eightplanets. The nine planet 2003 UB313 has alsobeen recently sighted. The nebula from whichour Solar system is supposed to have beenformed, started its collapse and coreformation some time 5-5.6 billion ago and theplanets formed about 4.6 billion years ago.Our solar system consists of the sun (the star),8 planets, 63 moons, millions of smallerbodies like asteroids and comets and hugequantity of dust-grains and gases.

A light year is a measure of distance andnot of time. Light travels at a speed of 300,00km/second. Considering this, the distancesthe light will travel in one year is taken to beone light year. This equals to 9.461x1012 km.The mean distance between the sun and theearth is 149,598,000 km. In terms of light

years, it is 8.311 minutes of a year. Out of theeight planets, mercury, venus, earth and marsare called as the inner planets as the liebetween the sun and the belt of asteroids theother five planets are called the outer planets.Alternatively, the first four are calledTerrestrial, meaning earth-like as they aremade up of rock and metals, and haverelatively high densities. The rest five arecalled Jovian or Gas Giant planets. Jovianmeans Jupiter-like. Most of them are muchlarger than the terrestrial planets and havethick atmosphere, mostly of helium andhydrogen. All the planets were formed in thesame period sometime about 4.6 billion yearsago. Some data regarding our solar systemare given in the box below.

The Solar System

Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune

Distance 0.387 0.723 1.000 1.524 5.203 9.539 19.182 30.058Density 5.44 5.245 5.517 3.945 1.33 0.70 1.17 1.66Radius# 0.383 0.949 1.000 0.533 11.19 9.460 4.11 3.88Satellites 0 0 1 2 16 about 18 about 17 8

* Distance from the sun is astronomical unit i.e. average mean distance of the earth is149,598,000 km = 1

@ Density in gm / cm3

# Radius : Equatorial radius 6378.137 km = 1


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Our Solar System 91

The Moon

The moon is the only natural satellite ofthe earth. Like the origin of the earth, therehave been attempts to explain how the moonwas formed. In 1838, Sir George Darwinsuggested that initially, the earth and themoon formed a single rapidly rotating body.The whole mass became a dumb-bell-shapedbody and eventually it broke. It was alsosuggested that the material forming the moonwas separated from what we have at presentthe depression occupied by the Pacific Ocean.However, the present scientists do not accepteither of the explanations. It is now generallybelieved that the formation of moon, as asatellite of the earth, is an outcome of ‘giant

impact’ or what is described as “the big splat”.A body of the size of one to three times thatof mars collided into the earth sometimeshortly after the earth was formed. It blasteda large part of the earth into space. Thisportion of blasted material then continuedto orbit the earth and eventually formed intothe present moon about 4.44 billion years ago.Development of Lithosphere

The earth was mostly in a volatile stateduring its primordial stage. Due to gradualincrease in density the temperature inside hasincreased. As a result the material insidestarted getting separated depending on theirdensities. This allowed heavier materials (like

iron) to sink towardsthe centre of theearth and the lighterones to movetowards the surface.With passage of timeit cooled further andsolidified andcondensed into asmaller size. Thislater led to thedevelopment of theouter surface in theform of a crust.During theformation of themoon, due to thegiant impact, theearth was furtherheated up. It isthrough the processof differentiationthat the earthforming material gotseparated into

Geological Time Scale

Eons Era Period Epoch Are/Years Life/Major ExtentsQuaternary Holocene 0 - 10.000 Modern Man

Plestocene 10.000-2 million Home Saptens

Catnozoic Tertiary Pitocene 2 -5 million Early Human Ancestor(From 65 Miocene 5 - 24 million Ape : Flowering Plantsmillion years and Treesto the Oligocene 24 - 37 Ma Anthropoid Apepresent Eocene 37 - 68 million Rabbits and Haretimes) Palaeocene 57 - 65 million Small Mammals:

Rats - Mice

Mesozoic Cretaceous 65 - 144 million Extinction of Dinosaurs65-245 Jurassic 144-208 million Age of Dinosaursmillion Triassic 208 - 245 million Frogs and turtlesMammals

Permtan 245 - 286 million Repttle dominate-replaceamphibtans

Carboniferous 286-360 million First Reptiles:Palaeozotc Vertebrates: Coal beds245-570 Devonian 360-408 million Amphibtansmillion Stlurtan 408-438 million First trace of life on land:

PlantsOrdovtctan 438-505 million first FishCambrtan 505-570 million No terrestrial Life:

Marine Invertebrate

Proterozoic 570-2,500 millionSoft-bodied arthropods

Archean 2,500-3,800 millionBlue green Algae:

Pre Untcellular bacteriaCambratan 3,800-4,800 million Oceans and ContinentsHadean 570 million form-Ocean and-4,800 - Atmosphere are rich inmillion Carbon dioxide

Origin of 5,000 million Origin ofthe sun


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different layers. Starting from the surface tothe central parts, we have layers like the crust,mantle, outer core and inner core. From thecrust to the core, the density of the materialincreases.Minerals & Rocks

The earth is composed of various kindsof elements. These elements are in solid formin the outer layer of the earth and in hot andmolten form in the interior. About 98 per centof the total crust of the earth is composed ofeight elements like oxygen, silicon,aluminum, iron, calcium, sodium, potassiumand magnesium, and the rest is constitutedby titanium hydrogen, phosphorus,manganese, sulphur, carbon, nickel and otherelements.

These substances are recognized asminerals. Thus, a mineral is a naturallyoccurring inorganic substance, having anorderly atomic structure and a definitechemical composition and physical properties.A mineral is composed of two or moreelements. But, sometimes single elementminerals like sulphur, copper, silver, gold,graphite etc. are found.

The elements in the earth’s crust arerarely found exclusively but are usuallycombined with other elements to makevarious substances.

Though the number of elements makingup the lithosphere are limited they arecombined in many different ways to makeup many varieties of minerals. There are atleast 2,000 minerals that have been namedand identified in the earth crust; but almostall the commonly occurring ones are relatedto six major mineral groups that are knownas major rock forming minerals.

The basic source of all minerals is the

hot magma in the interior of the earth. Whenmagma cools, crystals of minerals appear anda systematic series of minerals are formed inseq-uence to solidify so as to form rocks.

Minerals such as coal, petro-leum andnatu-ral gas are orga-nic substances found insolid, liquid and gaseous forms respectively.

Besides these main minerals, otherminerals like chlorite, calcite, magne-tic,haematite, bauxite and barite are also presentin some quantities in the rocks.

The Major Elements of the Earth’s Crust

Sl. No. Elements By Weight (%)

1. Oxygen 46.602. Silicon 27.723. Aluminum 8.134. Iron 5.005. Calcium 3.636. Sodium 2.837. Potassium 2.598. Magnesium 2.099. Others 1.41

Metallic Minerals

These minerals contain metal contentand can be sub-divided into three types:

(i) Precious metals: gold, silver,platinum etc.

(ii) Ferrous metals: iron and othermetals often mixed with iron to formvarious kinds of steel.

(iii) Non-ferrous metals: include metalslike copper, lead, zinc, tin, aluminumetc.

Hardness- relative resistance beingscratched; ten minerals are selected tomeasure the degree of hardness from 1-10.They are: 1. talc; 2. Gypsum; 3. calcite; 4.


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Our Solar System 93

fluorite; 5. apatite; 6. felspar; 7. quartz; 8.topaz; 9. corundum; 10. Diamond. Comparedto this for example, a fingernail is 2.5 andglass or knife blade is 5.5.Non-Metallic Minerals

These minerals do not contain metalcontent. Sulphur, phosphates and nitrates areexamples of non-metallic minerals. Cementis a mixture of non-metallic minerals.Rocks

The earth’s crust is composed for rocks.A rock is an aggregate of one or moreminerals. Rock may be hard or soft and invaried colours. For example, granite is hard,soapstone is soft. Gabbro is black andquartzite can be milky white. Rocks do nothave definite composition of mineralconstituents. Feldspar and quartz are themost common minerals found in rocks.

As there is a close relation between rocksand landforms, rocks and soils, a geographerrequires basic knowledge of rocks. There aremany different kinds of rocks which aregrouped under three families on the basis oftheir mode of formation. They are: (i) IgneousRocks- solidified from magma and lava; (ii)Sedimentary Rocks- the result of depositionof fragments of rocks by exogenousprocesses; (iii) Metamorphic Rocks- formedout of existing rocks undergoingrecrystallisation.Igneous Rocks

As igneous rocks form out of magmaand lava from the interior of the earth, theyare known as primary rocks. The igneousrocks (Ignis- in Latin means ‘Fire’) are formedwhen magma cools and solidifies. Youalready know that magma is. When magmain its upward movement cools and turns into

solid form it is igneous rock. The process ofcooling and solidification can happen in theearth’s crust or on the surface of the earth.

Igneous rocks are classified based ontexture. Texture depends upon size andarrangement of grains or other physicalconditions of the materials. If molten materialis cooled slowly at great depths, mineralgrains may be very large. Sudden cooling (atthe surface) results in small and smoothgrains. Intermediate conditions of coolingwould result in intermediate sizes of grainsmaking up igneous rocks. Granite, gabbro,pegmatite, basalt, volcanic breccias and tuffare some of the examples of igneous rocks.Sedimentary Rocks

The word ‘sedimentary’ is derived fromthe Latin word sedimentum, which meanssettling. Rocks (igneous, sedimentary andmetamorphic) of the earth’s surface areexposed to denudational agents, and arebroken up into various sizes of fragments.Such fragments are transported by differentexogenous agencies and deposited. Thesedeposits through compaction turn into rocks.This process is called lithification. In manysedimentary rocks, the layers of depositsretain their characteristics even afterlithification. Hence, we see a number of layersof varying thickness in sedimentary rocks likesandstone, shale etc.

Depending upon the mode of formation,sedimentary rocks are into three majorgroups: (i) mechanically formed- sandstone,conglomerate, limestone, shale, loess etc. areexamples; (ii) organically formed- geyserites,chalk, limestone, coal etc. are some examples;(iii) chemically formed- chert, limestone,halite, potash etc. are some examples.


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Metamorphic Rocks

The word metamorphic means ‘changeof form’. These rocks form under the actionof pressure, volume and temperature (PVT)changes. Metamorphism occurs when rocksare forced down to lower levels by tectonicprocesses or when molten magma risingthrough the crust comes in contact with thecrustal rocks or the underlying rocks aresubjected to great amounts of pressure byoverlying rocks. Metamorphism is a processby which already consolidated rocks undergorecrystallisation and reorganization ofmaterials within original rocks.Interior of the Earth

The earth’s radius is 6,370 km. No onecan reach the center of the earth and makeobservations or collect samples of material.Under such conditions, you may wonderhow scientists tell us about the earth’s interiorand the type of materials that exist at suchdepths. Most of our knowledge about theinterior of the earth is largely based onestimates and inferences. Yet, a part of theinformation is obtained through directobservations and analysis of materials.Direct Sources

The most easily available solid earthmaterial is surface rock or the rocks we getfrom mining areas. Gold mines in South Africaare as deep as 3-4 km. Going beyond thisdepth is not possible as it is very hot at thisdepth. Besides mining, scientists have takenup a number of projects to penetrate deeperdepths to explore the conditions in the crustalportions. Scientists world over are workingon two major projects such as “Deep OceanDrilling Project” and “integrated OceanDrilling Project”. The deepest drill at Kola,in Arctic Ocean, has so far reached a depth

of 12 km. This and many deep drilling projectshave provided large volume of informationthrough the analysis of materials collected atdifferent depths.

Volcanic eruption forms another sourceof obtaining direct information. As and whenthe molten material (magma) is thrown ontothe surface of the earth, during volcaniceruption it becomes available for laboratoryanalysis. However, it is difficult to ascertainthe depth of the source of such magma.Indirect Sources

Analysis of properties of matterindirectly provides information about theinterior. We know through the miningactivity that temperature and pressureincrease with the increasing distance from thesurface towards the interior in deeper depths.Another source of information are themeteors that at time reach the earth. Theother indirect sources include gravitation,magnetic field, and seismic activity.Earthquake

The study of seismic waves provides acomplete picture of the layered interior. Anearthquake in simple words in shaking of theearth. This is a natural event. It is caused dueto release of energy, which generates wavesthat ravel in all directions.Why does the earth shake?

The release of energy occurs along afault. A fault is a sharp break in the crustalrocks. Rocks along a fault tend to move inopposite directions. As the overlying rockstrata press them, the friction locks themtogether. However, their tendency to moveapart at some point of time overcomes thefriction. As a result, the blocks get deformedand eventually, they slide past one another


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Our Solar System 95

abruptly. This causes a release of energy, andthe energy waves travel in all directions. Thepoint where the energy is released is calledthe focus of an earthquake, alternatively, itis called the hypocenter. The energy wavestravelling in different directions reach thesurface. The point on the surface, nearest tothe focus, is called epicenter. It is the firstone to experience the waves. It is a pointdirectly above the focus.Earthquake Waves

All natural earthquakes take place in thelithosphere. It is sufficient to note here thatthe lithosphere refers to the portion of depthup to 200 km from the surface of the earth.An instrument called ‘seismograph’ recordsthe waves reaching the surface. Note that thecurve shows three distinct sections eachrepresenting different types of wavepatterns. Earthquake waves are basically oftwo types- body waves and surface waves.Body waves are generated due to the releaseof energy at the focus and move in alldirections travelling through the body of theearth. Hence, the name body waves. Thebody waves interact with the surface rocksand generate new set of waves called surfacewaves. These waves move along the surface.The velocity of waves changes as they travelthrough materials with different densities.The denser the material, the higher is thevelocity. Their direction also changes as theyreflect or refract when coming acrossmaterials with different densities.

There are two types of body waves.They are called P and S-waves. P-waves movefaster and are the first to arrive at the surface.These are also called ‘primary waves’. TheP-waves are similar to sound waves. Theytravel through gaseous, liquid and solid

materials. S-waves arrive at the surface withsome time lag.

These are called secondary waves. Animportant fact about S-waves is that they cantravel only through solid materials. Thischaracteristic of the S-waves is quiteimportant.

It has helped scientists to understandthe structure of the interior of the earth.Reflection causes waves to rebound whereasrefraction makes waves move in differentdirections. The variations in the direction ofwaves are inferred with the help of theirrecord on seismograph. The surface wavesare the last to report on seismograph. Thesewaves are more destructive. They causedisplacement of rocks, and hence, thecollapse of structures occurs.Propagation of Earthquake Waves

Different types of earthquake wavestravel in different manners. As they move orpropagate, they cause vibration in the bodyof the rocks through which they pass. P-waves vibrate parallel to the direction of thewave.

This exerts pressure on the material inthe direction of the propagation. As a result,it creates density differences in the materialleading to stretching and squeezing of thematerial. Other three waves vibrate perpen-dicular to the direction of propagation. Thedirection of vibrations of S-waves is perpen-dicular to the wave direction in the verticalplane. Hence, they create troughs and crestsin the material through which they pass. Sur-face waves are considered to be the mostdamaging waves.Emergence of Shadow Zone

Earthquake waves get recorded inseismographs located at far off locations.


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However, there exist some specific areaswhere the waves are not reported. Such azone is called the ‘shadow zone’. The studyof different events reveals that for eachearthquake, there exists an altogetherdifferent shadow zone.

It was observed that seismographs lo-cated at any distance within 105º from theepicenter, recorded the arrival of both P andS-waves. However, the seismographs locatedbeyond 145º from epicenter, record the ar-rival of P-waves, but not that of S-waves.Thus, a zone between 105º and 145º fromepicenter was identified as the shadow zonefor both the types of waves. The entire zonebeyond 105º does not receive S-waves. Theshadow zone of S-wave is much larger thanthat of the P-waves. The shadow zone of P-waves appears as a band around the earthbetween 105º and 145º away from theepicenter. The shadow zone of S-waves is notonly larger in extent but it is also a little over40 per cent of the earth surface.Measuring Earthquakes

The earthquake events are scaled eitheraccording to the magnitude or intensity ofthe shock. The magnitude scale is known asthe Richter scale. The magnitude relates tothe energy released during the quake. Themagnitude is expressed in absolute numbers,0-10. The intensity scale is named afterMercalli, an Italian seismologist. The inten-sity scale takes into account the visible dam-age caused by the event. The range of inten-sity scale is from 1-12.

Though the actual quake activity lastsfor a few seconds, its effects are devastatingprovided the magnitude of the quake is morethan 5 on the Richter scale.

Structure of the Earth

The Crust

It is the outermost solid part of theearth. It is brittle in nature. The thickness ofthe crust varies under the oceanic andcontinental areas. Oceanic crust is thinner ascompared to the continental crust. The meanthickness of oceanic crust is 5 km whereasthat of the continental is around 30 km. Thecontinental crust is thicker in the areas ofmajor mountain systems. It is as much as 70km thick in the Himalayan region.

It is made up of heavier rocks havingdensity of 3 g/cm3. This type of rock foundin the oceanic crust is basalt. The meandensity of material in oceanic crust is 2.7 g/cm3.The Mantle

The portion of the interior beyond thecrust s called the mantle. The mantle extendsfrom Moho’s discontinuity to a depth of 2,900km. The upper portion of the mantle is calledasthenosphere. The word astheno meansweak. It is considered to be extending upto400 km. It is the main source of magma thatfinds its way to the surface during volcaniceruptions. It has s density higher than thecrust’s (3.4 g/cm3). The crust and theuppermost part of the mantle are calledlithosphere. Its thickness ranges from 10-200km. The lower mantle extends beyond theasthenosphere. It is in solid state.The Core

As indicated earlier, the earthquakewave velocities helped in understanding theexistence of the core of the earth. The coremantle boundary is located at the depth of2,900 km. The outer core is in liquid statewhile the inner core is in solid state. Thedesnity of material at the mantle core bound-


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Our Solar System 97

ary is around 5 g/cm3 and at the centre ofthe earth at 6,300 km. the density value isaround 13 g/cm3. The core is made up of veryheavy material mostly constituted by nickeland iron. It is sometimes referred to as theknife layer.Volcanoes and Volcanic landforms

A volcano is a place where gases, ashesand/or molten rock material- lava- escape tothe ground. A volcano is called an activevolcano if the materials mentioned are beingreleased or have been released out in therecent past. The layer below the solid crustis mantle. It has higher density than that ofthe crust. The mantle contains a weaker zonecalled asthenosphere. It is from this that themolten rock materials find their way to thesurface. The material in the upper mantleportion is called magma. Once it startsmoving towards the crust or it reaches thesurface, it is referred to as lava. The materialthat reaches the ground includes lava flows,pyroclastic debris, volcanic bombs, ash anddust and gases such as nitrogen compounds,sulphur compounds and minor amounts ofchlorine, hydrogen and argon.Volcanoes

Volcanoes are classified on the basis ofnature of eruption and the form developedat the surface. Major types of volcanoes areas follows:Shield Volcanoes

Barring the basalt flows, the shieldvolcanoes the largest of all the volcanoes onthe earth, The Hawaiian volcanoes are themost famous examples. These volcanoes aremostly made up of basalt, a type of lava thatis very fluid when erupted. For this reason,these volcanoes are not steep. They become

explosive if somehow water gets into thevent; otherwise, they are characterized bylow-explosivity. The upcoming lava movesin the form of a fountain and throws out thecone at the top of the vent and develops intocinder cone.Composite Volcanoes

These volcanoes are characterized byeruptions of cooler and mokre viscous lavasthan basalt. These volcanoes often result inexplosive eruptions. Along with lava, largequantities of pyroclastic material and ashesfind their way to the ground. This materialaccumulates in the vicinity of the ventopenings leading to formation of layers, andthis makes the mounts appear as compositevolcanoes.Caldera

These are the most explosive of theearth’s volcanoes. They are usually so explo-sive that when they erupt they tend to col-lapse on themselves rather than building anytall structure. The collapsed depressions arecalled calderas. Their explosiveness indicatesthat the magma chamber supplying the lavais not only huge but is also in close vicinity.Flood Basalt Provinces

These volcanoes outpour highly fluidlava that flows for long distances. Some partsof the world are covered by thousands ofsq. km. of thick basalt lava flows. There canbe a series of flows with some flows attainingthickness of more than 50 m. Individual flowsmay extend for hundreds of km. The DeccanTraps from India, presently covering mostof the Maharashtra plateau, are a much largeflood basalt province. It is believed thatinitially the trap formations covered a muchlarger area than the present. Mid-OceanRidge Volcanoes: These volcanoes occur in


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the oceanic areas. There is a system of mid-ocean ridges more than 70,000 km long thatstretches through all the ocean basins. Thecentral portion of this ridge experiencesfrequent eruptions.Volcanic Landforms

Intrusive Forms: The lava that isreleased during volcanic eruptions on coolingdevelops into igneous rocks. The cooling maytake place either on reaching the surface oralso while the lava is still in the crustalportion. Depending on the location of thecooling of the lava, igneous rocks areclassified as volcanic rocks (cooling at thesurface) and plutonic rocks (cooling in thecrust). The lava that cools within the crustalportions assumes different forms. Theseforms are called intrusive forms.

Batholiths: A large body of magmaticmaterial that cools in the deeper depth of thecrust develops in the form of large domes.They appear on the surface only after thedenudational processes remove the overlyingmaterials. They cover large areas, and attimes, assume depth that may be several km.These are granitic bodies. Batholiths are thecooled portion of magma chambers.

Laccoliths: These are large dome-shaped intrusive bodies with a level base andconnected by a pipe-like conduit from below.It resembles the surface volcanic domes ofcomposite volcano, only these are located atdeeper depths. It can be regarded as thelocalized source of lava that finds its way to

the surface. The Karnataka plateau is spottedwith domal hills of granite rocks. Most ofthese, now exfoliated, are examples oflaccoliths or batholiths.Lapolith, Phacolith and Sills

As and when the lava moves upwards,a portion of the same may tend to move in ahorizontal direction wherever it finds a weakplane. It may get rested in different forms.In case it develops into a saucer shape,concave to the sky body, it is called lapolith.A wavy mass of intrusive rocks, at times, isfound at the base of synclines or at the top ofanticline in folded igneous country. Suchwavy materials have a definite conduit tosource beneath in the form of magmachambers (subsequently developed asbatholiths). These are called the phacoliths.

The near horizontal bodies of theintrusive igneous rocks are called sill or sheet,depending on the thickness of the material.The thinner ones are called sheets while thethick horizontal deposits are called sills.

Dykes: When the lava makes its waythrough cracks and the fissures developedin the land, it solidifies almost perpendicularto the ground. It gets cooled in the sameposition to develop a wall-like structure. Suchstructures are called dykes. These are themost commonly found intrusive forms in thewestern Maharashtra area. These areconsidered the feeders for the eruptions thatled to the development of the Deccan traps.


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Geography 99

LAND FORMS

11

After weathering processes have hadtheir actions on the earth materials makingup the surface of the earth, the geomorphicagents like running water, ground water,wind, glaciers, waves perform erosion.Erosion causes changes on the surface of theearth. Deposition follows erosion andbecause of deposition too, changes occur onthe surface of the earth.

A landmass passes through stages ofdevelopment somewhat comparable to thestages of life- youth, mature and old age.Running Water

In humid regions, which receive heavyrainfall running water is considered the mostimportant of the geomorphic agents inbringing about the degradation of the landsurface. There are two components of runningwater. One is overland flow in general landsurface as a sheet. Another is linear flow asstreams and rivers in valleys. Most of theerosional landforms made by running waterare associated with vigorous and youthfulrivers flowing along gradients. With time,stream channels over steep gradients turngentler due to continued erosion, and as aconsequence, lose their velocity, facilitatingactive deposition.

In the early stages, down-cuttingdominates during which irregularities suchas waterfalls and cascades will be removed.

In the middle stages, streams cut their bedsslower, and lateral erosion of valley sidesbecomes severe. Gradually, the valley sidesare reduced to lower and lower slopes. Thedivides between drainage basins are likewiselowered until they are almost completelyflattened leaving finally, a lowland of faintrelief with some low resistant remnants calledmonad nocks standing out here and there.This type of plain forming as a result of streamerosion is called a peneplain (an almost plain).The characteristics of each of the stages oflandscapes developing in running waterregimes may be summarized as follows:Youth

Streams are few during this stage withpoor integration and flow over originalslopes showing shallow V-shaped valleyswith no floodplains or with very narrowfloodplains along trunk streams. Streamsdivides are broad and flat with marshes,swamp and lakes. Meanders if presentdevelop over these broad upland surfaces.These meanders may eventually entrenchthemselves into the uplands. Waterfalls andrapids may exist where local hard rock bodiesare exposed.Mature

During this stage streams are plentywith good integration. The valleys are stillV-shaped but deep; trunk streams are broad


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enough to have wider floodplains withinwhich streams may flow in meanders con-fined within the valley. The flat and broadinter stream areas and swamps and marshesof youth disappear and the stream dividesturn sharp. Waterfalls and rapids disappear.Old

Smaller tributaries during old age arefew with gentle gradients. Streams meanderfreely over vast floodplains showing naturallevees, oxbow lakes, etc. Divides are broadand flat with lakes, swamps and marshes.Most of the landscape is at or slightly abovesea level.

EROSIONAL LANDFORMS

Vallyes

Valleys start as small and narrow rills;the rills will gradually develop into long andwide gullies; the gullies will further deepen,widen and lengthen to give rise to valleys.Depending upon dimensions and shape,many types of valleys like V-shaped valley,gorge, canyon, etc. can be recognized. Agorge is a deep valley with very steep tostraight sides and a canyon is characterizedby steep step-like side slopes and may be asdeep as a gorge. A gorge is almost equal inwidth at its top as well as its bottom. Incontrast, a canyon is wider at its top than atits bottom. In fact, a canyon is a variant ofgorge. Valley types depend upon the typeand structure of rocks in which they form.For example, canyons commonly form inhorizontal bedded sedimentary rocks andgorges form in hard rocks.Potholes and Pluge Pools

Over the rocky beds of hill-streamsmore or less circular depressions calledpotholes form because of stream erosion

aided by the abrasion of rock fragments. Suchlarge and deep holes at the base of waterfallsare called plunge pools. These pools also helpin the deepening of valleys. Waterfalls arealso transitory like any other landform andwill recede gradually and bring the floor ofthe valley above waterfalls to the level below.Incised or Entrenched Meanders

But very deep and wide meandersfound cut in hard rocks. Such meanders arecalled incised or entrenched meanders.River Terraces

River terraces are surfaces marking oldvalley floor or floodplain levels. Riverterraces are basically products of erosion asthey result due to vertical erosion by thestream into its own depositional floodplain.

DEPOSITIONAL LANDFORMS

Alluvial Fans

Alluvial fans are formed when streamsflowing from higher levels break into footslope plains of low gradient. Alluvial fans inhumid areas show normally low cones withgentle slope from head to toe and they appearas high cones with steep slope in arid andsemi-arid climates.Deltas

Deltas are like alluvial fans but developat a different location. The load carried bythe rivers is dumped and spread into the sea.It this load is not carried away far into thesea or distributed along the coast, it spreadsand accumulates as a low cone.Floodplains, Natural Levees and Point Bars

Floodplain is a major landform of riverdeposition. The flood plains in a delta arecalled delta plains.

Natural levees are found along the


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banks of large rivers. They are low, linearand parallel ridges of coarse deposits alongthe banks of rivers, quite often cut intoindividual mounds. During flooding as thewater spills over the bank, the velocity of thewater comes down and large sized and highspecific gravity materials get dumped in theimmediate vicinity of the bank as ridges. Theyare nearer the banks and slope gently awayfrom the river. The levee deposits are coarserthan the deposits spread by flood watersaway from the river. When rivers shiftlaterally, a series of natural levees can form.

Point bars are also known as meanderbars. They are found on the convex side ofmeanders of large rivers and are sedimentsdeposited in a linear fashion by flowingwaters along the bank.Meanders

In large flood and delta plains, riversrarely flow in straight courses. Loop-likechannel patterns called meanders developover flood and delta plains.

As meanders grow into deep loops, thesame may get cut-off due to erosion at theinflection points and are left as ox-bow lakes.

Braided Channels: When rivers carrycoarse material, there can be selectivedeposition of coarser materials causingformation of a central bar which diverts theflow towards the banks; and this flowincreases lateral erosion on the banks. As thevalley widens, the water column is reducedand more and more materials get depositedas islands and lateral bars developing anumber of separate channels of water flow.Deposition and lateral erosion of banks areessential for the formation of braided pattern.Or, alternatively, when discharge is less andload is more in the valley, channel bars and

islands of sand, gravel and pebbles developon the floor of the channel and the waterflow is divided into multiple threads. Thesethread-like streams of water rejoin andsubdivide repeatedly to give a typical braidedpattern.Groundwater

Here the interest is not on groundwateras a resource. Our focus is on the work ofgroundwater in the erosion of landmassesand evolution of landforms. The surfacewater percolates well when the rocks arepermeable, thinly bedded and highly jointedand cracked. After vertically going down tosome depth, the water under the groundflows horizontally through the beddingplanes, joints or through the materialsthemselves. It is this downward andhorizontal movement of water which causesthe rocks to erode. Physical or mechanicalremoval of materials by moving groundwateris insignificant in developing landforms. Thatis why; the results of the work ofgroundwater cannot be seen in all types ofrocks. But in rocks like limestone ordolomites rich in calcium carbonate, thesurface water as well as groundwaterthrough the chemical process of solution andprecipitation deposition develop varieties oflandforms. These two processes of solutionand precipitation are active in limestone’s ordolomites occurring either exclusively orinter-bedded with other rocks. Anylimestone or dolomite region showing typicallandforms produced by the action ofgroundwater through the processes ofsolution and deposition is called Karsttopography after the typical topographydeveloped in limestone rocks of Karst regionin the Balkans adjacent to Adriatic sea.


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The karst topography is alsocharacterized be erosional and depositionallandforms. Indian subcontinent is full ofexample of glaciers. It can be seen inmountainous area of Uttaranchal, HimachalPradesh, Jammu Kashmir. The source ofBhagirathi river is Gangotri glacier called‘Gaumukh’. The source of Alakananda riveris Alkapuri glacier. Where Alakhanda joinsBhagirathi at Devprayag it ows nomenclatureas “The Ganga”.

EROSIONAL LANDFORMS

Pools, Sinkholes,Lapies and Limestone Pavements

Small to medium sized round to sub-rounded shallow depressions called swallowholes form on the surface of limestone’sthrough solution. It might collapse leaving alarge hole opening into a cave or a void below(collapse sinks). The term do line issometimes used to refer the collapse sinks.Solution sinks are more common than collapsesinks. Quite often the surface run-off simplygoes down swallow and sink holes and flowas underground streams and re-emerge at adistance downstream through a caveopening. When sink holes and do-lines jointogether because of slumping of materialsalong their margins or due to roof collapseof caves, long, narrow to wide tranchescalled valley sinks or Uvalas form. Gradually,most of the surface of the limestone is eatenaway by these pits and trenches, leaving itextremely irregular with a maze of points,grooves and ridges or lapis. Especially, theseridges or lapis form due to differentialsolution activity along parallel to sub-paralleljoints. The lapie field may eventually turn intosomewhat smooth limestone pavements.

Caves: In areas where there are

alternating beds of rocks (shales, sandstones,quartzite’s) with limestones or dolomites inbetween or in areas where limestone’s aredense, massive and occurring as thick beds,cave formation is prominent.

Stalactites, Stalagmites and Pillars:Stalactites hang as icicles of differentdiameters. Normally they are broad at theirbases and taper towards the free endsshowing up in variety of forms. Stalagmitesrise up from the floor of the caves. In fact,stalagmites form due to dripping water fromthe surface or through the thin pipe, of thestalactite, immediately below it. Stalagmitesmay take the shape of a column, a disc, witheither a smooth, rounded bulging end or aminiature crater like depression. Thestalagmite and stalactites eventually fuse togive rise to columns and pillars of differentdiameters.Glaciers

Masses of ice moving as sheets over theland (continental glacier or piedmont glacierif a vast sheet of ice is spread over the plainsat the foot of mountains) or as linear flowsdown the slopes of mountains in broadtrough-like valleys (mountain and valleyglaciers) are called glaciers. The movementof glaciers is slow unlike water flow. Themovement could be a few centimeters to afew meters a day or even less or more.Glaciers move basically because of the forceof gravity.

We have many glaciers in our countrymoving down the slopes and valleys inHimalayas. Higher reaches of Uttaranchal,Himachal Pradesh and Jammu and Kashmir,are places to see some of them. RiverBhagirathi is basically fed by melt watersfrom under the snout (Gaumukh) of the


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Land Forms 103

Gangotri glacier. In fact, Alkapuri glacierfeeds waters to Alakananda river. RiversAlkananda and Bhagirathi join to make riverGanga near Deoprayag.

Erosion by glaciers is tremendousbecause of friction caused by sheer weightof the ice. The material plucked from the landby glaciers (usually large-sized angularblocks and fragments) get dragged along thefloors or sides of the valleys and cause greatdamage through abrasion and plucking.Glaciers can cause significant damage to evenun-weathered rocks and can reduce highmountains into low hills and plains.

As glaciers continue to move, debrisgets removed, divides get lowered andeventually the slope is reduced to such anextent that glaciers will stop moving leavingonly a mass of low hills and vast outwashplains along with other depositional features.The highest peak in the Alps, Matterhorn andthe highest peak in the Himalayas, Everestare in fact horns formed through headworderosion of radiating cirques.Erosional Landforms

Cirque: The cirques quite often arefound at the heads of glacial valleys. Theaccumulated ice cuts these cirques whilemoving down the mountain tops. They aredeep, long and wide troughs or basins withvery steep concave to vertically droppinghigh walls at its head as well as sides. A lakeof water can be seen quite often within thecirques after the glacier disappears. Suchlakes are called cirque or tarn lakes. Therecan be two or more cirques one leading intoanother down below in a stepped sequence.Horns and Serrated Ridges

Horns form through head ward erosionof the cirque walls. It three or more radiating

glaciers cut head ward until their cirquesmeet, high, sharp pointed and steep sidedpeaks called horns form. The divides betweencirque side walls or head walls get narrowbecause of progressive erosion and turn intoserrated or saw- toothed ridges sometimesreferred to as arêtes with very sharp crestand a zigzag outline.Glacial Valleys/Troughs

Glaciated valleys are trough-like and U-shaped with broad floors and relativelysmooth, and steep sides. The valleys maycontain littered debris or debris shaped asmoraines with swampy appearance. Theremay be lakes gouged out of rocky floor orformed by debris within the valleys. Therecan be hanging valleys at an elevation on oneor both sides of the main glacial valleys arequite often truncated to give them an appear-ance like triangular facets. Very deep glacialtroughs filled with sea water and making upshorelines (in high latitudes) are calledfjords/fiords.Depositional Landforms

The unasserted coarse and fine debrisdropped by the melting glaciers is calledglacial till.

Moraines: They are long ridges of de-posits of glacial till. Terminal moraines arelong ridges of debris deposited at the end(toe) of the glaciers. Lateral moraines formalong the sides parallel to the glacial valleys.The moraine in the centre of the glacial val-ley flanked by lateral moraines is called me-dial moraine.Eskers

When glaciers melt in summer, the waterflows on the surface of the ice or seeps downalong the margins or even moves throughholes in the ice. These waters accumulate


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beneath the glacier and flow like streams ina channel beneath the ice. Such streams flowover the ground (not in a valley cut in theground) with ice forming its banks. Verycoarse materials like boulders and blocksalong with some minor fractions of rockdebris carried into this stream settle in thevalley of ice beneath the glacier and after theice melts can be found as a sinuous ridgecalled esker.Outwash Plains

The plains at the foot of the glacialmountains or beyond the limits of continentalice sheets are covered with glacio-fluvialdeposits in the form of broad flat alluvial fanswhich may join to form outwash plains ofgravel, silt, sand and clay.Drumlins

Drumlins are smooth oval shaped ridge-like features composed mainly of glacial tillwith some masses of gravel and sand. Thelong axes of drumlins are parallel to thedirection of ice movement. They maymeasure up to 1 km in length and 30 m or soin height. One end of the drumlins facing theglacier called the stoss end is blunter andsteeper than the other end called tail. Thedrumlins form due to dumping of rock debrisbeneath heavily loaded ice through fissuresin the glacier. The stoss end gets blunted dueto pushing by moving ice. Drumlins give anindication of glacier movement.Waves and Currents

Coastal processes are the most dynamicand hence most destructive.

Some of the changes along the coast takeplace very fast. At one place, there can beerosion in one season and deposition inanother. Most of the changes along the coast

are accomplished by waves. When wavesbreak, the water is thrown with great forceonto the shore, and simultaneously, there isa great churning of sediments on the seabottom. Constant impact of breaking wavesdrastically affects the coasts. Storm wavesand tsunami waves can cause far-reachingchanges in a short period of time than normalbreaking waves. As wave environmentchanges, the intensity of the force of breakingwaves changes.

Other than the action of waves, thecoastal landforms depend upon (i) theconfiguration of land and sea floor; (ii)whether the coast is advancing (emerging)seaward or retreating (submerging)landward. Assuming sea level to be constant,two types of coasts are considered to explainthe concept of coastal landforms: (i) high,rocky coasts (submerged coasts); (ii) low,smooth and gently sloping sedimentarycoasts (emerged coasts).High Rocky Coasts

Along the high rocky coasts, the riversappear to have been drowned with highlyirregular coastline. The coastline appearshighly indented with extension of water intothe land where glacial valleys (fjords) arepresent. The hill sides drop off sharply intothe water. Shores do not show anydepositional landforms initially. Erosionfeatures dominate.

Along with rocky coasts, waves breakwith great force against the land shaping thehill sides into cliffs. With constant poundingby waves, the cliffs recede leaving a wave-cut platform in front of the sea cliff. Wavesgradually minimize the irregularities alongthe shore. The materials which fall off, andremoved from the sea cliffs, gradually break


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Land Forms 105

into smaller fragments and roll to roundness,will get deposited in the offshore. After aconsiderable period of cliff development andretreat when coastline turns somewhatsmooth, with the addition of some morematerial to this deposit in the offshore, awave-built terrace would develop in front ofwave-cut terrace. As the erosion along thecoast takes place a good supply materialbecomes available to long shore currents andwaves to deposit them as beaches along theshore and as bars (long ridges of sand and/or shingle parallel to the coast) in the nearshore zone. Bars are submerged features andwhen bars show up above water, they arecalled barrier bars. Barrier bar which getkeyed up to the headland of a bay is called aspit. When barrier bars and spits form at themouth of a bay and block it, a lagoon forms.The lagoons would gradually get filled upby sediments from the land giving rise to acoastal plain.Low sedimentary coasts

Along low sedimentary coasts the riversappear to extend their length by buildingcoastal plains and deltas. The coastlineappears smooth with occasional incursions ofwater in the form of lagoons and tidal creeks.The land slopes gently into the water.Marshes and swamps may abound along thecoasts. Depositional features dominate.

When waves break over a gently slopingsedimentary coast, the bottom sediments getchurned and move readily building bars,barrier bars, spits and lagoons. Lagoonswould eventually turn into a swamp whichwould subsequently turn into a coastal plain.The maintenance of these depositionalfeatures depends upon the steady supply ofmaterials.

Storm and tsunami waves cause drasticchanges irrespective of supply of sediments.Large rivers which bring lots of sedimentsbuild deltas along low sedimentary coasts.Erosional Landforms

Cliffs, Terraces, Caves and StacksWave-cut cliffs and terraces are two formsusually found where erosion is the dominantshore process. Almost all sea cliffs are steepand may range from a few m to 30 m or evenmore. At the foot of such cliffs there may bea flat or gently sloping platform covered byrock debris derived from the sea cliff behind.Such platforms occurring at elevations abovethe average height of waves is called a wave-cut terrace. The lashing of waves against thebase of the cliff and the rock debris that getssmashed against the cliff along with lashingwaves create hollows and these hollows getwidened and deepened to form sea caves.The roofs of caves collapse and the sea cliffsrecede further inland. Retreat of the cliff mayleave some remnants of rock standingisolated as small islands just off the shore.Such resistant masses of rock, originally partsof a cliff or hill are called sea stacks. Like allother features, sea stacks are also temporaryand eventually coastal hills and cliffs willdisappear because of wave erosion giving riseto narrow coastal plains, and with onrush ofdeposits from over the land behind may getcovered up by alluvium or may get coveredup by shingle or sand to form a wide beach.Depositional landforms

Beaches and Dunes

Beaches are characteristic of shorelinesthat are dominated by deposition, but mayoccur as patches along even the ruggedshores. Most of the sediment making up the


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beaches comes from land carried by thestreams and rivers or from wave erosion.Beaches are temporary features. The sandybeach which appears so permanent may bereduced to a very narrow strip of coarsepebbles in some other season. Most of thebeaches are made up of sand sized materials.Beaches called shingle beaches containexcessively small pebbles and even cobbles.

Just behind the beach, the sands liftedand winnowed from over the beach surfaceswill be deposited as sand dunes. Sand dunesforming long ridges parallel to the coastlineare very common along low sedimentarycoasts.Bars, Barriers and Spits

A ridge of sand and shingle formed inthe sea in the off-shore zone (from theposition of low tide waterline to seaward)lying approximately parallel to the coast iscalled an off-shore bar. An off-shore barwhich is exposed due to further addition ofsand is termed a barrier bar. The off-shorebars and barriers commonly from across themouth of a river or at the entrance of a bay.Sometimes such bars get keyed up to one endof the bay when they are called spits. Spitsmay also develop attached to headlands/hills.The barriers, bars and spits at the mouth ofthe bay gradually extend leaving only a smallopening of the bay into the sea and the baywill eventually develop into a lagoon. Thelagoons get filled up gradually by sedimentcoming from the land or from the beach itself(aided by wind) and a broad and widecoastal plain may develop replacing a lagoon.Winds

Wind is one of the two dominant agentsin hot deserts. Winds cause deflation,abrasion and impact. Deflation includes

lifting and removal of dust and smallerparticles from the surface of rocks. In thetransportation process sand and silt act aseffective tools to abrade the land surface. Theimpact is simply sheer force of momentumwhich occurs when sand is blown into oragainst a rock surface. It is similar tosandblasting operation. The wind actioncreates a number of interesting erosional anddepositional features in the deserts.Erosional Landforms

Pediments and Pedi plains

Landscape evolution in deserts isprimarily concerned with the formation andextension of pediments. Gently inclined rockyfloors close to the mountains at their foot withor without a thin cover of debris, are calledpediments. Such rocky floors from throughthe erosion of mountain front through acombination of lateral erosion by streams andsheet flooding.

Erosion starts along the steep marginsof the landmass or the steep sides of thetectonically controlled steep incision featuresover the landmass. Once, pediments areformed with a steep wash slope followed bycliff or free face above it, the steep wash slopeand free face retreat backwards. This methodof erosion is termed as parallel retreat ofslopes through back wasting.

So, through parallel retreat of slopes, thepediments extend backwards at the expenseof mountain front, and gradually, themountain gets reduced leaving an inselbergwhich is a remnant of the mountain. That’show the high relief in desert areas is reducedto low featureless plains called Pedi plains.

Playas: Plains are by far the mostprominent landforms in the deserts. In basinswith mountains and hills around and along,


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Land Forms 107

the drainage’s towards the center of the basinand due to gradual deposition of sedimentfrom basin margins, a nearly level plain formsat the centre of the basin. In times of sufficientwater, this plain is covered up by a shallowwater body.

Such types of shallow lakes are calledas playas where water is retained only forshort duration due to evaporation and quiteoften the playas contain good deposition ofsalts. The playa plain covered up by salts iscalled alkali flats.Deflation Hollows and Caves

Weathered mantle from over the rocksor bare soil, gets blown out by persistentmovement of wind currents in one direction.This process may create shallow depressionscalled deflation hollows. Deflation also cre-ates numerous small pits or cavities over rocksurfaces.

The rock faces suffer impact and abra-sion of wind-borne sand and first shallowdepressions called blow outs are created, andsome of the blow outs become deeper andwider fit to be called caves.

Many rock-outcrops in the deserts easilysusceptible to wind deflation and abrasionare worn out quickly leaving some remnantsof resistant rocks polished beautifully in theshape of mushroom with a slender stalk anda broad and rounded pear shaped cap above.Sometimes, the top surface is broad like atable top and quite often, the remnants standout like pedestals.Depositional Landforms

Wind is a good sorting agent.Depending upon the velocity of wind,different sizes of grains are moved along thefloors by rolling or saltation and carried insuspension and in this process of

transportation itself, the materials get sorted.When the wind slows or begins to die down,depending upon sizes of grains and theircritical velocities, the grains will begin tosettle.

So, in depositional landforms made bywind, good sorting of grains can be found.Since wind is there everywhere and whereverthere is good source of sand and withconstant wind directions, depositionalfeatures in arid regions can developanywhere.Sand Dunes

Dry hot deserts are good places for sanddune formation. Obstacles to initiate duneformation are equally important. There canbe a great variety of dune forms.Barchans

Crescent shaped dunes called barchanswith the points or wings directed away fromwind direction i.e., downwind, form wherethe wind direction is constant and moderateand where the original surface over whichsand is moving is almost uniform. Parabolicdunes form when sandy surfaces are partiallycovered with vegetation. That meansparabolic dunes are reversed barchans withwind direction being the same. Seif is similarto barchans with a small differences. Seif hasonly one wing or point. This happens whenthere is shift in wind conditions. The longwings of seifs can grow very long and high.Longitudinal dunes form when supply of sandis poor and wind direction is constant. Theyappear as long ridges of considerable lengthbut low in height. Transverse dunes arealigned perpendicular to wind direction.These dunes form when the wind directionis constant and the source of sand is anelongated feature at right angles to the wind


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direction. They may be very long and low inheight. When sand is plenty, quite often, theregular shaped dunes coalesce and lose their

individual characteristics. Most of the dunesin the deserts shift and a few of them willget stabilized especially near humanhabitations.

GENERAL SCIENCEForCivil Services


ISBN: 9789381362327Book Code: A11, 250`


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Geography 109

COMPOSITION AND STRUCTURE OF ATMOSPHERE

12

Composition and Structure of Atmosphere

Atmosphere is a mixture of differentgases and it envelopes the earth all round. Itcontains life-giving gases like oxygen forhumans and animals and carbon dioxide forplants. The air is an integral part of the earth’smass and 99 per cent of the total mass of theatmosphere is confined to the height of 32km from the earth’s surface. The air iscolourless and odourless and can be felt onlywhen it blows as wind.Composition of the Atmosphere

The atmosphere is composed of gases,water vapour and dust particles. Table showsdetails of various gases in the air, particularlyin the lower atmosphere. The proportion ofgases changes in the higher layers of theatmosphere in such a way that oxygen willbe almost in negligible quantity at the heightof 120 kin. Similarly, carbon dioxide andwater vapour are found only up to 90 kmfrom the surface of the earth.

Constituent Formula Percentageby Volume

Nitrogen N2 78.08Oxygen O2 20.95Argon Ar 0.93Carbond dioxideCo2 0.93Neon Ne 0.002Helium He 0.0005

Krypto Kr 0.001Xenon Xe 0.00009Hydrogen H2 0.00005

Gases: Carbon dioxide ismeteorologically a very important gas as itis transparent to the incoming solar radiationbut opaque to the outgoing terrestrialradiation. It absorbs a part of terrestrialradiation and reflects back some part of ittowards the earth’s surface. It is largelyresponsible for the green house effect. Thevolume of other gases is constant but thevolume of carbon dioxide has been rising inthe past few decades mainly because of theburning of fossil fuels. This has also increasedthe temperature of the air. Ozone is anotherimportant component of the atmospherefound between 10 and 50 km above theearth’s surface and acts as a filter and absorbsthe ultra-violet rays radiating from the sunand prevents them from reaching the surfaceof the earth.

Water Vapour: Water vapour is also avariable gas in the atmosphere, which de-creases with altitude. In the warm and wettropics, it ‘may account for four percent ofthe air by volume, while in the dry and coldareas of desert and polar regions, it may beless than one percent of the air. Water va-pour also decreases from the equator, to-wards the poles. It also absorbs parts of the


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insolation from the sun and preserves theearth’s radiated heat. It thus, acts like a blan-ket allowing the earth neither to become ‘toocold nor too hot. Water vapour also contrib-utes to the stability and instability in the air.

Dust Particles: Atmosphere has asufficient capacity to keep small solidparticles, which may originate from differentsources and include sea salts, fine soil, smoke-soot, ash, pollen, dust and disintegratedparticles of meteors. Dust particles aregenerally concentrated in the lower layers ofthe atmosphere; yet, convectional air currentsmay transport them to great heights. Thehigher concentration of dust particles is foundin subtropical and temperate regions due todry winds in comparison to equatorial andpolar regions. Dust and salt particles act ashygroscopic nuclei around which watervapour condenses to produce clouds.Structure of the Atmosphere

The atmosphere consists of differentlayers with varying density and temperature.Density is highest near the surface of the earthand decreases with increasing altitude. Thecolumn of atmosphere is divided into fivedifferent layers depending upon thetemperature condition. They are:troposphere, stratosphere, mesosphere,ionosphere and exosphere.

The troposphere is the lowermost layerof the atmosphere. Its average height is 13km and extends roughly to a height of 8 kmnear the poles and about 18 km at the equator.Thickness of the troposphere is greatest atthe equator because heat is transported togreat heights by strong convectional currents.This layer contains dust particles and watervapour. All changes in climate and weathertake place in this layer. The temperature in

this layer decreases at the rate of 1°C forevery 165m of height. This is the mostimportant layer for all biological activity.

The zone separating the tropsopherefrom stratosphere is known as thetropopause. The air temperature at thetropopause is about minus 80°C over theequator and about minus 45°C over the poles.The temperature here is nearly constant, andhence, it is called the tropopause. The strato-sphere is found above the tropopause andextends up to a height of 50 km. One impor-tant feature of the stratosphere is that it con-tains the ozone layer. This layer absorbs ul-traviolet radiation and shields life on the earthfrom intense, harmful form of energy.

The mesosphere lies above thestratosphere, which extends up to a height-of 80 km. In this layer, once again,temperature starts decreasing with theincrease in altitude and reaches up to minus100°C at the height of 80 km. The upper limitof mesosphere is known as the mesopause.The ionosphere is located between 80 and 400km above the mesopause. It containselectrically charged particles known as ions,and hence, it is known as ionosphere. Radiowaves transmitted from the earth arereflected back to the earth by this layer.Temperature here starts increasing withheight. The uppermost layer of theatmosphere above the ‘ionosphere is knownas the exosphere. This is the highest layer butvery little is known about it. Whatevercontents are there, these are extremelyrarefied in this layer, and it gradually mergeswith the outer space. Although all layers ofthe atmosphere must be exercising influenceon us, geographers are concerned with thefirst two layers of the atmosphere.


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Composition and Structure of Atmosphere 111

Water in the Atmosphere: The aircontains water vapour. It varies from zeroto four percent by volume of the atmosphereand plays an important, role in the weatherphenomena. Water is present in theatmosphere in three forms namely —gaseous, liquid and solid. The moisture in theatmosphere is derived from water bodiesthrough evaporation and from plants throughtranspiration. Thus, there is a continuousexchange of water between the atmosphere,the oceans and the continents through theprocesses of evaporation, transpiration;condensation and precipitation.

Water vapour present in the air isknown as humidity. It is expressequantitatively in different ways. The actualamount of the water vapour present in theatmosphere is known as the absolutehumidity. It is the weight of water vapourper unit volume of air and is expressed interms of grams per cubic metre. The abilityof the air to hold water vapor dependsentirely on its temperature. The absolutehumidity differs from place to place on thesurface of the earth. The percentage ofmoisture present in the atmosphere ascompared to its full capacity at a giventemperature is known as the relativehumidity. With the change of air temperature,the capacity to retain moisture increases ordecreases and the relative humidity is alsoaffected. It is greater over the oceans and leastover the continents.The air containingmoisture to its full capacity at a giventemperature is said to be saturated. It meansthat the air at the given temperature Isincapable of holding any additional amountof moisture at that stage. The temperature atwhich saturation occurs in a given sample ofair is known as dew point.

Evaporation and Condensation

The amount of water vapour in theatmosphere is added or withdrawn due toevaporation and condensation respectively.Evaporation is a process by which water istransformed from liquid to gaseous state.Heat is the main cause for evaporation. Thetemperature at which the water startsevaporating is referred to as the latent heatof vapourisation.Increase in temperatureincreases water absorption and retentioncapacity of the given parcel of air. Similarly,if the moisture content is low, air has apotentiality of absorbing and retainingmoisture. Movement of air replaces thesaturated layer with the unsaturated layer.Hence, the greater the movement of air, thegreater is the evaporation.

The transformation of water vapour intowater is called condensation. Condensationis caused b the loss of heat. When moist air iscooled, it may reach a level when its capacityto hold water vapour ceases. Then, the excesswater vapour condenses into liquid form. Ifit directly condenses into solid form, it isknown as sublimation. In free air,condensation results from cooling aroundvery small particles termed as hygroscopiccondensation nuclei. Particles of dust, smokeand salt from the ocean are particularly goodnuclei because they absorb water.Condensation also takes place when the moistair comes in contact with some colder objectand it may also take place when thetemperature is close to the dew point.Condensation, therefore, depends upon theamount of cooling and the relative humidityof the air. Condensation is influenced by thevolume of air, temperature, pressure andhumidity.


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