Environment

Environment: to encircle or to surround

Definition

• Environment : As per Environment (protection) Act, 1986, environment includes all the physical and biological surroundings of an organism along with their interactions. Environment is thus defined as “the sum total of water ,air and land and the inter-relationships that exist among them and with the human beings and other living organisms and material.

Urban and Rural environment

• Urban environment : 1.Profound influence of human beings• - natural landscapes in cities have been

changed and modified by man-made artificial structures like multi –storeyed buildings ,commercial complexes ,factories , transportation networks and so on.

• -Urban air , water and soil are loaded with various types of chemicals and wastes .

• -Diversity of plants and animals is much less and compared rural environment .

• - Urban population is more dense and has greater energy demands.

Scope of environmental studies

• In the recent years , the scope of env. Studies has expended dramatically the world over.Several career options have emerged in this field that are broadly categorized as :

• 1.Research and development in env.• 2.Green advocacy• 3.Green marketing• 4.Green media• 5.Environment consultancy

Contd.

• 1.Research and development in env.: • a.) Skilled env. Scientists examine various problems in a scientific

way and carry out Rand D activities for developing cleaner technologies and promoting sustainable development.

• b.) Env. Mgmnt and env. engg,. Are emerging as new career opportunities for for env. protection and mgmnt.

• c.) Industries are finding it difficult to dispose off the wastes produced as the pollution control laws are becoming more stringent.

• d.) In order to avoid expensive litigation , companies are now trying to adopt green tecnologies , which would reduce pollution.

•

Contd.

• e.) Market for pollution control technology is increasing the world over.

• f.) Cleaning up of the wastes produced is another potential market . • It is estimated to be $ 100 billion dollars per year for all American

buisness.• Germany and Japan having more stringent laws for many years

hace gained more experience in reducing effluents.• g.) In India also the Pollution contril boards are seriously

implementing pollution control laws and insisting on upgradation of effluents to meet prescribed standards before they are discharged on land or into a water body . Many companies not complying with the orders have been closed or ordered to shift.

Contd.

• 2.Green advocacy : With increasing emphasis on implementing various Acts and Laws related to environment , need for environmental lawyers has emerged , who should be able to plead to the cases related to water and air pollution , forest , wildlife etc.

• 3. Green Marketing : While ensuring the quality of products with ISO mark, there is an increasing emphasis on marketing goods that are environment friendly . Such products have ecomark or ISO 14000 cetification .Environmental auditores and environmental managers would be in great demand in the coing years .

Contd.

• 4.Green Media : Environmental awareness can be spread amongst masses through mass media like television , radio, newspaper , magazines , hoardings , advertisements etc. for which environmentally educated persons are required.

• 5. Environment consultancy : Many non-government organizations (NGO’s ) , industries and government bodies are engaging environmental consultants for systematically studying and tackling env. Realted problems.

Unit-1Ecosystems

• Ecosystem : An ecosystem is a self-regulating group of biotic communities of species interacting with one another and with their non-living environment exchanging energy and matter.

• Ecology is defined as the study of ecosystems .

Ecology

• Ecology : The term ecology was coned by Earnst and Haeckel in 1869.It is derived from the Greek words Oikos –home +logos –study. So ecology deals with the study of organisms in their natural home interacting with their surroundings .

• The surrounding or environment consists of other living organisms (biotic) and physical (abiotic) components.

Concept of Ecosystem

• Natural habitat of various living entities : Forests , Grasslands , Oceans, Lakes, Rivers , Mountains, deserts and estuaries.

• They ,however, show wide variations in their structural composition and functions.

• The living entities in them exchange matter and energy through constant interaction with their surroundings.

Contd.

• Some common questions asked :

How do these different unites like a hot desert , a dense evergreen forest , the Antarctic Sea or a shallow pond differ in the type of their flora and fauna , how do they they derive their energy and nutrients to live together , how do they influence each other and regulate their stability are the questions that are answered by ecology.

Contd.

• An ecosystem :• 1.is an integrated unit consisting of interacting plants, animals and

microorganisms whose survival depends upon the maintenance and regulation of their biotic and abiotic structures and functions.

• 2.The ecosystem is thus , a unit or a system which is composed of a number of sub-units , that are all directly or indirectly linked with each other. They may be freely exchanging energy and matter from outside-an open ecosystem or may be isolated from outside –a closed ecosystem.

Ecosystem Characteristics :

• Despite the large variations in size , structure , compositions etc. , all ecosystems are characterized by certain basic structural and functional features which are common:

• 1. Biotic structure and 2.) Abiotic Structure • 1. Biotic Structure : • a.) The plants , animals and microorganisms present in an

ecosystem form the biotic component.• b.)These organisms have different nutritional behaviour and status

in the ecosystems and are accordingly known as the Producers and Consumers , based on how they get their food.

Contd. • 1.a.) Producers : Mainly green plants which can synthesize their food

themselves by making use of carbondioxide present in the air and water in the presence of sunlight by involving chlorophylll , the green pigment present in the leaves, through the process of photosynthesis. They are also as photo autotrophs .

• b.) There are some microorganisms also which can produce organic matter to some extent through oxidation of certain chemicals in the absence of sunlight. They are known as chemosynthetic organisms or chemo-autotrophs. For instance in the ocean depths , where there is no sunlight ,chemoautotrophs sulphur bacteria make use of the heat generated by the decay of radioactive elements present in the earth’s core and released in the ocean depths. They use this heat to convert dissolved hydrogen sulphide and carbon dioxide into organic compounds.

Contd.

• 2. Consumers : All organisms which get their organic food by feeding upon other organisms are called consumers , which are of the following types:

• 1.Herbivires (plant eaters): They feed directly on producers and hence also known as the primary consumers. For example rabbit , insect , man.

• 2. Carnivires : (meat eaters) : They feed on other consumers .If they feed on herbivores they are called secondary consumers (e.g. frog) and if they feed on other carnivores (snake , big fish etc.) they are known as tertiary carnivores /consumers .

Contd.

• 3. Omnivores: They feed on both plants and animals, e.g. humans,rat , fox, many birds .

• 4.Detritivores : They feed on the parts of dead organisms , wastes of living , their cast –offs and partially decomposed matter e.g. beetles , termites ,ants ,crabs , earthworms etc.

• 5.Decomposers : They derive their nutrition by breaking down the complex organic molecules into inorganic nutrients . Various fungi and bacteria are decomposers .

Contd.

• In all the ecosystems , this biotic structure prevails .However in some it is the primary producers which predominate (e.g. in forests , agroecosystems )while in others the dcomposers predominate (e.g. deep ocean)

• 2. Abiotic structure : The physical and chemical components of an ecosystem constitute its abiotic structure . It includes climatic factors , edaphic(soil factors) , geographical factors , energy , nutrients and toxic substances.

• a.) Physical factors• b.) Chemical factors

Contd.

• a.)Physical factors: The sunlight and shade , intensity of solar flux , duration of sub hours , average temperature ,maximum-minimum temp. , annual rainfall , wind , latitude and altitude , soil type , water availability , water currents etc. are some of the important physical features which have a strong influence on the ecosystm.

• Example : The striking differences in solar flux , teperarure and precipitation ?(rainfall , snow etc.) pattern in a desert ecosystem , in a tropical rainforest and in tundra ecosystem.

Contd.

• b.) Chemical factors: Availability of major essential nutrients like carbon , nitrogen , phosphorous , potassiu , hydrogen , oxygen and sulphur , level of toxic substances , salts, causing salinity and various organic substances present in the soil or water largely influence the functioning of the ecosystem.

• All the biotic components of an ecosystem are influenced by the abiotic components and vice versa , and they are linked together through energy flow matter cycling.

Functional attributes of an ecosystem :

Every ecosystem performs under natural conditions in a systematic way.

1.It receives energy from the sun and passes it on through various biotic and abiotic componenets and infact , all life depends upon this flow of energy .

2.Besides energy various nutrients and water are also required for life processes which are exchanged by the biotic components within themselves and with their abiotic componenet swithin or outside the ecosystem.

3.The biotic comp. also regulate themselves in a very systematic manner and show mechanisms to encounter some degree of env, stress.

Contd.

• Major functional attributes of ecosystem :• 1. Food chain , food webs and trophic structure• 2.Energy flow• 3. Cycling of nutrients (Biogeochemical cycles)• 4. Primary and secondary production• 5. Ecosystem development and regulation

Trophic structure

• The structure and functions of the ecosystems are very closely related and influence each other intimately:

• 1. The flow of energy and nutrients is mediated through a series of feeding relationships in a definite sequence or pattern which is known as the food chain.

• 2. The producers and consumers are arranged in the ecosystem in a definite manner and their interaction along with the population size are expressed as tropic structure.

• 3. Each food level is known as trophic level and the amount of living matter at each trophic level at a given time is known as standing crop or standing biomass.

•

Food chains

• The sequence of eating and being eaten in an ecosystem is known as food chain.

• All organisms , living poor dead , are potential food for some other organism and thus, there is essentially no waste in the functioning of a natural ecosystem . A caterpillar eats a plant leaf; a sparrow eats the caterpillar , a cat or a hawk eats the sparrow and when they all die , they are all consumed by micoorganisms like bacteria or fungi (decomposers) which break down the organic matter and convert it into simple inorganic substances that can gain be used by the plants –the primary producres.

Contd.

• Some common examples of simple food chains are:• 1.Grass------- Grasshopper---------- Frog--- Snake ----

Hawk(Grassland ecosystem)

• 2. Photoplanktons ---- Water fleas----- small fish----- Tuna (Pond ecosystem)

• 3. Lichens------- reindeer------- Man (Arctic Tundra)

Contd.

• 1.Each organism in the ecosystem is assigned a feeding level or trophic level depending upon its nutritional status.

• Thus in the grassland food chain , grasshopper occupies the 1st trophic level , frog the 2nd and snake and hawk occupy the 3rd and the 4th trophic levels , respectively . The decomposers consume the dead matterof all these trophic levels.

Two major types of food chains

• 1.Grazing food chains

• 2. Detritus food chains

Grazing food chain• It starts with green plants (primary producres) and culminates in the

carnivores . • Example : Grass - Rabbit--- Fox

Detritus food chains

• It starts with dead organic matter which the detritivores and decomposers consume. Partially decomposed dead organic matter and even decomposers are consumed by detritivores and their predators . An example of the detritus food chain is the mangrove (estuary)

• 1. Here , a large quantity of leaf material falls in the form of litter into the water.

• 2. The leaf fragmenst are eaten by saprotrophs .(saprotrophs are those organisms which feed on dead organic matter ).

Contd.

• 3.These fallen leaves are colonized by small algae , which are also consumed by the saprotrophs of detritivores consisting of crabs , mollusks , shrimps , insect larvae , nematodes and fishes. The detritivores are eaten by small carnivorous fishes , which in turn are eaten by large carnivorous fishes.

• Leaf- algae- crabs-- crabs--- small carnivorous fish (Mangrove ecosystem)

• Dead organic matter -- fungi-- bacteria (Forest ecosystem)

CONTD.

• Thus the grazing food chain derives it senergy basically from plant energy while in the detritus food chain it is obtained primarily from palnt biomass , secondarily from microbial biomass and tertiarily from carnivores .Both the food chains occur together in natural ecosystems , but grazing food chain usually predominates.

Food web

• Food chains in ecosystems are rarely found to operate as isolated linear sequences.Rather , they are found to be interconnected and usually form a complex network with several linkages and are known as food webs. Thus, food web is a network of food chains where different types of organisms are connected at different trophic levels , so that there are a number of options of eating and being eaten at each trophic level.

Why has nature evolved food webs in ecosystem :

1.Food webs give greater stability to the ecosystem.

2. In a linear food chain , if one species becomes extinct or one species suffers then the species in the subsequent trophic levels are also affected.

3. In a food web , on the other hand , there are a number of options available at each trophic level .So, if one of the species is affected , it does not affect other trophic levels so seriouslly.

Example of a simple food chain :

Cladonia-> Reindeer -> Man

Grass -> Caribou-> Wolf

Contd.

• If due to some stress, the population of reindeer or caribou falls, it will leave little option for man or wolf to eatr from the ecosystem . Had there been more biodiversity ,it would have led to complex food giving the ecosystem more stability.

Significance of food chains and food webs

• 1. The two important functions of energy flow and nutrient cycling take place through food chains and food webs.

• 2. The food chains also help in maintaining and regulating the population size of different size of different animals and thus, help maintain the ecological balance .

• 3. Food chains show a unique property of biological magnification of some chemicals. There are several pesticides , heavy metals and other chemicals which are non-biodegradable in nature. Such chemicals are not decomposed by microorganisms and they keep on passing from one trophic level to another. And , at each successive trophic level , they keep on increasing in concentration .This phenomenon is known as biomagnification or biological magnification.

Case study

• Biomagnification of DDT: A striking case of biomagnification of DDT (A broad range insecticide) was observed when some birds like Osprey were found to suffer a sharp decline in their population. The young ones of these birds were found to hatch out in premature condition leading to their death. This was later found to be due to bio-magnification of DDT through the food chain. DDT sprayed for pest control was in very low concentration, but its concentration increased along the food chain through phytoplanktons to Zooplanktons and then to fish which was eaten by the birds. The concentration of DDT was magnified several thousand times in the birds which caused thinning of the shelves in the birds’s egges , causing death of the young ones .

•

Contd.

• It becomes very clear from the above instance that the animals occupying the higher trophic levels are at a greater risk of Biomagnification of toxic chemicals .Human beings consuming milk, eggs, and meat are at a higher trophic level. So, we have to stop indiscriminate use of pestcides and heavy metals if we wish to save ourselves form their biologically magnified levels.

The Four Spheres of the Earth

• The area near the surface of the earth can be divided up into four inter-connected "geo-spheres:" the lithosphere, hydrosphere, biosphere, and atmosphere. Scientists can classify life and material on or near the surface of the earth to be in any of these four spheres.The names of the four spheres are derived from the Greek words for stone (litho), air (atmo), water (hydro), and life (bio).

Lithosphere

• The lithosphere is the solid, rocky crust covering entire planet. This crust is inorganic and is composed of minerals. It covers the entire surface of the earth from the top of Mount Everest to the bottom of the Mariana Trench.

Hydrosphere

• The hydrosphere is composed of all of the water on or near the earth. This includes the oceans, rivers, lakes, and even the moisture in the air. Ninety-seven percent of the earth's water is in the oceans. The remaining three percent is fresh water; three-quarters of the fresh water is solid and exists in ice sheets

Biosphere

• The biosphere is composed of all living organisms. Plants, animals, and one-celled organisms are all part of the biosphere. Most of the planet's life is found from three meters below the ground to thirty meters above it and in the top 200 meters of the oceans and seas.

Atmosphere

• The atmosphere is the body of air which surrounds our planet. Most of our atmosphere is located close to the earth's surface where it is most dense. The air of our planet is 79% nitrogen and just under 21% oxygen; the small amount remaining is composed of carbon dioxide and other gasses.

Contd.

• All four spheres can be and often are present in a single location. For example, a piece of soil will of course have mineral material from the lithosphere. Additionally, there will be elements of the hydrosphere present as moisture within the soil, the biosphere as insects and plants, and even the atmosphere as pockets of air between soil pieces.

Biosphere

• The term "biosphere" was coined by geologist Eduard Suess in 1875, which he defined as:

• "The place on Earth's surface where life dwells."

Contd.

• The biosphere is the global sum of all ecosystems. It can also be called the zone of life on Earth, a closed (apart from solar and cosmic radiation), and self-regulating system. From the broadest biophysiological point of view, the biosphere is the global ecologicalsystem integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, hydrosphere and atmosphere.

Contd.

• The biosphere is postulated to have evolved, beginning through a process of biogenesis or biopoesis, at least some 3.5 billion years ago.

Hydrosphere

• The hydrosphere is the liquid water component of the Earth. It includes the oceans, seas, lakes, ponds, rivers and streams. The hydrosphere covers about 70% of the surface of the Earth and is the home for many plants and animals.

Contd.

• 1.The hydrosphere, like the atmosphere, is always in motion.

• 2.The motion of rivers and streams can be easily seen, while the motion of the water within lakes and ponds is less obvious.

• 3.Some of the motion of the oceans and seas can be easily seen while the large scale motions that move water great distances such as between the tropics and poles or between continents are more difficult to see.

Contd.

• 4.These types of motions are in the form of currents that move the warm waters in the tropics toward the poles, and colder water from the polar regions toward the tropics. These currents exist on the surface of the ocean and at great depths in the ocean (up to about 4km).

Characteristics of the ocean affecting its motion:

• 1. Temperature

• 2. Salinity

Contd.

• 1.Warm water which is less dense or lighter tends to move up toward the surface ,while colder water is more dense or heavier and therefore tends to sink to the bottom.

• 2. Salty water is also more dense or heavier and thus tends to sink ,while fresh or less salty water is less or lighter and thus tends to rise to the surface.

Contd.

3.The oceans currents are also affected by the motion of the atmosphere, or winds, above it. The energy in the wind gets transferred to the ocean at the ocean surface affecting the motion of the water there. The effect of wind is largest at the ocean surface.

The two important purposes of the ocean:

• 1. It is a large reservoir of chemicals that can contribute to the greenhouse effect in the atmosphere and energy absorbing 90% of the solar radiation which hits the surface.

• 2. It works with the atmosphere to redistribute the energy received from the sun such that heat in the tropics is trnseferred to the poles where the heat is generally lost to the space.

Biodiversity

• Biodiversity refers to the variety and variability among all groups of living organisms and the ecosystem complexes in which they occur.

• A marvelous spectrum of life occurs in all forms, sizes ,colors and shapes in all types of ecosystems ranging from the dreist deserts to the dense tropical rainforests and from the high snow-clad mountain peaks to the deepest of the ocean trenches .

• Each form of life has its own unique ecological relationship with its surroundings.

Contd.

• In the convention of Biological Diversity (1992) , biodiversity has been defined as the variability among living organisms from all sources including terrestrial , marine and other aquatic ecosystems and the ecological complexes of which they are a part.

Levels of Biodiversity

• Units of Biodiversity may range from the genetic level within a species to the biota ( combined flora and fauna of a region) in a specific region and may extend up to a great diversity found in different biomes( a major regional or global community such as grasslands or deserts)

Genetic Diversity

• Genes are the basic units of hereditary information transmitted from one generation to other. When genes within the same species show different versions due to new combinations ,it is called genetic variability . For example , all rice varieties belong to the species Oryza Sativa , but there are thousands of wild and cultivated varieties which show variations at the genertic level and differ in their colour ,size , shape , aroma, and nutrient content of the grain. This is called the genetic diversity of rice.

Species diversity

• This is the variability found within the population of a species or between different species of a community .It represents broadly the species richness and their abundance in a community .

Number of species on this biosphere :

• The current estimates given by the Wilson 1992 put the total number of living species in a range of 10 million to 50 million.

• Till now only about 1.5 million living and 300,000 fossil species have been actually described and given scientific names. It is quite likely that a large fraction of these species may become extinct even before they are discovered and enlisted.

Ecosystem Diversity

• 1.is the ecological complexity showing variations in ecological niches , trophic structure , food-webs , nutrient cycling etc.

• 2. The ecosystems also show varaitions with respect to physical parameters like moisture , temperature ,altitude , precipitation etc.

• Thus , there occurs tremendous diversity within the ecosystem along these gradients

Contd.

• Example : Forest Ecosystem :• It mainly has the dominance of trees.

• But if one were to study tropical rainforest , a tropical deciduous forest , a temperate deciduous forest and a boreal forest , one would find a huge variation because of the physical factors involved.

Importance of Diversity

• 1.Developed over millions of years of evolution.• 2. Destruction of this diversity would lead to disruption in

the ecological balance.• 3. One kind of diversity cannot be replaced with

another .Example : Coniferous trees of the boreal forests cannot take up the function of the trees of tropical deciduous forests and vice –versa because the ecosystem diversity has evolved with respect to the prevailing environmental conditions with well regulated ecological balance.

Biogeographically classification of India

• 1.India has different types of climate and topography in different parts of the country and these variations have induced enormous variability in flora and fauna.

• 2. India has a rich heritage of biological diversity and occupies the tenth position among the plant rich nations of the world.

India’s major biographic habitats

• 1.Upper regions of the Trans Himalayan Zone - Important Flora and Fauna- Pine ,Deodar ;Wild sheep ,Yak, ,Tibetan Ass ,Snow Leopard Marmot ,Wolf, Black necked crane .

• 2. Himalyan Zone of North-west,west , Centarl and Eastern region :

• Flora and Fauna found: Pine, Corktree,Sal, Dhaak(Butea),Castor

• Wild Bear ,Sambar, Leopard ,Sikkim Stag, Musk Deer

Contd.

• 3. Semi arid zone of Central India –Gujarat –Rajwara :• Flora and Fauna found :Acacia ,Date ,Palm ,Peepal • Gir Lion, Tiger and Sariska and Ranthambhore (Tiger

reserves)• 4. Western Ghat Zone of Malabar coast ;western

ghat ;Mountain region: Sheesham ;Peepal, Tuna; Bahera; Tortoise ,Frog; Lizards ,Snakes

• 5. Desert Zone of Hutch ,Thar,Ladakh • Flora and Fauna found : Acacia ,Zizphus,Khejri ,Date

palm ,Bastard ,Wild ass,Desert ,Cat,Fox ,RAT

Contd.

• 6. Deccan Peninsula : Deccan plateau South-Central plateau , Eastern plateau ,Chhota Nagpur ,centarl Highlands

• Flora and Fauna found: Acacia ,Palaash, ,Tuan, Pine , Castor ,

• Sambar, Sloth bear ,Tiger ,Chhetal ,Four –horned stag , Wild elephant ,wild buffalo

• 7. Gangetic plain: upper gangetic plain;Lower ganegtic plain:

• Flora and Fauna found: Sal,Acacia , Jamun, Mango , Bael

Contd.

• Black chinkara ,Stag, Rhinoceros, Gazzel ,Alligator, Turtle

• 8. North East India Zone of Bramaputra VALLEY ;North –Eastern Hills : Bamboo ,Sal, Jack fruit, Tuna, Chestnut ,Castor,

• Elephant ,Rhinoceros ,Yak ,Deer ,Porcupine

• 9. Islands :Andaman Islands ;Niocorbar Islands ;Lakshadweep Islands

Contd.

• Flora and Fauna found : Bahera,Harar ,Jack fruit, Cardamom, Coconut, Cloves , Dolphin, Alligator ,Molluscs

• 10. Coasts : West coast and East coast : Cocunut ,Banana ,Cashew nut

• Dugong,Dolphin ,Turtle ,Alligator,Molluscs.

Value of Biodiversity

• 1.Consumptive use value • 2. Productive use value • 3. Social value • 4. Ethical value • 5. Aesthetic value • 6. Option values • 7.Ecosystem service value

Value of Biodiversity • The value of Biodiversity in terms of its commercial utility , ecological services ,social and aesthetic value in enormous.• The multiple uses of Biodiversity :• (1.) Consumptive use or value: These are direct use values where the biodiversity product can be harvested and consumed directly e.g. fuel, food ,drugs, fibre

etc.• b.) Food : A large number of wildplants are consumed by human beings . • Edible plant species reported from the wild : 80,000.• 90% of the present day food crops have been domesticted from wild tropical plants.

•

Contd.

• Our agricultural scientists make use of the existing wild species of plants that are closely related to our crop plants for developing new hardy strains. Wild relatives usualy possess better tolerance and hardiness.

• A large number of wild animals are also our sources of food.• 2. Drugs and medicine : About 75% of the world’s population

depends upon plants or plant extracts for medicines.The wonder drug Pencillin used as an antibiotic is derived from a fungus called Pencillium.

• Tetracylin is obtained from a bacterium• Quinine is obtained from the bark of Cinchona tree• Digitalin is obtained from foxglove(a cure of heart ailments)

Contd.

• Vinblastin and Vincristine , two anti-cancer drugs have been obtained from Periwinkle(catharanthus)plant (it possesses anti-cancer alkaloids)

• A large number of marine animals are supposed to possess anti-cancer properties which are supposed to be explored systematically.

• Fuel: Our forests have been used since ages for fuel wood. The fossil fuels coal, petroleum and natural gas are also products of fossilized biodiversity. Firewood collected by individuals are not normally marketed , but are directly consumed by tribals and local vilagers , hence falls under consumptive value.

Contd.

• (2.) Productive use values: These are the commercially usable values where the product is marketed and sold. It may include lumber or wild gene resources that can be traded for use by scientists for introducing desirable traits in the crops and domesticated animals.

• Examples: Animal products like tusks of elephants, musk from musk deer, ,silk from silk-worm, wool from sheep , fur of many animals, lac from lac insects etc., all of which are traded in the market.

• Indsutries dependent upon the productive use values of biodiversity e.g., -the paper and pulp industry , plywood industry , railway, sleeper industry , silk industry, textile industry , ivory-works, leather industry, pearl industry etc.

Contd.

• Note : Despite international ban on trade in products from endangered species , smuggling of fur, hide , horns, live specimen etc. worth millins of dollars are being sold every year .

• Developing countries in Asia ,Africa, and latin America are the richest biodiversity centers and wildlife products are smuggled and marketed in large quantities to some rich westerbn countries and also to China and Hong Kong where export of cat skin and snake is booming buisness.

Contd.

• (3.) Social value : These are the values associated with the social life , customs , religion and psycho-spiritual aspects of the people .Many of the plants are considered holy and sacred in our country.

• Plants considered sacred: Tulsi(holy basil), Peepal, Mango, Lotus, Bael etc.

• The tribal people are very closely linked with the wildlife in the forests. Their social life , songs, dances and customs are closely linked woven around the wildlife.

• Many animals like cow, snake, bull , peacock, owl etc. also have a significant place in our psycho –spiritual arena and thus hold special social importance .

Ethical value

• 4.Ethical value : It is also known as existence value . It involves ethical issues like “all life must be preserved”. It is based on the concept of “live and let live” . If we want our human race to survive , then we must protect all biodiversity , because biodiversity is valuable.

• We are not deriving anything directly from kangaroo ir giraffe , but we all strongly feel that these species should exist in nature . This means that there is an ethical value or existence value attached to each species.

Aesthetic value

• 5.Aesthetic value : None of us would like to visit vast stretches of barren lands with no signs of visible life. People from far and wide spend a lot of time and money to visit wilderness areas where they can enjoy the aesthetic value of biodiversity and this type of tourism is known as “Eco-tourism”. The “willingness to pay” concept on such eco-tourism gives us even a monetary estimate for aesthetic value of biodiversity. Ecotourism is expected to genrate about 12 billion dollars of revenue annually , that roughly gives the aesthetic value of biodiversity.

Option Values

• 6. Option values: These values include the potentials of biodiversity that are presently unknown and need to be explored. There is a possibility that we may be able to find a cure for AIDS or cancer existing within the depths of a marine ecosystem , or a tropical rainforest.

• Thus option value is the value of knowing that there are biological resources existing on this biosphere that may one day prove to be an effective option for something important in future .

• Going by this line of thinking any species may prove to be a miracle species one day.

Ecosystem service value

• 7. Recently a non-consumptive use of value related to self –maintenance of the ecosystem and various important ecosystem services has been recognized . This refers to the services provided by the ecosystem like prevention of soil erosion , prevention of floods , maintenance of soil fertility ,cycling of nutrients , fixation of nitrogen , cycling of water , their role as carbon sinks , pollutant absorption and reduction of threat of global warming etc.

Contd.

• All the categories of Biodiversity value clearly indicate that ecosystem , species and genetic diversity have enormous potential value and a decline in biodiversity will lead to huge economic , ecological and socio-cultural losses.

Global Biodiversity

• 1. 1992 “Earth Summit” at Rio de Janerio revealed that there was a growing need to know and scientifically name the huge number of species which are still unknown on this earth.

• 2. Roughly 1.5 million species are known till date which is perhaps 15% or may be just 2% of the actual number.

• 3.Tropical deforestation alone is reducing the biodiversity by half a percent every year. Mapping the Biodiversity has, therefore, been recognized as an emergency task in order to plan its conservation and practical utilization in a judicious manner.

Terrestrial Biodiversity

• Terrestrial Biodiversity of the earth is best described as biomes, which are the largest ecological units present in different geographic areas and are named after the dominant vegetation e.g. the tropical rainforests , tall grass prairies ,savannas , tundra etc.

•

Contd.

• Inhabitants of the tropical rainforests: Millions of species of plants , birds, amphibians , insects as well as mammals.

• Many of these species have developed over the time in highly specialized niches and that makes them more vulnerable to extinction when their natural home or niche is destroyed.

• About 50-80% of global biodiversity lies in these rainforests . More than one-fourth of the world’s prescription drugs are extracted from plants growing in tropical rainforests.

Contd.

• Out of the 3000 plants identified by National Cancer research Institute as sources of cancer fighting chemicals , 70% come from tropical rain forests.

• Extracts from the creeping vines in the rainforests at Cameroon have proved effective in the inhibition of ;This has now gained popularity even in the western countries.

•

Protecting Biodiversity

• The silent valley in Kerela is the only place in India where tropical rain forests occur. There was abandoned mainly because it had put to risk our only tropical rain forest biodiversity .

Biological Diversity at national level:

• Every country is characterized by it sown biodiverity depending mainly upon its climate. India has a rich biological diversity of flora and fauna. Overall six percent of the global species are found in India .It is estimated that India ranks 10th among the plant rich countries of the world , 11th in terms of number of endemic species of higher vertebrates and 6th among the centers of diversity and origin of agricultural crops.

Contd.

• 1.The total number of living species identified in our country is 1,50,000 .

• 2.Out of a total of 25 Biodiversity hot-spots in the world , India possesses two, one in the north –east region(eastern Himalayas) and one in the western ghats.

• 3.India is also one of the 12 mega-biodiversity countries in the world.

India as a Mega –Diversity Nation

• 1. India is one of the 12 mega-diversity countries in the world .• The Ministry of Environment and Forests ,Government of India

(2000) records 47,000 species of plants and 81,000 species of animals which is about 7% and 6.5 % respectively of the global flora and fauna.

Contd.

• 1. Endemism: Species which are restricted to only to a particular area are known as endemic . India shows a good number of endemic species .About 62% of the amphibians and 50/5 of lizards are endemic to India .Western Ghats are the site of maximum endemism.

• 2.Center of origin: A large number of species are known to have originated in India .Nearly 5,000 species of flowering plants ahd their origin in India.

• Agro-Diversity point of view:- center of origin of 166 species of crop plants and 320 species of wild relatives of cultivated crops , thereby providing a broad spectrum of traits for our crop plants.

Contd.

• Marine Diversity : 1.) Along 7500 km long coastline of our country in the mangroves , estuaries , coral reefs , backwaters tec. There axists rich biodiversity. More than 340 species of the corals of the world are found here .

• The marine diversity is rich in mollusks , crustaceans (crabs etc.) , polychates( a type of worm) and corals. Several species of mangrove plants and seagrasses (Marine algae are also found in our country.

• A large proportion of the Indian biodiversity is still unexplored .There are about 93 major wet lands , coral reefs and mangroves which need to be studied in detail.

Contd.

• Indian forests cover 64.1 million hectares having a rich biodiversity of plants in then Trans-Himalayan forests, western ghats, coasts, deserts, gangetic plains, deccan plateau and the Andaman ,Nicobar and Lakshdweep islands. Due to very diverse climatic conditions there is a complete rainbow spectrum of biodiversity in our country.

Hotspots of Biodiversity

• Areas which exhibit high species richness as well as high species endemism are termed as hot spots of Biodiversity.

• There are 25 such hotspots of biodiversity on a global level out of which two are present in India , namely the Eastern Himalayas and Western Ghats.

Threats to Biodiversity

• 1. Extinction • 2.Loss of habitat• 3.Poaching • 4. Man-Wildlife conflicts

Contd.

• 1.Extinction: is a natural process of evolution .

• The process of extinction has become particularly fast in the recent years of human civilization.

• 2. Loss of habitat : Destruction and loss of natural habitat is the single largest cause of biodiversity loss. Billions of hectares of forests and grasslands have been cleared over the past 10,000 years for conversion into agricultural lands, pastures, settlement areas or development projects. Severe damage has been caused to wetlands thinking them to be useless ecosystems.

Contd.

• Poaching : Illegal trade of wildlife products by killing prohibited endangered animals i.e. poaching is another threat to wildlife .Despite international ban on trade in products from endangered species , smuggling of wildlife items like furs , hides , tusks , live specimens and herbal products worth millions of dollars per year continues. The developing nations in Asia ,Latin America and Africa are the richest sources of biodiversity and have enormous wealth of wildlife. The rich countries in Europe and North America and some affluent countries in Asia like Japan ,Taiwan and Hong Kong are the major importers of the wildlife products or Wildlife itself.

Contd.

• 1. The trading of such wildlife products is highly profit making for the poachers who just hunt these prohibited wildlife and smuggle it to other countries mediated through a mafia.

• THE COST OF ELEPHANT TUSKS : Upto $ 100 per kg.• THE COST OF ALEOPARD FUR COAT : $ 100,000 IN Japan• BIRD CATCHERS CAN FETCH UPTO $10,000 FOR A ARE

HYACINTH MACOW (a beautiful bird from Brazil)

Contd.

• 3. Man-Wildlife Conflicts : Sometimes wildlife causes immense damage and danger to man and under such conditions it becomes very difficult for the forest department to pacify the affected villagers and gain local support for wildlife.

• Instances of man-animal conflicts : • 1. In Sambalpur , Orissa 195 humans were killed in the alst 5 years

by elephants.In retaliation the villagers killed 98 elephants and badly injured 30 elephants .

• 2. Several instances of killing of elephants in the border regions of Kote –Chamarajanagar belt in Mysore have been reported.

Contd.

• The man-elephant conflict in this region arose because of the massive damage done by the elephants to the farmer’s cotton and sugarcane crops. The agonized villagers electrocute the elephants and sometimes hide explosives in the sugarcane fields to frighetn them away.

Contd.

• More killings are done by locals than by poachers. • In 2004 a man –eating Tiger was reported to kill 16 Nepalese

people and one 4-year old child inside the Royal Chitwan Nationla park , 240 km south west of Kathmandu.

• The park renowned for its wildlife conservation effort has become a zone of terror for the locals.

Causes of man-animal conflicts

• 1. Dwindling habitats of tigers , elephants , rhinos and bears due to shrinking forest cover compels them to move outside the forest and attack the field or sometimes even humans.

• 2.Human encroachment into the forest areas raises a conflict between man and wildlife , perhaps because it is an issue of survival for both.

• 3. Usually the ill , weak and injured animals have a tendency to attack man .Also, the female tigress attacks the humans if she feels that her new born cubs are in danger.

• But once the human flesh is tasted , the tiger does not eat any other animal.

Contd.

• 4.Very often the villagers put electric wiring around the their ripe crop fields.The elephants get injured and turn violent .

• 5. The cash compenastion paid by the governmnet in lieu of the damage caused to the farmers’ crop is inadequate . In Mysore a farmer gets a compensation of Rs.400/- per quintal of expected yield while the market price is Rs. 2,400/- per quintal .The agonized farmer therefore gets revengeful and kills the wild animals.

Remedial measures to curb the conflict

• 1. Tiger conservation project has made provisions for making available vehicles , tranquilizer guns, binoculars and radio sets etc. to tactfully deal with any imminen et danger.

• 2. Adequate compensation and cattle compensation scehme must be started , along with substantial cash compensation for loss of human life.

• 3.Solar powered fencing should be provided alongwith electric current proof trenches to prevent the animals from straying into fields.

Contd.

• 4. Cropping pattern should be changed near the forest borders and adequate fodder , fruit and water should be made avalible for the elephants within the forest zone.

• 5. Wildlife corridors should be provided for mass migration of big animals during unfavorable periods. About 300 km area is required for elephant corridors for their seasonal migration.

• 6.In Similipal Sanctuary , Orissa there is a ritual of wildlife animal hunting during months of April- May for which forest is burnt to flush out the animals. Due to the massive hunting by people , there is a decline in prey of tigers and they start coming out of the forest in search of prey .Now there is WWF-TCP initiative to curb this ritual of “Akhand Shikar” in Orissa.

Conservation of Biodiversity

• Gradually we are coming to realize that wildlife is not just “a game to be hunted”, rather a “gift of nature” to be nurtured and enjoyed.

• A number of measures are being taken the world over to conserve the Biodiversity including plants and wildlife.

• Two approaches to biodiversity conservation:

• 1. In situ conservation (within habitat) :This sis achieved by protection of wild flora and fauna in nature iteself e.g. Biosphere Reserves, National PARKS ,Sanctuaries, Reserve Forests etc.

Contd.

• 2. Ex situ conservation (outside habitats ) :This is done by establishment of gene banks , seed banks , zoos , bootanical gardens , culture collections.

In situ conservation

• At present we have 7 major Biosphere reserves , 80 National parks , 420 wildlife sanctuaries and 120 Botanical gardens in our country covering 4% of the geographic area.

The Biosphere Reserves

• The biosphere reserves conserve some representative ecosystems as a whole for long-term in situ conservation. In India we have :

• Nanda Devi (U.P) , Nokrek(Meghalya) , Manas (Assam) , Sunderbans(west Bengal) , Gulf of Mannar (Tamil Nadu), Nilgiri (Karnataka, Kerela, Tamil Nadu), Great Nicobars and Similipal (Orissa) biosphere reserves .

• Within the Biosphere reserves we may have one or more National Parks .For example , Nilgiri Biosphere reserve has two National Parks viz., Bandipur and Nagarhole National park.

Contd.

• A national park is an area dedicated for the conservation of wildlife alongwith its environment .It is alos meant for enjoyment through tourism but without imapring the env.

• Grazing of domestic animals , all private rights and forestry activities are prohibited within a NATIONAL Park .Each National park usually aims at conservation specifically of some particular species of wildlife along with others.

Contd.

• Some major National parks of our country are as follows:• 1. Kaziranga : Assam• 2. Gir national park : Gujarat• 3. Dachigam : Jand K • 4. Bandipur : Karnataka• 5. Periyar : Kerala• 6. Kanha: M.P.• 7. Corbett :Uttarakhand• 8. Dudwa :U.P• 9. Ranthambhore :Rajasthan• 10.Sariska : Rajasthan

Wildlife sanctuaries

• Wildlife sanctuaries are also protected areas where killing , hunting ,shooting or capturing of wildlife is prohibited except under the control of highest authority. However, private ownership rights are permissible and forestry operations are also permitted to an extent that they do not affect the wildlife adversely.

Contd.

• Some important wildlife sanctuaries in India :• 1.Ghana Bird sanctuary :rajasthan• 2. Hazaribagh Sanctuary :Bihar• 3. Sultanpur Bird Sanctuary :Haryana• 4. Nal Sarovar

Contd.

• Some important wildlife sanctuaries in India :• 1.Ghana Bird sanctuary :rajasthan• 2. Hazaribagh Sanctuary :Bihar• 3. Sultanpur Bird Sanctuary :Haryana• 4. Nal Sarovar ; Gujarat• 5. Abohar Wildlife Sanctuary :Punjab• 6. Mudamalai Wildlife Sanctuary :Tamil Nadu• 7. Jaldapara Wildlife Sanctuary :W.Bengal• 8. Wild Ass Sanctuary :Gujarat

Plant Sanctuary

• For plants there is one gene sanctuary for citrus (Lemon family)• And one for pitcher plant (an insect eating plant) in Northeast Indai.

Conservation contd.

• Projects to protect and conserve wildlife :• 1. Project tiger • 2. Gir Lion project• 3. Crocodile Breeding project • 4.Project elephant• 5. Snow leopard project

Ex situ conservation

• This type of conservation is mainly done for conservation of crop varieties , the wild relatives of crops and all the local varieties with the main objective of conserving the total genetic variability of the crop species for future crop improvement or afforestation programmes. In India , we have the following important gene bank /seed bank facilities :

• 1.National Bureau of plant Genetic Resources :new Delhi • 2. National Bureau of Animal Genetic Resources :Karnal,Haryana• 3. National Facility for plant tissue culture repository • The G-15 countries have also resolved to set up a network of gene

banks to facilitate the conservation of various varieties of aromatic and medicinal plants for which India is the networking co-ordinator country.

Sustainable development

• Sustainable development underscores that rate of consumption or use of natural resources should approximate the rate at which these resources can be substituted or replaced. It further requires that a nation or society is able to satisfy its requirements –social , economic and others –without jeopardizing the interest of the future generations.

• Sustainable development is defined as “meeting the needs of the present without compromising the ability of the future generations to meet their own needs.”

Contd.

• To test whether or not a proposal will achieve the goals of sustainability ,one must find out whether :

• 1. it protects our Biodiversity• 2. it prevents soil erosion• 3. it slows down population growth• 4. it increases forest cover• 5. it cuts off the emissions of CFC,SO,NO AND CO2• 6.it reduces waste generation • 7.it brings benefit to all

Sate of development uptil now:

• 1. Development has just been human oriented , that too for a few rich nations.

• 2. Developments in the field of science and technology have enhanced the levels of pollution to an unprecedented degree’

• Eg. Contaminated water• Polluted air• Adulterated food

• This is an example of unsustainable development which will lead to a total collapse of the interrelated systems of this earth.

Contd.

• 1.Fears about such unsustainable growth and development started in 1970’s . But a clear discussion on sustainable development emerged on an international level in 1992 , in the UN conference on Envronment and Development (UNCED) , popularly known as the “Earth summit” , held at Rio De Janeiro ,Brazil .

• Out of its five significant agreements Agenda 21 proposes a global programme of action on sustainable development in social , economic and political context for the 21st century.

Contd.

• Measures for sustainable development:• 1. Inter-generational equity• 2.Intra-generational equity

Contd.

• The essence of the declaration :• “ a new and equitable global partnership through the creation of new

levels cooperation among states………

Contd.

• 1. Inter-generational equity: This emphasizes that we shou7ld minimize any adverse impacts on our resources and environment for future generations i.e. we should hand over a safe , healthy and resourceful environment to our future generations .This can be possible only if we stop over-exploitation of resources , reduce waste discharge and emissions and maintain ecological balance.

Intra-generational equity

• This emphasizes that the development processes should seek to minimize the wealth gaps within and between nations. The Human Development Report of United Nations (2001) emphasizes that benefits of technology should seek to achieve the goals of intr-generational equity. The technology should address the problems of the developing countries, producing drought tolerant varieties for uncertain climates ,vaccines for infectious diseases , clean fuesl for domestic and industrail use .This type of tecnological development will support the economic growth of the ppor countries and help in narrowing the wealth gap and lead to sustainability.

Measures for Sustainable development

Using appropriate technology:

1. One which is locally adaptable , eco-friendly , resource efficient and culturally suitable.

2. It mostly involves lo\cal resources and local labour .

3. Indigenous technologies are more useful ,cost –effective and sustainable. Nature is often taken as a model ,using the natural conditions of that region as its components .This concept is known as “ design with nature”.

The technology should use less of resources and shold produce minimum waste.

Contd.

• 1.Reduce ,Reuse ,recycle approach• 2. Prompting environmental education and awareness• 3. Resource utilization as per carrying capacity : any system can

sustain a limited number of organisms on a long-term basis which is known as its carrying capacity. For this one must stop the over exploitation of resources.

• Carrying capacity has two basic components :• 1.Supporting capacity i.e. the capacity to regenerate • 2.Assimilative capacity : i.e. the capacity to tolerate different

stresses

Stockholm Conference on Env. ,1972

• The United Nations Conference on the Human Environment, having met at Stockholm from 5 to 16 June 1972,having considered the need for a common outlook and for common principles to inspire and guide the peoples of the world in the preservation and enhancement of the human environment,

• Proclaims that:• 1. Humans have the fundamental right to freedom , equlaity and

adequate conditions of life in an environment of equality that permits a life of dignity and well-being.

• 2. Human beings have responsibility to protect and improve the environment for the present and future generations.

Contd.

• The following two strategies emerged in this conference :• 1. The principles and action plan were evolved for controlling and

regulating human environment

• 2. Institutional and financial arrangements were proposed for achieving the goal for regulating human environment . This has been called the Magna Carta on environment.

•

Contd.

• The Conference calls upon Governments and peoples to exert common efforts for the preservation and improvement of the human environment, for the benefit of all the people and for their posterity.

Principles

• 1.Man has the fundamental right to freedom, equality and adequate conditions of life, in an environment of a quality that permits a life of dignity and well-being, and he bears a solemn responsibility to protect and improve the environment for present and future generations. In this respect, policies promoting or perpetuating apartheid, racial segregation, discrimination, colonial and other forms of oppression and foreign domination stand condemned and must be eliminated.

Contd.

• 2. The natural resources of the earth, including the air, water, land, flora and fauna and especially representative samples of natural ecosystems, must be safeguarded for the benefit of present and future generations through careful planning or management, as appropriate.

Contd.

• 3. The capacity of the earth to produce vital renewable resources must be maintained and, wherever practicable, restored or improved.

Contd.

• 4.Man has a special responsibility to safeguard and wisely manage the heritage of wildlife and its habitat, which are now gravely imperilled by a combination of adverse factors. Nature conservation, including wildlife, must therefore receive importance in planning for economic development.

Contd.

• 5. The non-renewable resources of the earth must be employed in such a way as to guard against the danger of their future exhaustion and to ensure that benefits from such employment are shared by all mankind.

Contd.

• 6. The discharge of toxic substances or of other substances and the release of heat, in such quantities or concentrations as to exceed the capacity of the environment to render them harmless, must be halted in order to ensure that serious or irreversible damage is not inflicted upon ecosystems. The just struggle of the peoples of ill countries against pollution should be supported.

Contd.

• 7. States shall take all possible steps to prevent pollution of the seas by substances that are liable to create hazards to human health, to harm living resources and marine life, to damage amenities or to interfere with other legitimate uses of the sea.

Contd.

• 8. Economic and social development is essential for ensuring a favorable living and working environment for man and for creating conditions on earth that are necessary for the improvement of the quality of life.

Contd.

• 9. Environmental deficiencies generated by the conditions of under-development and natural disasters pose grave problems and can best be remedied by accelerated development through the transfer of substantial quantities of financial and technological assistance as a supplement to the domestic effort of the developing countries and such timely assistance as may be required.

Contd.

• 10. For the developing countries, stability of prices and adequate earnings for primary commodities and raw materials are essential to environmental management, since economic factors as well as ecological processes must be taken into account.

Contd.

• 11. The environmental policies of all States should enhance and not adversely affect the present or future development potential of developing countries, nor should they hamper the attainment

• of better living conditions for all, and appropriate steps should be taken by States and international organizations with a view to reaching agreement on meeting the possible national and international economic consequences resulting from the application of environmental measures.

Contd.

• 12. Resources should be made available to preserve and improve the environment, taking into account the circumstances and particular requirements of developing countries and any costs which may emanate- from their incorporating environmental safeguards into their development planning and the need for making available to them, upon their request, additional international technical and financial assistance for this purpose

Contd.

• 13. In order to achieve a more rational management of resources and thus to improve the environment, States should adopt an integrated and coordinated approach to their development planning so as to ensure that development is compatible with the need to protect and improve environment for the benefit of their population.

Contd.

• 14. Rational planning constitutes an essential tool for reconciling any conflict between the needs of development and the need to protect and improve the environment.

Contd.

• 15. Planning must be applied to human settlements and urbanization with a view to avoiding adverse effects on the environment and obtaining maximum social, economic and environmental benefits for all. In this respect projects which arc designed for colonialist and racist domination must be abandoned.

Contd.

• 16. Demographic policies which are without prejudice to basic human rights and which are deemed appropriate by Governments concerned should be applied in those regions where the rate of population growth or excessive population concentrations are likely to have adverse effects on the environment of the human environment and impede development.

Contd.

• 17. Appropriate national institutions must be entrusted with the task of planning, managing or controlling the 9 environmental resources of States with a view to enhancing environmental quality.

Contd.

• 18.Science and technology, as part of their contribution to economic and social development, must be applied to the identification, avoidance and control of environmental risks and the solution of environmental problems and for the common good of mankind.

Contd.

• 19.Education in environmental matters, for the younger generation as well as adults, giving due consideration to the underprivileged, is essential in order to broaden the basis for an enlightened opinion and responsible conduct by individuals, enterprises and communities in protecting and improving the environment in its full human dimension. It is also essential that mass media of communications avoid contributing to the deterioration of the environment, but, on the contrary, disseminates information of an educational nature on the need to project and improve the environment in order to enable mal to develop in every respect.

Contd.

• 20. Scientific research and development in the context of environmental problems, both national and multinational, must be promoted in all countries, especially the developing countries. In this connection, the free flow of up-to-date scientific information and transfer of experience must be supported and assisted, to facilitate the solution of environmental problems; environmental technologies should be made available to developing countries on terms which would encourage their wide dissemination without constituting an economic burden on the developing countries.

Contd.

• 21. States have, in accordance with the Charter of the United Nations and the principles of international law, the sovereign right to exploit their own resources pursuant to their own environmental policies, and the responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment of other States or of areas beyond the limits of national jurisdiction.

Contd.

• 22. States shall cooperate to develop further the international law regarding liability and compensation for the victims of pollution and other environmental damage caused by activities within the jurisdiction or control of such States to areas beyond their jurisdiction.

Contd.

• 23.Without prejudice to such criteria as may be agreed upon by the international community, or to standards which will have to be determined nationally, it will be essential in all cases to consider the systems of values prevailing in each country, and the extent of the applicability of standards which are valid for the most advanced countries but which may be inappropriate and of unwarranted social cost for the developing countries.

Contd.

• 24. International matters concerning the protection and improvement of the environment should be handled in a cooperative spirit by all countries, big and small, on an equal footing.

• Cooperation through multilateral or bilateral arrangements or other appropriate means is essential to effectively control, prevent, reduce and eliminate adverse environmental effects resulting from activities conducted in all spheres, in such a way that due account is taken of the sovereignty and interests of all States.

Contd.

• 25. States shall ensure that international organizations play a coordinated, efficient and dynamic role for the protection and improvement of the environment.

• 26. Man and his environment must be spared the effects of nuclear weapons and all other means of mass destruction. States must strive to reach prompt agreement, in the relevant international organs, on the elimination and complete destruction of such weapons.

Emergence of env. issues

1.Climate change — Global warming • Global dimming • Fossil fuels • Sea levelrise • Greenhouse gas• Oceanacidification• Shutdown of thermohaline circulation • Environment impact of the coal industry• Urban Heat Islands

2. Conservation — Species extinction • Pollinator decline • Coral bleaching • Holocene extinction • Invasive species • Poaching • Endangered species

Contd.

• 3. Energy — Energy conservation • Renewable energy • Efficient energy use • Renewable energy commercialization • Environmental impact of the coal industry • Environmental impact of hydrauli fracturing

• 4. Environmental degradation — Eutrophication • Habitat destruction • Invasive species

• 5. Environmental health — Air quality • Asthma• Environmental impact of the coal industry • Electromagnetic fields • Electromagnetic radiation and health • Indoor air quality • Lead poisoning • Sic Building Syndrome • Environmental impac of hydraulic fracturing

Contd.

6.Genetic engineering — Genetic pollution • Genetically modified food controversies

7. Intensive farming — Overgrazing • Irrigation • Monoculture • Environmental effects of meat production • Slash and burn • Pesticide drift• Plasticulture

8. Land degradation — Land pollution • Desertification

9. Soil — Soil conservation • Soil erosion• Soil contamination • Soil salination

10. Land use — Urban sprawl • Habitat fragmentation • Habitat destruction

11. Nanotechnology— Nanotoxicology • Nanopollution

Contd.

• 12. Nuclear issues — Nuclear fallout • Nuclear meltdown • Nuclear power• Nuclear weapons • Nuclear and radiation accidents • Nuclear safety • High-level radioactive waste management

• 13. Overpopulation — Burial• Water crisis• Overpopulation in companion animals • Tragedy of the commons • Gender Imbalance in Developing Countries • Sub-replacement fertility levels in developed countries

• 14. Ozone depletion — CFC • Biological effects of UV exposure• 15. Pollution — Environmental impact of the coal industry • Nonpoint

source pollution • Point source pollution • Light pollution • Noise pollution • Visual pollution

Contd.

• 16. Water pollution — Environmental impact of the coal industry • Acid rain • Eutrophication • Marine pollution • Ocean dumping • Oil spills • Thermal pollution • Urban runoff • Water crisis • Marine debris • Microplastics • Ocean acidification • Ship pollution • Wastewater • Fish kill • Algal bloom • Mercury in fish • Environmental impact of hydraulic fracturing.

• 17. Air pollution — Environmental impact of the coal industry • Smog • Tropospheric ozone• Indoor air quality • Volatile organic compound • Atmospheric particulate matter• Environmental impact of hydraulic fracturing

Contd.

• 18. Reservoirs — Environmental impacts of reservoirs

• 19. Resource depletion — Exploitation of natural resources • Overdrafting

• 20. Consumerism — Consumer capitalism • Planned obsolescence • Over-consumption

• 21. Fishing — Blast fishing • Bottom trawling • Cyanide fishing • Ghost nets • Illegal, unreported and unregulated fishing • Overfishing • Shark finning • Whaling

• 22. Logging — Clearcutting • Deforestation • Illegal logging

Contd.

• 23. Mining — Acid mine drainage • Environmental impact of hydraulic fracturing • Mountaintop removal mining • Slurry impoundments

• 24. Toxins — Chlorofluorocarbons • DDT • Endocrine disruptors • Dioxin • Toxic heavy metals • Environmental impact of the coal industry • Herbicides • Pesticides • Toxic waste • PCB • Bioaccumulation • Biomagnification• Environmental impact of hydraulic fracturing

• 25. Waste — Electronic waste • Litter • Waste disposal incidents • Marine debris • Medical waste • Landfill• Leachate • Environmental impact of the coal industry • Incineration • Great Pacific Garbage Patch • Exporting of hazardous waste• Environmental impact of hydraulic fracturing

International Protocols

• 1. General Assembly’s Resolution of December ,1972• 2.Charter of Economic rights and duties of states ,1974• 3. UN-Habitat conference in human settlement of 1976 ,World water

conference of 1977 and other conferences • 4.Environmental Education conference • 5.World commission on environment and development• 6. Earth Summit 1992• 7.Earth Summit +5• 8.Earth Summit 2002 –Johannesburg Summit

1.General Assembly’s Resolution of Dec’1972

• 1.Stockholm conference was followed by the United Nation’s General Assembly resolution on Dec 15 ,1972 emphasizing the need of active cooperation among the states in the sphere of human environment.

• 2.The resolution designated June 5 as the World Env. Day and urged governments and organisations in the United Nations system to undertake on that day every year worldwide activities reaffirming their concern for the protection of environment.

• 3.Another resolution was passed which provided for institutional and financial arrangements for international cooperation for environment.

• 4.Amongs other decisions , provisions were made for establishing a Governing Council for Environmental Secretariat and Environment Fund .The Governing Council formulated long-term and short-term plans for the protection of env. Particularly realting to development.

Contd.

• 5.Following the Stockholm Conference many governments all over the world began establishing departments and agencies of environments and ministries of environments .

• 6.The developing countries started setting up agencies or ministries for the purpose expressing an equal concern about their aspirations for economic development and wanted to ensure that their development issues would not be affected due to environmental issues.

• 7. As the world forums started addressing problems concerning environment , differences rather than division emerged between countries of the North (Developed) and those of the South(Developing) .The South argued that the North had good living standards which they attained by their consumption style leading to damage of environment and resources.

2. Charter of Economic Rights and Duties of States , 1974

• The Charter of Economic Rights and Duties of States , 1974 is a document of UN. One of its articles states that:

• “The protection , preservation and the enhancement of the environment for the present and the future generations is the responsibility of all States .All States should cooperate in evolving international norms and regulations in the field of environment”.

3. UN-Habitat Conference on Human Settlement of 1976, World Water

Conference of 1977 and other conferences:

• The international efforts directed the protection and preservation of environment became vigorous in 1970’s and the 1980’s . Most important efforts are the following :

• 1. UN habitat conference on Human Settlements in VANCOUVER ,Canada in 1976.

• 2. World water Conference in Mardel Plata , Argentina in 1977 .The World Water Conference caleed upon the UN to establish a programme with a goal of providing clean drnking water and sanitation to all.

• 3. The UN desertification Conference held in Nairobi in 1977.• 4. Paris conference , held in 1986 called for “saving trees and

forests “. The conference was attended by Heads of States and Government officials from 36 countries.

4. Environmental Education conference

• In 1977 ,United Nations Environment Programme (UNDEP) and United Nations Educational ,Scientific and Cultural organisation(UNESCO) organised an Intergovernmental Education Confrence at Georgia. The conference was attended by over 400 delegates from 74 countries . The UNEP Executive Director understood that environment education was a matter of life and death and that problems of environment were jeopardising the development of mankind.

5.World commission on Environment and Development

• 1.In 1980’s , international community became seriously concerned with increasing problems of environment.

• 2.Problems of Ozone depletion , climate change (global warming) , declining of fisheries and forest cover , loss of Biodiversity , pollution and hazardous wastes attracted the attention at global level.

• 3. Issues of sustainable development became of paramount importance especially for the developing countries.

• 4. Norwegian Prime Minister ,Harlem Bruntdland was appointed the Chairman of the commission .The report of this commission called “Our common future” (1987) dealt with many issues but the issue of poverty in developing countries in relation to environmental damage was a special focus.

Contd.

• 5. It stated that problems of environment could not be resolved without poverty reduction .The commission also addressed problems relating to inequity between rich and poor countries. Brundtland Commissionserved as preparatory framework for Rio conference.

6. Earth Summit 1992

• 1. Covened by the UN (called the United Nations Conf. on Env. and develop. (UNCED) at Rio de Janerio in 1992.

• 2.An 800 page document , called Agenda 21 , was issued at the Conference.

• 3.It contains comprehensive blueprint for governments on everything from population strtegy , management of hazardous wastes , recycling , energy conservation , renewable energy , business strategies to role of women in environment.

• 4. While the guidelines and the principles procliamed at Rio Confrence are not legally binding , they carry a strong moral force to ensure their adoptation.

Contd.

• 5. The underlying idea of Agenda -21 is that humanity has reached a point where present policies on development and economic growth have not been able to tackle the problems of poverty , hunger and living conditions.They continue to cause continuing resource depletion and deterioration of ecosystem on which life on this planet depends.

• 6. If human beings have to be providedd with decent living conditions especially in developing countries , the management of ecosystem at local ,national and global levels have to be undertaken on priority basis.

Contd.

• Rio-Declaration: 3rd to 14th June ‘1992• 1.Reaffirming the Declaration of the United Nations Conference on

the Human Environment , adopetd at Stockholm on 16th June , 1972, and seeking to build upon it;

• 2.With the goal of establishing a new and equitable global partnership through the creation of new levels of cooperation among the States , key sectors of societies and people.

• 3. Working towards international agreements which respect the interets of all and protect the integrity of the global environmenatl and developmenatl system;

• 4.Recognising the integarl and interdependent nature of the Earth , our home.

Principles :

• 1. Human beings are at the center of concerns of sustainable development .They are entitled to a healthy and productive life in harmony with nature.

• 2. States have, in accordance with the Charter of the United Nations and the principles of international law , the sovereign right to exploit their own resources pursuant to their own environmental and development policies , and the responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment of other states or of areas beyond the limits of national jurisdiction.

Contd.

• 3. The right to development must be fulfilled as to equitably meet development and environmental needs of the present and future generations.

• 4. In order to achieve sustainable development , environmental protection shall constitute an integral part of the development process and cannot be considered in isolation from it.

• 5. All States and all people shall cooperate in the essential task of eradicating poverty as an indispensable requirement for sustainable development , in order to decrease the disparities in standards of living and better meet the needs of the majority of the peole of the world.

Contd.

• 6. The special situation and needs of developing countries , particularly the least developed and those most environmentally vulnerable , shall be given priority .International actions in the field of environment and development should also address the interests and needs of all countries.

• 7. States shall cooperate in a spirit of global partnership to conserve , protect and restore the health and integrity of Earth’s ecosystem .In view of the different contributions to global environmental degradation , States have common but differentiated responsibilities .The developed countries acknowledge the responsibility that they bear in the international pursuit of sustainable development in view of the pressures their societies place on the global environment and the technologies and financial resources they command.

Contd.

• 8. To achieve sustainable development and a highre qulaity of life for all people , States should reduce and eliminate unsustainable patterns of production and consumption and promote appropriate demographic policies.

• 9. States should cooperate to strengthen endogenous capacity –building development by improving scientific understanding through exchanges of scientific and technological knowledge and by enhancing the development ,adaptation , diffusion and transfer of technologies including new and innovative technologies.

• 10. Environmental issues are best handled with the participation of all concerned citizens , at the relevant level. At the national level , each individual shall have appropriate access to information concerning the environment that is held by public authorities ,

contd.

• including information on hazardous materials and activities in their communities , and the opportunity to participate in decision –making processes. States shall facilitate and encourage public awareness and participation by making information widely available. Effective access to judicial and administrative proceedings , including redress and remedy , shall be provided.

• 11. States shall enact effective environment legislation. Environmental standards , management objectives and priorities should reflect the environmental and developmental context to which they apply. Standards applied by some countries may be inappropriate and of unwarranted economic and social cost to other countries , in particular developing countries.

Contd.

• 12. States should cooperate to promote a supportive and open economic system that would lead to economic growth and sustainable development in all countries, to better address the problems of environmental degradation .trade policy measures for environmetal purposes should not constitute a means of arbitrary or unjustifiable discrimination or a disguised restriction on international trdae .Unilateral actions to deal with environmental challenges outside the jurisdiction of the importing country should be avoided .Environmental measures addressing transboundary or global environmental problems should , as far as possible , be based on an international consensus .

Contd.

• 13. States shall develop national law regarding liability and compensation for the victims of pollution and other environmetal damage .States shall also cooperate in an expeditious and more determined manner to develop further international law regarding liability and compensation for adverse effects of environmetal damage caused by activities within their jusrisdiction or control to areas beyond their jurisdiction.

• 14. Sates should effectively cooperate to discourage or prevent the relocation and transfer to other States of any activities or substances that cause environmental degradation or are found to be harmful to human health.

Contd.

• 15. In order to protect the environment , the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage , lack of full scientific certianty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.

• 16. National authorities should endeavour to promote the internalization of environmental costs and the use of economic instruments , taking into account the approach that the polluter should, in principle , bear the cost of pollution , with due regard to the public interests and without distorting international trade and investment.

Contd.

• 17. Environmental impact assessment , as a national instrument ,shall be undertaken for the proposed activities that are likely to produce harmful effects on the environment of those Staes .Every effort shall be made by the international community to help Staes so afflicted.

• 18. States shall immediately notify other States of any natural disaster or other emergencies that are likely to produce sudden harmful effects on the environment of those States. Every effort shall be made by the international community to help the states so afflicted.

Contd.

• 19. States shall provide prior and timely notification and relavant information to potentially affected Staes on activities that may have a siginificant adverse transboundary environmental effect and shallconsult with those States at an early stage and in good faith.

• 20. Women have a vital role in environment management and development .Their full participation is therefore essential to achieve sustainbal edevelopment.

• 21. The creativity , ideals and courage of the youth of the world should be mobilized to forge a global partnership in order to achieve sustainable development .

Contd.

• 22. Indigenous people and their communities and other local communities have a vital role in environmental management and development because of their knowledge and trdaitional practices. States should recognize and duly support their identity , culture and interests and enable their effcetive participation in the achievement of sustainable developemnt.

• 23. The environment and the natural resources of people under oppression , domination and occupation nshall be protected.

• 24. Warfare is inherently destructive of sustainable development.Staes shall therefore respect international law providing protection for the environment in times of armed conflict

Contd.

• and cooperate in it further development , as necessary.

• 25. Peace , development and environmental protection are interdependent and indivisible.

• 26. Staes shall resolve all their environmetal disputes peacefully and by appropriate means in accordance with the Charter of the United Nations.

• 27. States and the people shall cooperate in good faith and in a spirit of partnership in the fulfilment of the principles embodied in this Declaration and in the further development of international law in the field of sustainable development.

Earth Summit +5

• EARTH Summit of 1992 (Agenda 21 ) was a milestone in the promotion of sustainble development and environment. The nations of the world committed themselves to protect the environment and resource conservation for sustainable development both at national and global level .In 1997 UN convened a conference in New York to assess the progress made in five years since the Earth Summit of 1992;this conference being called as the Earth Summit +5 .The final document of Earth Summit +5 is a result of several rounds of negotiations among representatives of various governments .The highlights of Summit +5 are :

• 1. The governmenta acknowledged that global env. Has continued to deterioriate sine the Earth Summit 1992 with increasing emissions of greenhouse gases and generating of more solid wastes.

Contd.

• Also pollution and effluent treatment continue to be major problems.• 2. Renewable resources like fresh water ,forests , fish continue to

be used at an unsustainable rate.• 3.On the positive side it is noted that :• A.) World population is slowing down• B.) Food production is rising• C.) Life span has increased• At the same time , the number of poor is increasing and the gap

between the poor and the rich has grown both within and between the countries.

Contd.

• Earth summit +5 addressed itself the above concerns and the participating governments took action both within and between countries.

• 4. Earth Summit +5 addressed itself the above concerns and the participating governments took action on several fronts and agreed on the following:

• 1.Reconfirm the political commitment to sustainable development from all members of the international community , as well as all major groups of civil society.

• 2.Reconfirm the financial commitments and targets for official development assistance(ODA) made by industrialized countries at the Earth Summit , and call for intensified efforts to reverse the downward trend in ODA;

Contd.

• 3. Establish an Intergovernmental Forum on Forests under the Commission on Sustainable Development to cintinue policy dialogue on this issue , including more focussed consideration of elements for a possible legal instrument;

• 4. Open high-level Intergovernmental dialogue on fresh water , and on energy and transport , which will be taken up by the commission on Sustainable Development at the upcoming session.

• 5. Make a stronger commitment at the global level of such issues as tourism , changing production and consumption patterns ,and eco-efficiency;

• 6. Set a more focussed work programme for the Commission on Sustainable Development through the year 2002, when the next General Assembly review will be held.

Erath Summit 2002 –Johannesbur Summit

• The second world summit on sustainbale development was held in Johannesburg from August 26 to sept 4 ‘2002:

• Key outcomes of this Summit are :• 1. The Summit reaffirmed sustainable development as a

central element of international agenda and gave a new impetus to global action to protect environment and fight poverty. It was decided to establish World Solidarity Fund for the eradication of poverty.

Contd.

• 2. The linkages between poverty and environment /resource use was re-examined to strengthen this relationship.

• 3.Governments agreed to reaffirm the targets and commitments for action for better implementation of sustainable development.

• 4. Energy and sanitation issues became important elements of negotiation than previous international meetings.

• 5. It was decided to pay special attention and support for development of Africa.

• 6.Key role of Civil Society and NGO’s was recognized in promising partnership among business ,Governments and society . Many partnerships were announced during the Summit.

WTO

Kyoto Protocol

Unit-2 Pollution and Public Policy

• Water Pollution

Water pollution

• Water pollution can be defined as alteration in physical ,chemical or biological characteristics of water making it unsuitable for designated use in its natural state.

Sources of water pollution

• 1. Water required for : drinking, cooking ,bathing, washing ,irrigation, and for industrial operations.

• 2. Most of the water for such uses comes from rivers ,lakes , or groundwater sources .

• 3. Water has the property to dissolve many substances in it, therefore, it can easily get polluted .

• 4. Pollution of water can be caused by point sources or non-point sources .Point sources are specific sites near water which directly discharge effluents into them.

• 5.Major point sources of water pollution are industries, power plants, underground coal mines , offshore oil wells etc.

Contd.

• 6.The discharge from non-point sources is not at any particular site , rather , these sources are scattered , which individually or collectively pollute water.

• 7. Surface run-off from agricultural fields , overflowing small drains , rain water sweeping roads and fields , atmospheric deposition etc. are the non-point sources of water pollution.

•

Ground water pollution

• 1.Ground water forms about 6.2% of the total water available on planet earth and is about 30 times more than surface water (streams, lakes and estuaries).

• 2.Less prone to pollution as the soil mantle through which water passes helps to retain various contaminants due to its cation exchange capacity.

• 3. There are , however ,a number of potential sources of ground water pollution.

• Septic tanks , industry (textile , chemical, tanneries), deep well injection, mining etc. are mainly responsible for ground water pollution which is irreversible.

Contd.

• 4. Ground water pollution with arsenic , flouride and nitrate are posing serious health hazards.

Surface water pollution

• The major sources of surface water pollution:• 1. Sewage : Emptying the drains and sewers in fresh water bodies

causes water pollution .The problem is severe in cities.

• 2. Industrail effluents : Industrial wastes containing toxic chemicals, acids, alkalis, metallic salts, phenols, cyanides, ammonia, radioactive substances , etc. are sources of water pollution. They also cause thermal (heat) pollution of water.

• 3.Synthetic detergents :Synthetic detergents used in washing and cleaning produce foam and pollute water.

• 4. Agrochemicals: Agrochemicals like fertilizers (containing nitrtaes and phosphates ) and pesticides (insecticides ,fungicides ,herbicides etc.) washed by rain-water and surface run-off pollute water.

Contd.

• 5. Oil: Oil spillage into sea-water during and shipment polluet it.

• 6. Waste heat: Waste heat from industrial discharges increases the temperature of water bodies and affects distribution and survival of sensitive species.

Effects of water pollution

• 1.Oxygen demanding wastes• 2. Nitrogen and Phosphorous compounds • 3. Pathogens• 4. Toxic compounds

Contd.

• Organic matter which reaches water bodies is decomposed by microorganisms present in water .For this degradation oxygen dissolved in water is consumed.Lower dissolved oxygen (DO) is harmful to animals especially fish population .

• 2. Nitrogen and Phosphorous compouds (nutrients) Addition of compounds containing nitrogen and phosphorous helps in the growth of algae and other plants which when die and decay consume oxygen of water. Under anaerobic conditions foul smelling gases are produced.

• 3. Pathogens : Many wastewaters especially sewage contain many pathogenic (disease causing) and non-pathogenic micro-organisms and many viruses.

Contd.

4.Toxic compounds : Pollutants such as heavy metals , pesticides ,cyanides and many other organic and inorganic componds are harmful to aquatic organisms.

Control of water pollution

• It is easy to reduce water pollution from point sources by legislation. • However, due to absence of defined strategies it becomes difficult to

prevent water pollution from non-point sources.• The following points may help in reducing water pollution from non-

point sources:• 1. Judicious use of agrochemicals like pesticides and fertilisers

which will produce their surface run-off and leaching. Avoid use of these on sloped lands.

• 2.Use of nitrogen fixing plants to supplement the use of fertilizers.

Contd.

• 3. Adopting integrated pest management to reduce reliance on pesticides.

• 4. Prevent run-off of manure .Divert such run-off to basin for settlement .The nutrient rich water can be used as fertilizer in the fields.

• 5. Separate drainage of sewage and rain water should be provided to prevent overflow of sewage with rainwater.

• 6. Planting trees would reduce pollution by sediments and will also prevent soil erosion.

Contd.

• For controlling water pollution from point sources , treatment of wastewaters is essential before being discharged .

Water resources of India

• 1.The composition of municipal waste water varies from place to place .Sometimes industrial wastes also mix with sewage. Treatment of this kind of wastewater depends upon the characteristics and the desired quality of water.

• 2.The wastewater treatment plants are generally primary ,seondary or advanced.

• 3. The purpose of waste water treatment plant is to remove /reduce organic and inorganic substances, nutrients , toxic substances , kill pathogenic organism etc. so that the quality of water is improved to meet the permissible level of water to be discharged in some water body , on land or agricultural field.

Contd.

• Treatment of water aims at :• 1.reduction of BOD,COD,eutrophication of receiving

bodies• 2. prevention of bio-magnification of toxic substances in

food chains and prevention of disease due to pathogenic organisms present in water.

Steps involved in the treatment of water:

• 1.Primary treatment• 2.Secondary treatment• 2(a.). Trickling filters• (b.).Activated sludge process• (c.).Rotating Biological Contractor • (d.).Advanced sewage treatment • (e.).Upflow anaerobic sludge reactor(USAB)

1.Primary treatment

• 1. It is physical process for removal of debris , large particles with the help of a screen.The waste water after screening is passed through the grit chamber where sand , grit and other solids settle down.The water is then passed through sedimentation tank or clarifier where most of the suspended solids settle down due to gravity .For better removal of suspended solids ,sometimes chemically treated polymers are used. About 35% BOD and 60% of suspended solids are removed during the primary treatment.

2. Secondary treatment

• It is a bological process which involves microorganisms ,It removes upto 90% of the BOD and 90% of suspended solids .Biodegradable oxygen demanding wastes are stabilized .Following are the various approaches adopted in secondary treatment :

• 2(a.). Trickling filters• (b.).Activated sludge process• (c.).Rotating Biological Contractor • (d.).Advanced sewage treatment • (e.).Upflow anaerobic sludge reactor(USAB)

Contd.

• A.)Trickling filters : These consist of a bed of crushed stones /pebbles covered with slime which consists mainly of aerobic bacteria , algae , fungi , protozoa , worms, and insect larvae. Sewage is degraded by the aerobic bacteria when it passes through the bed and is collected at the bottom of the filter. Some of the treated sewage may be recirculated along the influent. It helps in better removal of organic matter and also keeps the filter moist when the flow rate over the filter is slow.

B.Activated Sludge process

• He effluent from the primary clarifier goes to the aeration tank .Aeration tank also receives microorganisms from the secondary settling tank known as the activated sludge. Oxygen is pumped into aeration tank for maintaing aerobic conditions .A fter a fw hours of agitation , the waste water goes to secondary settling tank where solids settle at the bottom.Th esldge is produced , dewatered and disposed off .This can be used for landfills or disposed off in ocean or used in croplands , pastures etc.

•

C. Rotating Biological Contractor (RBC)

• It consists of circular plastic discs which are arranged on a rotating shaft. Circular discs have microorganisms grown on tem. The discs are contained in a wastewater holding tank. About 40% area of the discs is submerged in the tank. The discs rotate in and out of water as the RBC rotates .The microorganisms present on the discs absorb organic matter when they are in water and obtain the required oxygen when the discs are out of water. Thus a high degree of organic matter removal is achieved.

D. Advanced sewage Treatment

• After the primary and secondary treatment many undesirable substances still remain in the effluent. Advanced water treatment involves the removal of such substances .the treatment , therefore, involves specific steps depending upon the type of substances to be removed.

• The materials to be removed in such treatmnet may include nitrates and phosphates (which cause eutrophication of receiving waters) , colour, bacteria , viruses , pesticides , toxic metals ,etc.

Contd.

• Chlorination of water is generally done to kill harmful bacteria and some viruses .However, chlorine can produce cancer causing chlorinated hydrocarbons by reacting with organic matter. Other, but costly methods of disinfection are the use of ultraviolet light and ozone treatment. The sludge produced after such treatment is used as a fertilizer in the fields .However, there are chances of toxic metals and other untreated substances to build up in the food chain or leach to the groundwater.

Upflow Anaerobic sludge (USAB)Reactor

• Anaerobic treatment is gaining importance as a method of wastewater treatment due to its effectiveness in treating wastewater and economic advantages. The USAB process consists of four stages of anaerobic digestion :

• 1. hydrolysis • 2. acidogenesis• 3. acetogenesis• 4. methanogenesis

Contd.

• A dense blanket of granular anaerobic biomass is used to conver organic compounds that are passed through the sludge blanket continuously. Biogas produced is collected at the top of the reactor. The wastewater to be treated is fed into the reactor at the bottom.As the influent flows through the loops And enters the reactor chamber , hydrolisis occurs .This process converts the influent into H2 ,co2, ch4,acetate , new cell-matter etc. COD removal of up to 80% is achieved .Methane and co2 are separated from the reactor.

Hydrological cycle 

• This cycle involves the continuous circulation of water in the Earth-atmosphere system. Of the many processes involved in the hydrologic cycle, the most important are evaporation, transpiration, condensation, precipitation, and runoff. Although the total amount of water within the cycle remains essentially constant, its distribution among the various processes is continually changing.

Contd.

• 1.Evaporation, one of the major processes in the cycle, is the transfer of water from the surface of the Earth to the atmosphere. By evaporation, water in the liquid state is transferred to the gaseous, or vapour, state. This transfer occurs when some molecules in a water mass have attained sufficient kinetic energy to eject themselves from the water surface.

Contd.

• A.) The main factors affecting evaporation are temperature, humidity, wind speed, and solar radiation. The direct measurement of evaporation, though desirable, is difficult and possible only at point locations.

• B.) The principal source of water vapour is the oceans, but evaporation also occurs in soils, snow, and ice. Evaporation from snow and ice, the direct conversion from solid to vapour, is known as sublimation.

• C.) Transpiration is the evaporation of water through minute pores, or stomata, in the leaves of plants. For practical purposes, transpiration and the evaporation from all water, soils, snow, ice, vegetation, and other surfaces are lumped together and called evapotranspiration, or total evaporation.

Contd.

• D.) Water vapor is the primary form of atmospheric moisture. Although its storage in the atmosphere is comparatively small, water vapour is extremely important in forming the moisture supply for dew, frost, fog, clouds, and precipitation. Practically all water vapour in the atmosphere is confined to the troposphere (the region below 6 to 8 miles [10 to 13 km] altitude).

• E.) The transition process from the vapour state to the liquid state is called condensation. Condensation may take place as soon as the air contains more water vapour than it can receive from a free water surface through evaporation at the prevailing temperature.

Contd.

• This condition occurs as the consequence of either cooling or the mixing of air masses of different temperatures. By condensation, water vapour in the atmosphere is released to form precipitation.

• F.) Precipitation that falls to the Earth is distributed in four main ways: some is returned to the atmosphere by evaporation, some may be intercepted by vegetation and then evaporated from the surface of leaves, some percolates into the soil by infiltration, and the remainder flows directly as surface runoff into the sea.

Contd.

• Some of the infiltrated precipitation may later percolate into streams asgroundwater runoff. Direct measurement of runoff is made by stream gauges and plotted against time on hydrographs.

• G.) Most groundwater is derived from precipitation that has percolated through the soil. Groundwater flow rates, compared with those of surface water, are very slow and variable, ranging from a few millimetres to a few metres a day. Groundwater movement is studied by tracer techniques and remote sensing.

Contd.

• Ice also plays a role in the hydrologic cycle. Ice and snow on the Earth’s surface occur in various forms such as frost, sea ice, and glacier ice. When soil moisture freezes, ice also occurs beneath the Earth’s surface, forming permafrost in tundra climates. About 18,000 years ago glaciers and ice caps covered approximately one-third of the Earth’s land surface. Today about 12 percent of the land surface remains covered by ice masses.

River Action plan