Irrigation Engg Lec 01

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<ul><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 1/36</p><p>Course Instructor</p><p>Engr. Afzal Ahmed</p><p>MSc Water Resource &amp; Irrigation Engineering</p><p>UET Taxila</p><p>Sc Ci!il Engineering</p><p>UET Taxila</p><p>Irrigation Engineering CE"#$#%'$(</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 2/36</p><p>Course ContentsWater Resources)</p><p>*lanning and de!elo+ment of ,ater resources +ro-ects. omestic/</p><p>Industrial/ Agricultural and other ,ater usages/ Water resources in*a0istan.</p><p>Irrigation:</p><p>e1nition and t2+es of irrigation. Merits and demerits of irrigation/Indus asin Irrigation S2stem (IBIS).</p><p>Canal Irrigation:</p><p>Elementar2 conce+t a3out canal head ,or0s/ selection of their site</p><p>and la2out/ ,eirs and 3arrages/ !arious com+onents and functions.</p><p>Measures ado+ted to control silt entr2 into canals/ silt e-ectors and</p><p>excluders. esign of ,eirs on +ermea3le foundations/ sheet +ilesand cut o4 ,alls. esign of irrigation channels/ 5enned26s and</p><p>7ace26s Theories. Rational methods for design of irrigationchannels. Com+arison of !arious methods. Com+uter Aided designof irrigation channels.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 3/36</p><p>Barrages and Headworks:</p><p>Canal head regulators/ falls/ 8umes/ canal outlets.</p><p>Cross drainage ,or0s) t2+es and functions. Canallining) ad!antages and t2+es. Maintenance ofirrigation canals.Monitoring of 8o,s"telemetr2 s2stem.</p><p>Irrigated Agriculture:</p><p>Soil",ater"+lant relationshi+. Water re9uirements ofcro+s/ dut2 of irrigation ,ater. elta of cro+s/consum+ti!e use/ estimation of consum+ti!e use/</p><p>methods used for assessment of irrigation ,ater.Irrigation methods and +ractices. Irrigationscheduling. Management of irrigation s2stems/+artici+ator2 irrigation management.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 4/36</p><p>Water logging and salinity:</p><p>Causes and e4ects of ,ater logging/reclamation of ,ater logged soils. rainsand tu3e ,ells. Causes and e4ects ofsalinit2 and al0alinit2 of lands in *a0istan.Reclamation methods. rainage net,or0 inirrigated areas.</p><p>Drainage:</p><p>e1nition/ 7and reclamation/ Surfacerainage/ Su3surface rainage/ Estimationof discharge ca+acit2 of Cross"drainage</p><p>structures/ is+osal of drainage e:uents.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 5/36</p><p>Text oo0</p><p>7insla2/ R.5. and ;ose+h/ .ill.</p><p>Reference oo0s?. 7insla2/ R.5. and ;ose+h/ .ill.</p><p>@. Siddi9ui/ I9tidar &gt;./ Irrigation and</p><p>rainage Engineering/ xford Uni!ersit2*ress</p><p>. I93al Ahmed/ Irrigation Engineering and&gt;2draulic Structures</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 6/36</p><p>Water Resources</p><p>Cha+ter Bo $?</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 7/36</p><p>IntroductionUtilisation of available water of a region for use of</p><p>a community has perhaps been practiced from the</p><p>dawn of civilization. In fact, the Harappa and</p><p>Mohenjodaro excavations have also shown</p><p>scientific developments of water utilization and</p><p>disposal systems. hey even developed an efficient</p><p>system of irrigation using several large canals. It</p><p>has also been discovered that the Harappancivilization made good use of groundwater by</p><p>digging a large number of wells.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 8/36</p><p>!f other places around the world, the earliest dams</p><p>to retain water in large "uantities were constructed</p><p>in #awa $#ordan% at about &amp;''' () and in *adi</p><p>+arawi $gypt% at about -' (). he /oman</p><p>engineers had built log water conveyance systems,</p><p>many of which can still be seen today, 0anats or</p><p>underground canals that tap an alluvial fan on</p><p>mountain slopes and carry it over large distances,were one of the most ingenious of ancient hydro1</p><p>technical inventions, which originated in 2rmenia</p><p>around 3'''() and were found in India since &amp;''</p><p>(). </p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 9/36</p><p>7og ,ater con!e2ances2stem</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 10/36</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 11/36</p><p>2lthough many such developments had ta4en</p><p>place in the field of water resources in earlier days</p><p>they were mostly for satisfying drin4ing water and</p><p>irrigation re"uirements. Modern day projects</p><p>re"uire a scientific planning strategy due to5</p><p>3. +radual decrease of per capita available water on</p><p>this planet and especially in our country.</p><p>-. *ater being used for many purposes and thedemands vary in time and space.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 12/36</p><p>*ater availability in a region 6 li4e county or state</p><p>or watershed is not e"ually distributed.</p><p>he supply of water may be from rain, surfacewater bodies and ground water.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 13/36</p><p>*ater resources project planning</p><p>he goals of water resources project planning maybe by the use of constructed facilities, or structural</p><p>measures, or by management and legal techni"ues</p><p>that do not re"uire constructed facilities. he latter</p><p>are called non1structural measures and may include</p><p>rules to limit or control water and land use which</p><p>complement or substitute for constructed facilities.</p><p>2 project may consist of one or more structural ornon1structural resources.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 14/36</p><p>*ater resources planning techni"ues are used to</p><p>determine what measures should be employed to</p><p>meet water needs and to ta4e advantage of</p><p>opportunities for water resources development, and</p><p>also to preserve and enhance natural waterresources and related land resources.</p><p>he scientific and technological development has</p><p>been evident during the twentieth century in major</p><p>fields of engineering. (ut since water resourceshave been practiced for many centuries, the</p><p>development in this field may not have been as</p><p>spectacular as, say, for computer sciences.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 15/36</p><p>However, with the rapid development of</p><p>substantial computational power resulting reducedcomputation cost, the planning strategies have seen</p><p>new directions in the last century which utilises the</p><p>best of the computer resources. 7urther, economic</p><p>considerations used to be the guiding constraint forplanning a water resources project. (ut during the</p><p>last couple of decades of the twentieth century</p><p>there has been a growing awareness for</p><p>environmental sustainability. 2nd now,</p><p>environmental constrains find a significant place in</p><p>the water resources project $or for that matter any</p><p>developmental project% planning besides the usual</p><p>economic and social constraints. </p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 16/36</p><p>8riorities for water resources planning</p><p>*ater resource projects are constructed to develop ormanage the available water resources for different</p><p>purposes. he water allocation priorities for planning and</p><p>operation of water resource systems should broadly be as</p><p>follows5 3. 9omestic consumption includes water</p><p>re"uirements primarily for drin4ing, coo4ing,</p><p>bathing, washing of clothes and utensils and</p><p>flushing of toilets.</p><p>-. Irrigation *ater re"uired for growing crops in a</p><p>systematic and scientific manner in areas even with</p><p>deficit rainfall. </p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 17/36</p><p>&amp;. Hydropowerhis is the generation of electricity by harnessing the power</p><p>of flowing water.</p><p>:. cology ; environment restoration</p><p>*ater re"uired for maintaining the environmental health of aregion.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 18/36</p><p>(asin 6 wise water resource project</p><p>development</p><p>he total land area that contributes water to a river iscalled a *atershed, also called differently as the</p><p>)atchment, /iver basin, 9rainage (asin, or simply a</p><p>(asin. he image of a basin is shown in 7igure 3.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 19/36</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 20/36</p><p>2 watershed may also be defined as a geographic area thatdrains to a common point, which ma4es it an attractive</p><p>planning unit for technical efforts to conserve soil and</p><p>maximize the utilization of surface and subsurface water</p><p>for crop production. hus, it is generally considered thatwater resources development and management schemes</p><p>should be planned for a hydrological unit such as a</p><p>9rainage (asin as a whole or for a &gt;ub1(asin, multi1</p><p>sectorially, ta4ing into account surface and ground waterfor sustainable use incorporating "uantity and "uality</p><p>aspects as well as environmental considerations.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 21/36</p><p>ools for water resources planning and</p><p>management</p><p>he policy ma4ers responsible for ma4ingcomprehensive decisions of water resources planning</p><p>for particular units of land, preferably a basin, are</p><p>faced with various parameters, some of which are</p><p>discussed in the following sections.</p><p>3. &gt;upply of water5</p><p>a. Water available in the unit</p><p>i. /ain falling within the region. his may be utilized</p><p>directly before it reaches the ground, for example, the</p><p>roof 6 top rain water harvesting schemes in water</p><p>scarce areas.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 22/36</p><p>ii. &gt;urface water bodies. hese static $la4es and ponds% and flowing$streams and rivers%, water bodies may be utilized for satisfying the</p><p>demand of the unit, for example by constructing dams across rivers.</p><p>iii. +round water reservoirs. he water stored in soil and pores of</p><p>fractured bed roc4 may be extracted to meet the demand, for</p><p>example wells or tube 6 wells.</p><p>b. Water transferred in and out of the unit</p><p>If the planning is for a watershed or basin, then generally the water</p><p>available within the basin is to be used unless there is inter basin water</p><p>transfer. If however, the unit is a political entity, li4e a nation or a state,</p><p>then definitely there shall be inflow or outflow of water especially that of</p><p>flowing surface water. /iparian rights have to be honored and extraction</p><p>of more water by the upland unit may result in severe tension.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 23/36</p><p>c. Regeneration of water within the unit(rac4ish water may be converted with appropriate technology to</p><p>supply sweet water for drin4ing and has been tried in many extreme</p><p>water scarce areas. *aste water of households may be recycled, again</p><p>with appropriate technology, to supply water suitable for purposes</p><p>li4e irrigation.</p><p>-. 9emand of water5</p><p>a. Domestic water requirement for urban population</p><p>his is usually done through an organized municipal water</p><p>distribution networ4. his water is generally re"uired fordrin4ing, coo4ing, bathing and sanitary purposes etc, for the</p><p>urban areas.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 24/36</p><p>b. Domestic and livestock water requirement forrural population</p><p>his may be done through individual effort of the users by tapping</p><p>a local available source or through co1operative efforts</p><p>c. Irrigation water requirement of cropped elds</p><p>Irrigation may be done through individual effort of the farmers or</p><p>through group cooperation between farmers, li4e 7armers?</p><p>)ooperatives. he demands have to be estimated based on the</p><p>cropping pattern, which may vary over the land unit due to</p><p>various factors li4e@ farmer?s choice, soil type, climate, etc.2ctually, the term AIrrigation *ater 9emandB denotes the total</p><p>"uantity and the way in which a crop re"uires water, from the time</p><p>it is sown to the time it is harvested.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 25/36</p><p>c. Industrial water needshis depends on the type of industry, its magnitude and the</p><p>"uantity of water re"uired per unit of production.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 26/36 </p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 27/36</p><p> Canals/unnelshese are conveyance structures for transporting water over long</p><p>distances for irrigation or hydropower.</p><p>hese structural options are used to utilise surface water to its maximum</p><p>possible extent. !ther structures for utilising ground water include</p><p>rainwater detentions tan4s, wells and tube wells.</p><p>2nother option that is important for any water resource project is</p><p>*atershed Management practices. hrough these measures, the water</p><p>falling within the catchment area is not allowed to move "uic4ly to drain</p><p>into the rivers and streams. his helps the rain water to saturate the soil</p><p>and increase the ground water reserve. Moreover, these measures reducethe amount of erosion ta4ing place on the hill slopes and thus helps in</p><p>increasing the effective lives of reservoirs which otherwise would have</p><p>been silted up "uic4ly due to the deposition of the eroded materials.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 28/36</p><p>Management tools for water resource</p><p>planning</p><p>he following management strategies are important for water resourcesplanning5</p><p>C*ater related allocation;re1allocation agreements between planning</p><p>units sharing common water resource.</p><p>C &gt;ubsidies on water use</p><p>C 8lanning of releases from reservoirs over time</p><p>C 8lanning of withdrawal of ground water with time.</p><p>C 8lanning of cropping patterns of agricultural fields to optimize the</p><p>water availability from rain and irrigation $using surface and;or</p><p>ground water sources% as a function of timeC )reating public awareness to reduce wastage of water, especially</p><p>filtered drin4ing water and to inculcate the habit of recycling waste</p><p>water for purposes li4e gardening.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 29/36</p><p>as4s for planning a water resources project</p><p>he important tas4s for preparing a planning report of a waterresources project would include the following5</p><p>C 2nalysis of basic data li4e maps, remote sensing images,</p><p>geological data, hydrologic data, and re"uirement of water use</p><p>data, etc.C &gt;election of alternative sites based on economic aspects</p><p>generally, but 4eeping in mind environmental degradation</p><p>aspects.</p><p>C &gt;tudies for dam, reservoir, diversion structure, conveyance</p><p>structure, etc.</p><p>C &gt;tudies for local protective wor4s 6 levees, riverban4</p><p>revetment, etc.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 30/36</p><p>C 7ormulation of optimal combination of structural and</p><p>non1structural components $for projects with flood</p><p>control component%.</p><p>C conomic and financial analyses, ta4ing into account</p><p>environmental degradation, if any, as a cost.</p><p>C nvironmental and sociological impact assessment.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 31/36 </p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 32/36</p><p>Punjab</p><p>he public irrigation infrastructure in the 8unjab consists of 3&amp; barrages</p><p> - siphons across major rivers</p><p> 3- lin4 canals and -&amp; major canal systems over an</p><p>aggregate length of &amp;:,ystem. It serves an area of D.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 33/36</p><p>Sindh</p><p>3: publicly owned irrigation systems, which receivewater from three barrages across the /iver Indus.</p><p>hese systems, with an aggregate length of 3D,''' 4m</p><p>of canals, serve an area of about indh, which serve a total area of over &amp;.&lt; million</p><p>hectares and have an aggregate length of about :,D''</p><p>4m.</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 34/36</p><p>5*5</p><p> &lt; publicly owned irrigation systems in the Indus (asin, whichserve</p><p> a total area of '.&amp;: million hectares. hese systems receive</p><p>water from two headwor4s across /iver &gt;wat and *arsa4</p><p>9am. In addition, there are six other canal systems, whichserve a total of '.3&amp; million hectares of land.</p><p>2lso has over -'' canals called Gcivil canalsG, which are</p><p>community or privately owned. hese irrigate an aggregate</p><p>area of '.D&amp; million hectares.</p><p>here are four surface drainage systems in 8 comprising of</p><p>:</p></li><li><p>7/21/2019 Irrigation Engg Lec 01</p><p> 35/36</p><p>Balochistan</p><p>(alochistan has two canal systems, which receivewater from the Indus (asin &gt;ystem through +uddu</p><p>(arrage and &gt;u44ur (arrage, located in &gt;indh. hese</p><p>canal systems serve a total area of '.&amp;&amp; million</p><p>hectares. !ne of these, the 8at7eeder )anal &gt;ystem, has been improved recently. In</p><p>addition, there are :&amp;3 independent...</p></li></ul>


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