SURFAC F-GROUNDWATF RINTFRACTIO NINTH F LAK FBFSFK ACATCHMFN T CFNTRA LRIFTVALLF YOFFTHIOPI A {FocusOnEffectofFentaleIrrigationProjectonLakeBeseka)

Abstract

Thisstudyhasbeencarriedoutinth eLakeBesekacatchment,locate dsom e195 kmnortheastofAddisAbaba.Themainobjectiveotthi sstudyistostudyth e effectotth enewlyestablishedirrigatio nprojectonth eleve lotLakeBeseka.It alsoinclude sth ewaterbalanceotth elak eanditscatchment. Themethodologyfollowe disconventionalwaterbalanceassessment,irrigatio n schedulesandetticiencyinrelatio ntolak elevel sandgroundwatermodeling. RS/GIShavealsobeenused. Thestudytargete donth eeffectotnewlyimplemente dFentaleIrrigatio nonLake Besekawaterleve levaluatingrespons eotth elak et oth eirrigatio nactivitiesnear thelak earea.Thestudyshedsligh tonth enatureotth eirrigatio nonth e subsequentGroundwatermovementthroug hth eaquifer. Theresulto tth estudyshowstha tth elak eismuchaffectedbysurpluswater fromtheirrigatio nprojects.Duet oFentaleirrigatio nprojectth eGroundwaterhas beenincreasin g37.07momperannumupto1998.Thisshow stha tth elak e waterleve lwasrisingat0.15mperyearwithcorrespondingstoragechangeot 5.38momperannum .Aftertullimplementatio nofth eFentaleirrigatio nproject underexistingirrigatio netticiencyth enetgroundwaterinflo wwillincreas efro m 48.34to61.07momannually,Thisshow stha tth elak ewaterleve lwillriseata rateot0.19mannuallywithth ecorrespondingstoragechang eot9.05mem. Thereforeth elak ewaterleve lreache s952.95mwithin11to12years(2020 -2021).Atthisstagth elak ewaterspillst oth eAwashRiverthroug hth esaddle pointlocatedatanelevationot952.95m.a.s.l . Thisstudyhascertainlimitation .Theamountotpumpedwaterhasnotbeen properlyrecorded .Groundwaterleve lmonitoringhasnotcarriedoutperiodically includingth eirrigatio nwaterinth edifferentfarm sandSystematicwaterquality monitoringotth eAwashRiver,th elak eandspringstha trelate dth eirrigatio n activitywerenotconductedregularly .