LAND USE LAND COVER DYNAMICS AND CLIMATE CHANGE IMPACT ON THE HYDROLOGY OF RIBB RIVER CATCHMENT, UPPER BLUE NILE BASIN, ETHIOPIA

Abstract

This iinvestigation iexpects ito iassess ithe ieffects iof iclimate iand iland-use ichange ion ithe ihydrology iof iRibb iwatersheds iusing ithe iSoil iand iWater iAssessment iTool i(SWAT). iRibb iwatershed iis ilocated iin ithe inorthwestern iEthiopia iRiver ibasin iwhich iextends ifrom i10.00ºN ito i11.00ºN ilatitude iand ifrom i35.00ºE ito i38.00ºE ilongitude. iThe iexamination idissected ithe ihydrologic ieffects iof iclimate iand iland-use ichanges iin itwo idifferent iways. iThe imain iperspective icomprises iof idescribing ihydrological ichanges itwo iverifiable iland iuse imaps i(Land iSat_8 i2001, i2017) iwere iutilized ito ispeak ito iland-use ichange ion ithe iwatershed, iand ihistorical iclimate idatasets i(1988-2017) iwas iutilized ito imake iSWAT imodels ifor iRibb iwatershed. iLand-use ichange irecognition iwas ifinished iusing iremote idetecting iprocedures iand ithe imaps iwere iprepared iusing iERDAS iImagine i14 iand iArc iGIS i10.3 isoftware. iClimate iand iLand iuse iis itwo iprimary ifactors istraightforwardly iimpacting ithe ihydrological iprocedures iof ithe iwatershed. iRCP i4.5 iand iRCP i8.5 iscenario iwere iused ito iproject ithe ifuture iclimate iof ithe i2050s, iand i2080's. iThe ianalysis iwas iperformed iin itwo ifuture iprojection, i2050 iand i2080 iconsidering ithe ireference ibaseline iperiod i1988-2017 iwith iboth iRCPs. iMaximum itemperature ichanges ifor iRCP i4.5 iraised iby i0.17°C ito i0.9°C iand i0.2°C ito i1.1°C, iand ifor iRCP8.5 i0.2°C ito i1.06°C iand i1.04°C ito i1.73°C iMean imonthly imaximum itemperature ichange ifor ithe i2050s iand i2080s. iand iMinimum itemperature ichanges ifor iRCP i4.5 iand iincrease iby i0.03°C ito i0.8°C iand i0.2°C ito i0.95°C iand ifor iRCP i8.5 i0.25°C ito i0.84°C iand i0.31°C ito i1.65°C ifor ithe i2050s iand i2080s itime iperiods iwith ireference ito ithe ibaseline iperiods irespectively. iAnd ialso, ithe imean imonthly iprecipitation ichange ishowed iincreasing i iby i4.25mm ito i6.25mm iand66.42mm ito i78.32mm ifor iboth iRCP4.5 iand iRCP8.5 iscenarios irespectively. iCombined iimpacts iof iland iuse iand iatmosphere ichanges iindicated ithat i88.15m3/s ifor ibaseline, i40.57 im3/s imore iin ithe i2050s, iand i38.48m3/s imore iin iThe i2080s ifor istream iflow icompared ito iclimate ichange iscenario. iThe icombination iof iclimate iand iland-use ichanges iwould ilead ito ia idecrease iin istream iflow i(73.55% ito i29% iin ithe i2050s iand i64.98% ito i14.67% iin ithe i2080s). iSWAT ioutput ito ibaseline irun i(1987-2017). iClimate iand ithe iland iuse iland/cover ichange iand iits imain iimpetus ion iRibb iwatershed iutilizing iLANDSAT_8 iimage ito icreate itwo ithe ihydrological imodel ioutcome ishows ithat ithe istream iwas itouchy ito iland icover ichange iby ilessening ibase istream iand iincrement itop istream ithis iis ibecause iof iincrement iagrarian iland iand ideforestation.