Applicabilityo fEmpiricalFormulaandTwo-DimensionalMathematical ModelsonPredictiono fSedimentDistributioni nSmallDamReservoirs: Casestudy-GomiteSmallDamIrrigatio nProject,Ethiopia.

Abstract

Mos tNatura lrive ricadic sar capproximatel ybalance dwit hrespec tt osedimen tinllo wan doutllow . Da meonstruetio ndramatieall >alter sthi sbalance ,creatin ga nimpounde drive rreac hcharaeteri/.e db y e.xtremel )lo wHow\eloeit \an deirieien tsedimen ttrapping .Th eimpotinde dreac hwil laccumulat e sedimen tan dlos estorag eeapaeits-unti labalanc eisagai nachieved ,whic hwoul dnormall yoccu ralte r th eimpedimen thasbecom efillet lu pwit hsedimen tan dca nn olonge rjirovid ewate rstorag ean dothe r henefit . Theactua llocatio nan dmanne riifdepositio nofsedimen talon gth ereservoi rbeddepen do nfactor slik e th elongitudina lslop eofth corigina lslreamhed .th eshap eofth creservoir ,th eparticl esi/e-distrihutio n oflh cincomin gsediments ,th eminera leharaeteristie softh cclay-siz esediments ,th echemistr yofth c water ,operatio npla nan doutllo weharaeteristie softh creservoir .Ihesedimen taccumulatio ni nadditio n •t oth elos so fstorag eeaiiaeil )ofth creservoii -adversel safl'eet sth efunctionin gol'th ereservoi routlets , recreationa lfacilitie san dimportan tinstallation si nth ebackwate rregions ,ii'any . ^=j i ^Nowaday si nth eda mprojects ,th emai nproble misestimatin gth esedimen tloa dlikel yt odeposi ti nth e 'reservoir san dpredictin gth esedimen tdisti-ibutio npattern si nthei rlif etim ei norde rt oll xth esil l elevatio no lth eoutlet so rth enewzer olevels . Sedimen tloa dl o(iomil ereser\-oi rfro mit swalershe disdelermiiie dusin gKlJSI.f TMode lan dth e a resul tdeviate sonl ybyd.79"'()fro mth eestimate dsedimen tdeposit sb ybathymetri csurve yan dals oth e sedimen tloa dt o(iomit creservoi risestimate dbyUSI.f iequatio nan ditisdeviate db y66.23 %fro mth e estimate dsedimen tdeposit sbyhathynietri esurve yan ditshow stha tth el\USI.L 2mode lismore applicabl etha nth eLSI. Lequation sfo reslimatio nofsedimen tyield sofGomit creservoir . Th ene wzer oelevatio no fGomit ereservoi risdetermine db yLmpiriea larea-reductio nmethod , limpirica larea-incremen tmetho dan dMathematica ltw odimensiona lmodel s((Xliil-2 D)an dwhe nw c compar eth ercsidl swil hth enewzer oelevalio nesliiiKilei-lfro mhalhymeti-i esurve yf'.mpiriea lai'eaivdiiLlioi iinellr^i ,IMi|ii;-k:i!.iieaoii ^ieiiieii linelhi' Jand((ilffl )mode ldeviate sb\O.dOiii.I.lO m an d((.v-^inres|veli\el\ .An ditallow sliia lih enewzer oleve ldetermine dh_ vih eihre emelhod sisnot highl ydeviate dfi-omlii ene wzer oelevation silelermine dfro mbtithymelri esurvey .Hutrelativel y • 4 v i CCHE2DmodelismoreapplicabletoestimatethenewzeroelevationofGomitereservoirsthanthe empiricalmethodsandalsowhenwecomparethetwoEmpiricalformulasrelativelyfornewzero elevationdeterminationEmpiricalArea-ReductionmethodismoreapplicablethantheEmpiricalAreaIncrementmethodforGomitereservoirs.