Reliablequantitativeestimationofbedaggradationordegradationisimportantforriver-trainingandwatermanagementprojects.Withthedevelopmentofwaterresources,sedimentproblemsassociatedwithadamarebecomingmoresevere.Thispaperdescribessomespecialproblemsinmathematicalmodelforcalculationofdegradationandaggradationinareservoir.Themaineffortsofthisstudyareonthetreatmentofsomephysicalprocessesoffinesedimenttransport(＜0.05mm).Problemsinareservoirareobviouslydifferentfromanaturalstream,suchastheturbidcurrentflow,orificesedimentflushing;andtheinitiationandconsolidationofcohesivesedimentdeposition.ThecaseofLiujiaxiaReservoir,whichislocatedintheupperreachesoftheYellowRiver,isemployedtoverifythemodel.Theresultsshowthatthemodelisapplicableintheevaluationofanengineeringplaningwithplentyoffinesedimentmovement.
