简介：Sedimentationfromsoilerosionisacriticalreservoirwatershedmanagementissue.Duetothedifficultyoffieldinvestigations,empiricalformulasarecommonlyusedtoestimatethesoilerosionrate.However,theseestimationsareoftenfarfromaccurate.Aneffectivealternativetoestimatingsoilerosionistoanalyzethespatialvariationof137Csinventoryinthesoil.137Cscanbeadsorbedbythesoilandiswidelyassumedtochangeitsdistributiononlywhendisturbedbyrainfallandhumanactivities.Thus,137Csdistributedinsoilscanbeausefulenvironmentaltracertoestimatesoilerosion.Inthisstudy,thenetsoillossestimateis108,346t/yrandthegrosserosionandneterosionratesare10.1and9t/hayrrespectively.Thesedimentdeliveryratioisthereforeestimatedtobe0.9basedonthetwoerosionrates.Becauseofthesteephillsidesinthewatershed,only10%ofthesedimentyieldstayedinthedepositionsitesand90%wastransportedtotheriverasthesedimentoutput.Soilerosionestimatesfromspatialvariationsofthe137CsactivityintheBaishiriverwatershedshowedsatisfactoryaccuracywhencomparedtosedimentyielddata.Usingsoil137CsconcentrationsisthereforeafeasiblemethodforestimatingsoillossordepositioninTaiwan.Datasampling,analysisandresultofthisapproacharegiveninthispaper.