简介：Intherillerosionprocess,run-onwaterandsedimentfromupslopeareas,andrillflowhydraulicparametershavesignificanteffectsonsedimentdetachmentandtransport.However,thereisalackofdatatoquantifytheeffectsofrun-onwaterandsedimentandrillflowhydraulicparametersonrillerosionprocessatsteephillslopes,especiallyintheLoessPlateauofChina.Adual-boxsystem,consistingofa2-m-longfeederboxanda5-m-longtestboxwith26.8%slopegradientwasusedtoquantifytheeffectsofupsloperunoffandsediment,andofrillflowhydraulicparametersontherillerosionprocess.Theresultsshowedthatdetachment-transportwasdominatedinrillerosionprocesses;upsloperunoffalwayscausedthenetrilldetachmentatthedownsloperillflowchannel,andthenetrilldetachmentcausedbyupsloperunoffincreasedwithadecreaseofrunoffsedimentconcentrationfromthefeederboxoranincreaseofrainfallintensity.Upsloperunoffdischargingintotherillflowchanneloranincreaseofrainfallintensitycausedtherillflowtoshiftfromastratumflowintoaturbulentflow.Upsloperunoffhadanimportanteffectonrillflowhydraulicparameters,suchasrillflowvelocity,hydraulicradius,Reynoldsnumber,FroudenumberandtheDarcy-Weisbachresistancecoefficient.Thenetrilldetachmentcausedbyupsloperunoffincreasedastherelativeincrementsofrillflowvelocity,ReynoldsnumberandFroudenumbercausedbyupsloperunoffincreased.Incontrast,thenetrilldetachmentdecreasedwithanincreaseoftherelativedecrementoftheDarcy-Weisbachresistancecoefficientcausedbyupsloperunoff.Thesefindingswillhelptoimprovetheunderstandingoftheeffectsofrun-onwaterandsedimentontheerosionprocessandtofindcontrolstrategiestominimizetheimpactofrun-onwater.