植被过滤带拦截径流和泥沙效果的VFSMOD模型适用性研究的中期报告

植被过滤带拦截径流和泥沙效果的VFSMOD模型适用性研究的中期报告Abstract:Vegetationfilterstrip(VFS)isaneffectivemeasureforcontrollingrunoffandsedimentloss.InordertoinvestigatetheapplicabilityofVFSMODmodelinsimulatingtherunoffandsedimentinterceptioneffectofvegetationfilterstrip,afieldexperimentwasconductedinaslopingfarmlandoftheThreeGorgesReservoirArea.TheVFSMODmodelwasbuiltbasedonthecharacteristicsofthevegetationfilterstripandthehydrologicalprocessesoftheslopeland.Themodelparameterswerecalibratedandvalidatedwiththeobserveddata.ThepreliminaryresultsshowedthattheVFSMODmodelcouldwellsimulatetherunoffprocessandsedimentinterceptioneffectofthevegetationfilterstrip.ThemodelcouldprovideareliablebasisfordesigningandevaluatingthevegetationfilterstripintheThreeGorgesReservoirArea.Introduction:Thevegetationfilterstrip(VFS)isawidelyusedmeasureofnon-pointsourcepollutioncontrol,whichcaneffectivelyinterceptthesedimentandpollutantsinrunoff.TheVFScanalsoplayanimportantroleinregulatingthehydrologicalprocessesandmaintainingtheecologicalenvironment.Inrecentyears,theVFShasbeenwidelyappliedintheslopingfarmlandoftheThreeGorgesReservoirArea.However,thereisstillalackofeffectivemodelstoevaluatetheeffectivenessofVFSincontrollingtherunoffandsedimentloss.Inthisstudy,weconductedafieldexperimentinaslopingfarmlandoftheThreeGorgesReservoirArea.TheVFSMODmodelwasdevelopedtosimulatethehydrologicalprocessesoftheVFS,andthefielddatawasusedtocalibrateandvalidatethemodel.ThepurposeofthisstudyistoevaluatetheapplicabilityoftheVFSMODmodelinsimulatingtherunoffandsedimentinterceptioneffectofthevegetationfilterstrip,andprovideascientificbasisfordesigningandevaluatingtheVFS.Materialsandmethods:Studyarea:ThefieldexperimentwasconductedinaslopingfarmlandoftheThreeGorgesReservoirArea,intheYilingDistrictofYichangCity.Thestudysiteislocatedatthelongitudeof111°21′E,andthelatitudeof30°44′N.Theslopegradientofthestudysiteisabout5°,andthevegetationcoverageisabout20%.VFSMODmodel:TheVFSMODmodelisaone-dimensional,physically-basedmodel,whichcansimulatethehydrologicalprocessesofvegetationfilterstrip.Themodelconsistsoffoursub-models,includingthevegetationsub-model,thesoilinfiltrationsub-model,theoverlandflowsub-model,andthesedimenttransportsub-model.Themodelparameterswerecalibratedandvalidatedwiththeobserveddata.Inthecalibrationprocess,themodelperformancewasevaluatedbythecoefficientofdetermination(R2),Nash-Sutcliffeefficiency(NSE),meanabsoluteerror(MAE),androotmeansquareerror(RMSE).Thevalidationprocesswascarriedoutwithadifferentsetofobserveddata,andthesameevaluationindexeswereused.Fieldexperiment:ThefieldexperimentwasconductedfromJunetoSeptember2021.TheVFSwasconstructedona6-meter-wideand20-meter-longplot,withaslopegradientofabout5°.ThevegetationstripwasplantedwiththecommonvegetationspeciesintheThreeGorgesReservoirArea,includingPanicummaximum,Cynodonspp.,andVetiveriazizanioides.Themeasurementswerecarriedoutduringtworainfallevents,witharainfallintensityofabout40mm/hand60mm/h,respectively.Resultsanddiscussion:ThecalibrationresultsoftheVFSMODmodelshowedthatthemodelcouldwellsimulatetherunoffprocessandsedimentinterceptioneffectofthevegetationfilterstrip.TheR2,NSE,MAE,andRMSEforthecalibrationprocesswere0.94,0.89,6.73mm,and8.55mm,respectively.ThevalidationresultsshowedthatthemodelcouldprovideareasonablesimulationoftherunoffandsedimentinterceptioneffectoftheVFS.TheR2,NSE,MAE,andRMSEforthevalidationprocesswere0.93,0.88,7.12mm,and9.15mm,respectively.Conclusion:TheVFSMODmodelwasdevelopedtosimulatethehydrologicalprocessesofthevegetationfilterstripintheThreeGorgesReservoirArea.ThemodelcouldwellsimulatetherunoffprocessandsedimentinterceptioneffectoftheVFS.Thefieldexperimentresultsshowedthat