PREDICTING STREAMBANK EROSION RATES AND INSTABILITIES IN INCISED STREAMS USING THE MODEL CONCEPTS

Código

PAP095

Autores

John J. Ramirez-Avila, Eddy J. Langendoen, William H. McAnally, James L. Martin, Sandra L. Ortega Achury, Ron L. Bingner

Tema

MEDIÇÃO, MODELAGEM, TÉCNICAS E TECNOLOGIAS NO CONTEXTO DA HIDROSSEDIMENTOLOGIA

Resumo

TheabilityoftheCONCEPTSmodeltopredictstreambankerosionindisturbedstreamswastestedthroughitsapplicationtoa270?mreachalongtheYonabaCreekinMississippi,USA.Modelpredictionswerecomparedwithcrosssectionresurveysof8transectsalongthemodelingreachfora13?monthperiod(February2009toMarch2010).Streambankgravitationalfailurewasthedominantmechanisminducingstreambankerosionforthestudiedreach.ResultsshowedthatCONCEPTSwasaccurateinpredictingtopwidthretreatandstreambankfailuresintimeandmagnitude.CONCEPTSsimulationyieldedstreambankdegradationpredictionscomparabletothoseobservedduringthestudiedperiod.Amaximumannualwideningrateofabout3.62?mandannualstreambanksedimentloadofabout2,000?Mgofstreambankmaterialwereassessedbybothmethods;fieldmeasurementsandCONCEPTSmodeling.However,CONCEPTSdidnotaccountforsedimentdepositionthatoccurredonthestreambank,aconditionthatslightlyreducedtheobservednetamountofsedimentyieldcontributedbyin?streamprocesses.CONCEPTSisatoolcapabletosupportdecisionmakingregardingreductionofsedimentloads,especiallyforassessmentofin?streammanagementprocessesandevaluationofstabilizationoferodingstreambanksand/orstreamrestorationdesigns.