HEC-RAS-Introduction

HEC-RASOverviewPresentedby:DehuiSuPhDPE,SeniorengineerOTHONINCHouston,Texas77042,USAPhone:713-975-8555Fax:[e-mail]-RASUSArmyCorpsofEngineers’HydraulicEngineeringCenterRiverAnalysisSystemDOSVersion-HEC-2-1970’sVersion2.0(Windows3.1orlater)-April1997Version3.0(Windows95/98orNT(4.0))-2001Version3.1(Windows95orhigher)January2003Version4.1(Windows95orhigher)March2008HEC-RASisdesignedtoperformone-dimensionalhydrauliccalculationsforafullnetworkofnaturalandconstructedchannels•SteadyFlowWaterSurfaceProfilesUnsteadayFlowSimulationSedimentTransportWaterQualityAnalysisHydraulicModelsSteadyFlow–WSPRO(FHA)–WSP2–HEC-2(lastoneoutin1991)–HEC-RAS(released1995)UnsteadyFlow–UNET–DAMBREAK–HEC-RASHydraulicCapabilities•Steadyflowwatersurfaceprofiles-singlereach,dendritic,mixedflowregime.•Unsteadyflowsimulation-fullnetworkofopenchannels,adaptedfromUNET•Sedimenttransport/Movableboundary-longtermtrendsofscouranddeposition(notready,onlybridgescour)HydraulicParameters•Velocity•Depth•Shear•Width•Area•etcHydraulicComputerModels:•HydraulicAnalysisComponents•GraphicalUserInterface•FileManagement•DataEntryandEditing•HydraulicAnalyses•TabulationandGraphicalDisplaysofInputandOutputData•ReportingFacilities•ContextSensitiveHelp•Flows•Geometry–CrossSection–Spacing–Structures•Manning’sn•CalibrationData•Graphical•Tabular•Profile•SectionOtherApplicationsandCapabilities•BridgeScour•Culverts•DropStructures•HydraulicJumps•SplitFlow•LateralWeirs•InChannelWeirs•GatedSpillwaysandWeirs•VerticalVariationinRoughness•GISimportandexportfeatures(HEC-GeoRAS3.1withArcView)HowdoyougetHEC-RAS?TheHEC-RASsoftwareandmanualareavailableforfreedownloadfromHECatthefollowinginternetaddress:User’sManual:providesanintroductionandoverviewofthemodelingsystem,installationinstructions,howtogetstarted,asimpleexample,detaileddescriptionsofeachofthemajormodelingcomponents,andhowtoviewgraphicalandtabularoutputHydraulicReferenceManual:describesthetheoryanddatarequirementsforhydrauliccalculationsApplicationsGuide:containsaseriesofexamplesthatdemonstratevariousaspectsofHEC-RAS.Limitations•Flowisconstantwithrespecttotime(unsteadyisoptional)•Flowisgraduallyvariedwithdistance•Dominantflowsinxdirection(1-D)•Channelslopeslessthan1:10HWheredoyougoforhelp?•Onlinehelp•HEC-RASdocumentation•HEC-RASSupportTeamfromNRCS(email:[e-mail])TheHEC-RASsoftwareisanengineeringtool.Notareplacementforsoundengineering.TheEnd