CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
TheIncorporationofRainfallintoHazardEstimatesforImprovedCoastalResiliency
DonaldT.Resio– UniversityofNorthFlorida([email protected])BruceA.Ebersole – JacksonStateUniversity ([email protected])
JohnAtkinson– Arcadis,Inc. ([email protected])
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
BruceEbersole (JSUMPIandleadstakeholderGroupcoordinator)hasformedanend-usercommitteetoprovidereview,feedbackandrecommendationsontheworkinprogress.FEMAHQFEMARegionIFEMARegionIIFEMARegionIIIFEMARegionIVFEMARegionVIUSCoastGuardUSACENOAA
EndUserEngagement
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
EndUserEngagement
• DirectcallswithStakeholderGroup(SG)members
• Semi-annualprogressreportssenttoSG(firstsentinJuly).
• BruceEbersole isfacilitatingcommunicationswiththeSC
• Interactionratewillincreaseinsecond12-monthsofproject,possiblyincludingwebinarsandon-sitemeetings
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
KnowledgeGapAddressedbyProject
• FEMAfloodmodelingandstatisticalmethodscurrentlytreatstreamandrainfall-inducedfloodingseparatelyfromcoastalflooding,whichleadstoaswathoflandbetweenthetwoapproachesthatisunder-estimated
• Statisticalmethodsandmodelingmethodshavetobeupdatedtoexplorethefollowinggoals:• Acoupledmodelingsystemthatisdefensibleandaccurateforallcriticalprocesses
affectingfloodingincoastalareasandisadaptabletoallcoastalareaswithintheU.S.• Astatisticalmethodologythatiscapableofincorporatingadditionalsourcesof
variationininundationlevels,whilepreservinganoverallefficiencythatallowsthecoupledmodelingsystemtobeappliedeffectivelytoallcoastalareaswithintheU.S.
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
• Re-examinefundamentalassumptionswithinstatisticalmethodologies,particularwithrespecttoeffectsofnaturalstructureonprobabilities(JPsubmittedtoNaturalHazards)
• QuantifyrelationshipsbetweenTropicalCyclones(TCs)andrainfallpatternsaffectingfloodingincoastalareas
• Developstatisticalframeworkforestimatingprobabilitiesofcoastalinundationthatmaintainsaccuracystandardsandoverallefficiencyintermsofnumbersofsimulationsrequired
• Investigateoptionsformodelcouplingthatprovidethefollowing:• abilityofrivermodelstoaccountforsurge• abilityofsurgemodelstoaccountforriverflow&stage• accuratecoupledmodelsystemthatreproducesimportantphysics• systemthatisstable&computationallyefficient
ResearchApproach
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
• Completedanalysisofrainfallpatternsandstatisticalframeworkforcombiningrainfall,tides,river/streamdischargeandantecedentconditionsintoastatisticallyrobust,defensiblemethodology,efficientandadaptabletomultiplelocations(Reportcompleted1/31/2017)
ResearchWorkandAccomplishments(RainPatterns&Statistics)
• Findingstodate:• RainfalloffshoreisinfluencedprimarilybySeaSurfaceTemperature(SST)andStormSize• TimingofrainfallwiththepointofclosestproximityofstormcentertoNorfolksuggeststhatthe
onshorerainfallslightlylagsthestormpassage,butismainlyconcentratedina24-hourintervalcenteredonthepointofclosestapproachinhurricanesintheNorfolk/HamptonRoadsarea
• Stormtrackistheprimarydiscriminatorofboththedurationandintensityofrainfallinstorms• ResponseFunction(RF)methodismuchmoreadaptablethanBayesianQuadrature(BQ)for
incorporationofspatiallyinhomogeneousprocessesintostatisticalframework
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
ResearchWorkandAccomplishments1
Rainfallfromall17“major”stormsintheNorfolkarea
14
2
3
1– Surgeandhighrainfall2– Littlesurgeandmoderaterainfall3– Moderatesurgeandhighrainfall4– Littlesurgeandlittlerainfall
EOFsforMajorStorms EOFsforMinorStorms
TrackCategorization
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
ResearchWorkandAccomplishments2
Hydrologic
Coastal Coastal
Hydrologic
Combined
AnnualExceedanceProbabilityforcoastalsurgesandcoupledcoastalandhydrologic/rainfallflooding
EXAMPLESOFEXPECTEDSTATISTICALPRODUCTSFROMTHEOVERALLPROJECT
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
ResearchWorkandAccomplishments(CoupledModeling)
• Investigatedimpactofprecipitation&riverstageonsurge(whatarewemissinginpresentmethodology?)• UsesNechesRiver(Texas)astestcase• Procedure
• ObtaintwoexistingmodelsthatincludetheNeches• 2DsurgemodelfrompreviousTX-FEMAstudy• 1DriverinemodelfromUSACE• Comparesimulationsforseveralevents• Systematicallyadjustdomainoverlapandboundarylocation• Optimizethe“best”couplingprocess• Identifythephysicalconditionsthatimpactthecouplingstrategy
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
ResearchWorkandAccomplishments(CoupledModeling)
HEC-RAS•Wellknownandrespectedmodeltocomputestage-flowrelationshipsforriversandstreams•Canbeusedinunsteadymodewithtimevaryingboundaryconditions•Sourcecodeisnotpubliclyavailable•Veryefficientperstorm,butnoteasilyautomated
•Existing,calibrated/validatedHEC-RASmodelofNechesRiveravailablefromUSACE•USACEmodelmodifiedandcoupledwithTX-FEMAADCIRCmodel
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
• One-waycouplingappearsfeasibleforcoupledsimulations(usingsubdomain+BC)• AutomationdevelopedforHEC-RASusingVBAandMatlab calls• RainfallcanbeaddedonADCIRCsub-domainbasiswithBC• TimingoffloodinginHEC-RASandADCIRCinphaseinmosttests• HEC-RAShasmoredampingthanADCIRC• HEC-RAScannotaccountforeffectsofLakeSabine(implicationsforHamptonRoads
andotherregions)• HEC-RASdoesnotaccountforwind• Other1Drivermodelsmayperformbetter(SOBEK,SWAT)• Forallsurgeconditions,totalstage(backwatercurve)inriverincreasewithflowrate• Forincreasingsurge,HEC-RASunderpredictstotalsurgeby1to2ft
ResearchWorkandAccomplishments(ModelCoupling– draftconclusions)
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
ResearchWorkandAccomplishments(CoupledModeling)
ModelComparisonforHurricaneIke
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
EducationalEfforts
• ParticipatedinSUMREXProgramwithRudyBartels– PhDstudentfromLSU
• PlansinplacetogiveresearchpresentationatLSUandcontinueworkwithRudyBartelsandProfessorBarryKeim forajournalpublication
• UNFPhDstudentAmandaTritingerparticipatedinlastyearsCESonbehalfofDHS
CRC1st AnnualMeetingMarch2-3,2016TheUniversityofNorthCarolinaatChapelHill
• DHSGoal1.3– ManageRiskstoCoastalInfrastructure,KeyLeaders,andEvents: Pasteventshavedemonstratedthreatposedtoinlandareasisoftenunderestimated,withdamagesduetoinlandfloodingcomparabletoareasatthecoast.Thisprojectwillhelpremediatethisdeficiency,therebyenhancingourdecision-makingcapabilitiesrelatedtoresilience.
• DHSGoal5.1– MitigateCoastalHazardsandRisks:Multidisciplinaryteamswillbeutilizedtodevelopimprovedhazardmapsincoastalareasthatwilldispersecostsmoreequitably.
• DHSGoal5.3– EnsureEffectiveEmergencyResponse :Thisprojectwillprovideimprovedquantitativetime-spacepatternsofeventhazards,whichwillbeveryvaluabletoemergencyresponders.
• DHSGoal5.4– RapidlyRecoverfromCatastrophicEvents:Thisprojectwillprovideaccurateinformationontheinteractionofhazardswithcriticalinfrastructureandthepatternsoftheseindividualhazardsduringindividualevents,asneededforeffectivepost-disasterplanningandforminimizingfutureexposure.
AnticipatedProjectImpact(1)
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
• Developandtestastatisticalandmodelingframeworkovertheexpectedrangeofforcing.
• Delineatemagnitudesandareasofsignificantdifferencesandinvestigateimpactsoninundationprobabilities
• DevelopobjectivemethodologyforRFapproachtostormselectionthatincludesrainfall,hydrologicinputs,andantecedentconditions.
• Evaluateperformanceofthenewlyreleased2DversionofHEC-RAS• Compare2DHEC-RASperformancewithSOBEKand/orSWATforADCIRCcoupling• Deploycoupledsystemondifferentriversystemtoseeifconclusionsaregeneral
(possiblylowerJamesRiverarea)• Includeprecipitationinsurgemodel• Definea“flashiness”parameterforriverbasinstoidentifywherecouplingismore
importantduringprecipitationevents
ExpectedFutureResearchWorkandAccomplishments
CRC2ndAnnualMeetingFeb.1-3,2017TheUniversityofNorthCarolinaatChapelHill
• Developtestconcepts(withstakeholderinput)forNorfolk-HamptonRoadscoupledsurge-rain-hydrologicmodelingsystem
• UsingexistingdatafrompreviousFEMAfloodmapstudiesinthisarea,developasetofsub-domainmodelsfortesting.
• Investigatethestabilityandaccuracyof1-waycouplingto2-waycoupling• Estimatetheareasandsignificanceofimpactsofcoupledmodelingcomparedto
surge-onlymodeling• Evaluatethemodelingsystemandstatisticalframeworkfortransitiontofull-
scaleapplications• Providerecommendationsonanyneededalterationstothesystemneeded
beforetransition,ifany
ProposedFollow-onWork