PAGE 4 Mymostprofoundthanksgotomyparents,NadezhdaandVladimir,fortheirloveandendlesssupport.Iwishtoexpressmysincereappreciationtomyadvisorandsupervisorycommitteechairman,Dr.Y.PeterSheng.Iwouldalsoliketothankthemembersofmysupervisorycommittee,Dr.RobertG.Dean,Dr.UlrichH.Kurzweg,Dr.RobertJ.Thieke,andDr.AndrewB.Kennedy.IwouldalsoliketothankYanfengZhang,VladimirParamygin,JeKing,KijinPark,TaeyunKim,JunLee,JustinDavis,DetongSun,DaveChristian,EnriqueGutierrez,andTatianaLomasko. iv PAGE 5 page ACKNOWLEDGMENTS ............................. iv LISTOFTABLES ................................. ix LISTOFFIGURES ................................ xii ABSTRACT .................................... xxii CHAPTER 1INTRODUCTION .............................. 1 1.1LiteratureReview ............................ 2 1.1.1WaveEectonSurfaceStress ................. 3 1.1.2WaveEectinWave-CurrentInteractionattheBottom ... 5 1.1.3WaveEectthroughRadiationStress ............. 9 1.1.4Miscellaneous .......................... 12 1.2StormSurgeModelReview ...................... 12 1.2.1SLOSH .............................. 14 1.2.2TAOS .............................. 14 1.2.3SPH/WIFM ........................... 15 1.2.4HAZUS .............................. 15 1.2.5ADCIRC ............................. 16 1.2.6SURGE ............................. 17 1.2.7POMcoupledwithWAVEWATCH-IIwavemodel ...... 18 1.2.8CH3D .............................. 19 2THISSTUDY ................................. 20 2.1CH3D-SSMS:WhatMakesitaBetterModel? ............ 20 2.2GoalsandQuestionstobeAnswered ................. 21 2.3ComponentsofCH3D-SSMS ...................... 22 2.3.1Wind ............................... 22 2.3.2RegionalCirculationModel:ADCIRC ............. 29 2.3.3RegionalWaveModel:WAVEWATCH-III .......... 31 2.3.4LocalCirculationModel:CH3D ................ 32 2.3.4.1Governingequations ................. 33 2.3.4.2ImplementationofWetting-and-DryingAlgorithmintoCH3D ...................... 38 2.3.4.3SurfaceandBottomStresses ............. 44 v PAGE 6 ... 45 2.3.4.5RadiationStress ................... 51 2.3.5LocalWaveModel:SWAN ................... 53 3METHODOLOGY .............................. 58 3.1Introduction ............................... 58 3.2CouplingMechanism .......................... 58 4TESTSIMULATIONS ............................ 64 4.1ValidationofWetting-and-DryingSchemeImplementedinCH3D . 64 4.1.1Description ............................ 64 4.1.2Validation ............................ 65 4.1.2.1TestCase1:Wall ................... 65 4.1.2.2TestCase2:Wind .................. 67 4.1.2.3TestCase3:AnalyticalSolution .......... 68 4.2ValidationofAtmosphericPressureGradientTermsImplementedinCH3D ................................. 73 4.2.1Description ............................ 73 4.2.2Validation ............................ 74 4.3ValidationofNear-BottomWave-CurrentInteraction ........ 76 4.3.1Description ............................ 76 4.3.2Validation ............................ 76 4.3.2.1PureOscillatoryFlow ................ 77 4.3.2.2CurrentSuperimposedonanOscillatoryFlow ... 79 4.4ValidationofWaveSetupCalculatedbasedonSWAN-CH3Dcou-pling ................................... 81 4.4.1Description ............................ 81 4.4.2Validation ............................ 82 4.5ValidationofCrossandLongshoreCurrentsBasedonREF/DIF-CH3DCoupling ............................. 84 4.5.1DescriptionofCross-shoreandLongshoreCurrents ..... 84 4.5.2Validation ............................ 86 4.6ValidationofWaveHeightSimulatedbySWANUnderStormCon-ditions .................................. 91 5VALIDATIONOFTHESTORMSURGEMODELINGSYSTEM .... 94 5.1HurricaneIsabel(2003) ......................... 94 5.1.1DescriptionAccordingtoNHC ................. 94 5.1.2ComputationalDomain ..................... 96 5.1.3FieldData ............................ 97 5.1.4ForcingandBoundaryConditions ............... 100 5.1.5Results:SimulatedWave .................... 108 5.1.6Results:SimulatedWaterLevel ................ 114 5.1.7ErrorAnalysisofCalculatedWaterLevel ........... 122 vi PAGE 7 ................ 136 5.1.9Results:SimulatedCurrents .................. 146 5.2HurricaneCharley(2004) ........................ 150 5.2.1DescriptionAccordingtoNHC ................. 150 5.2.2ComputationalDomain ..................... 152 5.2.3Data ............................... 153 5.2.4Results:SimulatedWaterLevel ................ 156 5.2.5ErrorAnalysisofCalculatedWaterLevel ........... 167 5.2.6Results:SimulatedFloodLevel ................ 175 5.3HurricaneFrances(2004) ........................ 183 5.3.1DescriptionAccordingtoNHC ................. 183 5.3.2ComputationalDomain ..................... 185 5.3.3Data ............................... 186 5.3.4Results:SimulatedWaterLevel ................ 188 5.3.5ErrorAnalysisofCalculatedWaterLevel ........... 192 5.3.6Results:SimulatedFloodLevel ................ 199 6FUTUREENHANCEMENTSANDAPPLICATIONS .......... 201 6.1ModelingofMorphologicalImpactsofExtremeStorms ....... 201 6.2RipCurrentForecasting ........................ 201 7CONCLUSIONS ............................... 203 APPENDIX ASAFFIR-SIMPSONHURRICANESCALE ................. 208 BFORMULAETOCALCULATEERRORS ................. 210 CBESTTRACKSFORISABEL,CHARLEY,ANDFRANCES ...... 211 DWINDSPEEDANDDIRECTIONDURINGHURRICANEISABEL:WNAANDWINDGENVS.MEASURED ................. 216 EOUTERBANKS/CHESAPEAKEBAYCOMPUTATIONALGRIDEX-AMPLEPLOT ................................ 228 FHURRICANEISABEL:SIMULATEDRESULTSVS.MEASUREDDATA 230 F.1Simulatedvs.MeasuredWaterLevel ................. 230 F.2Simulatedvs.MeasuredSurge ..................... 238 GHURRICANECHARLEY:SIMULATEDVS.MEASUREDWATERLEVEL .................................... 242 HHURRICANEFRANCES:SIMULATEDRESULTSVS.MEASUREDDATA ..................................... 247 vii PAGE 8 ................. 247 H.2Simulatedvs.MeasuredSurge ..................... 250 ILOW-PASSFILTER ............................. 252 REFERENCES ................................... 254 BIOGRAPHICALSKETCH ............................ 261 viii PAGE 9 Table page 1{1Asummaryofstormsurgemodels. ..................... 13 2{1Winddatasummary. ............................. 24 2{2Parametersusedtocreatethe\lookuptable". ............... 51 4{1WaveparametersusedtoimposeHurricaneFloyd(1999)boundarycon-ditions. .................................... 92 4{2ComparisonofcalculatedandmeasuredwaveheightduringHurricaneFloyd(1999). ................................. 92 4{3ComparisonofcalculatedandmeasuredwaveheightduringHurricaneFloyd(1999)withwavesetupbeingaccountedfor. ............ 93 4{4WaveparametersusedtoimposeHurricaneBonnie(1998)boundarycon-ditions. .................................... 93 4{5ComparisonofcalculatedandmeasuredwaveheightduringHurricaneBonnie(1998). ................................ 93 5{1MeasuredstormtidecrestsatseveralsitesinNorthCarolina,Virginia,andMaryland. ................................ 96 5{2Tide,windandwavestationsusedforvalidationofthemodelduringHurricaneIsabel. ............................... 99 5{3ADCIRCtidalconstituentsandtheirperiodsusedintheCH3DmodeltosimulateHurricaneIsabel. ......................... 101 5{4TidalconstituentparametersatDuckPier,NCcalculatedbasedonAD-CIRCtidalconstituentsandIOSprogram. ................. 102 5{5TidalconstituentparametersatBeaufort,NCcalculatedbasedonAD-CIRCtidalconstituentsandIOSprogram. ................. 103 5{6ErrorsofWNAandWINDGENwindspeedanddirectioncomparedwithmeasuredatwindstationsduringHurricaneIsabel. ............ 105 5{7Alistofsimulationswithvariouscombinationsofsixmodelfeatures(psymboldenotesthefeaturewasincludedduringthesimulation). ..... 122 ix PAGE 10 ......... 124 5{9MeasuredpeakwaterelevationsatsevenstationsduringHurricaneIs-abelusingWNAwindandvariouscombinationsofstormsurgemodelfeatures. .................................... 130 5{10Calculatedpeakstormsurge(withtidessubtracted)atsevenstationsduringHurricaneIsabelusingWNAwindandvariouscombinationsofstormsurgemodelfeatures. ......................... 131 5{11Alistofsimulationswithvariouscombinationsofsixmodelfeatures(psymboldenotesthefeaturewasincludedduringthesimulation). ..... 167 5{12ErrorsofwaterelevationattidestationsduringHurricaneCharley. ... 169 5{13MeasuredpeakwaterelevationsatfourstationsduringHurricaneCharleyusingWINDGENwindandvariouscombinationsofstormsurgemodelfeatures. .................................... 173 5{14Calculatedpeakstormsurge(withtidessubtracted)atfourstationsdur-ingHurricaneCharleyusingWINDGENwindandvariouscombinationsofstormsurgemodelfeatures. ........................ 173 5{15Comparisonbetweenreportedhighwatermarkvaluesandoodlevelscalculatedusingtwotechniques ....................... 181 5{16Alistofsimulationswithvariouscombinationsofsixmodelfeatures(psymboldenotesthefeaturewasincludedduringthesimulation). ..... 193 5{17ErrorsofwaterelevationattidestationsduringHurricaneFrances. ... 194 5{18MeasuredpeakwaterelevationsatthreestationsduringHurricaneFrancesusingWNAwindandvariouscombinationsofstormsurgemodelfeatures. 198 5{19Calculatedpeakstormsurge(withtidessubtracted)atthreestationsduringHurricaneFrancesusingWNAwindandvariouscombinationsofstormsurgemodelfeatures. ......................... 198 7{1Summaryofsimulatedhurricanes. ...................... 207 C{1BesttrackforHurricaneIsabel,6-19September2003. ........... 212 C{2BesttrackforHurricaneCharley,9-14August2004. ............ 214 C{3BesttrackforHurricaneFrances,31August-7September2004. ..... 215 F{1Alistofsimulationswithvariouscombinationsofsixmodelfeatures(psymboldenotesthefeaturewasincludedduringthesimulation). ..... 230 x PAGE 11 ..... 242 H{1Alistofsimulationswithvariouscombinationsofsixmodelfeatures(psymboldenotesthefeaturewasincludedduringthesimulation). ..... 247 xi PAGE 12 Figure page 2{1TheADCIRCcomputationalgrid. ...................... 30 2{2TheWAVEWATCH-IIINorthAtlanticregionalcomputationalgrid. ... 32 3{1Adiagramofvariousphysicalprocesses.Thoseinredareaccountedforinthismethodology. ............................. 59 3{2Adiagramofthecouplingprocess. ..................... 63 4{1Thewalltestcase:computationallayout. .................. 66 4{2Thewalltestcase:calculatedwatersurfaceelevation. ........... 66 4{3Thewindtestcase:computationallayout. ................. 67 4{4Thewindtestcase:calculatedwatersurfaceelevation. .......... 68 4{5Tidalcase:comparisonwithanalyticsolutionatt=0. ........... 70 4{6Tidalcase:comparisonwithanalyticsolutionatt=/6. ......... 70 4{7Tidalcase:comparisonwithanalyticsolutionatt=/3. ......... 71 4{8Tidalcase:comparisonwithanalyticsolutionatt=/2. ......... 71 4{9Tidalcase:comparisonwithanalyticsolutionatt=2/3. ......... 72 4{10Tidalcase:comparisonwithanalyticsolutionatt=5/6. ......... 72 4{11Tidalcase:comparisonwithanalyticsolutionatt=. ........... 73 4{12Analyticalsolutionofwatersurfaceelevationduetoatmosphericpres-suregradientforasimpliedhurricane. ................... 75 4{13Dierenceinwaterelevationbetweentheanalyticalandnumericalsolu-tions. ...................................... 76 4{14Comparisonbetweenmeasured( JonssonandCarlsen , 1979 )[dashedlinewithsquares]andcalculated[solidline]velocityprolesforeightphaseangles. ..................................... 78 4{15Verticalproleofthecalculatedphaselagbetweenhorizontalvelocitiesandfreestreamvelocity. ........................... 78 xii PAGE 13 JonssonandCarlsen ( 1979 )experiment[dashedlinewithsquares]. ............... 79 4{17Comparisonbetweenmeasured( BakkerandDorn , 1978 )[dashedlinewithsquares]andcalculated[solidline]velocityprolesforeightphaseangles. ..................................... 80 4{18Bottomstressduetowave-currentinteractioncalculatedusingthe1-DBBLmodelbasedonthenumericalsimulationofthe BakkerandDorn ( 1978 )laboratoryexperiment. ........................ 81 4{19LayoutofStiveandWindexperimentalsetup(from StiveandWind ( 1982 )). 82 4{20LayoutofMoryandHammexperimentalsetup(from MoryandHamm ( 1997 )). .................................... 84 4{21Comparisonbetweenmeasuredandcalculatedwavesetup( MoryandHamm ( 1997 )experiment). .......................... 85 4{22Calculatedfreesurfaceelevationandcurrentpatternalongwiththelo-cationswhereverticalvelocityprolesweremeasured(lettersAthroughN). ....................................... 87 4{23Simulated(reddashedline)vs.measured(greensolidline)longshoreve-locities:prolesA,B,C,andN. ....................... 88 4{24Simulated(reddashedline)vs.measured(greensolidline)cross-shorevelocities:prolesA,B,C,andN. ..................... 89 4{25Simulated(reddashedline)vs.measured(greensolidline)longshoreve-locities:prolesD,F,I,andH. ....................... 89 4{26Simulated(reddashedline)vs.measured(greensolidline)cross-shorevelocities:prolesD,F,I,andH. ...................... 90 4{27Simulated(reddashedline)vs.measured(greensolidline)longshoreve-locities:prolesEandG. .......................... 90 4{28Simulated(reddashedline)vs.measured(greensolidline)cross-shorevelocities:prolesEandG. ......................... 90 4{29TheFRFinstrumentsetupatDuck,NC .................. 91 5{1BesttrackofHurricaneIsabel(courtesyofNOAANHC). ......... 95 5{2TheOuterBanksandChesapeakeBaygriddomainforIsabelsimulation. 98 5{3LocationofthenineRiverInputMonitoringsites(courtesyofUSGS). . 100 xiii PAGE 14 ................................... 101 5{5WINDGENandWNAvs.measuredwindspeedanddirectionatCapeLookout,NCduringHurricaneIsabel. ................... 104 5{6WINDGENandWNAvs.measuredwindspeedanddirectionatDuckPier,NCduringHurricaneIsabel. ...................... 104 5{7SignicantwaveheightandpeakwaveperiodobtainedfromWAVEWATCH-IIIcomparedwithmeasuredwaveheightatNDBCstation41001. .... 107 5{8SignicantwaveheightandpeakwaveperiodobtainedfromWAVEWATCH-IIIcomparedwithmeasuredwaveheightatNDBCstation41002. .... 107 5{9LocationoftheVIMSinstrumentpackageatGloucesterPoint,VA. ... 108 5{10Simulatedsignicantwaveheightvs.measuredfromtheFRFWaveriderbuoyduringHurricaneIsabel. ........................ 109 5{11Simulatedpeakwaveperiodvs.measuredfromtheFRFWaveriderbuoyduringHurricaneIsabel. ........................... 110 5{12Simulatedwavedirectionvs.measuredfromtheFRFWaveriderbuoyduringHurricaneIsabel. ........................... 111 5{13Atestcase:wavesetupandcurrentsinducedbywavesapproachingtheshorefromsouth-westtonorth-east(toppanel),andfromnorth-westtosouth-east(bottompanel). .......................... 112 5{14Simulatedsignicantwaveheightandpeakwaveperiodvs.measuredfromtheFRFpierduringHurricaneIsabel. ................ 113 5{15Simulatedsignicantwaveheightandpeakwaveperiodvs.measuredatVIMSduringHurricaneIsabel. ....................... 114 5{16Comparisonofsimulatedvs.measuredwaterelevationatBeaufort,NC.Twosimulatedresultsareshown:oneusingWNAwindandtheotherusingWINDGENwind. ........................... 115 5{17Comparisonofsimulatedvs.measuredwaterelevationatDuck,NC.Twosimulatedresultsareshown:oneusingWNAwindandtheotherusingWINDGENwind. ............................... 115 5{18Comparisonofsimulatedvs.measuredwaterelevationatChesapeakeBayBridge,VA.Twosimulatedresultsareshown:oneusingWNAwindandtheotherusingWINDGENwind. ................... 116 xiv PAGE 15 ........................... 116 5{20Comparisonofsimulatedvs.measuredwaterelevationatMoneyPoint,VA.Twosimulatedresultsareshown:oneusingWNAwindandtheotherusingWINDGENwind. ........................... 117 5{21Comparisonofsimulatedvs.measuredwaterelevationatKiptopeke,VA.Twosimulatedresultsareshown:oneusingWNAwindandtheotherusingWINDGENwind. ........................... 117 5{22Comparisonofsimulatedvs.measuredwaterelevationatLewisetta,VA.Twosimulatedresultsareshown:oneusingWNAwindandtheotherusingWINDGENwind. ........................... 118 5{23MaximumwaterelevationrelativetoNAVD88(includestide,surgeandwavesetup)calculatedduringsimulationofHurricaneIsabelintheOuterBanks/ChesapeakeBayusingWNAwind. ................. 120 5{24MaximumwavesetupelevationrelativetoNAVD88calculatedduringsimulationofHurricaneIsabelinthesouthernpartofOuterBanksus-ingWNAwind. ................................ 121 5{25Simulatedstormsurge(waterlevelminustide)atthesevenstationsthrough-outtheOuterBanks/ChesapeakeBayusingWNAwind. ......... 121 5{26Separatelysimulatedtide,wavesetup,andsurge,andtheirlinearsuper-positionatDuck. ............................... 133 5{27Linearlycoupledwaterelevationvs.waterelevationcalculatedthroughdynamiccouplingatDuck,NC. ....................... 133 5{28Linearlycoupledwaterelevationvs.waterelevationcalculatedthroughdynamiccouplingatDuck,NC. ....................... 134 5{29Linearlycoupledwaterelevationvs.waterelevationcalculatedthroughdynamiccouplingneartheSouthRiver,NC.ThelocationisinitiallydryandgetsoodedduringIsabel.Afterthesurgerecedes,itbecomesdryagain. ..................................... 135 5{30Linearlycoupledwaterelevationvs.waterelevationcalculatedthroughdynamiccouplingononeoftheemergentislandsoftheOuterBanks,NC.ThelocationisinitiallydryandgetsoodedduringIsabel.Afterthesurgerecedes,itbecomesdryagain. .................. 135 5{31Linearlycoupledwaterelevationvs.waterelevationcalculatedthroughdynamiccouplingnearGloucester,VA.ThelocationisinitiallydryandgetsoodedduringIsabel.Afterthesurgerecedes,itbecomesdryagain. 136 xv PAGE 16 ........ 137 5{33MaximumsimulatedinundationintheeasternpartoftheOuterBanksduringHurricaneIsabelusingWNAwind(toppanel).Thebottompanelshowsthetimeduringwhichthemaximumoodoccurred. ........ 138 5{34MaximumsimulatedinundationintheChesapeakeBayduringHurri-caneIsabelusingWNAwind(toppanel).Thebottompanelshowsthetimeduringwhichthemaximumoodoccurred. .............. 139 5{35MaximumsimulatedinundationinthesouthernpartoftheOuterBanksduringHurricaneIsabelusingWINDGENwind(toppanel).Thebot-tompanelshowsthetimeduringwhichthemaximumoodoccurred. .. 140 5{36MaximumsimulatedinundationintheeasternpartoftheOuterBanksduringHurricaneIsabelusingWINDGENwind(toppanel).Thebot-tompanelshowsthetimeduringwhichthemaximumoodoccurred. .. 141 5{37MaximumsimulatedinundationintheChesapeakeBayduringHurri-caneIsabelusingWINDGENwind(toppanel).Thebottompanelshowsthetimeduringwhichthemaximumoodoccurred. ........... 142 5{38Pre-storm(top)andpost-storm(middle)airphotostakeninthesouth-ernOuterBanks. ............................... 144 5{39Pre-storm(top)andpost-storm(middle)airphotostakenintheeasternOuterBanks. ................................. 145 5{40LocationofKittyHawk,NCwherecurrentsweremeasured. ....... 146 5{41LocationofGloucesterPoint,VAwherecurrentsweremeasured. ..... 147 5{42Measured(left)andsimulated(right)\SouthtoNorth"currentatKittyHawk,NCduringHurricaneIsabel. ..................... 148 5{43Measured(left)andsimulated(right)\WesttoEast"currentatKittyHawk,NCduringHurricaneIsabel. ..................... 148 5{44Measured(left)andsimulated(right)\SouthtoNorth"currentatGlouces-terPoint,VAduringHurricaneIsabel. ................... 149 5{45Measured(left)andsimulated(right)\WesttoEast"currentatGlouces-terPoint,VAduringHurricaneIsabel. ................... 149 5{46BesttrackofHurricaneCharley(courtesyofNOAANHC). ........ 150 5{47TheCharlotteHarborgriddomain. ..................... 153 xvi PAGE 17 ...................... 154 5{49Measuredwinddirectionvs.WINDGENandWNAwinddataatFtMy-ers,FLduringHurricaneCharley. ...................... 155 5{50Measuredwindspeedvs.WINDGENandWNAwinddataatNaples,FLduringHurricaneCharley. ........................ 155 5{51Measuredwinddirectionvs.WINDGENandWNAwinddataatNaples,FLduringHurricaneCharley. ........................ 156 5{52Comparisonofsimulatedvs.measuredwaterelevationatBigCarlosPass.Twosimulatedresultsareshown:oneusingWNAwindandanotherus-ingWINDGENwind. ............................. 157 5{53Comparisonofsimulatedvs.measuredwaterelevationatEsteroBay,lo-cation1.Twosimulatedresultsareshown:oneusingWNAwindandanotherusingWINDGENwind. ....................... 157 5{54Comparisonofsimulatedvs.measuredwaterelevationatEsteroBay,lo-cation2.Twosimulatedresultsareshown:oneusingWNAwindandanotherusingWINDGENwind. ....................... 158 5{55Comparisonofsimulatedvs.measuredwaterelevationatFtMyers.Twosimulatedresultsareshown:oneusingWNAwindandanotherusingWINDGENwind. ............................... 158 5{56Simulatedvs.measuredwaterelevationatEsteroBay,location1.Dashedlinesspecifythethreetimeinstantswhenwindsnapshotsweretaken. .. 159 5{57WNAwindeldsnapshot1(Aug-1320:55,JulianDay=226.872)alongwithtotaldepthcontoursintheEsteroBayarea. ............. 160 5{58WINDGENwindeldsnapshot1(Aug-1320:55,JulianDay=226.872)alongwithtotaldepthcontoursintheEsteroBayarea. .......... 160 5{59WNAwindeldsnapshot2(Aug-1320:55,JulianDay=226.872)alongwithtotaldepthcontoursintheEsteroBayarea. ............. 161 5{60WINDGENwindeldsnapshot2(Aug-1320:55,JulianDay=226.872)alongwithtotaldepthcontoursintheEsteroBayarea. .......... 161 5{61WNAwindeldsnapshot3(Aug-1401:20,JulianDay=227.055)alongwithtotaldepthcontoursintheEsteroBayarea. ............. 162 5{62WINDGENwindeldsnapshot3(Aug-1401:20,JulianDay=227.055)alongwithtotaldepthcontoursintheEsteroBayarea. .......... 162 xvii PAGE 18 ....... 163 5{64MaximumwaterelevationrelativetoNAVD88(includestide,surgeandwavesetup)calculatedduringsimulationofHurricaneCharleyinChar-lotteHarborusingWINDGENwind. .................... 165 5{65Simulatedstormsurge(waterlevelminustide)atthefourstationsusingWINDGENwind. ............................... 166 5{66MaximumsimulatedinundationinCharlotteHarborusingWINDGENwind(toppanel).Thebottompanelshowsthetimeduringwhichthemaximumoodoccurred. .......................... 176 5{67MaximumsimulatedinundationinCharlotteHarborusingWNAwind(toppanel).Thebottompanelshowsthetimeduringwhichthemaxi-mumoodoccurred. ............................. 177 5{68Pre-storm(top)andpost-storm(middle)airphotostakennearCaptivaIsland.Aclose-upofourcalculatedoodmap(bottom)veriesthepres-enceofwaterovertheland. ......................... 179 5{69Pre-storm(top)andpost-storm(middle)airphotostakennearSanibelIsland. ..................................... 180 5{70NauticalchartofcoastalareasintheCharlotteHarborareaimpactedbyHurricaneCharley. ............................ 181 5{71ManpointsatahighwatermarkleftbystormsurgecausedbyHurri-caneCharleyonNorthCaptivaIsland. ................... 182 5{72BesttrackofHurricaneFrances(courtesyofNOAANHC). ........ 183 5{73TheTampaBaygriddomain. ........................ 187 5{74Comparisonofsimulatedvs.measuredwaterelevationatClearwater,FL.Twosimulatedresultsareshown:oneusingWNAwindandtheotherusingWINDGENwind. ........................... 188 5{75Comparisonofsimulatedvs.measuredwaterelevationatStPete,FL.Twosimulatedresultsareshown:oneusingWNAwindandtheotherusingWINDGENwind. ........................... 189 5{76Comparisonofsimulatedvs.measuredwaterelevationatPortMana-tee,FL.Twosimulatedresultsareshown:oneusingWNAwindandtheotherusingWINDGENwind. ........................ 189 xviii PAGE 19 ............................ 191 5{78Simulatedstormsurge(waterlevelminustide)atthethreestationsus-ingWNAwind. ................................ 192 5{79MaximumsimulatedinundationinTampaBayusingWNAwind(toppanel).Thebottompanelshowsthetimeduringwhichthemaximumoodoccurred. ................................ 200 D{1WINDGENandWNAvs.measuredwindspeedanddirectionatCapeLookout,NCduringHurricaneIsabel. ................... 217 D{2WINDGENandWNAvs.measuredwindspeedanddirectionatDuck,NCduringHurricaneIsabel. ......................... 218 D{3WINDGENandWNAvs.measuredwindspeedanddirectionatChesa-peakeLight,VAduringHurricaneIsabel. .................. 219 D{4WINDGENandWNAvs.measuredwindspeedanddirectionatChesa-peakeBayBridge,VAduringHurricaneIsabel. .............. 220 D{5WINDGENandWNAvs.measuredwindspeedanddirectionatKip-topeke,VAduringHurricaneIsabel. .................... 221 D{6WINDGENandWNAvs.measuredwindspeedanddirectionatMoneyPoint,VAduringHurricaneIsabel. ..................... 222 D{7WINDGENandWNAvs.measuredwindspeedanddirectionatGlouces-terPoint,VAduringHurricaneIsabel. ................... 223 D{8WINDGENandWNAvs.measuredwindspeedanddirectionatLe-wisetta,VAduringHurricaneIsabel. .................... 224 D{9WINDGENandWNAvs.measuredwindspeedanddirectionatHPLWS,VAduringHurricaneIsabel. ......................... 225 D{10WINDGENandWNAvs.measuredwindspeedanddirectionatChop-tankRiver,VAduringHurricaneIsabel. .................. 226 D{11WINDGENandWNAvs.measuredwindspeedanddirectionatNorthBay,VAduringHurricaneIsabel. ...................... 227 E{1ComputationalgridnearChesapeakeBaymouth. ............. 228 E{2ComputationalgridintheSouthOuterBanksarea. ............ 229 F{1Comparisonofsimulatedvs.measuredwaterelevationatBeaufort,NC. 231 xix PAGE 20 .. 232 F{3Comparisonofsimulatedvs.measuredwaterelevationatChesapeakeBayBridge,VA. ............................... 233 F{4Comparisonofsimulatedvs.measuredwaterelevationatGloucesterPoint,VA. ...................................... 234 F{5Comparisonofsimulatedvs.measuredwaterelevationatMoneyPoint,VA. ...................................... 235 F{6Comparisonofsimulatedvs.measuredwaterelevationatKiptopeke,VA. 236 F{7Comparisonofsimulatedvs.measuredwaterelevationat,Lewisetta,VA. 237 F{8Comparisonofsimulatedvs.measuredstormsurgeelevationatBeau-fort,NC.CalculatedresultsarebasedonSimulation3usingWNAwind. 238 F{9Comparisonofsimulatedvs.measuredstormsurgeelevationatDuck,NC.CalculatedresultsarebasedonSimulation3usingWNAwind. ... 239 F{10Comparisonofsimulatedvs.measuredstormsurgeelevationatChesa-peakeBayBridge,VA.CalculatedresultsarebasedonSimulation3us-ingWNAwind. ................................ 239 F{11Comparisonofsimulatedvs.measuredstormsurgeelevationatGlouces-terPoint,VA.CalculatedresultsarebasedonSimulation3usingWNAwind. ...................................... 240 F{12Comparisonofsimulatedvs.measuredstormsurgeelevationatMoneyPoint,VA.CalculatedresultsarebasedonSimulation3usingWNAwind. 240 F{13Comparisonofsimulatedvs.measuredstormsurgeelevationatKiptopeke,VA.CalculatedresultsarebasedonSimulation3usingWNAwind. ... 241 F{14Comparisonofsimulatedvs.measuredstormsurgeelevationatLewisetta,VA.CalculatedresultsarebasedonSimulation3usingWNAwind. ... 241 G{1Comparisonofsimulatedvs.measuredwaterelevationatBigCarlosPass,FL. ....................................... 243 G{2Comparisonofsimulatedvs.measuredwaterelevationatEsteroBay#1,FL. .................................... 244 G{3Comparisonofsimulatedvs.measuredwaterelevationatEsteroBay#2,FL. .................................... 245 G{4Comparisonofsimulatedvs.measuredwaterelevationatFtMyers,FL. 246 xx PAGE 21 . 248 H{2Comparisonofsimulated(usingWNAwind)vs.measuredwatereleva-tionatStPete,FL.Calculatedresultsarebasedonvesimulations. .. 249 H{3Comparisonofsimulated(usingWNAwind)vs.measuredwatereleva-tionatPortManatee,FL.Calculatedresultsarebasedonvesimulations. 249 H{4Comparisonofsimulatedvs.measuredstormsurgeelevationatClear-water,FL.CalculatedresultsarebasedonSimulation3usingWNAwind. 250 H{5Comparisonofsimulatedvs.measuredstormsurgeelevationatStPete,FL.CalculatedresultsarebasedonSimulation3usingWNAwind. ... 251 H{6Comparisonofsimulatedvs.measuredstormsurgeelevationatPortMan-atee,FL.CalculatedresultsarebasedonSimulation3usingWNAwind. 251 xxi PAGE 22 Astormsurgemodelingsystem,CH3D-SSMS,thatcouplesregionalandlocalscalecirculationandwavemodelswasdeveloped.ThemodelcalculatesstormsurgeelevationduringhurricaneeventsusingeithersimpleanalyticwindeldorwindeldsproducedbysophisticatedwindmodelssuchasNCEPWNAandWINDGEN.TheCH3Dmodelisdynamicallycoupledwithawavemodel,SWAN,accountingforwavesetup,waveenhancedsurfacestress,andwaveenhancedbottomfriction.Themodelalsofeaturesarobustoodinganddryingschemethatallowssimulatingofstorminducedinundation.TheCH3Dmodelisalsocoupledwitharegionalscalecirculationmodel,ADCIRC,thatprovidesstormsurgeelevationconditionsalongopenboundaries.ThemodelwasvalidatedbysimulatingHurricanesIsabel,Charley,andFrances. Theeectsofvariousinteractionsamongstormsurge,tide,windandwaveonsurgewereinvestigated.ForIsabelandFrances,WNAwindwasmoreaccuratethanWINDGENwindandproducedmoreaccuratestormsurge.ForCharley,WINDGENwasmoreaccuratethanWNAandproducedmoreaccuratesurge.WhenIsabel,Charley,andFrancesweresimulatedusingtideandwindonly,the xxii PAGE 23 Thedynamicallycoupledwaterelevationwascomparedwithlinearlysuperim-posedresultsofindependentlysimulatedtide,wavesetup,andsurge.Theeectistwofold:overopenwater,dynamiccouplingproducesslightlymoreaccuratestormsurge,andoverland,theinundationcalculatedthroughdynamiccouplingoccursearlierandismoresignicant. Theeectofexcludingthewetting-and-dryingfeatureduringstormsurgesimulationswasalsoexaminedandfoundsignicant.DuringCharley,whenthefeaturewasdisabled,thecalculatedwaterelevationatitspeakwassignicantlyoverestimated. xxiii PAGE 24 HurricanesarethemostdevastatinganddamaginghazardsimpactingtheUnitedStates.Today,hurricanedamagecostsbillionsofdollars.Accordingtothe NationalOceanicandAtmosphericAdministration(NOAA) ( 2005 ),duringthelastcentury,23hurricaneshadeachcauseddamageinexcessof$1billiondollars.DamagefromhurricaneAndrew(1992)alonewasestimatedatmorethan$25billiondollarsinSouthFloridaandLouisiana.Industrydatashowthat65%ofinsuredlossesfromnaturalhazardsintheU.S.overthepast50yearsareduetohurricanes.From1990through1999hurricanescaused140deathsand$50billioninpropertydamageintheU.S.Coastalstormsaccountfor71%ofrecentU.S.disasterlossesannuallywitheacheventcostingroughly$500million.In2004,forthersttimeinhistory,fourmajorhurricanes,Charley,Frances,IvanandJeanne,madelandfallinFlorida.The2004hurricaneseasonwillgodownasthemostcostlyseasononrecordintheU.S.( NOAA , 2005 ),with$42billionestimateddamage,deathstotaling59,anddeathsoutsideoftheU.S.atover3,000.Inaddition,Floridalostmanylivesandpartofthe2,170milesofshorelines.AbridgeandsectionsofI-10weredestroyedandtransportationinterruptedformanydays.Withpopulationanddevelopmentcontinuingtoincreasealongcoastalareas,agreaternumberofpeopleandpropertyarevulnerabletohurricanethreat.Hurricanescannotbecontrolledbutthevulnerabilitycanbereducedthroughaccurateforecasting. Themajordamagecausedbyhurricanesisassociatedwithstormsurgesandcoastalooding.Accordingto NOAA ( 1999 ),astormsurgeisalargedomeofwater,80to160kmwide,thatsweepsacrossthecoastlinenearwhereahurricane 1 PAGE 25 makeslandfall.Itcanbemorethan4.5mdeepatitspeak.Thesurgeofhighwatertoppedbywavescanbedevastating.Alongthecoast,stormsurgeisthegreatestthreattolifeandproperty. Notonlycanhurricanesdamagehousesandbuildingsinhighlypopulatedcoastalresidentialandcommercialareasbutalso,withinjustafewhours,theycancausedrasticchangesinthecoastlineasanoutcomeofmorphologicalresponse.Thismayresultinanecologicalimbalanceofestuarinesystems,especiallythosethatareseparatedfromtheoceanbybarrierislands,whichareacommonfeatureofFlorida'scoastline.Inordertoreducecoastalhazardsassociatedwithhurri-canes,itisnecessarytohaveanaccuratepredictionmodelofstormsurgeandcoastalooding,whichisessentialfordevelopingcosteectivestormmitigationandpreparation. Accuratestormsurgesimulationsarealsoessentialforproducingaccurateoodinsuranceratemaps(FIRMs)forcoastalcounties.Floridacoastalcountiesalonecontributemorethan40%ofthetotalinsurancepremiumscollectedbytheNationalFloodInsuranceProgram(NFIP)administeredbytheFederalEmergencyManagementAgency(FEMA). ShengandAlymov ( 2002 )showedthattheFEMAmethodologyonoodinsuranceratesinPinellascounty,Florida( FEMA , 1988 ),whichisbasedonthe1-DWHAFISmodel,overestimatespossibledamagethatmaybecausedbythe100-yearstormevent.Theuseofamorerobuststormsurgemodelwilllikelyresultinsignicantsavingsininsurancepremiums. BodeandHardy ( 1997 )pointedoutthelackof PAGE 26 robuststormsurgemodelsfortropicalstorms.Duringthelasttenyears,morehurricaneandstormsurgedatahavebeencollectedinFloridaandelsewhere,providingagoodopportunitytodevelopandvalidatenewstormsurgemodels.Manyexistingstormsurgemodelscontainrathersimplephysicseventhoughphysicallymeasurableattributes,suchaswaterlevel,actuallyincludethecombinedeectsofphysicalprocessessuchaswavesandtides.Theytakeintoaccountonlyafewhurricaneparameterssuchaspressuredecit,sizeofthestorm,itstranslationspeed,anddirection. Janssen ( 1991 )theseasurfacestressdependsnotonlyonwindspeedbutroughnessduetowavesaswell.Thetotalstressneartheseasurfaceisthesumoftheturbulentpartandwave-inducedpart, wheretistheturbulentstresswhichaccordingtothemixing-lengthhypothesiscanbeparameterizedasfollows: @z2(1{2) where=0:4isvonKarmanconstant;U(z)isthewindspeedatheightz;aistheairdensity. Janssen ( 1991 )alsointroducedtheeectiveroughnesslength,ze,asopposedtotheroughnesslength,z0,whenwavesareabsent.Theeectiveroughnesslengthisafunctionofthewave-inducedstress. Inderivationofhiswave-inducedstress, Janssen ( 1991 )usedthefollowingwindprole: whereuisthefrictionvelocity. PAGE 27 Ifequation 1{3 isdierentiated,squaredandcomparedwithequation 1{2 atz=z0,thefollowingrelationshipbetweenz0andzeisobtained: AssumingthatCharnok-likeexpressionz0=u2/gisvalid,thevalueofistunedinsuchawaythatze=u2/gforoldwindsea.Theoldwindseatermmeansthatwavesarenolongerdevelopingundercurrentwindconditionandthewave-inducedstressforsuchseadiminishes,yieldingze!z0.Foryoungwaves(travelingmuchslowerthatthewind)almosttheentiresurfacestressisduetowaves;therefore,w=approachesone. ZhangandLi ( 1996 )appliedthetheoryofJanssenintheircouplingofathird-generationwavemodelandatwo-dimensionalstormsurgemodel.ComparingtheirresultswithmeasureddataoftwostormeventsthattookplaceinthenorthernSouthChinaSea,theyfoundthattheintroductionofawavedependentdraggivesasignicantimprovementovertheuseofthe SmithandBanke ( 1975 )stressrelationwhichunderestimatedthesurgesby10%. whereCD=(0:066jU10j+0:63)103. Mastenbroeketal. ( 1993 )alsostudiedtheeectofawave-dependentdragcoecientonthegenerationofstormsurgesintheNorthSea.Toestimatetheeectsofwavesontheboundarylayer,thetheoryofJanssenwasused.Theresultswerecomparedtomeasureddataforthreestormperiods.Thecalculationswiththewave-dependentdraggaveasignicantimprovement.InturnthecalculationswiththeSmithandBankestressrelationunderestimatedthesurgesby20%. Donelanetal. ( 1993 )investigatedtheaerodynamicroughnessoftheseasurface,z0,usingdatafromLakeOntario,fromtheNorthSeaneartheDutch PAGE 28 coast,andfromanexposedsiteintheAtlanticOceanothecoastofNovaScotia.Theyfoundthatnormalizedroughnessdependsstronglyonwaveage(Cp/u)whereCpisthephasespeedofthewavesatthespectralpeak.Theirequationforthewaveenhanceddragcoecientis TheauthorsnormalizedroughnessbytheRMSwaveheightandusingthefrictionvelocity,u,ofthewindstressandconcludedthatinbothcasesyoungwaveswererougherthanmaturewaves. Xieetal. ( 2001 )investigatedtheinuenceofsurfacewavesonoceancurrentsinthecoastalwatersbyusingacoupledwave-currentmodelingsystem.Theytookintoaccountthefactthatthewave-inducedwindstressisnotonlyafunctionofwindspeedbutthewave-modieddragcoecientaswell,whichinturnisafunctionofthespectralpeakfrequencyofwaves.Foryoungwavesthespectralpeakfrequencyislarge,andaccordingly,thewave-inducedsurfacestressislarge.However,forfullydevelopedwindwavesthespectralpeakfrequencyissmall,andaccordingly,theeectofwavesonsurfacestressisrelativelysmall.Theauthorsnotethatthewavespectralpeakfrequencyincreasesasthewaterdepthdecreases.Intheirstudythemagnitudeofthepeakspectralfrequencyincreasesfromabout0.6rads1intherelativelydeeposhorewatertoapproximately0.9-1.0rads1intheshallowcoastalwaters.Asaconsequence,underaconstantwindtheeectofwavesonwindstressislargerintheshallowerwaterthaninthedeeperwater. GraberandMadsen ( 1988 ),theshapeofthewavespectruminnite-depth PAGE 29 watersissignicantlyinuencedbythebottomfriction.Duringastormeventwhenwavesarelargetheareaofsuchaninuenceextendsfaroshore. GrantandMadsen ( 1979 )developedananalyticaltheorytodescribethecombinedmotionofwavesandcurrentsinthevicinityofaroughbottomandtheassociatedboundaryshearstressbyconsideringacombinedwave-currentfrictionfactor.Themagnitudeofthemaximumboundaryshearstressduetocombinedwaveandcurrentis 2fcwj~ubj2(1{7) wherethecombinedfrictionfactorfcwisafunctionofj~uaj=j~ubj;j~uajisthemagnitudeofthesteadycurrentvelocityvectorataheightaabovethebottom;j~ubjisthemaximumnear-bottomorbitalvelocityfromlinearwavetheory; Schoellhamer ( 1993 )pointedoutweaknessesofthe GrantandMadsen ( 1979 )methodologywhichincludetheintroductionofactitiousreferencevelocityatanunknownlevel,theassumptionofthelogarithmiclayerbeingconstantwhichisnotcorrectwhenwavesarepresent. TangandGrimshaw ( 1996 )adaptedthe GrantandMadsen ( 1979 )bottomboundarylayertheorytostudytheeectofincreasedbottomfrictionduetowind-wavecurrentinteractionusinga2-Dshallowwaternumericalmodel.Theyshowedthatthe GrantandMadsen ( 1979 )theorymaybreakdowninveryshal-lowwaterwherethewaveamplitudesbecomelarge.Toavoidtheproblemtheauthorsintroducedanempiricalwave-breakingcriterionintothebottomfrictionformulation: ifaW PAGE 30 Basedontheirnumerical(hencenotveried)results, TangandGrimshaw ( 1996 )concludedthatalthoughthewind-waveenhancementofthebottomstressissignicantonlyinthenearshorezoneofshallowwater,thereisadramaticreductionintheseasurfaceelevationandthecurrentsinthisregion. SignellandList ( 1997 )studiedtheeectofwave-enhancedbottomfrictiononstorm-drivencirculationinMassachusettsBaybasedonasimpliedformofthe GrantandMadsen ( 1979 )theorydescribedby Signelletal. ( 1990 ).Theyfoundthatthedragcoecientincreasesdramaticallybyafactorof2-6.Themostsignicantdragcoecientenhancementtookplaceintheshallowregionsneartheshoreline.Inresponsetotheincreasedbottomdrag,however,bottomcurrentswerereducedby30%-70%.Sincethebottomstressisproportionaltobottomdragandtothesquareofthebottomvelocity,themeanbottomshearstressincreasedonlyby10%-60%insteadofafactorof2-6. Wangetal. ( 2000 )analyzedseveralimportantmechanismsforstorm-inducedentrainmentofestuarinesedimentsusingeldmeasurements.Theirstudyshowedthatthebottomshearstress,computedusingawave-currentinteractionmodelbased,again,onthe GrantandMadsen ( 1979 )theory,increasedsignicantlyduringepisodicwindevents.Thecurrentsandwavestendedtoenhanceeachothersothattheshearstressesduringthepeaksofstorms,computedfromthewave-currentinteractionmodel,wereapproximatelythreetimeslargerthanusingthetraditionalquadraticlaw.Alargere-suspensioneventwascausedbyafrontalpassagewhenstrongwind-drivencurrentsaugmentedthetidalcurrents.Itwasalsopointedoutinthisstudythatthetimingofstormwaveswithrespecttotidalphasewasacriticalfactor. LiuandDalrymple ( 1978 )proposedasimpleempiricalmodelwhichwasalsousedby SunandSheng ( 2002 )intheirstudyof3-Dwave-inducedcirculation.The PAGE 31 bottomshearstressisdenedas whereUwbisthemaximumnear-bedwaveorbitalvelocityestimatedfromlinearwavetheory;~ubisthenear-bedwave-averagedvelocity;Cdisthefrictioncoecientwhichcanbecalculatedaccordingtothelawofthewall Sheng ( 1986 ) whereisvonKarmanconstant,z0=ks=30withksbeingtheNikuradseequivalentsandroughness,andzbistheverticaldistanceofthelowergridpointabovethebottom. Thissimplemodelassumesthatwavesandcurrentsareco-linearwhichisratherunrealistic.Asaresultoftheassumption,thebottomstresswillbeoverestimatedwhenwaveandcurrentdirectionsdeviatefromeachother. Xieetal. ( 2001 )alsoemphasizethatsurfacewavesproducetwooppositeeectsoncirculation:energyinputthroughsurfacestressandenergydissipationthroughbottomstress.Theneteectofwave-inducedsurfaceandbottomstressescanbequitedierentunderdierentwinddirections.Thiseectcaneitherenhanceordampthesurfacecurrent.Theauthorsshowedthattheeectofwave-inducedbottomstressismoresignicantforalongshorewindsthanforcross-shorewinds.Theirresultsindicatedthattheeectofwavesoncurrentsismainlypresentinshallowcoastalwatersandattenuatesrapidlyoshoreaswaterdepthincreases. Xieetal. ( 2001 )alsonotethattheeectsofwave-inducedsurfaceandbottomstressesalsodependonthewindspeed.Intropicalcyclonesituationsthewave-inducedsurfaceshearstressisgenerallymoreimportantthanthatdueto PAGE 32 wave-inducedbottomstress,andhencetheeectofwindwavesusuallyincreasesthemagnitudeofstormsurge. JohnsonandKofoed-Hansen ( 2000 )studiedtheinuenceofbottomfrictiononseasurfaceroughness.Theirinvestigationsshowthatthebottomdissipationkeepswavesyoung,whichresultsinincreasedwindfriction. Wavesetupgenerallyoccursinthesurfzone.Thebreakingwavesproduceex-cessmomentumuxintheshorewarddirectionwhichisusuallytermed\radiationstress."Asthebrokenwavescontinuetopropagatetowardtheshore,theexcessmomentumuxorradiationstressdiminishes.Inthesteadystate,theshorewarddecreaseinradiationstressisbalancedbyashorewardincreaseinthewaterlevel.Thisraisesthewatersurfaceelevationwithinthesurfzonetohigherthanthestillwaterlevel(SWL)producingsetup.ItalsopushesthewaterleveloutsideofthesurfzonetolowerthantheSWLproducingsetdown. Itisnecessarytoaccountforwavesetupwithinthesurfzoneduringthecalculationofstormsurgeelevation.Thereasonforthatisthatthesetupmaybeverysignicantespeciallyduringastormevent.Accordingto DeanandDalrymple ( 1991 )thewavesetupneartheshoreisabout19%ofthebreakingwaveheight.Thesignicantwaveheightduringthe100-yearstormestimatedby FederalEmergencyManagementAgency(FEMA) ( 1988 )intheGulfofMexicois8.86mwiththeperiodof11.5sec.Thebreakingwaveheightduringthestormaccordingto DeanandDalrymple ( 1991 ,p.116)mayreach8.5massumingaplanebeach, PAGE 33 and0odeepwaterincidentangle.Therefore,thewavesetupmayreach1.62mattheshore,whichisasignicantvalueasfarasoodingcausedbythewavesetupisconcerned. Itwouldbeincorrecttoaddthecalculatedwavesetupontopofthecalculatedstormsurgeelevationlinearlysincethereisanon-linearinteractionbetweenthetwo.Moreover,itispracticallyimpossibletodistinctlyseparatethewavesetupfromeverythingelsebasedonthesurfaceelevationdatacollectedintheeld.Therefore,wavesetupshouldbeintroducedintheequationsintermsofradiationstresses,sothatthecalculatedsurfaceelevationwouldincludeitinternallyinanon-linearfashion. Longuet-HigginsandStewart ( 1964 )deriveddepth-integratedradiationstressquantitiesthatareusedinmanynumericalmodelsincludingstormsurgemodelsaccountingforwave-inducedsetup. Mastenbroeketal. ( 1993 )and ZhangandLi ( 1996 )incorporatedradiationstresstermsbasedonthe Longuet-HigginsandStewart ( 1964 )formulationintotwo-dimensionaloceancirculationequationsandinvestigatedtheimportanceofradiationstressincalculationofstormsurge. Mastenbroeketal. ( 1993 )reportedthatonlyinoneofthethreecasestheystudiedtheradiationstressincreasedthesurgesome5%.Intheothertwocasestheeectoftheradiationstresswasinsignicant.Similarly, ZhangandLi ( 1996 )concludedthattheinclusionoftheradiationstressimprovestheaccuracyofthecomputedresultsslightlyby2%. Ithastobepointedoutthatthestudyby Mastenbroeketal. ( 1993 )tookplaceintheNorthSeawithstationsalongtheDutchandBritishcoasts.Theauthorsdonotspecifyhowdeepthelocationsoftheirstationsare.Itishardtoestimatetheimportanceoftheradiationstressifitisnotbeingestimatedinrelativelyshallowwaterwherewavesetupisformedundertheinuenceofthebreakingwaves.Also,thesurgemodeltheyuseddoesnotaccountforooding PAGE 34 anddrying.Thismakesthemodelinadequateinshallowwaterregions.Thesameconclusionisvalidforthemodelusedby ZhangandLi ( 1996 ).TheirgridislocatedinthenorthernSouthChinaSeaandthedepthsoftheirstationlocationsarenotspeciedeither. ShengandAlymov ( 2002 )implementedthe Longuet-HigginsandStewart ( 1964 )radiationstressesintheCH3D( Sheng , 1987 )modelandsimulated2-Dwavesetupeldsduringthe100-yearstormeventfortwostudyareasinPinellasCounty,Florida.Thesetupvaluevariedfromapproximately0.5mto1.0m.Therewassomeeectonwavesetupwhenwaveswereapproachingat40oanglewhich,accordingto Deanetal. ( 1995 ),isthemostlikelyangleofapproachofthe100-yearstormeventinPinellasCounty.Also,thestudyshowedthatthegridresolutionhassomeeectoncalculatedwavesetupespeciallyintheareaswherebathymetryhassteepergradients.Coarsegridsarenotcapableofresolvingthesebathymetricgradientsandasaresultthecalculatedwavesetupistypicallylowerthanthatcalculatedusinganergrid. SunandSheng ( 2002 )coupledCH3DwiththeREF/DIFwavemodel( KirbyandDalrymple ( 1994 ))andshowedsignicanteectsofwavesonwaterlevelandcoastalcurrents.Theycomparedsimulatedwavesetuptomeasuredlaboratorydataandfoundthatthecalculatedwavesetupisusuallyoverestimatedandproposedthattheoriginalwaveforcingshouldbereducedbymultiplyingwaveforcingbyacoecientof0.8.ThisisratheranadhocapproachandthehighradiationstressesmighthavecomefromoverestimatedwavescalculatedbyREF/DIF. Recently,someeortshavebeenmadeinordertoderiveverticallyvaryingradiationstress. Mellor ( 2003 )exploitedthree-dimensionalequationsofmotiondecomposingvelocitiesintothreecomponents:meancurrent,wave,andturbulence. PAGE 35 Hisradiationstresstermsareverticallydependantand,ifdepthintegrated,appearinamoreconventionalformasin Longuet-HigginsandStewart ( 1964 ). ( 2002 )foundthatthemaximumsurgeheightsdependonthetidalphasewhenthehurricanelandfalloccurs:maximumsurgeheightoccurswhenhurricanelandfalloccursatseveralhoursafterthepeaktide. ShengandAlymov ( 2002 )simulatedthestormsurgeinPinellasCountyusingthePEMmodel( DavisandSheng , 2002 )andfoundthatthemaximumsurgeheightsandoodingpatternsforthecountyaredramaticallydierentwhenthehighresolutionALSMdataareusedasopposedtotheUSGS0.25-degreedata. ShengandAlymov ( 2002 )usedthe2-DversionofCH3DandREF/DIFtosimulatethewavesetup,andusedtheSWAN( Holthuijsenetal. , 2000 )tosimulatethewind-inducedsurgeinPinellasCounty.However,thecalculationsofthesurge,setup,andwave-inducedsurgewereperformedseparatelyandaddedlinearlyforsimplicity. PAGE 36 Table1{1: Asummaryofstormsurgemodels. AnalyAssimiBoundary WaveWaveWave Rain/ River Tide ValiOperaLocal/ 2-D 3-D ting tical lated Fitted enhanced induced Setup EvapoDisdation tional Regional Model and Wind Wind Grid Surface Bottom ration charge Grid Drying Stress Friction Nesting p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p1 p p p p p p p p p p p2 p p p p p p p p p p p p3 p ( 2004 )-HurricaneGeorges2 ( 2000 )-TyphoonWinnie3Thisstudy-HurricanesIsabel,Charley,andFrances PAGE 37 Jelesnianskietal. , 1992 ).ThemodelisrunbytheNationalHurricaneCentertoestimatestormsurgeheightsandwindsresultingfromhistorical,hypothetical,orpredictedhurricanesbytakingintoaccountpressuredecit,size,forwardspeed,track,andwinds.Themodeldoesnottakeintoaccounttide,precipitation/evaporation,riverow,wind-drivenwaves. SLOSHisusedbyNOAANWSandtheU.S.ArmyCorpsofEngineerstocreateoodmapsrepresentingtheMaximumoftheMaximum(MOM)stormsurgecompositeofhypotheticalstorms. Comments:SLOSHisanoutdatedmodelwhichneedstoberevisedandimproved.Ittendstoproducelargeuncertaintyinthepredictedoodedareabecauseofitsrelativelycoarseresolution(0.5-7km)andinabilitytotconvolutedshorelines. Watson , 1995 ; WatsonandJohnson , 1999 ).TAOSissimilartoSLOSHandiscapableofcalculatinganestimateofstormsurge,waveheight,maximumwinds,inlandooding,debrisandstructuraldamage.Themodelhasbeenrunonover25signicanthistoricalstormsfromaroundtheworld.Comparingover500peaksurgeobservationswithTAOSmodelestimatesforthesamelocationandtime,themodelgeneratesresultswithin0.3m80%ofthetime,andlessthan0.6m90%ofthetime. Comments:Asfarasthestormsurgepartisconcerned,theTAOSmodeldoesnotdiermuchfromtheSLOSHmodel,sincethestormsurgephysicsarerepresentedinasimilarwayinbothmodelsand,therefore,itdoesnottakeinto PAGE 38 accountimportantphysicalprocessesassociatedwithstormsurge,e.g.,wave-inducedeects. Schwerdtetal. , 1979 ; Cialone , 1991 )arecomponentsofCoastalEngineeringResearchCenter'sCoastalModelingSystemusedbytheU.S.ArmyCorpsofEngineers. TheSPHisatwo-dimensional,parametricmodeldevelopedinastretchedCartesiancoordinatesystemforrepresentingwindandatmosphericpressureeldsgeneratedbyhurricanes.ItisbasedontheStandardProjectHurricanecriteriadevelopedbyNOAA,andthemodel'sprimaryoutputsareresultingwindvelocityandatmosphericpressureeldswhichcanbeusedinstormsurgemodeling.TheSPHmodelcanberunindependently,oritcanbeinvokedfromwithinmodelWIFM. TheWIFMisatwo-dimensional,time-dependent,long-wavemodelforsolvingtheverticallyintegratedNavier-StokesequationsinastretchedCartesiancoordinatesystem.Themodelsimulatesshallow-water,long-wavehydrodynamicssuchastidalcirculationand,makinguseofwindeldsproducedbySPH,stormsurges.WIFMcontainsmanyfeaturessuchasmovingboundariestosimulatewettinganddryingoflow-lyingareasandsubgridowboundariestosimulatesmallbarrierislands,jetties,dunes,orotherstructuralfeatures.Modeloutputincludesverticallyintegratedwatervelocitiesandwatersurfaceelevations. Comments:WIFMisasimpleandoutdatedmodelwhichdoesnotaccountforwaveeect. PAGE 39 Ithasthecapabilitytoestimateearthquakelosses,andoodandwindmodelsarebeingdeveloped. TheHurricaneLossEstimationModelwhichisapartoftheHAZUSmodelincorporatesseasurfacetemperatureintheboundarylayeranalysis,andcalculateswindspeedasafunctionofcentralpressure,translationspeed,andsurfaceroughness.Themodeladdresseswindpressure,windbornedebris,surge,waves,atmosphericpressurechange,duration/fatigue,andrain. TheFloodLossEstimationModeliscapableofassessingriverineandcoastalooding.Itestimatespotentialdamagestoallclassesofbuildings,essentialfacilities,transportationandutilitylifelines,andagriculturalareas.Themodelestimatesdebris,shelterandcasualties.Directlossesareestimatedbasedonphysicaldamagetostructure,contents,andbuildinginteriors.Theeectsofoodwarningandvelocityaretakenintoaccount. Theoodmodelusesgeographicinformationsystemsoftwaretomapanddisplayoodhazarddata,andtheresultsofdamageandlossestimatesforbuildingandinfrastructure.Italsoenablesuserstoestimatetheeectsofoodingonpopulations. Luet-tichetal. , 1992 )solvestheequationsofmotionforauidonarotatingearth.TheseequationsarebasedonhydrostaticpressureandBoussinesqapproximationsandhavebeendiscretizedinspaceusingtheniteelementmethodandintimeusingthenitedierencemethod. ADCIRCcanberuneitherasatwo-dimensionaldepthintegrated(2DDI)modelorasathree-dimensional(3D)model.Ineithercase,elevationisobtainedfromthesolutionofthedepth-integratedcontinuityequationinGeneralizedWave-ContinuityEquationform.Velocityisobtainedfromthesolutionofeitherthe PAGE 40 2DDIor3Dmomentumequations.Allnonlineartermshavebeenretainedintheseequations.ADCIRCcanberunusingeitheraCartesianorasphericalcoordinatesystem. ADCIRCboundaryconditionsinclude:speciedelevation(harmonictidalconstituentsortimeseries),speciednormalow(harmonictidalconstituentsortimeseries),zeronormalowslipornoslipconditionsforvelocity,externalbarrieroverowoutofthedomain,internalbarrieroverowbetweensectionsofthedomain,surfacestress(windand/orwaveradiationstress),atmosphericpressure,outwardradiationofwaves(Sommereldcondition).ADCIRCcanbeforcedwith:elevationboundaryconditions,normalowboundaryconditions,surfacestressboundaryconditions,tidalpotential,andearthload/selfattractiontide. Comments:ADCIRCisawidelyusedmodel.Sincethemodelisbasedonniteelementnumerics,ithastheabilitytoexploitverylargecomputationaldomainswithsparseresolutionindeepwaterareasandsmallgridspacinginshallowwaterareasornearcomplexboundaries. Weaver ( 2004 )implementedaone-waycouplingofa2-DversionofADCIRCwithawavemodel,WAM-3G,toaccountforradiationstress;nootherwaveeectwasconsidered.HeperformedahindcastofthestormsurgeduringHurricaneGeorges(1998)intheNorthGulfofMexicoandconcludedthattheadditionofwaveforcingimprovedtheoverallpredictivecapabilitiesandreducedtheRMSerrorofthecalculatedstormsurgeby20%to50%. BlumbergandMellor ( 1987 ).SURGEsimulatesandpredictsstormsurge,ooding,overwash,waterrecession,andassociatedhorizontalcurrents.ThemodelmakesuseofNOAA/NOS PAGE 41 bathymetrydataandhightresolutionUSGS/NOAALIDARsurveydata.Hurri-caneAndrew(1992)andHurricaneCarla(1967)wereusedformodelvericationinLouisianaandLavacaBay,TX,respectively. Comments:TheprosoftheSURGEmodelincludeitsthree-dimensionality,theabilitytousedneresolutioncomputationalgrids,thecapabilitytosimulatewetting-and-dryingofthecoastalarea.Themajordeciencyistheabsenceofwaveeects,e.g.,radiationstress,wave-enhancedsurfacestress,andwave-inducedbottomfriction. Moon , 2000 , 2005 ).Analyticwindmodel( Holland , 1980 )isusedtocalculatedhurricanewindeld.ThemodelwasappliedtonumericalexperimentsintheYellowandEastChinaSeasduringTyphoonWinnie(1997). Theoceancirculationmodelcalculatescurrentsandsurfaceelevation(newwa-terdepth)whichisfedbackintothewavemodeltocomputethewavedependentdragcoecienttobeusedinthewavemodelthenexttimestep.Thisprocessisrepeated.Eachmodelhasitsowntimestepduetothereasonthattimescalesofchangeofwaveparametersandtidalcurrentsarequitedierent.Thewavemodelhasa360sectimestepandtheoceanmodelhasa1800sectimestep.Therefore,afterevery5timestepsofrunningthewavemodeltheoceanmodelisrunandthecouplingtakesplace. Comments:ThePOM/WAVEWATCH-IIcouplingwasperhapstherstat-tempttoexploitatwo-waycouplingbetweenanoceancirculationmodelandawavemodel.Thecouplingtakesintoaccounttheeectsofunsteadyandinhomo-geneouscurrents,unsteadydepth,tides,wind,surfaceheatux,riverdischarge. PAGE 42 Someofthedecienciesincludetheinapplicabilityofthemodelinshallowwa-terregions;bottomfrictiondependsonlyoncurrents,i.e.noeectofwavesisconsidered;wetting-and-dryingisnotconsidered;wavesetupisnottakenintoaccount. Sheng ( 1986 , 1990 ).Themodelcanbeusedtosimulatetheestuarine,coastal,andriverinecirculationdrivenbywind,tide,anddensitygradients.Themodelusesaboundaryttedcurvilineargridinthehorizontaldirectionstoresolvethecomplexshorelineandgeometry,andaterrain-following-gridintheverticaldirection.ThemodelusesaSmagorinskitypehorizontalturbulentdiusioncoecient,andarobustturbulenceclosuremodel( ShengandVillaret , 1989 )fortheverticalturbulentmixing. CH3Dhasbeenappliedtosimulatethe2-Dand3-DcirculationinnumerouswaterbodiesinFlorida(e.g.,TampaBay,SarasotaBay,IndianRiverLagoon,FloridaBay,BiscayneBay,St.JohnsRiver,andLakeOkeechobee)andU.S.(e.g.,ChesapeakeBay).ManyoftheCH3Dapplications,aswellastheCH3Dformulationanddevelopment,aredescribedon In2002,CH3Dwasmodiedtoincludewetting-and-dryingcapability( Shengetal. , 2002 )andcoupledwithawavemodelSWANtosimulatetheoodelevationinPinellasCountyduringthe100-yearstorm( ShengandAlymov , 2002 ).Thewetting-and-dryingversionofCH3DwillbethefoundationoftheCH3D-SSMSforthisstudy. PAGE 43 ThischapterprovidesadetaileddescriptionoftheCH3D-SSMSintegratedstormsurgemodelingsystemincludingeachofthefourmodelsitisbasedon:tworegionalmodels,ADCIRC(circulation)andWAVEWATCH-III(wave);andtwolocalmodels,CH3D(circulation)andSWAN(wave). Shengetal. ( 2004 ).Themodelingsystemincludessurge-wave-tide-windcouplinginthecoastal-estuarine-overlandregion,aswellascouplingbetweenlocalandregionalscales. ThetableshownatthebeginningofSection 1.2 demonstratesthattheCH3D-SSMSmodelingsystemhasmorefeaturesthananyotherexistingstormsurgemodel.SuchanimportantelementaswaveswhichisincludedinCH3Dthroughcouplingwithawavemodel,SWAN,isunjustlyneglectedbymostoftheothermodels.Dynamiccouplingwithtideisalsogenerallyignoredassumingthatpredictedtidecanbelinearlyaddedontopofthecalculatedstormsurge.Local/Regionalcouplingissomethingthatisbeingexploitedbymanylately.Theusefulnessofthisfeatureistobeabletopredictandforecaststormsurgelocallyusingnegrids,whichincludehighresolutionshorelines,bathymetryandtopography.Theboundaryconditionsforthelocalmodelareprovidedbymeansofnestedcouplingwiththeregionalmodel.DetailsofthemethodologyusedinthisstudycanbefoundinChapter 3 . 20 PAGE 44 G1)Produceanadvancedstormsurgemodelwithrobustphysicsbyincorpo-ratingthenonlinearinteractionbetweensurge,tide,wave,andwindandallowingtheuseofaverynespatialresolution.Themodelwillbecapableofperforminginshallowwaterregionsandsimulatingwetting-and-drying. G2)Producenelyresolvedboundary-ttedcurvilineargridsfortheOuterBanks/ChesapeakeBay,TampaBay,andCharlotteHarborareasbyutilizinghigh-resolutionbathymetryandtopographydata. G3)ValidatethemodelingsystembysimulatingHurricanesIsabel(2003),Frances(2004),andCharley(2004)andcomparingthecalculatedresultswithmeasureddata. G4)ProduceoodmapsbasedonsimulationsofIsabel,Frances,andCharley. G5)Performasensitivityanalysisoftheeectofnonlinearinteractionsamongstormsurge,tide,wind,andwave,aswellastheeectofwetting-and-dryingandtheeectofthedynamiccouplingversusalinearsuperpositionofseparatelysimulatedtide,wavesetup,andsurge. Q1)Howsignicantistheeectofthenonlinearinteractionbetweentheturbulentandwave-inducedstresses? Q2)Howsignicantistheeectofthenonlinearinteractionbetweenbottomstressesduetocurrentsandwaves? Q3)Howdoeswetting-and-dryingaectstormsurgesimulations? Q4)Isdynamiccouplingbetterthanlinearsuperposition? PAGE 45 2.3.1Wind Severaltypesofwinddataareusedinthisstudy.Thersttypeisassociatedwiththeactualwindmeasuredfrombuoysintheopenoceanorwindtowersonland.TheNationalDataBuoyCenter(NDBC)isanagencywithintheNationalWeatherService(NWS)oftheNationalOceanicandAtmosphericAdministration(NOAA),whichoperatesandmaintainsanetworkofdatacollectingbuoysandcoastalstationsalongtheU.S.coastline( AnothernetworkofstationsdeployedintheGulfofMexicoistheCoastalOceanMonitoringandPredictionSystem(COMPS).COMPS( PAGE 46 takemeteorologicalmeasurementssuchaswind,airtemperature,humidity,baro-metricpressure,precipitation,radiation,visibility;andmarinemeasurementssuchaswaterlevel,watertemperature,salinity,currentvelocity,andwaveparameters. Theabovetwotypesofwinddatafromeldmeasurementsareusefulforvalidatingwindmodels,butcannotbeusedalonetogeneratethewindeldneededforstormsurgemodeling. Anothertypeofwinddataiswindsnapshotdatawhichareproducedbyvariouswindmodels,rangingfromsimpletohighlysophisticated.Thesedatacoverlargeareasandaremoresuitableforstormsurgemodeling.Thereareafewdierentwindsnapshotdatasets.ThesummaryofthistypeofwinddataispresentedinTable 2{1 . PAGE 47 Table2{1: Winddatasummary. Source Type Vert. Cycles Cycle Mean Analysis/ AssimiWind Data (BGD/ ResoluLevel Length/ Sea Forecast/ lated Over Set HUR/ tion Snapshot Level Measured Land CMB) Frequency Pressure NCEP BGD 12km 10m 00,06, 84hrs yes FCAST no yes 12,18 6hrs NDAS BGD 12km 10m 00,06, 6hrs yes ANL yes yes 12,18 6hrs GFDL NCEP HUR varies 35m 00,06, 126hrs yes FCAST no yes 12,18 6hrs GDAS HUR varies 35m 00,06, 6hrs yes ANL yes yes 12,18 6hrs HRD NOAA HUR 6km 10m varies no MEAS no no WINDGEN Ocean CMB 22km 10m 00,06, ?hrs yes ANL+FCAST yes yes weather 12,18 1hr WNA NCEP CMB 28km 10m 00,06, 120hrs no ANL+FCAST yes no 12,18 3hrs PBL Ocean HUR any 20m yes no yes weather Analytical Holland ( 1980 ) HUR any sfc yes no yes WRF NCEP BGD 4km 10m 00,06, 36/84hrs yes ANL+FCAST yes yes 12,18 3hrs MM5 NCEP BGD 12km 10m 00,06, 48hrs yes ANL+FCAST yes yes 12,18 3hrs PAGE 48 WNAandWINDGENwindswereextensivelyutilizedinthisstudy.Twootherwindmodelsthatweretested:acomplexPlanetaryBoundaryLayer(PBL)modelandamuchsimpleranalyticwindmodel( Holland , 1980 )basedonthehypothesisofanexponentialdecayofatmosphericpressurefromthecenterofastorm. ThePBLmodelisbasedon Chow ( 1971 )vortexmodel.ThemodeliscapableofcalculatingverticallyaveragedthroughthedepthofthePBLvelocitiesduringastormevent. Themodel'sgoverningequationofhorizontalmotionwrittenincoordinatesxedtotheearthis( Cardoneetal. , 1992 ) dt+f~K~V~Vg=1 where~V=~Vave~Vcisthehorizontalwindrelativetothecenterofthecyclone; Theinteractionbetweentheboundarylayerandthefreeatmosphereisexpressedintermsofthegeostrophicwindeld(verticalvelocityatthetopoftheboundarylayer)andthesurfacestress(frictionaldissipationofthekineticenergy PAGE 49 intheboundarylayer).Furtherparameterizationofthemodelincludesverticaluxesofmomentum,heatandmoisture. Thisparameterizationisbasedonmatchingofmeanprolesofwind,tempera-ture,andmoisturebysurfaceandouterlayersimilaritytheories. Thegeneralformoftheparametricrelationsmaybewrittenas u=(ln[z0/h]+Am)v u=Bmsign(f)(V0)/=(ln[z0/h]0+Cm)(qq0)/q=(ln[z0/h]+Dm)(2{2) whereuandvaretheverticallyaveragedhorizontalvelocitycomponents(inthedirectionofthesurfaceshearandperpendiculartoit,respectively);z0istheroughnessparameter;isvonKarman'sconstant;Vandqarethemeanlayervirtualpotentialtemperatureandspecichumidity,respectively(thesubscript0denotesthevalueatz0);isapotentialtemperaturescaleexpressedintermsoftheheatux,H;qisaspecichumidityscaleinvolvingthemoistureux;andAm,Bm,Cm,andDmareuniversalfunctionsofdimensionlesssimilarityparameters. Arya ( 1977 )presentedthefollowingexpressionsforthesimilarityfunctionsinwhichthedepthofthePBL,h,isspeciedasanindependentvariable.Ifh L2(unstable)then ue0:2h/LCm=ln(h/L)+3:7(2{3) PAGE 50 andifh L+2(stable)then whereL=u3VCP Fornear-neutralconditions,2