Floods in a Changing Climate: Hydrologic Modeling

210 Pages·2013·14.322 MB·English

by  P. P. Mujumdar, D. Nagesh Kumar

more information - www.cambridge.org/9781107018761

FloodsinaChangingClimate
HydrologicModeling
Hydrologic modeling of floods enables more accurate assessment of climate change impacts
onfloodmagnitudesandfrequencies.Thisbooksynthesizesvariousmodelingmethodologies
available to aid planning and operational decision-making, with emphasis on methodologies
applicableindata-scarceregions,suchasdevelopingcountries.Topicscoveredinclude:physical
processes that transform precipitation into flood runoff, flood routing, assessment of likely
changesinfloodfrequenciesandmagnitudesunderclimatechangescenarios,anduseofremote
sensing,GIS,andDEMtechnologiesinmodelingoffloodstoaiddecision-making.Problems
includedineachchapter,andsupportedbylinkstoavailableonlinedatasetsandmodelingtools
accessible at www.cambridge.org/mujumdar, engage the reader with practical applications of
themodels.
This is an important resource for academic researchers in the fields of hydrology, climate
change,andenvironmentalscienceandhazards,andwillalsobeinvaluabletoprofessionalsand
policy-makersworkinginhazardmitigation,remotesensing,andhydrologicengineering.
ThisvolumeisthesecondinacollectionoffourbookswithintheInternationalHydrology
Series on flooddisaster managementtheory and practice within the context ofanthropogenic
climatechange.Theotherbooksare:
1–FloodsinaChangingClimate:ExtremePrecipitationbyRameshTeegavarapu
2–FloodsinaChangingClimate:InundationModellingbyGiulianoDiBaldassarre
3–FloodsinaChangingClimate:RiskManagementbySlodobanSimonovic´
P. P.MujumdarisaProfessorintheDepartmentofCivilEngineeringattheIndianInstitute
ofScience(IISc),Bangalore,India,andholdsanAssociateFacultypositionintheDivechaCenter
forClimateChangeatIIScBangalore.HeisalsoChairmanoftheWaterResourcesManagement
CommitteeoftheInternationalAssociationforHydro-EnvironmentResearch(IAHR).Professor
Mujumdar’sareaofspecializationiswaterresourceswithafocusonclimatechangeimpacts
thatincludesdownscalinganduncertaintymodeling.Healsoworksasaprofessionalconsultant
acrossareasincludingfloodplainmanagement,reservoiroperation,urbanstormwaterdrainage,
liftirrigation,andhydropowerdevelopment.HeisaDistinguishedVisitingFellowoftheRoyal
AcademyofEngineering,UK,andiscurrentlyamemberoftheEditorialBoardofthejournal
AdvancesinWaterResources.
D. Nagesh Kumar is a Professor in the Department of Civil Engineering at the Indian
InstituteofScience(IISc),Bangalore,India,andholdsanAssociateFacultypositionintheCenter
forEarthSciences.HisprimaryresearchareasincludeapplicationsofremotesensingandGISin
hydrologicmodeling,softcomputing,hydrologicteleconnections,andwaterresourcessystems.
ProfessorKumaralsoworksinprofessionalconsultancyinareassuchasriverbasinplanning
and management, flood routing, downscaling for climate change projections, and reservoir
operation.HeiscurrentlyanAssociateEditoroftheJournalofHydrologicEngineering.
INTERNATIONAL HYDROLOGY SERIES
TheInternationalHydrologicalProgramme(IHP)wasestablishedbytheUnitedNationsEducational,ScientificandCulturalOrganization
(UNESCO)in1975asthesuccessortotheInternationalHydrologicalDecade.Thelong-termgoaloftheIHPistoadvanceourunderstanding
ofprocessesoccurringinthewatercycleandtointegratethisknowledgeintowaterresourcesmanagement.TheIHPistheonlyUNscienceand
educationalprogrammeinthefieldofwaterresources,andoneofitsoutputshasbeenasteadystreamoftechnicalandinformationdocuments
aimedatwaterspecialistsanddecision-makers.
TheInternationalHydrologySerieshasbeendevelopedbytheIHPincollaborationwithCambridgeUniversityPressasamajorcollectionof
researchmonographs,synthesisvolumes,andgraduatetextsonthesubjectofwater.Authoritativeandinternationalinscope,thevariousbooks
withintheseriesallcontributetotheaimsoftheIHPinimprovingscientificandtechnicalknowledgeoffresh-waterprocesses,inproviding
researchknow-howandinstimulatingtheresponsiblemanagementofwaterresources.
editorial advisory board
SecretarytotheAdvisoryBoard
MrShabhazKhanDivisionofWaterScience,UNESCO,IrueMiollis,Paris75015,France
MembersoftheAdvisoryBoard
ProfessorB.P.F.BragaJrCentroTechnolo´gicadeHidra´ulica,Sa˜oPaulo,Brazil
ProfessorG.DaganFacultyofEngineering,TelAvivUniversity,Israel
DrJ.KhouriWaterResourcesDivision,ArabCentreforStudiesofAridZonesandDryLands,Damascus,Syria
DrG.LeavesleyUSGeologicalSurvey,WaterResourcesDivision,DenverFederalCenter,Colorado,USA
DrE.MorrisScottPolarResearchInstitute,Cambridge,UK
ProfessorL.OyebandeDepartmentofGeographyandPlanning,UniversityofLagos,Nigeria
ProfessorS.SorooshianDepartmentofCivilandEnvironmentalEngineering,UniversityofCalifornia,Irvine,California,USA
ProfessorK.TakeuchiDepartmentofCivilandEnvironmentalEngineering,YamanashiUniversity,Japan
ProfessorD.E.WallingDepartmentofGeography,UniversityofExeter,UK
ProfessorI.WhiteFennerSchoolofEnvironmentandSociety,AustralianNationalUniversity,Canberra,Australia
titles in print in this series
M.Bonell,M.M.HufschmidtandJ.SGladwellHydrologyandWaterManagementintheHumidTropics:HydrologicalResearchIssuesand
StrategiesforWaterManagement
Z.W.KundzewiczNewUncertaintyConceptsinHydrologyandWaterResources
R.A.FeddesSpaceandTimeScaleVariabilityandInterdependenciesinHydrologicalProcesses
J.Gibert,J.MathieuandF.FournierGroundwater/SurfaceWaterEcotones:BiologicalandHydrologicalInteractionsandManagementOptions
G.DaganandSNeumanSubsurfaceFlowandTransport:AStochasticApproach
J.C.vanDamImpactsofClimateChangeandClimateVariabilityonHydrologicalRegimes
D.P.LoucksandJ.S.GladwellSustainabilityCriteriaforWaterResourceSystems
J.J.BogardiandZ.W.KundzewiczRisk,Reliability,Uncertainty,andRobustnessofWaterResourceSystems
G.KaserandH.OsmastonTropicalGlaciers
I.A.ShiklomanovandJ.C.RoddaWorldWaterResourcesattheBeginningoftheTwenty-FirstCentury
A.S.IssarClimateChangesduringtheHoloceneandtheirImpactonHydrologicalSystems
M.BonellandL.A.BruijnzeelForests,WaterandPeopleintheHumidTropics:Past,PresentandFutureHydrologicalResearchforIntegrated
LandandWaterManagement
F.GhassemiandI.WhiteInter-BasinWaterTransfer:CaseStudiesfromAustralia,UnitedStates,Canada,ChinaandIndia
K.D.W.NandalalandJ.J.BogardiDynamicProgrammingBasedOperationofReservoirs:ApplicabilityandLimits
H.S.Wheater,S.SorooshianandK.D.SharmaHydrologicalModellinginAridandSemi-AridAreas
J.DelliPriscoliandA.T.WolfManagingandTransformingWaterConflicts
H.S.Wheater,S.A.MathiasandX.LiGroundwaterModellinginAridandSemi-AridAreas
L.A.Bruijnzeel,F.N.ScatenaandL.S.HamiltonTropicalMontaneCloudForests
S.MithenandE.BlackWater,LifeandCivilization:Climate,EnvironmentandSocietyintheJordanValley
K.A.DaniellCo-EngineeringandParticipatoryWaterManagement
R.TeegavarapuFloodsinaChangingClimate:ExtremePrecipitation
P.P.MujumdarandD.NageshKumarFloodsinaChangingClimate:HydrologicModeling
G.DiBaldassarreFloodsinaChangingClimate:InundationModelling
S.Simonovic´FloodsinaChangingClimate:RiskManagement
Floods in a Changing Climate
Hydrologic Modeling
P. P. Mujumdar and D. Nagesh Kumar
IndianInstituteofScience,Bangalore
cambridgeuniversitypress
Cambridge,NewYork,Melbourne,Madrid,CapeTown,
Singapore,Sa˜oPaulo,Delhi,MexicoCity
CambridgeUniversityPress
TheEdinburghBuilding,CambridgeCB28RU,UK
PublishedintheUnitedStatesofAmericabyCambridgeUniversityPress,NewYork
www.cambridge.org
Informationonthistitle:www.cambridge.org/9781107018761
(cid:2)C P.P.Mujumdar,D.NageshKumarandUNESCO2012
Thispublicationisincopyright.Subjecttostatutoryexception
andtotheprovisionsofrelevantcollectivelicensingagreements,
noreproductionofanypartmaytakeplacewithoutthewritten
permissionofCambridgeUniversityPress.
Firstpublished2012
PrintedintheUnitedKingdomattheUniversityPress,Cambridge
AcatalogrecordforthispublicationisavailablefromtheBritishLibrary
LibraryofCongressCataloginginPublicationdata
Mujumdar,P.P.,1958–
Floodsinachangingclimate.Hydrologicmodeling/P.P.Mujumdar,D.NageshKumar.
pages cm.–(Internationalhydrologyseries)
Includesbibliographicalreferencesandindex.
ISBN978-1-107-01876-1
1.Hydrologicmodels–Remotesensing. 2.Floodforecasting. 3.Flooddamageprevention.
4.Climaticchanges–Environmentalaspects. I.NageshKumar,D.(Dasika),1963– II.Title.
GB656.2.H9M85 2012
511.48(cid:3)9011–dc23 2012015666
ISBN978-1-107-01876-1Hardback
CambridgeUniversityPresshasnoresponsibilityforthepersistenceor
accuracyofURLsforexternalorthird-partyinternetwebsitesreferredto
inthispublication,anddoesnotguaranteethatanycontentonsuch
websitesis,orwillremain,accurateorappropriate.
Contents
ForewordbyRobertL.Wilby pagevii 4.3 Imagerectification 95
Preface ix 4.4 Imageenhancement 95
Glossary xi 4.5 Imageinformationextraction 101
Listofabbreviations xiii 4.6 Landuse/landcoverinformation 107
4.7 Utilityofremotesensingforhydrologic
1 Introduction 1 modeling 107
1.1 Hydrologicmodels 1 4.8 Demonstrationofimageprocessingusing
1.2 Remotesensingforhydrologicmodeling 2 MATLAB 112
1.3 GISandDEMforhydrologicmodeling 2 4.9 Conclusionsandfuturescope 118
1.4 Assessmentofclimatechangeimpacts 3 Exercises 119
1.5 Organizationofthebook 4
5 Geographicinformationsystemsforhydrologic
2 Hydrologicmodelingforfloods 5 modeling 120
2.1 Introduction 5 5.1 Introduction 120
2.2 Estimationoffloodpeakdischarge 6 5.2 RepresentationofspatialobjectsinGIS 120
2.3 Intensity–duration–frequencyrelationship 10 5.3 GISforproximityanalysis 122
2.4 Floodrouting 12 5.4 Digitalelevationmodels 123
2.5 Abriefreviewofcommonlyusedhydrologic 5.5 Applicationsofdigitalelevationmodeling 125
models 19 5.6 Othersourcesofdigitalelevationdata 129
2.6 Empiricalmodels 29 5.7 Combiningdigitalimagesandmaps 132
2.7 Summary 40 5.8 Integrationofspatial,non-spatial,andancillary
Exercises 40 dataintoadistributedhydrologicmodel 133
5.9 GISandremotesensingforfloodzonemapping 134
3 Climatechangeimpactassessment 43
5.10 Web-basedGIS 140
3.1 Introduction 43
5.11 Summary 144
3.2 Projectionofhydrologicimpacts 45
Exercises 145
3.3 Dynamicaldownscalingapproaches 45
3.4 Statisticaldownscalingapproaches 47 6 Casestudiesandfutureperspectives 146
3.5 Disaggregationmodels 64 6.1 Casestudy:MalaprabhaReservoircatchment,
3.6 Macroscalehydrologicmodels 68 India 146
3.7 Hypotheticalscenariosforhydrologic 6.2 Casestudy:MahanadiRiverbasin,India 158
modeling 71 6.3 Futureperspectives 164
3.8 Modelingoffloodsunderclimatechange 71 6.4 Summary 165
3.9 Uncertaintymodeling 75
3.10 Summary 83 References 167
Exercises 86 Index 176
4 Remotesensingforhydrologicmodeling 88 Colorplatesappearbetweenpages18and19.
4.1 Introduction 88
4.2 Digitalimages 91
v

Foreword
How much higher does the flood wall need to be built? How fallseriesbasedonavailabledata;orjustspecifyingaplausible
muchlargerdoesthereservoirspillwayneedtobe?Howmuch rangeofvaluesforsensitivitytesting.Indeed,giventhelargeand
morecapacityisneededintheurbandrainagesystem?Theseare irreducible uncertainties in climate model predictions, a strong
thetypeofquestionsthatfloodsareconfronting,givenexpected case can often be made for simpler methods. Depending on the
changes in rainfall intensity, timing and volume of peak flows, risk–reward,aclimatechangesafetymarginmaybesetwithout
andsealevelsunderclimatechange. evenreferringtoclimatemodels.Insituationswherethestructure
Therearenosimpleanswers.Infact,climatechangeisjustone hasashort(lessthan20years)life-span,theconcernwillbecli-
driver of flood risk amongst many others. Rapid urbanization, matevariabilitynotclimatechange.Inotherheavilydiscounted
development in floodplains, removal of natural vegetation, arti- cases,futureclimatechangesmaybeirrelevanttotheviabilityof
ficialdrainage,andsoforth,canallcompoundflooding.There- aschemeandshorter-termgoalsmaybeparamount.
fore, it is helpful to regard the climatic hazard as a multiplier Despitethelargeuncertaintyinfuturefloodrisk,hydrologists
of flood risk that may already be increasing because of other still have plenty to offer adaptation planners. More accurate,
socio-economic trends and/or human changes to the landscape. timely, and clearly articulated flood warnings will continue to
Itthenfollowsthattheadaptationresponseswillinvolvecooper- improvethesafetyofvulnerablepopulationslivingwithunavoid-
ation amongst many disciplines: the hydrologist to quantify the able flooding. Simulations of flood depths and areas will help
impactofenvironmentalchangesonriverflows;theeconomistto planners to zone floodplains and regulate development in haz-
weighupthecostsandbenefitsofdifferentoptions;thegeogra- ardousplaces.Fieldmonitoringandmodelingwillcontributeto
phertoseethebroadersocio-physicalcontextoftheschemeand improved understanding of the physical processes that generate
non-structuralchoices;theengineertoimplementthedesignand extremefloodsindifferentenvironments.Remotelysenseddata
deviseoperationalrules;andthepoliticiantopersuadetaxpayers andseasonalforecastscaninformtheoperationofinfrastructure
topayfortheproject! tooptimizebenefitsacrossmultipleobjectives(suchasfloodcon-
The unavoidable truth is that structural measures for reduc- trol, hydropower production, and water supply). Such activities
ing flood risk need hard numbers to dimension the flood wall, arenotalwaysperceivedasadaptation,buttheydocontributeto
spillway,anddrainagesystem.Thisischallengingenoughunder flood risk management just as much as the wall, spillway, and
presentclimateconditionsbecauseweseldomhavelongenough drainagesystem.
hydrometeorologicalrecords(ifany);therecordswehavemaybe Theauthorsofthisbookaretobecommendedforguidingprac-
corruptedbyotherlong-termchangesintheriverbasin;andthere titioners, step-by-step, through some of the analytical tools and
is plenty of subjectivity in our methods for estimating extreme techniquesforevaluatingfloodriskundernon-stationaryclimate
flowstatistics.Toaddclimatechangetothissituationistopresent conditions.Thetruebenefitwillcomefromrecognizingthepart
atechnicalchallengesteepedinuncertainty.Meanwhile,theengi- playedbytheseapproacheswithinalargerarmouryofstrategies
neerstillneedsnumberstogettheprojectunderway. formanagingfloodhazardsovercomingdecadesandbeyond.
The scientific community offers the practitioner a bewilder-
ing set of methodologies. For example, there are many differ- RobertL.Wilby
ent ways of conjuring future rainfall intensity: regional climate ProfessorofHydroclimaticModelling,
downscaling(usingphysicalorstatisticalmodels);MonteCarlo DepartmentofGeography,
andre-samplingtechniquesforconstructinglargesyntheticrain- LoughboroughUniversity,UK
vii