基于GIS的洪水灾害风险区划研究(10)

基于GIS的洪水灾害风险区划研究

24地　　　理　　　学　　　报　　　　　　　　　　　　　55卷

AGIS-basedApproachtoFloodRiskZonation

ZHOUCheng2hu,WANQing,HUANGShi2feng,CHENDe2(StatekeyLaboratoryofResourcesandEironmInfor,

ChinaAcademyofSciences,ingAbstract:Floodriskcan,ters,asprobabilitytimeconsequence.Itconsistsofvuanalysisanddamageevaluation.Avarietyofmedandapplied.Amongthem,QuantitativeRiskAnalysis(QRA)aethodofquantifyingriskthroughsystematicexaminationofthefactorscontributingtothefloodhazardandaffectingtheseverityoffloodconsequence,theirinteractionandrelativecontributiontotheoccurrenceoftheflood.TheQRAtechniqueiswellestablishedinmanyfieldssuchaschemicalengineeringandhazardousmaterialsprocessing.TheapplicationofQRAtofloodriskisrelativelynewandstillunderdevelopment.Whilethebasicriskassessmentconceptsandtoolscanbeused,themethodologiesneedtobeadapted.Category-basedmodelforfloodriskanalysisisusedtoassignavaluetoeachdriven-factorsuchastriggeringfactorofrainfall,dambreak,groundsurfaceconditionsoftopography,landcover,andothers.Thekeystothemodelaretosynthesisthespatial-referenceddataandcreatetheriskzone.

ThediffusionofGeographicalInformationSystems(GIS)technologyopensuparangeofnewpossibilitiesforhazardmitigationanddisastermanagement.MicrozonationisgreatlyfacilitatedbythekindofautomationthatGISoffers,especiallyasitinvolvescomparison,indicesandoverlaysinmuchthesamewaythatGISdoes.Inthisarticle,ArcInfoGIShasbeenchosentoquantitativelyrepresenttheinfluencingfactors,spatializethedataintotheuniformgridsystem,andtransferallthedataitemintotheeffectdegreesontheprobabilityofflooding.Atlast,withthesupportofArc InfoGRIDmodel,acategoricalmodelforfloodriskzonationhasbeenputforward.TheapproachhasbeenappliedtotheLiaoheriverbasin,thenorth-easternofChina,flooddisasterriskzonation.TheresultsshowthatthefloodriskofthelowerreachesoftheLiaoheriverismoreseriousthanotherplaces,whichaccordwiththefact.ThecasestudyshowesthattheGIS-basedcategorymodeliseffectiveinfloodriskzonation.

Keywords:GeographicalInformationSystem;Floodhazard;Riskzonation