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CRISIS2007
SujanRajAdhikariCatalogofearthquakes
Statisticalprocess.seismicity.geophysics.geology.wavepropagationanalysis
CRISIS2007
CRISIS2007usesaprobabilisticmethodforcalculatingseismichazardinregions.ThemaindatarequiredbyCRISIS2007aregeometricseismicsources,seismicsourcesandrelationshipsattenuationseismicintensities.Eachsourcecanberepresentedgeometricallyinanarea,apolylineorpoint.SeismicityofthesourcescanbemodeledbyPoissonprocessorthroughthecharacteristicearthquakemodel.Seismichazardcalculationsaremadeformeshpointsthatmayornotrectangularinshape.CRISIS2007containsnumerousgraphicaidsthatfacilitatedatagenerationandanalysisofresults.Therearecertainrulesofeachcountrytoestablishtheminimumrequirementsthatneedtodesignbuildingswhichhelpindecisionmakingforengineersandgivegreatersecuritytoownersandoccupantsofbuildings.Theserulescontainparameterstoestimateeffectsonstructuresbytheoccurrenceofearthquakes.Aprocessoftenusedtodeterminetheseaccelerationsareusedtoestimateseismicforces,can
besummarizedinthefollowingdiagram.Portionofitscorrespondingcrustalseismicity.seismicsources
lawsofattenuationofseismicwavescharacteristicsofthepathfromitsorigintotheplaceofstudy.
seismichazard,expressedintermsofprobabilityofexceedingthemaximumaccelerationinacertainperiod..
Lostfunctionsinbuildingsduetoseismiceffects.Vulnerabilityfunctions.Optimization.Experience.
Designseismiccoefficients.Designspectra.Designseismicforces.
Figure:calculationofseismicforcesrequiredinthedesignofbuildings
CRISIS2007ispartoftheplatformdevelopedbytheconsortiumCAPRAERNasacodesystemandopenarchitecture.CRISISestimatesthesizeoffutureearthquakes.Forthis,estimatedexceedanceratesofseismicintensity.Theexceedancerateistheaveragenumbersoftimesthatdoincertainsitearepresentedintensitiesgreaterthanorequaltoagivenone.Theexceedancerateistheinverseofthereturnperiod.forexample,toperformcalculationsCRISIScanbedeterminedthatacitycanbeexpectedevery100yearsanaccelerationinthefirmgroundof0.32g,0.83gandanaccelerationofabuildingwithaperiodof0.15s.CRISIS2007requiresfollowingtocalculatetheexceedanceratesofseismicintensity:1)Definingtheareasthatgenerateearthquakes(seismicsource)2)Thefixingoftherecurrencerelationsofmagnitudeforeachseismicsource3)Thelawsofattenuationofseismicwaves4)Precisetheregionunderstudybyagridofdotsand5)Otherparameters
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CRISIS2007
GridsitesTheCRISIS2007programhasameshscreentodefinethecalculationsitesrepresentingtheregionunderstudy.Eachgridpointisidentifiedbyitslongitudeandlatituderespectively.CRISIS2007calculatedexceedanceratesofseismicintensitiesforeachofthepointsofthemeshcalculation.Thelimitsofthemesharedefinedbytheregiontostudy.However,thechoiceofmeshdensitydependsonseveralfactors.Asthemeshisdenser,youcanexpectmoredetaileddefinitionsofoutcomes.However,averydensemeshalsocaninvolvealotofcomputercalculationtime.
Fig:DefiningtheMesh
GeometryoftheseismicsourcesInCRISIS2007thegeometryofthesourcescanbemodeledas:1.Sourcearea,withtheuseofapolygonwithatleastthreevertices,eachvertexrequireslatitude,alength.Withthistypeofsourcecanberepresented,forexample,subductedplates,2.Sourcefaultwiththeuseofpolylines,and3.Pointsource,usedprimarilyforacademicpurposes.
Fig:GeometryofSeismicSource
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CRISIS2007
SeismicsourcesTheconcentrationoftheoriginsofearthquakesincertainareascandelineateseismicsources.Eachsourcefunctionisdefinedbytwocharacteristics:geometryandseismicity.Therefore,afterdefiningthegeometryofasource,CRISIS2007requiresdatarepresentingseismicity.Thatis,parametersthatdescribesapproximatelythenumberandsizeofearthquakeswithparticularcharacteristics,whichhaveoriginatedduringtimeinaregion.CRISIS2007canchoosebetweentwomodesofoccurrenceofearthquakes,whosemaindifferenceisthattheoccurrenceofearthquakesisindependentoftimeinthefirst(PoissonModel),whilethesecondoccurrenceofearthquakesdependsonthetimewhentheprocessofslippredictable(CharacteristicModel).PoissonmodelThedatarequiredbytheprogramforeachseismicsource,withrecurrenceofearthquakessimilartoprocessPoissionarebasicallyparametersthatdefinethecurveoftheexcedancerateofthemagnitude,wherelamda0,BITAandMUareparametersthatestablishtheshapeofthecurveandM0isfromthecatalog.
Fig:PoissonModel1.Thresholdmagnitude(M0).ThecatalogofearthquakesisassumedtobecompleteforM>M0.EarthquakeswithMM0
=Standarddeviationofthemagnitudeofthetremorscharacteristic
=DenotesstandardnormaldistributionTodefinetheexpectedmagnitudeasafunctionoftime,itisimplicitlychoosingtheprobabilitydistributionoftimebetweenevents.Invariousstudieshasbeentoconsiderthatthetimebetweeneventshaslognormaldistributionissuccessful.
Fig:CharacteristicModel
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MedianvalueofthetimesbetweencharacteristicearthquakeswithM>M0.ThisistheinverseoftheexceedancerateforM>M0.Standarddeviationofthemagnitudeofthecharacteristicearthquake.Itisassumedindependentoftime.Minimumpossiblemagnitudeofacharacteristicearthquake.EarthquakeswithMalpha/M,R0}istheprobabilitythattheintensityA,exceedsthevalueofthecurrentAlpha,givenacertainmagnitudeanddistance.Inthiscase
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where=denotesstandardnormaldistributionStandarddeviationoftheattenuationlawAverageintensityattenuationtable,givenamagnitudeandadistanceAdditionallyconsideringtheuncertaintiesintheparameterspthatdefinethecurvegivestheexceedanceratesmagnitude
Resultfile*.resfilecontainsthedatausedinformationforcalculatingseismichazard.ifyouchosetoprintalsoresultsinthisfile,thenyouwillfindheretheexceedanceratesofintensityforeachsite,andsomeparametersdescribingthecalculationsmadeineachgridpoint.*.GRAfilecontainsonlythetotalexceedanceratesofintensityforeachsiteandeachstructuralperiod.*.mapfilecontainsintensitiesforreturnperiodsfixedforeachsiteandeachstructuralperiod.*.fuefilecontainstheexceedanceratesofintensityduetoeachseismicsourceforeachsiteandeachstructuralperiodGraphicresultsofseismichazardThepostprocessorCRISISispossibletoobtainseismichazardmapsasshowninthefigure.Mapcorrespondstotheexpectedaccelerationreturninaperiodas100yearsforastructuralperiod0,ie,acceleratingexpectedtooccurinthedrylandofColombia.TheprogramreadstheexpectedaccelerationanywhereinColombia,withjustclickingthemousepointeronthemap.IfitisalsoconsideredinthecalculationsfordifferentintensitiesstructuralPeriods,thenitispossibletoobtainuniformhazardspectraasshowninthefigure.
Fig:SeismicHazardMapofNepal
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Fig:exceedanceratecurvesanduniformhazardspectrumofapointwithinthecountryandareturnperiodof100yearsofKathmanduCity
ExceedanceratesforseismicsourceTheoutputfile*fuecontainingtheexceedanceratesforeachsiteyieldduetoseismicsourceallowsgraphslikefigure,wherewecanidentifythecontributionofspecificsourcestotheseismichazardofasite.Theprogramprimarilyaimstoassistengineersindecisionsmakingwhichrequiredtodesignbuildingstowithstandearthquakes.TheresultsforCRISIS2007willbebetterastheyreducetheuncertaintiesinthemanyparametersthatinvolvedinthecalculationofseismichazard.Theincreasingavailabilityofrecordstofacilitatethegenerationofseismicparameterswhichbestdescribesthedifferentregions.
Fig:graphicexceedancerateofaccelerationforthecityofColombia
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1ComprehensiveAnalysisforProbabilisticRiskAssessment(CAPRA-GIS)
1.1Introduction
CAPRA-GISisageographicinformationsystemdevelopedbyERN,whichisorientedtoprobabilisticriskcalculations.
TheCAPRAinitiativestartedinJanuary2008,asapartnershipbetweenCEPREDENAC,theUNInternationalStrategyforDisasterReduction(ISDR),theWorldBankandtheInterAmericandevelopmentbank.Themainobjectiveistoraiseawarenessamongdisasterpronecountriesbyprovidingthemwithasetoftoolsthatwouldletthembetterunderstandtheriskofadversenaturalevents.Theultimategoaloftheinitiativeistohelpmainstreamdisasterriskmanagementintolocaldevelopmenttohelpreducedisasterloss.
CAPRAprovidesasetoftoolstoconductriskassessments.Thefirstphaseoftheinitiativeaimedatdevelopinganintegratedplatformforprobabilisticriskassessment.TheplatformdevelopedbyERNprovidesuserswithasetoftoolstoanalyzemagnitude,distributionandprobabilityofpotentiallossesduetovariousadversenaturalevents.Thesemetricsareprojectedonageographicalinformationsystem(CAPRAGIS)thatallowsforvisualizationandanalysis.Inabsenceofsuchevaluations,governmentencountersmajorobstaclestoidentify,designandprioritizeriskreductionmeasures.
1.2Howitworks
TheCAPRAmethodologyappliestheprinciplesofprobabilisticriskassessmenttotheanalysisofhurricane,earthquake,volcano,flood,tsunamiandlandslidehazards.CAPRAplatformintegratessoftwaremodulesrelatedtohazard,vulnerabilityandriskmodeling.
1.2.1HazardModule
WithintheCAPRAplatform,hazardassessmentiscarriedoutbygeneratingaseriesofstochasticeventsthat:(i)havedifferentmagnitudes,(ii)havedifferentfrequenciesofoccurrence,(iii)correspondtohistoricalobservedtrendsofrecurrenceofthehazardunderanalysis,and(iv)representthesetofpossibleeventswithdifferentintensityindifferentgeographiclocations.
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1.2.2ExposureandVulnerabilityModule
CAPRAallowsforthecreationofadynamicdatabaseofexposureofinfrastructure,buildingsandpopulation.Italsocontainsalibraryofvulnerabilityfunctions(relationbetweentheseverityofahazardandtheprobabledamage.Italsoallowsusersthroughafriendlyinterfacetocustomizethesefunctionsorincludenewones.Toassesstheeffectonpopulation,relationshipsofhabitationareproposed,basedonthebuildinguses.Valuesofexposureofatriskassetsareestimatedfromsecondarysourcessuchasdatabases,orcanbederivedbysimplifiedproceduresbasedongeneralsocialandmacroeconomicinformation,suchaspopulationdensity,constructionstatisticsormorespecificinformation.Simplifiedexposuremodelsareusedwhentheasset-by-assetspecificinformationisnotavailable.
1.2.3RiskModule
Theprobabilisticriskassessmentisbasedonamulti-riskanalysisapproach.Theplatformallowstheusertoevaluatethefullrangeofpossibledamagethatcouldbeattributedtoone(scenarioanalysis)orasequence(stochastic)ofcatastrophicevents.Thisapproachallowstheassessmentof:
Totalannuallossesorprobablemaximumlossassociatedwithaspecifichazard(includinglossesassociatedwithallsecondaryevents),forexample,totalprobabilisticlossesassociatedwithahurricane=sumofprobabilisticlossesassociatedwithwind,stormsurge,floodingandlandslides.Totallossesassociatedwithacategoryofriskassociatedwithdifferenttriggerevents,suchas:totalprobabilisticlossesassociatedwithlandslides=sumofprobabilisticlossesassociatedwithlandslidestriggeredbyrainfall,earthquakesandhurricanerainstorms.
WithinCAPRA,majorriskestimatesaredescribedintermsof:AnnualExpectedLoss(AEL)PureRiskPremium(PRP),LossExceedanceCurve(LEC)andProbableMaximumLoss(PML).
LoadAME&visualizationfile
ClickonbuttonLoadvisualizationfile
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CRISIS2007
SelectCapraProject
ClickonProjectconfigurationwizard
Riskcalculationandpostprocessingwizardwillappeared
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1.Selectanalysistype-Bysinglescenery-Probabilistic2.SiteEffect3.SelectInfrastructuresforcalculation4.Hazardconfigurationforestimation
oFileoforiginoAvailablescenariooAssociatedvulnerability
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