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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CRISIS2007

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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CRISIS2007

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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CRISIS2007

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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