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Spotlight

MappingRisk,

BuildingResilience-

ExposureAnalysisof

PaciicUrbanAreas

LivablePaciicCitiesandTowns:

UrbanizationStrategiesfor

Resilience,Sustainability,

andInclusion

mm

©2026InternationalBankforReconstructionandDevelopment/TheWorldBank

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Telephone:202-473-1000;Internet:

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Annex1–GroundMotionCharacterization35

TableofContents

AcronymsandAbbreviationsiv

ListofFiguresiv

ListofTablesv

Acknowledgementsvi

ExecutiveSummary1

1.Introduction

1.1Regionalcontext:Pacificcitiesandtowns

4

4

2.Methodology

7

2.1ExposureAssessment

7

2.2EarthquakeHazardMethodology

10

2.2.1SeismicSourceCharacterization

10

2.2.2GroundMotionCharacterization

10

2.2.3HazardCalculationandOutputs

10

2.2.4ScopeandKeyFindings

12

2.3TropicalCycloneHazardMethodology

12

2.3.1ModelingFrameworkandHistoricalData

12

2.3.2WindieldandTopographicModeling

13

2.3.3StochasticEventGenerationandCalibration

13

2.3.4HazardAssessmentOutputs

14

2.4FloodHazardMethodology

15

2.4.1Fluvial/PluvialFloodAnalysis

16

2.4.2CoastalFloodAnalysis

17

3.ExposureatRiskResults

19

3.1EarthquakeEaR

19

3.2TropicalCycloneEaR

22

3.3FloodEaR

24

3.3.1Fluvial/PluvialFloodEaR

24

3.3.2CoastalFloodEaR

28

4.ConclusionsandRecommendations31

4.1OptionsforConsideration33

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ivSpotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas

AcronymsandAbbreviations

CMIP6

CoupledModelIntercomparisonProjectPhase6

D-RAS

Disaster-ResilienceAnalytics&Solutions(GPURL,WorldBankGroup)

EaR

ExposureatRisk

FSM

FederatedStatesofMicronesia

GFDRR

GlobalFacilityforDisasterReductionandRecovery

GMPE

GrundMotionPrediction

IBTRACS

InternationalBestTrackArchiveforClimateStewardship

PGA

PeakgroundAcceleration

PIC

PacificIslandCountry

RMI

MarshallIslands

Sa

Spectralacceleration

SPC

PaciicCommunity

SSP5-8.5

SharedSocioeconomicPathway5–8.5W/m²radiativeforcingscenario

ListofFigures

Figure1

MapofthePacificregion

5

Figure2

ComparisonofadministrativezoneextentsandpopulationrastersforApia,Samoa

8

Figure3

BuildingfootprintsusedforthecalculationofExposureatRisk

9

Figure4

Exampleof500-year-return-periodgroundmotionsintheSolomonIslands

11

Figure5

ReturnperiodcurvesforApia,Samoa,andPortVila,Vanuatu,forpeakgroundacceleration

12

Figure6

Mapoftropicalcyclonesustainedwindspeedswitha50-yearreturnperiodintheWesternPacificandCoralSea

14

Figure7

MethodologyusedforfloodmodelinginFastFloodforthe38cities

15

Figure8

FastSweepingAlgorithmusedinfluvial/pluvialfloodanalysis(D-RASTeam)

16

Figure9

Floodanalysis,PortVila(D-RASTeam)

17

Figure10

ScenarioforpreliminarystormsurgeanalysisneartheinternationalairportinAraiState,Palau

18

Figure11EarthquakeExposureatRiskbycountry20

Figure12Populationexposedtoearthquakehazardin2024and2050forthe38cities

20

Figure13Changeinpopulationexposedtoearthquakehazardbetween2024and2050forthe21

38cities

Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreasv

Figure14

EarthquakeExposureatRiskbycountryandsub-countrylocationswherelargevariationsexistacrossacountry

22

Figure15

Economicexposuretocyclonesin2024and2050forthe38cities

23

Figure16

Economicexposuretocyclonesvs.windspeedin2050forthe38cities(onlyhighereconomicexposurecitiesarelabeledforclarity)

24

Figure17

Absolutechangeinpopulationexposedtopluvial/fluvialfloodingfrom2024to2050inthe38cities

26

Figure18

Relativechangeinpopulationexposedtopluvial/fluvialfloodingfrom2024to2050inthe38cities

27

Figure19

Changeineconomicexposuretopluvial/fluvialfloodingfrom2024to2050inthe38cities

28

Figure20

Changeinpopulationexposedtocoastalfloodingfrom2024to2050inthe38cities

29

Figure21

Changeininundatedbuildingareafrom2024to2050inthe38cities

30

Figure22

VisualcomparisonofEaRrankingsforNadiandSuva,Fiji(D-RASTeam)

34

ListofTables

Table1RankingofPacificcitiesandtownsexposedtoflood,earthquake,andtropical2

cyclonehazards

Table2AnalyzedPacificcitiesandtowns

6

Table3Citieswiththegreatestexposureofpopulationtofloodsin2024and205025

Table4

RankingofPacificcitiesandtownsexposedtoflood,earthquake,andtropicalcyclonehazards

31

Acknowledgments

ThisreportwaspreparedbyateamledbyRashminGunasekeraandJamesDaniell,comprisingAndreasSchaefer,BastianVanDenBout,JohannesBrand,RoberthRomero,AndreasLang,HarrietteStone,AnnikaMaier,andKerriCoxoftheWorldBank’sDisasterResilienceAnalyticsandSolutions(D-RAS)team,withinputsfromJianVun,JessicaSchmidt,andAndresMaglione.TheworkwasconductedundertheguidanceofStephenN.NdegwaasDivisionDirectorforPapuaNewGuineaandthePaciicIslandsCountries,andBjörnPhilippandMingZhangastheWorldBank’sEastAsiaandPaciicUrbanDisasterRiskManagementandLandPracticeManagers,withstrategicadviceandinputsfromAndreBaldandEricDickson.

Theteamwasfortunatetoreceiveexcellentadviceandguidancefromthefollowingpeerreviewersduringthereportpreparationprocess:AnaCamposGarcia,JanaEl-Horr,LinusPott,andPaulaRestrepoCadavid.

DevanKreisbergwastheeditorandNurizaSaputrawasresponsibleforthedesignandtypesettingofthereport.

ThisreportwasmadepossiblewithinancialsupportfromtheAfricaCaribbeanPaciic–EuropeanUnionDisasterRiskManagementProgram,managedbytheGlobalFacilityforDisasterReductionandRecovery(GFDRR).

viSpotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas

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Spotlight–MappingRisk,BuildingResilience:ExposureAnalysisofPaciicUrbanAreas

Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas1

Executive

Summary

CitiesandtownsinthePaciicregionfacesigniicantrisksfromnaturalhazards.Theserisksareprojectedtoincreasewithclimatechangeandincreasingurbanization,yettheyarenotwellunderstood.AsacomplementarytechnicalreporttoLivablePacificCitiesandTowns:UrbanizationStrategiesforResilience,Sustainability,andInclusion,thisSpotlightdetailstheresultsfromriskmodelingandscientiicanalysesdesignedbyWorldBankstafftoidentifytheexposureatrisk(EaR)fromcriticalnaturalhazardsin38urbanareasin10PaciicIslandCountries(PICs).ThekeyindingsaresummarizedinBox4oftheLivablePaciicCities

andTownsmainreport.Theseresultscansupportmoretechnicaldecision-makersandpractitionersbyinformingurbanplanningandriskreductioninterventions,guidingdisasterriskinancing,shapingadaptivesocialprotectionmeasures,andprovidingabaselineforfutureassessmentsandanalyses.

EaRanalysisrevealswhoandwhatisatriskfromdifferentnaturalhazards.ThisreportpresentsEaRcalculations–incorporatingclimatechangeprojections–forrisksassociatedwithearthquakes;coastal,pluvial(surface)andluvial(river)looding;andtropicalcyclones(wind).Inthisstudy,exposure1isrepresentedbyalltheelements

ofthebuildingstock,expressedintermsoftheireconomicvalue(inU.S.dollars);thepopulation;andthebuilt-upsurface(insquaremeters).InordertocalculatetheEaR,alocation’sexposurelayersareoverlaidwithhazardmapsfordifferenttypesofhazardsandreturnperiods.2Byfocusingonhazardextentsratherthandetaileddamagefunctions,theapproachavoidstheneedforhighlyaccuratedepthorintensityinformationandinsteadprovidesaconsistentmeasureofexposureacrosshazardsandreturnperiods.TheEaRfora1-in-100-yearloodingevent,forexample,doesnotrepresenttheexposureimpactedbyasingle100-yearevent;instead,itrepresentsallexposurethatcanbeexpectedtoexperiencesomedegreeoflooding(indifferentyears)witha1percentannualprobability.

Thefollowinganalysisisbasedonstochastichazardeventsimulationsfortheabovementionedhazards,incorporatingupto10,000yearsofeventsimulations.Empiricaldatawereutilizedtogenerateloodhazardmapsforbaselineconditionsandforclimateprojectionstotheyear2050.Updatedbuildingexposuremodelsfor2024and2050werecreatedbasedonrecentcensusdataanddemographicanalyses.

1Deinedasassets,suchasresidentialandnon-residentialbuildings,thatareatriskorexposedtonaturalhazards.

2Areturnperioddescribesthelikelihoodofaneventoccurring(forexample,a100-yearreturnperiodindicatesthattheeventislikelytohappenonaverageonceevery100years).

mm

2Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas

Keyresults

EaRresultsfor38urbanareasin10PICsarerankedbyhazard,withlowerrankingsrepresentinghigherEaR,i.e.,anurbanarearankednumber1representsthehighestEaRofthe38areas(Table1).Keyresultsinclude:

•PortVilaandLuganville(Vanuatu)，Honiara(SolomonIslands)，andNadiandSuva(Fiji)consistentlyrankhighlyinEaRacrossallhazardtypes.

•Honiararanksexceptionallyhighinlood(irsttosixth)andearthquake

(eighth)exposure,butcomparativelylowfortropicalcyclones(23rd).

•SouthTarawa(Kiribati)，Majuro(MarshallIslands)，

andFunafuti(Tuvalu)intheAtollnationsrankirst,second,andthird(respectively)forcoastallooding,butFunafutiisalsohighlyexposedtotropicalcyclones(ninth),whileSouthTarawaandMajuroalsorankhighforpluvialandluvialloodhazards(11thand13th).

Between2024and2050,theexposureofpopulationsandassetsacrossthe38urbanareasisexpectedtoincreaseby130percentforearthquakesand74percentforcyclonehazards.Forloods,populationexposurewillincreaseby126percentandeconomicexposureby63percent.Forcoastallooding,the38urbanareaswillseeanoverall95percentincreaseinpopulationexposureanda60percentriseineconomicexposure.

Table1:RankingofPaciiccitiesandtownsexposedtolood,earthquake,andtropicalcyclonehazards

City/Town

Country

Coastal

FloodRank

Baseline

Coastal

FloodRank

SSP5-8.5

Pluvial

andFluvial

FloodRank

Baseline

Pluvial

andFluvial

FloodRank

SSP5-8.5

Earthquake

Rank

Tropical

Cyclone

Rank

PortVila

Vanuatu

10

11

6

8

3

3

Luganville

Vanuatu

18

19

9

10

4

5

Honiara

SolomonIslands

6

5

2

1

8

23

Nadi

Fiji

22

13

3

3

21

1

Suva

Fiji

15

17

1

5

18

6

Nausori

Fiji

21

15

5

6

16

4

Nuku'Alofa

Tonga

11

16

13

19

5

12

Tandai

SolomonIslands

9

8

8

2

9

25

Malango

SolomonIslands

14

10

10

4

6

24

Lautoka

Fiji

23

21

7

7

22

2

Funafuti

Tuvalu

5

3

18

14

30

9

Noro

SolomonIslands

13

12

14

12

1

33

Koror

Palau

20

22

27

28

12

8

Apia

Samoa

27

28

4

9

17

18

Weno

FederatedStatesofMicronesia

3

4

15

16

33

22

Haveluloto

Tonga

25

25

28

30

7

13

Neiafu

Tonga

28

27

30

32

2

15

Majuro

MarshallIslands

1

2

12

13

29

34

Tofoa-Koloua

Tonga

31

33

24

27

10

14

Ebeye

MarshallIslands

4

6

21

25

26

28

Nett

FederatedStatesofMicronesia

12

14

19

18

24

29

Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas3

City/Town

Country

Coastal

FloodRank

Baseline

Coastal

FloodRank

SSP5-8.5

Pluvial

andFluvial

FloodRank

Baseline

Pluvial

andFluvial

FloodRank

SSP5-8.5

Earthquake

Rank

Tropical

Cyclone

Rank

Faleasiu

Samoa

32

29

20

21

15

19

Vaitele

Samoa

36

24

17

17

19

20

SouthTarawa

Kiribati

2

1

11

11

37

37

Meyuns

Palau

33

34

36

36

11

7

Airai

Palau

35

36

29

29

14

11

Ngetkib

Palau

34

35

37

35

13

10

Kolonia

FederatedStatesofMicronesia

17

20

23

23

23

32

AleisaSasa'e

Samoa

36

37

25

15

20

21

Betio

Kiribati

7

7

22

22

35

35

Ailinglaplap

MarshallIslands

16

23

33

33

27

27

Bikenibeu

Kiribati

8

9

26

24

38

38

Palikir

FederatedStatesofMicronesia

36

37

16

20

25

30

Vaitupu

Tuvalu

26

32

34

37

31

16

Nukufetau

Tuvalu

29

30

38

38

32

17

Teaoraereke

Kiribati

19

18

31

26

36

36

Nui

Tuvalu

24

26

35

34

34

26

Jaluit

MarshallIslands

30

31

32

31

28

31

Thecolorsinthetablerepresentlevelsofexposuretolood,earthquake,andtropicalcyclonehazards,rangingfromdarkerred(highestexposure)todarkergreen(lowestexposure).

4Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas

1.

Introduction

RegionalContext:

PaciicCitiesandTowns

1.1

offourcitiesandtownsinFijianalyzedunderthisassessment).Across12PICs,57percentofthebuiltinfrastructurelieswithin500metersofthecoastline.3Thisgeographicalexposureincreasesrisk,especiallywhencombinedwiththehighvulnerabilityofurbanbuildingsandinfrastructure,whichareoftennotdesignedormaintainedtowithstandthegrowingimpactsofnaturalhazardsandclimatechange(e.g.,non-compliancewithcurrentbuildingcodes).Decision-makersfrequentlylackaccesstothedataandtoolsneededtoadequatelyplanforandprioritizeriskreductionortointegrateresilienceintourbandevelopment.Asaresult,whendisastersstrike,urbanSystems—includinghousing,services,andcriticalfacilities—tendtorecoverslowly.Thislimitedabilityto“bounceback”iscompoundedbyinsuficientcontingencyplanning,weakbusinesscontinuitymeasures,andoverallconstraintsingovernmentcapacitytostrengthenresilienceintheurbansector.4

CitiesandtownsinPaciicIslandCountries(PICs)areamongtheworld’smostvulnerableandmostexposedtonaturalandclimate-relatedhazards.

Theyfacesigniicantrisksfromawiderangeofnaturalhazards,includingtropicalcyclones,loods,andearthquakes.Theserisksareprojectedtointensifywithclimatechange,whichwillleadtorisingsealevels,morefrequentandsevereextremeweatherevents,andincreasedpressuresonfragileecosystems.Theexpansionofurbanandperi-urbandevelopment,concentratedespeciallyinhazard-proneareas,furtherincreasestheexposureofpeopleandassetstothesehazards.Despitethegrowingurgency,thefullscaleanddistributionoftheserisks—particularlytheirimpactsonurbanpopulationsandbuilt-upenvironments—remaininsuficientlyunderstoodandquantiied.

Paciiccitiesandtownsaretypicallylocatedalongopencoasts,oftenatornearsealevel(forexample,seeFigure1,whichshowsthelocations

3LalitKumarandSubhashniTaylor,“ExposureofcoastalbuiltassetsintheSouthPaciictoclimaterisks,”NatureClimateChange5,no.11(November2015):992–996,

/10.1038/nclimate2702

.

4Seemainreport,LivablePacificCitiesandTowns:UrbanizationStrategiesforResilience,Sustainability,andInclusion,formoredetailedanalysis.

Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas5

Figure1:MapofthePaciicregion

Note:ThemapinsetshowsVitiLevu,thelargestislandinFiji,andthelocationoffourcitiesthatwereanalyzed.

(Source:WorldBankCartographyUnit.)

WhilenaturalhazardsareamajordriverofriskforallPICstatesanddependencies,thisreportfocuseson38citiesandtowns(Table2),representingurbanareasofvaryingsizeandsigniicance.Thesecitiesarelocatedacross10countriesinthePaciicregion:theFederatedStatesofMicronesia,Fiji,Kiribati,theMarshallIslands,Palau,Samoa,theSolomonIslands,Tonga,Tuvalu,andVanuatu.Thecountriesaredispersedandgeographicallyremote.Mosthavesmallpopulationsandlimitedlandareas,whichimpedeeconomiesofscaleandmakeitmorechallengingtoprovideurban

infrastructure,urbanservices,anddisasterriskmanagementprogramsatthesamelevelaslargernations.

Giventhesecompoundingchallenges,thereisapressingneedtosystematicallyassesstheexposureofpopulations,infrastructure,andotherassetstomultiplehazardsacrossthePaciic.Thisreportaimstoillthisknowledgegapbyquantifyingthecurrentandfuturebuilt-upelementsandpopulationatrisk,providingabaselineforriskreductionplanninganddecision-making.

6Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas

mm

Table2:AnalyzedPaciiccitiesandtowns

City/Town

Country

Suva

Fiji

Lautoka

Fiji

Nadi

Fiji

Nausori

Fiji

Palikir

FederatedStatesofMicronesia

Nett

FederatedStatesofMicronesia

Kolonia

FederatedStatesofMicronesia

Weno

FederatedStatesofMicronesia

SouthTarawa

Kiribati

Betio

Kiribati

Bikenibeu

Kiribati

Taoraereke

Kiribati

Koror

Palau

Meyuns

Palau

Airai

Palau

Ngetkib

Palau

Ebeye

MarshallIslands

Majuro

MarshallIslands

Jaluit

MarshallIslands

Ailinglaplap

MarshallIslands

Apia

Samoa

Vaitele

Samoa

Faleasiu

Samoa

AleisaSasa'e

Samoa

Honiara

SolomonIslands

Tandai

SolomonIslands

Malango

SolomonIslands

Norro

SolomonIslands

Neiafu

Tonga

Nuku'alofa

Tonga

Haveluloto

Tonga

Tofoa-Koloua

Tonga

Funafuti

Tuvalu

Vaitupu

Tuvalu

Nui

Tuvalu

Nukufetau

Tuvalu

Luganville

Vanuatu

PortVila

Vanuatu

Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas

7

2.

Methodology

2.1ExposureAssessment

Theexposureassessmentprovidesthefoundationforestimatingthebuilt-upelementsatriskinthe38selectedurbanareasofthe10PICs.Itthereforeformsacriticalcomponentofthis

report’sanalysis.Theassessmentinvolvedthreeelements:thecities’administrativeboundaries,theirpopulations,andtheirbuildingstock.

Arangeofdatasourceswereconsideredtodelineatetheadministrativezoneextentsoftheanalyzedcitiesmoreaccurately.However,foreachcity,signiicantupdatesweremadetothesesources—todelineateadministrativezoneextents,toestimatethepopulation,andtodeterminetheevolutionofexposureprojectedoutto2050.Theseupdatesensuredthattheanalysiscapturesnotonlycurrentconditionsbutalsopotentialfuturedynamicsinhazardexposure.

urbanproiles.Adecisionwasthenmadeonthemostsuitablerepresentationofeachcity’sadministrativeextentthroughvisualinterpretationofpopulationdistributionpatterns,infrastructurenetworks,buildingagglomerations,andavailablerecentaerialphotographs.Thisiterativeprocessensuredthatthedelineatedzonescapturedthefunctionalurbanfootprintofeachcity,ratherthanadheringsolelytoformaladministrativeboundaries,whichareoftenincompleteorinconsistentacrossPICs.

Thechoiceofdifferentadministrativezoneswasnottrivial,andthereisopportunityforgovernmentstoconsiderstandardization.Inthemeantime,asubstantialnumberofadministrativezoneshavebeencollectedandcheckedaspartofthisexposureassessment.

Oficialadministrativeboundarydatasetswereusedasastartingpoint,complementedbyenumerationareasfromthemostrecentpopulationcensuses.Incaseswhereoficialboundariesweremissing,inconsistent,oroutdated,theanalysisincorporatedalternativereferences,suchasGoogleMapscityandtownboundarydelineationsandUN-Habitat

Populationdatawerecarefullyreviewedandcross-validatedusingmultiplesources.Globalpopulationdatasetsorrasters,includingtheGlobalHumanSettlementLayerandtheHighResolutionSettlementLayer,werecheckedforconsistencyandaccuracyinrepresentingsettlementpatternsinPaciiccities.Inaddition,populationrasterdatafromThePaciicCommunity(SPC)wereincorporatedandcomparedagainst

mm

8Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas

theseglobaldatasets(seeFigure2foranexampleofthisprocessinApia,Samoa).Tofurtherreinetheestimates,censusvaluesfromthelast50yearswereexaminedforeachcountry,allowingtheanalysistocapturehistoricaltrendsinpopulationgrowthandurbanization.Thesedatawerecombinedwithavailableprojectionsoffuturepopulationtrendsinordertodeveloprobustestimatesofpopulationdistributionfor

eachcity,bothforthebaselineyearof2024andfor2050.Censusreadingsandotherdatasetswerecollectedtounderstandcurrentpopulationratesandprojectthepopulationchangeto2050.Previousassessmentshaveoftenbeenmarredbychangesinadministrativezones,countingmethods,andotherissues,whichmeantthatitwasdificulttoensuretheaccuracyofincreasesandratesofchange.

HighResolution

SettlementLayer

(HRSL)

PaciicCommunity

(SPC)

PopulationGrid

GlobalHuman

SettlementLayer

(GHSL)

PopulationGrid

Figure2:ComparisonofadministrativezoneextentsandpopulationrastersforApia,Samoa

DifferentCity

Footprints

A

B

Overview

Country:Samoa

City:Apia

Source:WorldBankD-RASTeam

夕

Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas9

Theassessmentfocusedspeciicallyonbuildingexposure,expressedintermsofthebuildingstockanditseconomicvalue.Whileotherelements

ofexposure,suchasinfrastructurenetworksorlivelihoods,arealsohighlyrelevant,thescopeofthisstudywaslimitedtothebuildinglayer,whichisthemostconsistentandcomparabledatasetacrosscountries.Itisimportanttonotethat,ifbroaderinfrastructureassetswereincluded,theEaRofthesecitiesandtownswouldbemuchhigher.

Variousbuildingstockdatawerecollectedaspartofthework,includingdataobtainedthroughOpenStreetMapextraction,GlobalBuildingAtlas,theGlobalHumanSettlementLayer,andother

sources.Thesewereusedtoprovideabaselineofbuildingfootprintsaffectedineachcountryandasavalidationcheckofthepopulationintheadministrativezones.ExamplesareshowninFigure3.

Theresultingexposuredatasets—comprisingadministrativezoneextentsanddistributedbuildingstockandpopulation—werethenpreparedforintegrationwiththehazardcomponentsdescribedinthefollowingsections.Together,theseinputsenabledthecalculationofEaR,representingthepopulationandbuilt

environment(buildingsonly)expectedtobeaffectedunderdifferenthazardscenariosandreturnperiods.

Figure3:BuildingfootprintsusedforthecalculationofExposureatRisk

Source:WorldBankD-RASTeam

mm

10Spotlight:MappingRisk,BuildingResilience-ExposureAnalysisofPaciicUrbanAreas

5Apowerlawthatexpressestherelationshipbetweenthenumberofearthquakesandtheirmagnitudeatanytimeinterval.Ithelpstorepresenttheoverallseismicityrateinagivenlocation.

2.2EarthquakeHazardMethodology

TheteamconductedacomprehensiveProbabilisticSeismicHazardAssessmenttoevaluateearthquakehazards.Theassessmentutilizesastate-of-the-artstochasticsimulationapproachtoquantifythepotentialforearthquake-inducedgroundshaking.Thecalculationframeworkisanalogoustoindustry-standardmodelsliketheOpenQuakeEngine.

2.2.1SeismicSourceCharacterization

ThefoundationoftheProbabilisticSeismicHazardAssessmentisadetailedseismicsourcemodelthatrepresentsthelocationsand