using macro-level exposure indicators for future disaster ......
TRANSCRIPT
Gizem Mestav Sarica, PhD CandidateProf. Pan Tso-Chien, ED-ICRM
Using Macro-Level Exposure Indicators for Future Disaster Risk Assessment in Megacities
Background & Aim• Following the rapid urban growth in recent years, exposure could be considered as themost dynamic
componentinriskassessmentprocesses.• Estimationofspatiotemporalchangeofexposureisacriticalandintricatetaskespeciallyformegacities
whicharecomplexsystemswithhighlosspotentials.• Theconventionallossestimationapproachesrequireadetailedinventorydatabaseofstructures.
Alternatively,macro-levelsocio-economicexposureindicatorsareused,relyingonregularlyupdateddata.• Thisstudyaimstoprojectthenaturaldisasterlossbasedonthespatiotemporalvariabilityofexposure,
assumingadirect relationbetween lossesdue tophysicaldamagesandbusiness interruption,and theeconomicproductivityofaregion.
Conclusions and Future Work• SLEUTHUrbanGrowthModelwasusedtoassessthespatiotemporalchangeinbuilt-upareaatrisk
forselectedmegacitiesconsideringdifferenttypesofnaturaldisasters.• Itwasobservedthateachcityisuniqueandshowsdifferenttrendsfrompasttofuture.However,the
increaseofbuilt-upareainhazardousregionsshouldbeassessedcarefullyfordisasterriskreduction.• Followingthebuilt-upareapredictionforfuture,grid-basedpopulationandGDPareplannedtobe
usedforfuturelossestimationofselectedmegacitiesconsideringdeterministicandprobabilisticseismichazardanalysisapproaches.
Contact Us: ExecutiveDirector,ICRM([email protected])N1-B1b-07,50NanyangAvenue,Singapore639798Tel:+6565921866Website:http://icrm.ntu.edu.sg
www.ntu.edu.sg
References:-Opendataforresilienceinitiativefieldguide,GFDRR(2014)-SilvaEAandClarkeKC2002CalibrationoftheSLEUTHurbangrowthmodelforLisbonandPorto,PortugalComputers,EnvironmentandUrbanSystems26525–552-WaldDJ,QuintorianoV,HeatonTHandKanamoriH.1999RelationshipsBetweenPeakGroundAcceleration,PeakGroundVelocity,andModifiedMercalliIntensityinCaliforniaEarthquakeSpectra15557-564
What is Risk?
Urban Growth Prediction - 2030 Built-up Area at Risk
Methodology
Urban Growth Modelling
HAZARDThe likelihood, probability, or chance of a potentially destructive phenomenon
VULNERABILITYThe likelihood that assets will be damaged or destroyed when exposed to a hazard event
EXPOSUREThe location, attributes, and values of assets that are important to communities
RISK = HAZARD x VULNERABILITY x EXPOSUREThe composite of the impacts of ALL potential events
Built-upArea
Hazard
Built-up Area at
Risk
• As an initial step before the loss estimation, the change in built-up area at seismic risk and flood risk were obtained using the urban growth model projections for selected megacities, namely Istanbul, Jakarta, Metro Manila and Shenzhen.
• For this purpose, hazard maps obtained from different sources and built-up area from past, today and future are overlaid.
Aster GDEM Landsat
US
GS
Slope
Excluded Area
Transportation(At least 2 snapshots)
Urban Extent(At least 4 snapshots)
Hillshade
Test Mode
Coarse Calibration
Fine Calibration
Final Calibration
Prediction Mode
Urban Growth Prediction for 2030
QG
ISS
LEU
TH
Cal
ibra
tion
Mod
e Inputs
Jakarta
Metro Manila Istanbul Shenzhen
• Built-up Area at Seismic Risk was obtained for 10% Probability of Exceedance in 50 years for Jakarta, Metro Manila and Istanbul.
• Built-up Area at Flood Risk was obtained for Shenzhen.
Met
ro M
anila
Jaka
rta
Istanbul
Shenzhen
• Asaninitialstepbeforethelossestimation,thechangeinbuilt-upareaatseismicriskandfloodriskwereobtainedusingtheurbangrowthmodelprojectionsforselectedmegacities,namelyIstanbul,Jakarta,Metro Manila and Shenzhen.
• Forthispurpose,hazardmapsobtainedfromdifferentsources andbuilt-up area frompast, today and futureareoverlaid.
• Built-up Area at Seismic Risk wasobtained for 10% Probability ofExceedancein50yearsforJakarta,MetroManilaandIstanbul.
• Built-up Area at Flood Risk wasobtainedforShenzhen.
HAZARDThelikelihood,probability,orchanceofapotentiallydestructivephenomenon
VULNERABILITYThelikelihoodthatassetswillbedamagedordestroyedwhenexposedtoahazardevent
EXPOSUREThelocation,attributes,andvaluesofassetsthatareimportanttocommunities
RISK = HAZARD x VULNERABILITY x EXPOSUREThecompositeoftheimpactsofALLpotentialevents