Development of Flood Vulnerability Index Estimation System  Jang, Dae Won, Kim, Byung Sik, Kim, Bo Kyung, Seoh, Byung Ha, and Yoon, Suk Young  Jang, Dae Won, Kim, Byung Sik, Kim, Bo Kyung, Seoh, Byung Ha, and Yoon, Suk Young

Excess Flood Vulnerability Index Background Objectives of the study Excess Flood Vulnerability estimation System System Demonstration 5 5 Index

Background Flood Damage  For the last thirty-year period, rainfall intensity is increased  Consequently, property damage has increased dramatically.  However, human casualty has decreased Rainfall Intensity over 50mmDamage trendPropertydamage HumanCasualty year frequency Damage(billion $) Casualty Rainfall Intensity & Flood Damage in Korea

National river: Design frequency (200year) Regional river: Design Frequency (100year) Agricultural area: 50year Urban area : 500year Wetland area : 10year River Flood control considering regional unit Small river: Design Frequency (50year) Paradigm change Classification of the river in Korea: 1. National River (1 st Class river) 2. Regional River (2 nd Class river) 3. Small River(3 rd Class river)

I t fails to suggest an actual solution to cope with floods Objectives of the study  Korea selects flood control safety level based on the estimation of Potential Flood Damage; PFD)  But PFD just show overall safety level for flood damage in mid and large basins.  So, PFD can not correspond properly to the flood  This research will improve the limitations of PFD.  So, we developed Excess Flood Vulnerability Index(EFVI) for the analysis about vulnerability that did not considered in PFD  And also we developed Excess Flood Vulnerability estimation System(EFVS) that can evaluate the vulnerability.

Procedure of the study Analysis of FDI Application (Anseong-Cheon basin) System Construction developed Vulnerability Index Analysis of PFD

Potential Flood Damage (PFD)  PFD was developed and used in National Water Resources Planning in Korea for analyzing flood potential in the regional unit or concerned area of the river basin and for the decision making for the priority of investment for flood prevention project  PFD = f (Flood Potential, Risk)  Flood Potential = f (Population, Property, Urbanized Ratio, Infra- structure)  Risk = f (Flood Damage, Design Rainfall, Improved Ratio of Levee, Dams and Reservoirs, Runoff)

Potential Flood Damage (PFD) - The regions of class A of PFD has increased from 27 to 35 (30% increase) - Southeast coastal regions and central regions need to be invested with higher priority for the flood prevention measures.

 Standardized Human Casualty Index (SHCI) = std (N. of Human casualties of unit area / Population of unit area)  Standardized Property Damage Index (SPDI) = std (Value of damaged property of unit area / Value of total property of unit area)  Standardized Inundated Area Index (SIAI) = std (Inundated area of unit area / Total area of unit area) Flood Damage Index (FDI) FDISHCISPDI SIAI

Flood Damage Index for an area of Han river Basin (1982~2003) Property Damage Index Inundation Area Index Casualty Index Flood Damage Index PFD is widely used for representing the degree of potential of flood damage. FDI just corresponds to property damage index. However we have difficulty in the use for flood defense measures or projects because index does not correspond to the flood frequency.

 We considered the climatic, Hydro-geological, Socio-Economic, flood Protection components and developed EFVE and EFVS Excess Flood Vulnerability Index(EFVI)

 Benouar & Mimi(2001) Risk = Hazard x Vulnerability divided by Disaster Management Vulnerability is defined as the weakness/strength of the element at risk Flood Risk Area Inundation map Erosion Risk Area Hazard risk area damage magnitude Basin Slope Critical Facility Critical FacilityClimatic Environmental Social Mitigation Economic HazardIndexDesign VulnerabilityIndexDesign What kinds of indicators do we have for Vulnerability and Hazard indices?

 Components for Excess Flood Vulnerability Index(EFVI)

Determine weighting values of indicators  Weighting values of the indicators were decided by conducting a survey to the specialists in industrial, academic, and research fields  We use AHP analysis for determining weighting values (Saaty, 1980) componentsindicatorsWeights Hydro-geological Natural Hazard Risk Area3 Flood damage magnitude map3 Basin slope2 Runoff coefficient2 Socio-economic Fire and Rescue facility1 Water treatment Facility1 Pump Station1 Electric power Station1 Hospital1 Density of Population4 Financial ratio3 Climatic Frequency of Extrem rainfall (p ≥80mm/hr) 1 protection Investment percent for structual counter measure(Levee) 2

rainfall slope Population Weight i / max Estimation of EFVI EFVICG S P Flood Protection Components Hydro-Geological components Socio-Economic components Climatic Components

1step User Demand analysis 1step User Demand analysis 2step System design 2step System design 3step GIS DB design 3step GIS DB design 4step Analysis module 4step Analysis module 5step EFVS 5step EFVS 6step System integration 6step System integration System development process STATEEFVI EFVS EFVS (Excess Flood Vulnerability estimation System)

Climatic vulnerability estimation System [STATE] - STAtistical diagnostic Tool for Extreme weather [STATE] -Heavy rainfall threshold -Greatest 5-day rainfall -Average wet-day rainfall -Longest dry period -Heavy rainfall proportion -Heavy rainfall days -Hot-day threshold -Cold-night threshold -Frost days -Longest heatwave STATE analysis results

Drainage Area : 1,699.6km² 1,699.6km² River Length : 66.4km 66.4km Average Annual Precipitation : 1,225mm 1,225mm July, August, September Rainfall (total) : 670mm 670mm Anseng-cheon basin Pilot Study Area

Input weighting value EFVI = C + G + S - P EFVS EFVS [input weighting values]

Grade for vulnerability We can see grade point for the following 4 components EFVS [the grade point of a small basin] EFVS

도시화율이 높을 수록 불투수율이 높음 Infomation EFVS Hydro-geological analysis - Basin slope - Runoff coeff - Natural Hazard Risk Area - Erosion Risk Area - Sea Level Rise Zone - Flood damage magintude EFVS [Estimation of Runoff coefficient]

EFVS Hydro-geological analysis - Basin slope - Runoff coeff - Natural Hazard Risk Area - Erosion Risk Area - Sea Level Rise Zone - Flood damage magintude EFVS [Hazard Risk Area]

Hydro-geological analysis - Basin slope - Runoff coeff - Natural Hazard Risk Area - Erosion Risk Area - Sea Level Rise Zone - Flood damage magnitude EFVS EFVS [Estimation of Flood damage magnitude]

- Density of population - Financial ratios Socio-Economic analysis EFVS EFVS [Population density]

- Density of population - Financial ratios Socio-Economic analysis EFVS EFVS [Financial ratios]

EFVI EFVI and PFD are showing similar results PFD Comparison of PFD and EFVI estimated from EFVS Result

Basin characteristic Vulnerability information EFVS – Second Stage (basin characteristics) Future Research Plan

Critical Facility (Critical Facility Analysis – Pump station) – Pump station) EFVS EFVS – Second Stage (facility-pump station)

Inundation Map (Anseong-cheon basin) EFVS EFVS – Second Stage (Inundation of the basin)

What kings of flood Defense countermeasure Should we construct in this basin ? EFVS – Second Stage (decision of flood defense measures)

Demonstration of EFVS

Q & A