Development of Flood Development of Flood Vulnerability Index Vulnerability Index Estimation System Estimation System

Development of Flood Development of Flood Vulnerability Index Vulnerability Index Estimation System 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 Excess Flood Vulnerability Index

BackgroundBackground

Objectives of the studyObjectives of the study

Excess Flood Vulnerability estimation System

Excess Flood Vulnerability estimation System

11

22

33

44

System DemonstrationSystem Demonstration55

Index

Background

FloodDamage

For the last thirty-year period, rainfall intensity is increased Consequently, property damage has increased dramatically. However, human casualty has decreased

Rainfall Intensity over 50mm Damage trend

- 4

- 2

0

2

4

6

8

1974 1978 1982 1986 1990 1994 1998 2002

()

재산

피해

조원

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

()

인명

피해

인

재산피해

인명피해

PropertyPropertydamagedamage

HumanHumanCasualtyCasualty

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

1975 1980 1985 1990 1995 2000 2005

연도

평

균발

생회

수

1998년

1.8배

year

fre

que

ncy

Dam

age

(bill

ion

$)

Cas

ua

lty

Rainfall Intensity & Flood Damage in Korea

National river: Design frequency

(200year)

Regional river: Design Frequency

(100year)

Agriculturalarea: 50year

Urban area: 500year

Wetland area

: 10year

River Flood control considering regional unit

Small river: Design Frequency

(50year)

Paradigm changeClassification of the river in Korea: 1. National River (1st Class river) 2. Regional River (2nd Class river) 3. Small River(3rd Class river)

It fails to suggest an actual solution to cope with floods

It 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)

SystemConstruction

developed Vulnerability

Index

Analysis of PFD

Potential Flood Damage (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)

FDI SHCI SPDI SIAI

1982 1985 1990 1995 2000

3

2

1

0

Flood Damage Index for an area of Han river Basin (1982~2003)

Property Damage IndexInundation Area IndexCasualty IndexFlood 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 AreaFlood Risk Area

Inundation mapInundation map

Erosion Risk AreaErosion Risk Area

Hazard risk areaHazard risk area

damage magnitudedamage magnitude

Basin SlopeBasin Slope

Critical FacilityCritical Facility

ClimaticClimatic

EnvironmentalEnvironmental

SocialSocial

MitigationMitigation

EconomicEconomic

HazardHazard

IndexIndex

DesignDesign

VulnerabilityVulnerability

IndexIndex

DesignDesign

What kinds of indicators do we have for Vulnerability and

Hazard indices?

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)

components indicators Weights

Hydro-geological

Natural Hazard Risk Area 3Flood damage magnitude map 3

Basin slope 2Runoff coefficient 2

Socio-economic

Fire and Rescue facility 1Water treatment Facility 1

Pump Station 1Electric power Station 1

Hospital 1Density of Population 4

Financial ratio 3

Climatic Frequency of Extrem rainfall

(p≥80mm/hr)1

protectionInvestment percent for structual counter

measure(Levee)2

rainfall

1

1 4

21

2

24

slope

Population

1.0 4

2.01

1.5 0.5

1.00.5

Weight

Weight

0.25 1.0

0.50.25

0.75 0.25

1.00.5

i / maxi / max

1

2

4

2.5 5.5

3.53.0

Estimation of EFVI

EFVI C G S P

Flood ProtectionComponents

Flood ProtectionComponents

Hydro-Geologicalcomponents

Hydro-Geologicalcomponents

Socio-Economiccomponents

Socio-Economiccomponents

ClimaticComponents

ClimaticComponents

1step User Demand analysis1step User Demand analysis

2step System design2step System design

3step GIS DB design3step GIS DB design

4step Analysis module4step Analysis module

5step EFVS5step EFVS

6step System integration6step System integration

System development process

STATE EFVI

EFVS

EFVS (Excess Flood Vulnerability estimation System)

Climatic vulnerability estimation System Climatic vulnerability estimation System

- STAtistical diagnostic Tool for Extreme weather[STATE][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 resultsSTATE analysis results

Drainage Area : Drainage Area :

1,699.6km²1,699.6km²River Length : River Length :

66.4km66.4kmAverage Annual Average Annual

Precipitation :Precipitation :

1,225mm1,225mm

July, August, September July, August, September

Rainfall (total) :Rainfall (total) :

670mm670mm

Anseng-cheon basinAnseng-cheon basin

Pilot Study Area

Input weighting valueInput weighting value

EFVI EFVI == CC ++ GG ++ SS -- PP

EFVSEFVS

EFVS EFVS [input weighting values] [input weighting values]

Grade for vulnerability Grade for vulnerability

We can see grade point forWe can see grade point for

the following 4 componentsthe following 4 components

EFVS EFVS [the grade point of a small basin] [the grade point of a small basin]

EFVSEFVS

도시화율이 높을 수록도시화율이 높을 수록불투수율이 높음불투수율이 높음

InfomationInfomationEFVSEFVS

Hydro-geological analysisHydro-geological analysis

- Basin slope- Basin slope

- - Runoff coeffRunoff coeff

- Natural Hazard Risk Area- Natural Hazard Risk Area

- Erosion Risk Area- Erosion Risk Area

- Sea Level Rise Zone- Sea Level Rise Zone

- Flood damage magintude- Flood damage magintude

EFVS EFVS [Estimation[Estimation of Runoff coefficient] of Runoff coefficient]

EFVSEFVS

Hydro-geological analysisHydro-geological analysis

- Basin slope- Basin slope

- Runoff coeff- Runoff coeff

- - Natural Hazard Risk AreaNatural Hazard Risk Area

- Erosion Risk Area- Erosion Risk Area

- Sea Level Rise Zone- Sea Level Rise Zone

- Flood damage magintude- Flood damage magintude

EFVS EFVS [Hazard Risk Area] [Hazard Risk Area]

Hydro-geological analysisHydro-geological analysis

- Basin slope- Basin slope

- Runoff coeff- Runoff coeff

- Natural Hazard Risk Area- Natural Hazard Risk Area

- Erosion Risk Area- Erosion Risk Area

- Sea Level Rise Zone- Sea Level Rise Zone

- - Flood damage magnitudeFlood damage magnitude

EFVSEFVS

EFVS EFVS [Estimation of Flood damage magnitude] [Estimation of Flood damage magnitude]

- - Density of populationDensity of population

- Financial ratios- Financial ratios

Socio-Economic analysisSocio-Economic analysis

EFVSEFVS

EFVS EFVS [Population density] [Population density]

- Density of population- Density of population

- - Financial ratiosFinancial ratios

Socio-Economic analysisSocio-Economic analysis

EFVSEFVS

EFVS EFVS [Financial ratios] [Financial ratios]

EFVIEFVI

EFVI and PFD are showing

EFVI and PFD are showing

similar results

similar results

PFDPFD

Comparison of PFD and EFVI estimated from EFVSComparison of PFD and EFVI estimated from EFVS

Result

Basin characteristicBasin characteristic

VulnerabilityVulnerability informationinformation

EFVSEFVS–– Second Stage (basin characteristics) Second Stage (basin characteristics)

Future Research Plan

Critical FacilityCritical Facility

(Critical Facility Analysis (Critical Facility Analysis

––Pump station)Pump station)

EFVSEFVS

EFVSEFVS– Second Stage (facility-pump station)– Second Stage (facility-pump station)

Inundation MapInundation Map

(Anseong-cheon basin) (Anseong-cheon basin)

EFVSEFVS

EFVSEFVS– Second Stage (Inundation of the basin)– Second Stage (Inundation of the basin)

What kings of flood What kings of flood

Defense countermeasureDefense countermeasure

Should we construct in this basin ?Should we construct in this basin ?

EFVSEFVS– Second Stage (decision of flood defense measures)– Second Stage (decision of flood defense measures)

Demonstration of EFVS

Q & A