Flood Risk Management and Urban Resilience Workshop II May 28-29, 2013 Venue: COEX, Seoul, Republic of Korea Effective Flood Risk Assessment Methodologies National Disaster Management Institute, NDMI Tae Sung Cheong 1
Contents Introduction 3 Software Measures: Early warning System 6 Hardware Measures: SSWRPs 9 Risk Assessment Methods 15 Summary 22 2
Hazards : Flash Flood & Heavy Rainfall a) Annual average number of 1hr rainfall b) Annual average number of 3hrs rainfall Rainfall 1970s 1980s 1990s 2000s > 30mm 48.0 60.6 68.2 72.3 > 50mm 5.1 10.0 10.3 12.3 > 80mm 0.3 0.5 0.9 1.1 Rainfall 1970s 1980s 1990s 2000s > 50mm 55.1 71.5 75.3 88.1 > 80mm 9.7 16.4 16.6 21.1 > 100mm 3.7 6.8 6.5 8.6 c) Annual average number of 12hrs rainfall d) Annual average number of 24hrs rainfall Rainfall 1970s 1980s 1990s 2000s > 100mm 38.4 53.2 56.8 62.3 > 150mm 8.1 13.9 16.8 16.9 > 200mm 2.6 4.6 4.9 5.8 Rainfall 1970s 1980s 1990s 2000s > 100mm 60.7 87.2 92.5 100.3 > 150mm 18.4 28.5 31.4 32.8 > 200mm 7.3 10.6 12.7 12.4 Rainfall intensity is increasing and heavy rain is localized at spot area 3
Damages on Small Stream Watershed Poor Drainage System Small Discharge Capacity Unmanaged Channel Shape Poor Sewage System High Speed Flow by Slope Debris Flow & Old Structure (a) Urban Area (b) Agricultural Area (c) Mountainous Area 4
How Can Manage Flood Risk in SSs? 5
Flood Risk Management and Urban Resilience Workshop II May 28-29, 2013 Venue: COEX, Seoul, Republic of Korea Software Measures : Early Warning System 6
WEB-GIS Based ISS for Warning 7
Why Information Sharing? Actual/Potential Damages Ratio to Warning Time Education, Training & Warning can Reduce the Damages The State of Queensland, 2002 8
Flood Risk Management and Urban Resilience Workshop II May 28-29, 2013 Venue: COEX, Seoul, Republic of Korea Hardware Measures : Small Stream Restoration 9
SSWRP for DRM Channel Restoration City, Culture & Theme Stream Ecology, Community Stream Bridge Reconstruction Artificial Park Area Purchase Land for Flood Plane (a) Prevention Flood (b) Sustainable Develop. (c) Resilient Recovering 10
Why SSWRP? Enhancement of Local Community DRR is Considered Damages are decreasing with restoration SS Number : 26,595 SS Length : 62,040km Restoration Number : 22,641 Restoration Length : 35,815km Restoration Ratio : 51.2% 11
Priority & Needs High Middle Low Priority Restoration Sustainable Development Keep Ecology, Resources Preparedness Resilience Recovering Theme, Needs Based Recovering Purchase Land, Flood Plane Recovering 12
S Guideline for Priority Setting 13
Concept Diagram of MCDM Objectives Identification Weight Criteria : AHP : PROMETHEE Alternatives Sensitive Analysis Decision Making Criteria Identification Rank Alternatives Flood Plane Urban Area Levee Increase 14
Flood Risk Management and Urban Resilience Workshop II May 28-29, 2013 Venue: COEX, Seoul, Republic of Korea Risk Assessment Methods 15
Concept of Flood Risk Assessment Technology Model (Flood, Typhoon Landslide) Hazard Map Risk Map Loss Function Inventory (Building, Facilities, Land use) Disaster Risk Map Direct Indirect Death, injury Building, Facilities Corruption Health, population problem Economic activity impediment 16
Information Based Assessment Measured Flood Map Estimated Flood Map Local Government, NEMA NGIS Depth-Damages DB DEM, 1/25,000 Land Use, 1/50,000 Item GIS Information Building House, Community Building, APT Item Land Use Information Agric. Land Rice Paddy, Farm, Orchard, Corps GIS DB Case Building Damage (10,000$) Agri. Damage (10,000$) Total Damage (10,000$) 1 1,030.6 27.2 1,057.8 2 1,793.6 39.3 1,832.9 3 2,456.4 43.7 2,500.1 4 3,035.1 48.1 3,083.2 Damage Loss DB 17
Model Based Assessment Data Analysis Simulations Meteo. Hydro-Info. GIS Inventory Damage/Loss Assessment 18
Disaster Information Tool TXET Information Metrological DB Channel DB Disaster DB GIS Information Characteristics DB Statistical DB Hazards DB Inventory D I T Disaster Model Floods Typhoon Landslide Physical Model Assessing Tool Risk Vulnerability Damage/Loss Assess Model Inventory Based Input Data Support System Pre-processing of Input Data to fit the Model Post-processing of Assessment Results Automatic Data Calibration and Establish Inventory DB 19
Platform for Assessment Information Service Upgrade Information User Version : 30m; Open GIS Information User Service Developer System Information Information Developer Upgrade Service Developer Pro Version : 10m; ESRI ArcGIS 20
Utilization of Platform Government : Preparedness and Prevention Climate Change Scenario Assessment Establish Optimized Management Plan Lead High Value DRM Technologies Develop ICT Based Software Measures Finance/Insurance : Revitalization of Flood Insurance Damage Loss Assessment Develop Flood Insurance Product Market Develop Risk Finance Products Disaster Risk Exchange Management Damage Loss Assessment Platform Personal/Enterprise : Assets Loss Assessment Prepare Measures by Oneself Response for Disaster Legislation/Code Create High Value Business (Disaster Risk Assessment) NDMI : Assessment Agency Assessment Technology Development and Management Post-Disaster Damage Loss Assessment Assessment Tool/Model Calibration Education and Training of DRA/M 21
Flood Risk Management and Urban Resilience Workshop II May 28-29, 2013 Venue: COEX, Seoul, Republic of Korea Summary 22
Lesson and Learned Development of Organic Assessment Platform to integrate disaster information(inventory, Hazards, Disasters) and simulation results Design of optimal workflow including compatibility and accessibility to assess damage/loss by using disaster information and model results Establishment of development plan for the Disaster Information Tool Development of platform to adapt national disaster management law and it will support decision making to set priority of preparedness and recovering projects and prepare hazard map Including assessment obligation in national disaster management law to assess risk and damage/loss of all national development projects USA added assessment obligation in the disaster mitigation act of 2000 [DMA 2000] to prepare hazard maps and disaster mitigation plans. 23
Challenges Lack of data (hazards and exposure) as basis for risk analysis Limited experts on climate change, risk assessment and geologic/hydro-meteorologic hazards at the local level Political will to adhere to local plans and investment programs 24
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