SPATIAL DECISION SUPPORT FOR INTEGRATED DISASTER RISK REDUCTION HYDROLOGICAL HAZARDS AND RISK ASSESSMENT

Transcription

1 SPATIAL DECISION SUPPORT FOR INTEGRATED DISASTER RISK REDUCTION HYDROLOGICAL HAZARDS AND RISK ASSESSMENT CEES VAN WESTEN

2 10 criteria for Disaster Resilient Cities.

3 Sustainable and risk prepared Medellin

4 Analyse the risk change of planning alternatives Probability Present situation Alt 1: Land use change 1 Alt 2: Land use change 2 Future hazard situation Scripts for automatization of risk calculation 1/200 Future EaR SDSS Losses Future vulnerability Probability Current situation Alt 1R: Land use change 1 + Risk reduction Alt 2R: Land use change 2 + Risk reduction 1/200 Losses

5 RiskChanges Spatial Decision Support System Spatial Decision Support System for the Analysis of Changing Risk Integrating assets mapping products with hazard footprints and vulnerability curves multi-hazard risk assessment web-based interface using open source software tools Documentation: Online SDSS (cloudserver):

6 Use of the RiskChanges SDSS Current Planning Future scenarios: situation alternatives: Evaluation Risk Short mitigation term: of recovery current planning risk / rapid changes Evaluation Early Climate Warning change of risk after a disaster event Recovery Land use change Current situation Evaluation of current risk Evaluation of risk after a disaster event Future scenarios: Short term: recovery / rapid changes Climate change Land use change Planning alternatives: Risk mitigation planning Early Warning Recovery

7 Data input module Study area Administrative units Hazard data sets: Hazard type Hazard intensity Spatial probability Return period Elements-at-risk dataset Type Value Population

8 Hazard maps Debrisflow (DF) hazardflashflood (FL) hazardlandslide (LS) hazard Impact pressure (IP) Water depth (DE) Spatial probability (SP) Tsunami (TS) hazard Water Depth (DE) Return period: 20 years Return period: 20 years Return period: 20 years DF_IP_20_A0 FL_DE_20_A0 LS_SP_20_A0 Return period: 20 years TS_DE_20_A0 Return period: 50 years Return period: 50 years Return period: 50 years DF_IP_50_A0 FL_DE_50_A0 LS_SP_50_A0 Return period: 100 years TS_DE_100_A0 Return period: 100 years DF_IP_100_A0 Return period: 100 years FL_DE_100_A0 Return period: 100 years LS_SP_100_A0 Return period: 200 years TS_DE_200_A0

9 Example Hue, Vietnam. Flood hazard maps (different return periods)

10 Example Hue, Vietnam. Elements-at-risk maps (building footprints)

11 Project Alternatives Scenarios Future years

12 Possible planning alternatives For example the following planning alternatives could be analyzed when considering an area prone to flashflood, debrisflows and landslides: Planning Alternatives Description Codes A0 (no risk Do nothing 2014_A0_S0 reduction) A1 Engineering Construction of engineering structures (e.g. flood walls, sotriage 2014_A0_S1 basins) A2 Ecological Ecological disaster risk reduction measures (e.g. protective forest, 2014_A0_S2 bioengineering) A3 Relocation Relocation of high risk elements-at-risk 2014_A0_S3

13 Possible future scenarios Name Land use change Climate change Scenario 1 Business as usual Rapid growth without taking into account the risk information No major change in climate expected Scenario 2 Risk informed planning Rapid growth that takes into account the risk information and extends the alternatives in the planning No major change in climate expected Scenario 3 Worst case Rapid growth without taking into account the risk information Scenario 4 Most realistic Rapid growth that takes into account the risk information and extends the alternatives in the planning Climate change expected, leading to more frequent extreme events Climate change expected, leading to more frequent extreme events

14 Loss Analysis

15 Risk analysis

16 Example Hue (Vietnam): Loss map

17 Example Hue: Risk Map

18 Cost-benefit analysis and Multi Criteria Evaluation Results of the risk calculation as input; Investment, maintenance costs, Indicators: CBR, NPV, IRR Combine with other indicators: social, economic, environmental

19 Future risk for different scenarios and alternatives Scenario 1: Business as usual Scenario 2: Risk-informed planning Scenario 3: Worst Case Scenario 4: Climate change adaptation

20 09/11/201512/12/ /05/2015 After the first Before After monsoon the the earthquake season Resource: Google earth

21 Data flow DEM SLOPE MAP TERRAIN UNITS LAND COVER RUN OUT ANALYSIS INVENTORY OF EVENTS Central office Data preparation Slope steepness class Low (<15 0 ) Moderate ( ) Steep (35(b) ) Very steep/cliff (>50 0 ) Field observations Local knowledge Decision tree in App. Local evaluation by local people per terrain unit Central Web-server To be consulted by other organisations (a)

22 DECISION SUPPORT FOR RISK MANAGEMENT IN CARIBBEAN SMALL ISLAND STATES World Bank GFDRR 5 countries Spatial planning Infrastructure management

23 Post-Maria landslide and floods (2017)

24 Decision support for post disaster recovery App to support planning department in building permits

25 Spatial Decision Support Systems For Integrated DRR Earthquake related Storm related Drought related Changing Multi-Hazard Risk Climate change VGI / RS Asset Landuse change Vulnerability Population Rural assets Spatial Resilience Spatial Planning CBA / MC Evaluation Early Warning Recovery