Assessing Natural Hazard Risk in Urban Areas

1. Assessing Natural Hazard Risk in Urban Areas Henrike Brecht Louisiana State University Emergency Management Higher Education Conference, June 7, 2007

2. Why a Risk Index? • Identifying Risk: • Key element in disaster reduction • Enables informed policy making • Index: • Summarizes a body of knowledge • Easy to understand • Facilitates comparisons Emergency Management Higher Education Conference, June 7, 2007

3. Urban Risk Index • Follow-up of World Bank Disaster Hotspots • Multi-hazard index • All cities worldwide with more than 100,000 inhabitants • Outcome: Relative risks of • mortality • economic losses Emergency Management Higher Education Conference, June 7, 2007

4. What is Risk? Risk = Hazard x Exposed Elements x Vulnerability • Hazard • Derived from historic hazard data • Exposed Elements • City Population • City GDP • Vulnerability • Population vulnerability: derived from historic death tolls • Economic vulnerability: derived from historic economic losses Emergency Management Higher Education Conference, June 7, 2007

5. Data Inputs: Hazards • Five major hazards • Vector data was gridded, raster data was resampled at 1 km resolution. Emergency Management Higher Education Conference, June 7, 2007

6. Data Inputs: Cyclones Emergency Management Higher Education Conference, June 7, 2007

7. Data Inputs: Landslides Emergency Management Higher Education Conference, June 7, 2007

8. Data Inputs: Floods Emergency Management Higher Education Conference, June 7, 2007

9. Data Inputs: Earthquakes Emergency Management Higher Education Conference, June 7, 2007

10. Data Inputs: Exposed Elements • City population numbers (Henderson) • City GDP (World Bank) • City footprints: GRUMP (Global Rural-Urban Mapping Project) by CIESIN Emergency Management Higher Education Conference, June 7, 2007

11. Data Inputs: Exposed Elements Emergency Management Higher Education Conference, June 7, 2007

12. Data Inputs: Vulnerability • Not based on social vulnerability indicators • Damage rates by hazard • EM-DAT (Emergency Disaster Database) • Population vulnerability: • historic death tolls per hazard • Economic vulnerability: • economic loss rate per hazard Emergency Management Higher Education Conference, June 7, 2007

13. Outcomes • For each city • Mortality risk index • Economic risk index • Relative risk levels Emergency Management Higher Education Conference, June 7, 2007

14. Earthquake Mortality Risk Emergency Management Higher Education Conference, June 7, 2007

15. Conclusion • Index is a comprehensive summary and enables comparisons • Guides policy making and resource allocation • Index creation is impeded due to lack of accurate data • Macro analysis which does not replace careful risk assessments for cities Emergency Management Higher Education Conference, June 7, 2007

16. A Glance Ahead • Individual city assessment • Improve global flood and landslide hazard data • Improve global loss data Emergency Management Higher Education Conference, June 7, 2007

17. Thank you. Henrike Brecht henrike@hurricane.lsu.edu Emergency Management Higher Education Conference, June 7, 2007