Flood Loss Assessment APFM methodology

1. Flood Loss AssessmentAPFM methodology Regional Programme on Disaster Risk Reduction in South East Europe Training workshop on flood risk assessment 27 September – 1 October 2010 Istanbul, Turkey Tommaso Abrate Climate and water Department World meteorologicalorganization

2. Purposes of an economic assessment Assess the overall deviation of economic activities from the “normal” course as a result of the flood

3. Why an economic assessment? • Assessing net benefits derived from using a flood plain • Design of appropriate policies and strategies • Reconstruction planning • Rescue and emergency coordination

4. Various phases of flood assessment Flood risk assessment and policy reform In-depth evaluation Early recovery assessment Rapid assessment Time Event

5. Types of floods • Flash floods • Riverine flooding

6. Sorces of flood losses data • Actual data collected from historical events • Direct measurements • Water marks, witnesses, etc • Potential losses based on stage – damage relationships

7. Main impact factors • Depth of inundation • Flow velocity (esp. flash floods) • Duration of the inundation • Timing • Sediment and pollution load

8. Stage – damage curve for content and structural damages

9. Velocity and depth relation as a damage factor

10. Simulated dyke break: depth

11. Terminology • Damages: related to the physical damage of public and private assets (infrastructures, houses, vehicle, etc.) caused by the contact with water • Losses: broader meaning, including secondary and tertiary losses, including intangible ones (human lives) and “things that could have been”

12. Terminology (ctd) • Direct losses • Indirect losses • Tangible losses • Intangible losses

13. Flood losses Tangible direct losses Tangible indirect losses Intangible losses Damages to: Buildings Content of building Infrastructures (road, bridges) Crops and animals Loss and disruption of: Agricultural production Industrial production Communication Health and education Utility supplies (électricity, gas) Loss of life Physical injuries Loss of heritage sites Primary Stress, Physical and psychological trauma Water borne diseases Increased mortality Secondary Salinization Black out Fire Loss of added value Contamination of water supply Traffic congestion Food shortages Loss of income Homelessness Loss of livelihoods Permament loss of unisured possesion Braking of community ties due to displacement or risettlements Enhanced rate of property decay Long term structural damages Some business are bankrupt Reduce GDP Tertiary (long term)

14. Actual vs potential losses

15. Rapid assessment during flooding • Objectives: • Collect factual information for emergency response and management • Identifying the administrative level concerned (local, national, international) • Limited time availability, evolving situation • Casualties, displaced people • Inundation map • Flooded assets • Expected evolution of the event • Assets at risk • Status of lifelines (access roads, hospitals, electricity, water and food supply, etc.)

16. Early recovery assessment • Purpose: • guiding the recovery process and it priorities • designing financial mechanisms • Evaluation of coping capacity • Identification of management mistakes • Focus on tangible and direct losses and on actual costs and damages

17. Early recovery assessment (ctd) • Public and private losses • Who's bearing the losses? • Magnitude with respect to coping capacity,locally and nationally • Social aspects of the losses

18. In-depth assessment

19. Annual flood losses

20. Disaggregation of losses by sector

21. Conclusions • Collect data before the flood event • Involve local communities • There is not a universal formula for all contexts • Develop an agreed procedure • Collect data on losses and on who has to bear them • Compare losses and benefits • Institutional framework for data collection