Flood Loss AssessmentFlood Loss AssessmentAPFM methodologyAPFM methodology

Regional Programme on Disaster Risk Reduction in South East EuropeTraining workshop on flood risk assessment

27 September – 1 October 2010Istanbul, Turkey

Tommaso AbrateClimate and water Department

World meteorologicalorganization

Purposes of an economic assessment

Assess the overall deviation of economic activities from the “normal” course as a result of the flood

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

Various phases of flood assessment

Time

Event

Flood risk assessment and policy reform

In-depth evaluation

Early recovery assessment

Rapid assessment

Types of floods

• Flash floods

• Riverine flooding

Sorces of flood losses data

• Actual data collected from historical events– Direct measurements– Water marks,

witnesses, etc

• Potential losses based on stage – damage relationships

Main impact factors

• Depth of inundation

• Flow velocity (esp. flash floods)

• Duration of the inundation

• Timing

• Sediment and pollution load

Stage – damage curve for content and structural damages

Velocity and depth relation as a damage factor

Simulated dyke break: depth

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”

Terminology (ctd)

• Direct losses

• Indirect losses

• Tangible losses

• Intangible losses

Flood losses

Tangible direct losses

Intangible losses

Tangible indirect losses

Primary

Secondary

Tertiary(long term)

Damages to:BuildingsContent of buildingInfrastructures (road, bridges)Crops and animals

Loss and disruption of:Agricultural productionIndustrial productionCommunicationHealth and educationUtility supplies (électricity, gas)

Loss of added valueContamination of water supplyTraffic congestionFood shortagesLoss of income

SalinizationBlack outFire

Stress, Physical and psychological traumaWater borne diseasesIncreased mortality

Loss of lifePhysical injuriesLoss of heritage sites

HomelessnessLoss of livelihoodsPermament loss of unisured possesionBraking of community ties due to displacement or risettlements

Enhanced rate of property decayLong term structural damages

Some business are bankruptReduce GDP

Actual vs potential losses

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.)

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

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

In-depth assessment

Annual flood losses

Disaggregation of losses by sector

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