International Institute for Geo-Information Science and Earth Observation (ITC) Introduction GIS and RS for Introduction GIS and RS for risk assessment risk assessment Cees van Westen & Mark van der Meijde Department Earth Systems Analysis, ITC Enschede, Netherlands ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Disaster management cycle disaster prevention • disaster preparedness • disaster relief • Rehabilitation • Reconstruction • Traditional approach. Is it really a cycle? ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Key elements of Disaster Management Key elements of Disaster Management Pre-disaster phases Post-disaster phases Risk Mitigation Risk Transfer Preparedness Emergency Rehabilitation Identification response and Reconstruction Hazard Physical/structur Insurance/ Early warning Humanitarian Rehabilitation/re Assessment al mitigation reinsurance systems. assistance / construction of works Communication rescue damaged critical systems infrastructure Vulnerability Land-use Financial Monitoring and Clean-up, Macroeconomic assessment planning and market forecasting temporary and budget building codes instruments repairs and management restoration of services Risk Economic Privatization of Shelter facilities Damage Revitalization of Assessment incentives public services Emergency assessment affected sectors with safety planning (exports,tourism) regulations GIS mapping Education, Calamity funds Contingency Mobilization of Incorporation of and scenario training and planning (utility recovery disaster building awareness companies / resources mitigation public services) components in reconstruction Risk assessment is central in the entire process of Disaster Management • Sources: Worldbank, DMF & USAID ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Risk Risk • Risk is the exposure or the chance of loss due to a particular hazard for a given area and reference period. It may be expressed mathematically as the probability that a hazard impact will occur multiplied by the consequences of that impact . -ADPC • Note: Definitions of risk in the hazards literature vary from those that equate risk with probability to those that see risk as the product of a probability and a particular kind of impact occurring ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Losses Losses • Disaster losses include the direct impacts like the loss of life, housing and infrastructure as well as indirect impacts on production in utility services, transport, labor supplies, suppliers and markets. Secondary losses include impacts on macroeconomic variables such as economic growth, balance of payments, public spending and inflation. The impacts are felt more by developing countries. ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) TYPES OF LOSSES TYPES OF LOSSES Physical Economic Human - social • Fatalities • Ground deformation • Interruption of business or loss of ground due to damage to buildings • Injuries quality and infrastructure • Structural damage or • Loss of income or • Loss of productive Primary collapse to buildings employment opportunities workforce through fatalities, and infrastructure Effect injuries and relief efforts • Homelessness • Non-structural • Capital costs of response damage and damage and relief to contents • Losses borne by the • Disease • Progressive insurance industry deterioration of weakening the insurance • Permanent disability damaged buildings market and increasing Secondary and infrastructure premiums • Psychological impact which are not Effect • Loss of markets and trade repaired • Loss of social cohesion due opportunities through short- to disruption of community term business interruption • Loss of confidence by • Political unrest (govt. investors, withdrawal of response is perceived as investment inadequate) • Capital costs of repair ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) The most complicated simple formula The most complicated simple formula RISK = HAZARD * VULNERABILITY * AMOUNT Hazard = Probability of event with a certain magnitude • Triggering mechanism • Type of event • Magnitude: Volume, domino effect, distance, duration, speed etc Vulnerability = Degree of damage. Function of: • magnitude of event, and • type of elements at risk Amount = Quantification of the elements at risk e.g. • Replacement costs of buildings, infrastructure etc. • Loss of function or economic activities • Number of people ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Hazard, Vulnerability and elements at risk Hazard, Vulnerability and elements at risk Natural hazard (H): the probability of occurrence • of a potentially damaging phenomenon within a specified period of time and within a given area. Vulnerability (V): the degree of loss to a given element • or set of elements at risk (see below) resulting from the occurrence of a natural phenomenon of a given magnitude. It is expressed on a scale from 0 (no damage) to 1 (total loss). Elements at risk the population, properties, economic • activities, including public services, etc. at risk in a given area. ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Specific and total risk Specific and total risk • Specific risk (Rs): the expected degree of loss due to a particular natural phenomenon. It may be expressed by the product of H, V and costs C. Rs = H * V * C • Total risk (Rt): the expected number of lives lost, persons injured, damage to property, or disruption of economic activity due to a all natural phenomena. It is therefore the sum of the specific risks for all return periods and all types of events. SUM( Rs = H * V * C) For all elements at risk For all magnitudes For all hazard types ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Hazard, vulnerability and risk? Hazard, vulnerability and risk? RISK = HAZARD * VULNERABILITY * AMOUNT Hazard= PROBABILITY of event with a certain magnitude Vulnerability = Degree of damage. Function of: • magnitude of event, and • type of elements at risk Amount = Quantification of the elements at risk e.g . • Replacement costs of buildings, infrastructure etc. • Loss of function or economic activities • Number of people ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Hazard, vulnerability and risk? Hazard, vulnerability and risk? RISK = HAZARD * VULNERABILITY CAPACITY Capacity = expresses the positive managerial and operational resources and procedures for reducing risk factors ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Hazard, vulnerability and risk? Hazard, vulnerability and risk? • Example: US $ 50.00 $ 50.000 10 y 10 year ears R RP V = V = 1 � Hazard = probability within a given period = 0.1 / year � Risk = hazard * vulnerability * amount = 0.1 * 1 *50.000 = 5.000 US $ ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Hazard, vulnerability and risk? Hazard, vulnerability and risk? • Example: US $ 200.0 $ 200.000 US $ 50.00 $ 50.000 US $ 100.0 $ 100.000 V = V = 0.5 V = V = 0.1 10 year 10 y ears R RP V = V = 1 � Risk = hazard * vulnerability * amount = 0.1 * ( (0.5*200.000)+ (0.1*100.000)+ (1 * 50.000)) = 0.1 * 160.000 = 16.000 $ ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Hazard, vulnerability and risk? Hazard, vulnerability and risk? • Example: US $ 50.00 $ 50.000 50 y 50 year ears R RP V = 1 V = V = V = 0.1 10 year 10 y ears R RP 2 y 2 year ears R RP V = = 0.01 0.01 1 � Hazard = 0.5 * 0.01 * 50.000 + Ri Risk c sk curve rve 0.1 * 0.1 * 50.000 + 0.5 0.5 0.02 * 1 * 50.000 = 0.1 0.1 0.02 0.02 = 250 + 500 + 1000 0 0 1000 1000 10000 10000 = 1750 US $ ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Elements at risk Vulnerability N ∑ = Risk P E V ( i ) ( i ) ( i ) i For all Consequence credible Probability hazards of failure
International Institute for Geo-Information Science and Earth Observation (ITC) In reality In reality • Example: Pr Price is ice is ? ??? Depth = th = ???? ???? RP = RP = ?? ?? V = = ???? ???? � Risk = hazard * vulnerability * amount = ? * ? * ? = unknown What is needed: hazard assessment , elements at risk mapping, vulnerability assessment, cost estimation. ISL 2004
International Institute for Geo-Information Science and Earth Observation (ITC) Risk = Hazard * Vulnerability * Amount Risk = Hazard * Vulnerability * Amount • Very complicated topic US $ 50.00 $ 50.000 50 y 50 year ears R RP V = V = 1 V = 0.1 V = 10 year 10 y ears R RP 2 y 2 year ears R RP V = = 0.01 0.01 1 In practice this is very complicated: Ri Risk c sk curve rve • Quantifying probability 0.5 0.5 • Mapping all elements at risk • Quantifying vulnerability 0.1 0.1 • Multi-hazard risk assessment 0.02 0.02 0 0 1000 1000 10000 10000 ISL 2004
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