VOLUME 2 MODULE 4 RISK AND VULNERABILITY ASSESSMENT
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Consequence analysis, risk estimation and risk evaluation The key questions for these steps are: What will be affected by these hazards? How bad are the effects?
As discussed previously, consequence analysis requires the identification of the elements at risk and defining spatial vulnerability of these same elements. The elements at risks may include the population and the infrastructure, among others. Risk estimation, on the other hand, involves estimating the risk expressed as the likelihood of fatality, injury or damage per unit time. And finally, risk evaluation is the determination of the significance of the estimated risk for those affected. The consequence analysis requires the conduct of an inventory of population and/or assets that may be affected and estimating potential losses (or damage) from hazards. Note that each hazard type has unique characteristics that influence loss (or damage) estimation in an area depending on magnitude, duration or intensity. For example, the effects of floods are dependent on flood depth and duration; while fatality is significantly linked to the speed of onset. Likewise, various hazards will impact elements differently. For example, buildings are damaged variably by an earthquake based on materials of construction and design of the building itself.
Risk estimation follows after the potential fatality and property damages had been estimated in the consequence analysis step. Risk estimation involves estimating the risk (annual basis) expressed as the expected annual number of lives lost, and annual damage to property (in monetary value). Finally, the risk evaluation can be undertaken using the same approaches contained in the analysis of exposure and vulnerability. Note that risk evaluation essentially focuses on prioritization of control measures (e.g. DRR, CCA) in the absence of a risk acceptability criteria in the country. As with hazard assessment, the entire process (from consequence analysis to risk evaluation) is iterative – the steps are repeated for each hazard. Additional information can be found in NEDA‘s Guidelines on Mainstreaming Risk Reduction in Sub-national Development and Land Use/Physical Planning in the Philippines.
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