The mitigation process begins with understanding the nature of risks. This requires a risk assessment consisting of three steps:
- Risk identification: finding, identifying and describing existing and future risk situations.
- Risk analysis: determining the nature and relative magnitude of risks.
- Risk evaluation: evaluation of the outcomes of the identification and analysis by the political decision makers, on the basis of their political preferences and criteria.
Single hazard approach
In a single hazard approach one focuses on analysing the risk of a specific type of disaster or crisis, usually in a specific geographic area and for a specific time period. In practice, many available examples of such analysis have been found, for example for forest fires, floods and landslides. This type of risk analysis is aimed at determining which of the identified risk locations face the greatest risk, in order that specific risk and/or crisis management policies can be implemented. The methods for single risk hazard risks vary widely. For example, for forest fires other risk factors are decisive than for floods. The results of such risk analysis therefore are mostly difficult to compare. On the other hand, such a risk-specific approach may offer clues to more specific targeted policies than a generic risk-transcending approach.
All hazard approach
In an all hazard approach in principle, all conceivable safety risks could be considered simultaneously. This means that risks like explosions must be made comparable to social unrest, or major infectious diseases to disruption of public utilities. To be able to compare completely different risks in an all hazard approach some sort of ‘yardstick’ is needed, with which the consequences of a risk for the various types of “vital interests” of society may be measured in a comparable way. The concept of vital interests has long been used by several countries andis now also part of the joint approach to national risk assessment within the EU, as proposed in the ‘Staff Working Paper on Risk Assessment and Mapping Guidelines for Disaster Management’. A commonly used approach for all-hazard analysis is called scenario analysis. Insight in actual and future hazardous situations does not automatically translate into a risk analysis. It is impossible to try to separately analyze the hundreds or even thousands indentified hazardous situations. Instead, in a scenario analysis a representative sce-nario is made for every relevant risk category. The main reason for the use of scenar-ios as an instrument for risk assessment is the possibility to define the critical elements in the development of a disaster or crisis, as a basis for strategic policies. A scenario analysis enables the identification of the most important factors with which the outcome of a disaster or crisis can be influenced positively, by means of both risk reduction (probability, effect and vulnerability) and disaster preparedness.