he understanding of mitigation starts with the understanding of risk. In practice the participating partners of MiSRaR use different definitions of risk, derived from international literature. Comparison has shown that the various definitions ultimately amount to the same thing. The definitions only put different elements of the risk concept on the foreground. The two main definitions are:

Risk = probability x impact

Risk = hazard x vulnerability

An important distinction is that between the English terms risk and hazard, which in several languages both translate into the same word. Given the second definition the difference between a risk and a hazard lies in the vulnerability of the risk recipients: a potential hazard involves only the (likely) negative effect of an incident (disaster or crisis). The degree of vulnerability of people and the environment for such an effect determines whether this also amounts to a significant risk. To illustrate: a flooding itself can be seen as a hazard. However, if this occurs in an uninhabited area, without economic or ecological value, there is no or little risk.

Vulnerability is a composite concept, which consists of exposure and susceptibility. To illustrate: the extent to which buildings are vulnerable to a flood, depends both on the extent of the exposure (what is the height of the water?) and the degree to which it is actually truly affected by water (of what material and how solid is it built?).

The difference between the two definitions lies in the grouping of concepts. Combining these concepts creates the following aggregate definition: