The paper combines different concepts of risk analysis and risk evaluation. Eight evaluative criteria have been derived in order to develop a risk classification consisting of six relevant categories. The most important criteria are the probability of occurrence and the extent of damage . Another important criterion is certainty of assessment being expressed as confidence interval of probability and the extent of damage. If the certainty of assessment is low, one needs to characterize the nature of the uncertainty in term of statistical confidence intervals, remaining uncertainties and plain ignorance.
Ubiquity defines geographic dispersion of potential damages.
Persistency defines the temporal extension of damage. Reversibility describes the possible restoration of the situation to the state before the damage occurred. A long time of latency between the initial event and the actual impact of damage characterizes the delay effect . Finally, the potential of mobilization is understood as violation of individual, social or cultural interests and values generating social conflicts and psychological reactions by the affected people. Based on these eight criteria six relevant risk types can be deduced.