Geographical Societal Risk: a useful method for understanding Societal Risk

摘要

Being a densely populated country, the Netherlands have extensive experience usingsafety regulations in land-use planning. Risk criteria have to be verified in urbandevelopment planning. Individual Risk (IR) is easily illustrated using Iso-Risk Contours,but the concept of Societal Risk (SR) is difficult to comprehend by local authorities andland use planners. The Dutch authorities therefore identified the need for a geographicpresentation of the Societal Risk, which would illustrate most affected/ problem areas.TNO has taken the opportunity to develop an area-specific approach to Societal Risks.This method considers the risks not from the perspective of the source causing the risks,but from the perspective of receivers of the risk, making it possible to quantifyaggregated risk from various sources. The Societal Risk maps proposed by TNO use twokinds of maps: the Societal Risk “Area” map and a “Contribution” map which illustrateshigh-risk hot spots. The method has now been implemented in a software tool andsupplied to regional environmental service offices. The tool makes it possible to quicklyvalidate the influence of a change in population distribution, for instance as a result ofurban development plans. Since risk from transport activities are also incorporated, it isalso possible to vary transport intensities, or changes in transport routes. Thegeographical feedback, provided by the maps, appears to be very useful in thecommunication between risk evaluation experts and for instance spatial planners.Furthermore, the illustrative colored areas proves to make users much more aware of theimportance and possible range of effects of potential accidents. The methodologicalbackground and application of the Societal Risk maps will be described in the paper.