New prospects for the spatialisation of technological risks by combining hazard and the vulnerability of assets

Abstract

Risk is currently considered as a function of hazard and the exposure of assets, depending on their vulnerability, on an area within which a disaster could occur. However, in France, technological risk management is shared between a technician management focused on hazard, where assets are identified only from direct exposure, and vulnerability assessment of the assets, which are rarely incorporated in their entirety. Early studies, which tried to take into account these two parts of management, are limited, as a result of incomplete identification of assets and their vulnerabilities. An absence or an inadequate combination between hazard and the vulnerability of assets is also frequently observed. Indeed, they are mainly based on the combination of territorial vulnerability through quantification of the hazard, which is not unproblematic: the characterisation of the hazard, translated into quality criteria in terms of technological hazards, is not a linear relation. To solve these problems, a geographical information system-based methodology is therefore suggested in this study, where hazard perimeters are combined with the vulnerabilities of the exposed assets in a qualitative way. It is based on a process that uses geospatial operations and a specific semiology to provide an efficient mapping of the global risk. This methodology could be applied to any kind of territory, hazard and assets, to produce operational and useful knowledge of technological risk cartography. It can also be considered as a first step to a more global Natech risk assessment, since floods may cause severe damages to the local industrial facilities and trigger major accidents involving human, material and environmental assets.