Vulnerability Assessment of Mining Subsidence Hazards

Between 1996 and 1999, five mining subsidence events occurred in the iron-ore field in Lorraine, France, and damaged several hundred buildings. Because of the thousand hectares of undermined areas, an assessment of the vulnerability of buildings and land is necessary for risk management. Risk assessment methods changed from initial risk management decisions that took place immediately after the mining subsidence to the risk assessment studies that are currently under consideration. These changes reveal much about the complexity of the vulnerability concept and about difficulties in developing simple and relevant methods for its assessment. The objective of this article is to present this process, suggest improvements on the basis of theoretical definitions of the vulnerability, and give an operational example of vulnerability assessment in the seismic field. The vulnerability is divided into three components: weakness, stakes value, and resilience. Final improvements take into account these three components and constitute an original method of assessing the vulnerability of a city to subsidence.