Post-Mining Risk Management and multi-hazard approaches, methodology and application

Abstract

After intensively exploiting the mineral resources of its subsoil for several centuries, French mining sites have gradually closed. The “post-mining” of a site mine is concerned by many hazards which can occur such as: ground movement phenomena (subsidence, collapses), rising gas, irreversible disruptions in underground water circulation induced by mining can potentially cause disturbances, both in terms of water circulation patterns (Flooding in low areas, disruption of waterway flows) and water quality (pollution). The multi-hazards assessment methodology consists of four steps: the identification and the assessment of the singles hazards, the identification of the potential hazard interactions, the identification of the level and the consequences of the interactions and the finally the adjustment and the mapping of the hazard interaction. The matrix tool and interaction organigrams are used to identify the potential interactions. The paper presents the methodology for the interaction between two main hazards: flooding and ground movement. The interaction methodology was applied on two case studies: shallow chalk mine and deep coal mine (France). The results demonstrate the importance of multi-hazard assessment. This analysis depends on the quality and the quantity of existing data for carrying out the multi-hazard assessment.