A comparative analysis of semi-quantitative multi-hazard methodologies with an application to a post-mining area

Closed and abandoned coal mines are increasing globally, leading to a growing emphasis on their transition into sustainable post-mining areas. This focus marks the era of just transition, highlighting the importance of equitable reclamation efforts. The complexity of mining landscapes makes them susceptible to multiple hazards, which can occur simultaneously or successively, a concept known as multi-hazard. This study emphasizes the need for a comprehensive approach to multi-hazard analysis, which is an essential part of the sustainable reclamation and safety of post-mining areas, directly impacting the safety and well-being of communities. The research compares four widely employed semi-quantitative multi-hazard methodologies: the Analytic Hierarchy Process (AHP), the Entropy Weight Method (EWM), the partial multiplication factor method, and the spatiotemporal method. Each method's strengths and limitations are evaluated by applying it to a specific post-mining area, incorporating an innovative multi-hazard scenario assessment. The implementation and comparison of the methods revealed that each one has particular advantages: AHP is widely used with supporting background, EMW is straightforward to implement, the partial multiplication factor method demonstrates more precisely multi-hazard principles, and the spatiotemporal method is the only one that considers temporal frequency. However, none of the methods accounts for the sequence of hazards within scenarios. While AHP and EWM provide consistent rankings, the partial multiplication factor and spatiotemporal methods show greater variability in multi-hazard index (MHI) values, highlighting the influence of both hazard intensity and interactions.