Risk assessment of multi-disaster in Mining Area of Guizhou, China

Increased slope and soil instability due to rainfall infiltration and artificial exploitation is a significant cause of multi-disaster in mining areas. Many kinds of research have been conducted to evaluate the susceptibility of single geological disaster species such as landslides, collapses, ground subsides, and debris flows. However, due to the coupling effect of different stages, the evaluation system index's construction is often disregarded during mining-induced multi-disaster risk assessments. Hence, we propose a relatively complete evaluation index system to assess the multi-disaster risk that considers the assessment processes of disaster susceptibility, hazard, and vulnerability in mining areas. The procedure for the proposed method includes three main steps. In step 1, we analyze the spatial probability assessment due to topographic, geological, and geomorphic indicators. In step 2, the hazard assessment indexes system and multi-disaster models are established using different rainfall probability periods, considering the annual maximum daily rainfall. In step 3, the vulnerability assessment method of multi-disaster was proposed according to the calamity environment and considering hazard distribution and bearing body characteristics. The risk evaluation system for multi-disaster mining areas is established based on the previous three steps. We validated the proposed model by analyzing mining exploitation in Panguan town, China. Our model classifies the likelihood of multi-disaster occurrence in mining areas according to five risk levels: very high, high, moderate, low, and very low. The multi-phase risk assessment map is drawn with different rainfall frequencies (10%, 5%, 2%, and 1%, respectively), providing reasonably scientific guidance on the mining region's emergency response capacity.