Risk Assessment of water inrush under an unconsolidated, confined aquifer: the application of GIS and information value model in the Qidong Coal Mine, China

The mineable coal seam at Qidong coal mine, Huaibei coalfield, is adjacent to the overlying unconsolidated confined aquifer, which may induce water inrush hazards threatening the safe mining. This study presents an information value model (IVM) for the risk assessment of water inrush based on the information value and the geographic information system (GIS). In contrast to the general risk assessment model, this model was considered to improve the selection of the evaluation factor, which predicts the water inrush risk by using the best combination of factors. In general, the selection of the factors always had been decided by individual decision-makers. It was significantly subjective, which, in turn, make the prediction results quite different from the fact. Thus, it is of great significance to optimize the selection of evaluation factors before predicting the water inrush risk. This model was applied to the Qidong coal mine in North China. Then, the prediction results were further verified by the field distribution of water inrush, and the evaluation result is believed to be satisfactory. In addition, the AHP was also adopted for the risk assessment to compare with IVM. The AUC values of AHP and IVM without the optimization of factor selection are 0.6883 and 0.8229, respectively, and are 0.7253 and 0.8494 after the optimized selection, respectively. The results show that the IVM has a better prediction accuracy, and the prediction accuracy is increased after the optimization of factor selection, which indicates the IVM and the optimization could further help the future mining operation.