A new risk prediction method for water inrush from high-position separated layers in mine areas of Jurassic coal field

Water inrush from high-position separation layers in the Jurassic coal field represents a novel type of hydraulic disaster, inflicting substantial damage upon coal mines. This study, using Zhaoxian Coal Mine in the Huanglong Coalfield as a case study, introduces a regional risk forecasting methodology that integrates aspects of subjectivity, objectivity, and variable weight theory. Eight principal factors were identified for this analysis:coal seam thickness, aquifer permeability coefficient, distance of the aquifer from the coal seam, aquifer thickness, aquifer’s unit water intake, head height of the aquifer, geological structure, and the cumulative thickness of mudstone in the Yan’an and Zhiluo formations.The study employed the Variable Weight Method (VWM) to adjust the normal weights determined by the Analytic Hierarchy Process (AHP) and the Entropy Weight Method (EWM). This led to the development of a mathematical model for water inrush risk assessment in the Zhaoxian No. 1 mining area, culminating in a comprehensive evaluation index for water inrush risk. In conjunction with the engineering geological conditions of Zhaoxian, surface extraction and drainage holes were utilized to precisely manage the water sources of the hazard. The results indicate that the AHP−EWM−VWM method can accurately pinpoint areas at high risk of water inrush. The comprehensive weight evaluation underscores that reducing the aquifer water level is a crucial strategy for preventing and controlling water damage. The implemented surface pumping holes have been effective in mitigating the risk of water inrush in the mining area, demonstrating the study’s significant value in guiding the effective prevention and control of water inrush in the Jurassic coal field.