A multiscale assessment model for mining-induced groundwater disturbance risk to multi-aquifer and its application in disaster reduction

The disturbance caused by coal resource development alters the groundwater runoff conditions, leading to negative environmental effects. In addition, groundwater influx into mining shafts poses significant risks to both personnel safety and property. Due to the high cost of pre-treatment and the potential risk of groundwater pollution, accurately predicting the risk of disturbance, precisely narrowing the scope of governance, and scientifically proposing prevention measures are crucial for the ecological and geological environmental protection of this region. Firstly, the range of the water-conducting fractured zone was clarified. Subsequently, the sedimentary environment of the multi-aquifer connected by the fractured zone was analyzed, and the sedimentary environment index and hydrodynamic index were added to the previously used controlling factors. A multiscale system of primary controlling factors was then established combining with drilling information. Then, the analytic hierarchy process (AHP) and grey relational analysis (GRA) method were applied to calculate the subjective and objective weights. On this basis, the comprehensive-weight model based on AHP-GRA improved by variable weight (VW) was constructed. Finally, the groundwater disturbance risk was obtained based on the three-map method. The assessment results were validated by comparing the prediction results with the groundwater inrush points. The results showed that the assessment results were consistent with the actual situation, and the accuracy of the comprehensive-weight model was increased by 75% compared with the constant-weight model. Precisely narrow down the area of governance and scientifically propose prevention and control measures.