Evaluation of water richness of weathered bedrock aquifers based on subjective and objective combination of TOPSIS-RSR

The weathered bedrock aquifer is one of the main sources of water inrush from Jurassic coalfields in Shanbei, Seriously threatening the safety of mining; It is an important link in mine water prevention and control to accurately predict the water-rich condition of weathered bedrock aquifer, which is of great significance for ensuring mine safety production. Taking the water-richness of the weathered bedrock aquifer in the west plate of Hongliulin well field as the research background, five influencing factors such as the thickness of weathered bedrock, lithological combination, degree of weathering, elevation of the top surface of the weathered bedrock and depth of burial were selected as the evaluation indexes, and an evaluation system of the water-richness of the weathered bedrock aquifer was established. Based on the comprehensive evaluation theory, a subjective-objective assignment method combining Fuzzy Analytic Hierarchy Process (FAHP) analysis and Coefficient of Variation (CV) objective assignment method is proposed to assign the weights of each indicator, which fully takes into account the subjectivity of the human factor and the characteristics of the data itself, and improves the objectivity of the assignment of the indicators; and based on the subjective-objective combination of the assignment method, a water-richness evaluation model is constructed with the sorting by the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method, and the graded by the Rank-Sum Ratio (RSR) assistance. The model was used to evaluate the water-richness of the weathered bedrock aquifer in the study area, and the evaluation results were converted into a visual partition map, and the partition results were verified by integrating the unit water influx of the pumping test boreholes. The results show that there are 41 pumping test boreholes in the west of Hongliulin, the results of the partition of the pumping test boreholes are consistent with the results of the unit surge division, with the exception of the B23-27, L6 water, and Z4 pumping test boreholes, and it indicates that the results of the model's water-richness zoning evaluation are basically reliable, and it shows that the model has high accuracy and scientificity, enriches the water-richness evaluation method, and provides new ideas and methods for the evaluation of water-richness of mine aquifers under similar conditions.