Coordinated Development Model of Coal–Water–Ecology in Open-Pit Combined Underground Mining Area

In this paper, a coal–water–ecology (CWE) index system is firstly constructed based on an analysis of the current situation regarding coal mining, water resource utilization, and the ecological environment in an open-pit combined underground mining area. Three methods are used to determine the weights of each index in the system. Then, the TOPSIS model and coupling coordination degree model are adopted to construct the coordinated development model for CWE. Finally, the coordinated development status of CWE in the mine area is analyzed, and the next improvement measures are pointed out. The CWE index system contains 3 dimensions, 6 aspects, and 21 indicators. Combining the weights with game theory makes the weight coefficients more concentrated, reduces the dispersion of single weights, and makes the results of the fusion weights more reliable. The TOPSIS model and coupling coordination degree model can successfully characterize the coordinated development of CWE system factors. The proximity degrees of the CWE system in the study area show an increasing trend year by year. Although the coupling degree of CWE increases slowly year by year, it exhibits little coordination, with an average value of 0.4. Economic benefits, the water resource utilization rate, and the green land area are the three indices with the greatest weights. While ensuring the economic benefits of coal mining, coal enterprises should focus on improving the water resource utilization rate. The reduction in the green land area should also be emphasized in open-pit mining.