Simulation of coal mining mode in the Chang River Basin based on damage of water and soil resources

In order to study the damage degree of water and soil resources under different coal mining modes,the sys-tem dynamics model of coal-water and soil resources economic system was constructed based on the system dynamics theory. After many times of operation improvement,the model passed the test and was used to analyze the development charac-teristics of the water and soil resource damage system under different situations. Through the analysis of the model operation,three most sensitive factors affecting the amount of coal mining,cultivated land and water resources are the recovery rate,wastewater treatment rate and reclamation rate. Under the premise of controlling the coal mining volume below 6 Mt,the cultivated land area and the total water supply amount are controlled at 31. 25 km2 and more than 18. 72 Mt respectively,three main influencing factors are reset,the simulated operation shows the damage of soil and water resources under three different coal mining modes from 2017 to 2030 in the coal mine area of the Chang River Basin. The difference in the development of water and soil resources under different scenarios of coal mining scale is obvious. Under the economic optimization mode,the growth rate of the national economy has increased signifi-cantly,but the area of cultivated land has decreased slightly,and the total water supply has decreased rapidly,which is easy to affect local people with insufficient water resources,so this mode is not in the long-term interest of economic development. Regarding to the resource optimization mode,the growth rate of annual gross national product is signifi-cantly reduced under this model,the area of cultivated land and total water supply increase rapidly,and the resource-based development model can maintain the healthy and steady development of resources,but it is not conducive to eco-nomic development. With the SD-MOP integrated optimization mode,the coal mining scale is properly controlled,the national output value can be steadily increased under the premise of steadily increasing,and the gradual increase of land and water resources can be ensured,taking into account both economic benefits and natural resources. The optimi-zation plan is a process of rational utilization of coal resources,water and soil resources,and economic-ecological doub-le optimization. It is also a process of improving the utilization efficiency of coal resources,water and land resources in the study area,and helps to optimize the quantitative structure,hierarchical structure and benefit structure of coal,wa-ter and land resources in the Chang River Basin. After the continuous test of these three modes,it is concluded that the integrated optimization coal mining mode is an optimal mining mode.