Determining the scale of coal mining in an ecologically fragile mining area under the constraint of water resources carrying capacity.

A reasonable mining scale is very important for the development of mining areas. In view of the lack of water resources in arid and semi-arid areas, this paper studies the scale of coal mining in arid and semi-arid areas under the constraint of the water resources carrying capacity (WRCC) with the aim of realizing the conservation mining of ecological environment. From the perspectives of market demand side, production side and the constraint side, a "trinity" decision model was constructed to investigate the main factors influencing the scale of coal mining. By introducing the optimal control theory with profit taken as objective function, the coal price and coal reserves were regarded as boundary conditions, and WRCC was set as constraint condition. Based on H-J-B equation algorithm, the decision-making equation for mining scale under the constraints of market demand and WRCC was obtained. Through comparing the mining scales under the two constraints, the mode of "water-based mining scale" was formulated, which is conductive for realizing the balance between coal mining and ecological environment development.