Arid And Semi-arid Regions Coal Mining Ecological Impact Studies

With the development of economy, China's energy demand is growing rapidly. In China's energy structure, coal occupies an extremely important position. At present, coal resources easily exploited in eastern China, has basically dried up. With the difficulty of exploitation increasing, the center of coal mining has shift to the northwest region.Northwest China is arid and semi arid areas, with dry climate, scarce water, poor vegetation, serious soil erosion and desertification, where ecological environment is very fragile. The exploitation of coal resources is bound to increase the burden of local environment, making the environment worse. Compared with developed countries, underground mining takes up a larger proportion in China, which accounts 92.5% of total reserves. Vegetation dependent on groundwater is more evident in arid and semi arid areas, where is short of water. Land subsidence, groundwater dewatering caused by underground mining in this region make vegetation destruction and desertification. Thus, according to regional characteristics, to establish a rational, scientific, feasible ecological impact assessment index system of coal mining has an important significance on the local ecological environment.Through data collection, field surveys, expert consultation, literature research and other methods, the paper analyzed the mechanism of the ecological impact caused by coal mining; from the aspects of exploitation intensity and natural background, divided the ecological impact of coal mining into land use, land subsidence, groundwater level change, ecological sensitivity, four subsystems; selected 14 quantitative indicators; constructed ecological impact assessment index system of coal mining in arid and semi arid areas.Then this paper took Shenmu Dabaodang coalmine as an example, verified the reliability and direction of the index system. The results show that:when the first layer was all exploited, serious impact region accounts 16% of the total area, mainly in east and south-central area; minimal impact region accounts 37% of the total area, located in the northern and western part; the rest is medium impact region. Finally, according to the ecological impact, this paper presented the corresponding mitigation measures.This paper systematically analyzed the ecological impacts of coal mining in arid and semi arid areas, established the corresponding evaluation index system of ecological impact, providing a useful reference for the environmental impact assessment in this region.