Influence of dump vegetation coverage and topographic changeson soil and water loss in drainage basin

The phenomenon of soil erosion in coal mine dumps is very serious, and blindly rebuilding vegetation in this area will consume a lot of resources. Reasonable vegetation coverage settings will help guide the vegetation restoration in the mining area.Based on the hydraulic erosion prediction model GeoWEPP, on the basis of the field survey combined with remote sensing technology to obtain the measured data, the influence of the change of vegetation coverage of the dump site on the water and soil loss in the study area was explored with the mine group as the research scale, and the dump site was obtained. The optimum range of vegetation coverage was obtained too. The main reasons for the increase of soil and water loss in the basin where the Xilinhot mining group was located were analyzed. On this basis, the change of the water and soil loss in the basin under the change of the topographic pattern was further simulated, and the influence of the change of the basin topography and surface vegetation coverage on the water and soil loss of the basin was studied.Taking 10% vegetation coverage as the interval, 10%-90% coverage as the interval, and 50 years as the simulation 〖JP+2〗duration, the regional soil simulation was〖JP〗LMused to analyze the water and soil loss in the watershed where the mine group was located. On this basis, the non-linear mean change point method was used to analyze the vegetation coverage of the dump site when the ecological benefit was maximized. The results show that: ① Topographic change is the main reason for the increase in soil erosion in the study area. The impact of terrain change on the increase in soil erosion is much higher than the mitigation effect of the vegetation reconstruction in the dump site.② The slope of the dump site is the main source area for soil erosion. It is difficult to alleviate the soil erosion situation only by the vegetation reconstruction in this area. The vegetation reconstruction of the dump site should be carried out on the basis of landform remodeling to achieve the maximum benefits of the ecological environment optimization in this district. ③ The normalized value of soil and water loss is distributed as a power function with the increase of vegetation coverage. The optimal range of vegetation coverage of Xilinhot mining group dumps is calculated by the mean change point method to be 40%-50%. As well as the setting range of the vegetation coverage of the dump in the case of the smallest amount of water and soil loss in thewatershed.