Water Loss And Soil Erosion Characteristics Research Of Coal Mining Subsidence Slope Soil Based On Mining With Filling

Water and Soil erosion is one of the important environmental problems in today’s world,with the mining of coal resources, more and more coal mining subsidence areas come out,it makes the water and soil erosion problem in coal mining subsidence areas need to be focused on.through the comparison and analysis of the current situation of water and soil erosion between the mining with filling subsidence area and the mining without filling subsidence area,and the water and soil erosion research of mining with filling subsidence area under the laboratory simulated rainfall conditions,this thesis has explored the impact of water and soil erosion in mining subsidence area by mining with filling method,and the water and soil erosion characreristic in mining with filling subsidence area.the research has the theory and practice significance for the promotion of the mining with filling method and can provide theoretical guidance for the management of water and soil erosion in subsidence area.This thesis has contrasted and analyzed the present situation of soil physical and chemical properties of mining with filling subsidence area、mining without filling subsidence area and non-subsidence area. under the condition of rainfall simulation in the laboratory,this thesis has explored the water sediment concentration influence factors in subsidence slope, analyzed the correction between soil detachment rate and water erosion power factors and the relationship between the soil detachment rate and water sediment concentration.The results were expected:1. For the composition of soil particles in subsidence slope area,the content of sand is about10%, the content of silt is about45%,and the content of clay is about45%, the soil material belongs to clay soil2. The incidence of physical and chemical properties in the surface soil of WuGou coal mining minning with filling subsidence area is slight. The water content of slope soil reduced from subsidence basin to the top. But from the distribution of soil profile,there were no obvious change,the water content is about0.35cm3/cm3, it was very close to the data of filed water content. The soil total soluble salt content was low in the mining with filling subsidence slope soil,soil bulk density and PH had no significant difference from non-subsidence area.3. The Hydraulic characteristic parameters had no significant difference between subsidence area and non-subsidence area,the damage degree in the mining without filling subsidence area was serious.4. There was soil nutrient loss exists in the mining with filling subsidence area,but it was slight.the organic matter content was low in the research area,they were all about1-1.5%, lack of nitrogen and potassium,rich of phosphorus.these three parameters increased from the slope top to the slope toe, but the amplification was not obvious.5. In the heavy rainfall and10°slope condition, the soil sediment concentration was exponential rise,so,if the slope of the subsidence area beyond a certain limit,the subsidence area can have serious soil erosion.6. In the same rainfall condition, the flow shear stress is the main water erosion dynamic factors affecting soil erosion rate. In the same slope condition,the energy consumption per unit width is the main water erosion dynamic factors affecting soil erosion rate.7. In the condition of laboratory rainfall simulation,the soil erosion rate had functional relationship with the water sediment concentration,it can be summarized as fitting equation like:Dr=aSwb, Dr is soil erosion rate, Sw is water sediment concentration,0<a<0.02,1<b<2.