Investigation And Experimental Study On Soil Erosion Of Dump Slope In Yongli Coal Mine Inner Mongolia

China is a major coal mine production，strip mining is widely used because of its strongproduction capacity，low cost，high mechanization degree, and which is more widely used inthe energy source of shanxi-shaanxi-inner mongolia. With the large-scale open-pit miningdump emerged. A serious negative impact on the local ecological environment caused bydump which has special layered structure, poor soil, loosely slope, a extremely low vegetationcoverage. The slope with severe soil erosion has more severely effect on regional ecological.The research object is the dump slope of yongli opencast coal mine. The research methods arefield investigation, runoff and sediment reductions and runoff scouring experiment. Researchcarried out in different spatial and temporal variation of the slope rill erosion control measures,sediment reduction effects and runoff and sediment yield and other aspects of the proceduredescribed.(1) Compared with bare slope three kinds of measures will reduce of soil bulk densityand the fractal dimension of soil particle. All the dump slopes is higher than the native slopeon soil bulk density and the fractal dimension of soil particle. The “salix psammophilacheckerboard+broadcasting grass+sea-buckthorn” measure can inhibit the development ofrill, five years later; rill erosion was only8.89%of the bare slope.“salix psammophilacheckerboard” measure has a worst protective effect, whose rill erosion was163%of the bareslope in five years later.(2) All types of slope erosion sediment has enrichment in <0.1mm of soil particlessignificantly, the average enrichment rate is1.34.“astragalus adsurgens straw mulch”measure and “straw mat mulch” measure have a higher enrichment rate,“salix psammophilacheckerboard” measure’s enrichment is the worst, the average enrichment rate is1.12. theresult revealed that benefit in runoff reduction was different as the difference of protectionmethods, the order was straw mat mulch, astragalus adsurgens straw mulch, salixpsammophila checkerboard, which, compared with bare slope, runoff decreased65.53%,63.35%,3.19%, respectively. The benefit in runoff reduction of broadcasting grass was notobvious. The benefit in sediment reduction was different as the difference of protectionmethods, the order was straw mat mulch, astragalus adsurgens straw mulch, broadcastinggrass, salix psammophila checkerboard, which, compared with bare slope, sediment decreased93.63%,91.46%,36.64%,30.75%, respectively. (3) All measures have similar runoff process, but sediment yield significant differences.On the first-year slopes,“broadcasting alfalfa” measure has best runoff reductions, about42.9%;“salix psammophila checkerboard” measure has worst runoff reductions, about1.1%;the other four measures about31.9%～39.0%.“broadcasting alfalfa” measure has bestsediment reductions, about92.0%;“salix psammophila checkerboard” measure has worstrunoff reductions, about4.0%; the other four measures about64.2%～87%. On the third-yearslopes,“90%coverage” measure has best runoff and sediment reductions, respectively36.8%and59.0%;“50%coverage” measure has worst runoff and sediment reductions, respectively6.5%and15.8%. All measures have similar rule of relationship between water and sediment,Y=aXb(Y represents sediment, X represents runoff).