Study On Soil Saturated Water Conductivity Of Slope Soil In Dump Of Open-pit Coal Mine And Influencing Factors

Reclamation of dump in open-pit coal mine is the primary problem of ecological restoration in industrial and mining areas.Soil moisture is an important link of reclamation and restoration of dump.Soil saturated hydraulic conductivity reflects the characteristics of water infiltration and leakage.Therefore,it is of great significance for the ecological distribution of industrial and mining areas to clarify the saturated hydraulic conductivity of soil on the slope of dump site and its influencing factors.In this paper,the slope of Haizhou Open-pit Coal Mine dump is taken as the research object,and the variation law and spatial variation characteristics of soil saturated hydraulic conductivity and physical and chemical properties at different slope positions and different soil layers are analyzed by means of field sampling,indoor physical and chemical properties determination,data processing and statistical analysis.The results are as follows:(1)The variation range of soil bulk density is 1.04-1.58g/cm~3;the total soil porosity varies between 40.89%-59.73%;the total soil water content varies between 9.08%-17.83%;the dump soil is mainly sandy soil;the variation range of soil organic matter is 0-0.29g/kg;the saturated water conductivity varies between 0.14-4.33mm/min,and the distribution of soil saturated water conductivity on slope surface is uniform and higher than that of soil saturated water conductivity.Platform position.(2)Soil bulk density,porosity and water content are weak variability at the slope scale.The coefficient of variation is between 0.051-0.129,0.036-0.697 and 0.058-0.149,respectively.Soil organic matter and saturated hydraulic conductivity have moderate variability,and the coefficient of variation is between 0.165-0.425 and 0.167-0.314,respectively.(3)The soil bulk density,total porosity,capillary porosity,water content,non-capillary porosity of 10-20 cm soil layer,0-10 cm sand,silt and clay all have strong autocorrelation.(4)The soil bulk density of different soil layers showed a spatial variation trend of decreasing first and then increasing along the slope length,and the vertical variation degree was low;the total soil porosity of different soil layers showed a trend of increasing first and then decreasing along the slope length;the soil moisture content of downhill and platform was lower than that of other parts of the slope,and the variation degree of soil moisture in vertical direction was lower than that of other parts of the slope.There are great differences in the size and pattern of the quality content in the vertical direction of each slope position.(5)Saturated hydraulic conductivity of soil is negatively correlated with soil bulk density and clay content,and negatively correlated with total porosity,natural water content,capillary water capacity,field water capacity,saturated water content and organic matter content.The regression equation between saturated hydraulic conductivity and soil physical and chemical properties is established as follows:Ks=-6.910(soil bulk density)+0.002(soil total porosity)-0.012(soil saturated water content)+0.276(soil clay content)-1.089(soil organic matter content).