The Soil Factor Analysis And Quality Evaluation Of Slope In Subsidence Area Of Shaanbei Coal Mine

The soil ecological environment in the coal mining area of northern Shaanxi is fragile and sensitive to human production activities.In-depth study of the characteristics of the soil environment in the subsidence area of coal mining,taking the slope soil in the subsidence area of,the North Shaanxi Coal Mine as the research object,taking the field investigation,laboratory testing and combining mathematical tools and other mathematical statistics to select the soil bulk density,porosity,Moisture content,mechanical composition,pH value,total organic carbon,total nitrogen,ammonium nitrogen,available potassium,available phosphorus;study of soil factor changes and different subsidence years,soil factor characteristics and different locations in subsidence areas under different subsidence years Soil fertility evaluation in subsidence area under the subsidence period.The main conclusions are as follows:(1)Mining subsidence has certain influence on soil physical and chemical indicators.Soil moisture content in subsidence area decreases,pH value increases,and soil nutrient content in subsidence area is lower than non-subsidence area.(2)The physical and chemical indicators of soil in the subsidence area of coal mine tend to be stable with the time of subsidence,especially the soil nutrient index.On the slope position,the soil water content decreased by 75%and 67%in the depth of 0 cm?10 cm and the subsidence in 5?6 years,and the total organic carbon in the soil decreased by 87%in the depth of 40 cm?60 cm.In the depth of 0 cm-10 cm,the soil available potassium content decreased by 62%,the subsidence was 7?8 years,and the total organic carbon content in the depth of 20 cm?40 cm decreased by 67.5%.(3)Under the same period of time,the overall physical and chemical indicators of the sag and slope subsidence areas are larger than the bottom.Compared with the non-subsidence area,the soil ammonium nitrogen decreased by 83%in the depth of 0 cm?10 cm and the total organic carbon content in the soil depth decreased from 10 cm to 20 cm.%,the soil moisture content decreased by 67.5%in the depth of the slope from 40 cm to 60 cm.(4)Nemerow comprehensive index method was used to evaluate soil fertility in non-subsidence and subsidence areas.It was concluded that the soil in the subsidence area was in a state of poverty,and the total organic carbon content of soil was the lowest among all the research indicators,which affected the comprehensive score.It can be seen from the soil fertility comprehensive score that the soil fertility has recovered with the subsidence time,but it has not reached the non-subsidence area standard.