Soil physicochemical properties and quality assessment in the coal mining area of Loess Plateau in Northern Shaanxi

The ecological environment of the Loess Plateau in northern Shaanxi is very fragile,and the soil degradation caused by the development of coal resources cannot be ignored.This paper selects three areas of mining,treatment and nature of a coal mine in the Shenfu Mining Area of the Loess Plateau in northern Shaanxi to conduct field investigation and sampling,compare and analyze the physicochemical properties of soil.The experiment uses the TOPSIS technology based on the entropy weight method to evaluate the soil quality.The results indicate that:soil particle content is ranked as sand> silt> clay.The powder content is the largest in the mining area and decreases with the increase of distance,but sand and silt have the opposite distribution pattern.Research shows that the clay grains have little change and less content.The test indicates that the soil moisture content has an overall upward trend with the increase of distance,and changes greatly near the edge of the mining area.The overall soil is alkaline,the pH value is the lowest in the mining area,and fluctuates greatly with distance,while the electrical conductivity is the highest in the mining area,and shows a downward trend with increasing distance.The results show that soil organic matter,total nitrogen and available phosphorus increase with distance,and reach the maximum in natural area.The content of available potassium is the highest in the mining area and decreases with the increase of distance.The soil quality in the mining area is poor,and the soil quality in the treatment area has improved,but it needs to be further improved compared with the natural area.In the process of coal mining,the soil is disturbed greatly.Although the physical and chemical properties of the soil can be improved by improving the soil matrix and planting vegetation,it needs a relatively long period of time for the soil to be restored after being disturbed.The ecological management of the mining area should be combined with the local natural conditions and adapted to the characteristics of the regional environment.Measures should be based on the principle of “adapting measures to local conditions and categorizing policies”,plan should be made comprehensively,and an environmentally sustainable approach should be adopted.Eventually,the ecological environmental protection and high-quality development of coal resources can be achieved.