Variation of soil erodibility on loess slope under various subsidence years in coal mining subsidence area located Northern Shaanxi

Soil erodibility can not only quantitatively describe the anti erosion ability of soil,but also reflect the effect of soil erosion caused by human activities. Studying the impact of coal mining damage on soil erodibility is conducive to the protection of ecological environment in coal mining areas. Taking the typical subsidence slope soil (shallow with vertical depth of 20 cm) with subsidence years of 1-5 a and 6-10 a in Northern Shaanxi coal mine area as the research object,the soil mechanical composition and organic matter content were measured by MS2000 laser particle sizer and total organic carbon analyzer respectively. On this basis,the soilerodibility K-value was calculated by EPIC model. The spatial variation characteristics of soil mechanical composition and organic matter are clarified,and the effect of soil and water loss on subsidence slope is revealed. The results show that:① The mining subsidence in Northern Shaanxi coal mining area can not change the soil texture type. With the increase of settlement years,the degree of soil desertification at the top of the slope intensifies,the degree of soil desertification at the middle of the slope slows down,and the decreasing trend of soil sand content and the increasing trend of clay content at the foot of the slope are becoming more obvious. The deterioration of soil physical structure of 10-20 cm soil layer at the top of the slope for 1-5 a is most serious,and the improvement of soil physical structure of 10-20 cm soil layer at the foot of the slope for 6-10 a is most obvious;② The mining subsidence can reduce the content of soil organic matter at the top and middle of the slope,with an average decrease of 20.8%-55.3%. With the increase of subsidence years,the decline of soil organic matter content at the top of the slope intensifies,and the decline of soil organic matter content in the middle of the slope slows down. The deterioration of soil chemical structure of 0-10 cm soil layer at the top of the slope subsided for 6-10 a deteriorated most seriously,but the effect on the content of soil organic matter at the foot of the slope was not obvious;③ Mining subsidence in Northern Shaanxi coal mining area have the effect of improving the erodibility of surrounding soil. With the increase of subsidence years,the increase of soil erodibility K-value at the top,middle and foot of slope slows down. The increase of soil erodibility K-value of 0-10 cm soil layer at the top of the slope for 1-5 a is the most significant,the change of soil erodibility K-value of 0-10 cm soil layer at the middle of the slope for 6-10 a and at the foot of the slope after different subsidence years is not obvious. The mining subsidence significantly expand the difference of soil erodibility between the two layers at the top of the slope and reduce the difference of soil erodibility between the two layers at the middle and foot of the slope; ④ The 8-value of soil erodibility at the top of subsidence slope in Northern Shaanxi coal mine area is large and the soil anti-corrosion ability is poor. Artificial measures such as soil structure improvement and fertilization should be considered for accurate prevention and control of soil erosion,and natural measures should be considered at the foot and middle of slope. The results can provide scientific basis for accurate prevention and control of soil erosion,ecological environment protection and high-quality development in coal mining areas in the middle reaches of the Yellow River Basin.