Influence Of Ground Collapse Caused By Coal Mining Activities On The Water Characteristics Of Sandy Soil

The subsidence area caused by coal mining brings many bad influence to ecological environment of earth's surface. This investigation was taken in Shenfu-Dongsheng coal mining subsidence area. Comparison of the space-time dynamic regularity of soil water between subsidence area and the control as well as investigating in physical appearance of soil were done. in order to find out and recognize the dynamic changes of soil water of sand-land in this area. Grasp the water dynamic regularity which was influenced by subsidence, was the foundation for rational utilization of soil water and make the program of reclamation.The observation results show:(1) Water content in different parts of slop are not significant after rain, the maximum depth of infiltration is 85cm, along with the date passed; the water content of earth's surface changed greatly, and the deep level of soil changed slowly, it seems not affected from rainfall; The vegetation in the research area mainly depend on the precipitation. soil water content is lower in June and July and higher in May, August and September.(2) Study of the soil texture of research area makes clear that the soil texture is sandy clay, discrepancy of soil physical composition between subsidence area and no subsidence area are not significantly; It is found that the main influential factor of soil density of sandstorm area is soil layer through analysis of influential factor of soil density, subsidence impact on soil density is not significant; the field moisture capacity is affected to a certain extent after subsidence, the field moisture capacity tend to decreased after subsidence; the height of soil capillary rising which was determinated is 43cm.(3) Along with density of subside cracks increased, the soil water content decreased, and the water loss rate increased; along with the distance of crack increased, the water content increased, and the water loss rate decreased; the discrepancy of the water content among different subsidence areas and no subsidence areas is exist; the water content of no subsidence area are higher than that of subsidence area in different months and soil depth; there is no significant regularity of water content between subsidence in 2004 and subsidence in 2005.