黄土矿区开采沉陷引起的土壤湿度变化特征研究

Variation of Soil Moisture Caused by Mining Subsidence in Loess Mining Area and Its Mechanism Analysis

西部黄土覆盖区大规模地下采煤导致严重的地表沉陷及地理环境破坏。选取土壤湿度作为地理环境因子,利用彬长大佛寺矿区2007~2017年的遥感数据构建温度植被干旱指数(TVDI)模型,分析开采沉陷区和非采动影响区土壤湿度变化的基本特征。基于开采沉陷理论分析研究区域的水平变形和地表裂缝发育特征,通过土样实验获取沉陷区不同位置的土体密实度和含水量数据。遥感结果表明,矿区土壤湿度在1月较大,在7月较小,开采沉陷区的土壤湿度变化量相对于非采动影响区更高。经综合分析表明开采沉陷变形和裂缝发育引起土壤密实度降低,加剧地表水的吸收与蒸发效应,导致沉陷区土壤湿度呈现上述变化特征,初步揭示了黄土矿区开采沉陷对于土壤环境的扰动效应。

The large-scale underground coal mining in the west loess area leads to a serious surface subsidence and the damage of the geographical environment. Soil moisture was selected as a geographic environmental factor, the remote sensing data of the mining area in Binchangdafosi in 2007-2017 were used to construct the temperature vegetation drought index(TVDI) model, and the basic characteristics of soil moisture in the mining subsidence area and the non-mining affected area were analyzed. Based on the theory of mining subsidence, the characteristics of horizontal deformation and surface fracture development in the study area were analyzed. Soil compactness and water content data at different positions in the subsidence area were obtained by soil sample experiment. The results of remote sensing showed that the soil moisture in mining area was larger in January and smaller in July, and the change of soil moisture in the mining subsidence area was higher than that in the non-mining area. Comprehensive analysis showed that the mining subsidence deformation and crack development decreased the soil compactness and intensified the absorption and evaporation of surface water. These results preliminary revealed the disturbance effect of mining subsidence on soil environment in loess mining area.