采煤沉陷对沙地土壤水分运移的影响

为研究采煤沉陷对风沙区土壤水分生态环境的影响,对毛乌素沙地南缘补连塔矿采煤沉陷后风沙土土壤水分时空变化规律及土壤密度、土壤机械组成和水分运移过程(水分入渗、土壤蒸发)进行了研究。结果表明:沉陷使得水分恢复期土壤水分条件发生变化,增加了60~80 cm深度处土壤水分的变异性,但沉陷区与对照区之间差异未达显著性水平。在采煤沉陷后1 a的相对稳定期,与对照区相比,沉陷区粗粉粒(0.01~0.05 mm)含量明显增加,而细黏粒(0.001 mm)含量减小;在初始入渗率上,表现为沉陷区较高,在稳定入渗率上,表现为对照区较高,但差异较小,而沉陷明显增加了水分的垂直入渗深度,减小了表层土壤持水能力;同时,沉陷区土壤蒸发量明显增大,不利于土壤水分的保持。经相关性分析,沉陷使得土壤水分与影响因素之间的相关性增强。

Effects of mining subsidence on soil water movement in sandy area

Soil water ecological environment is a key factor for the growth and survival of plants.To study the influence of mining subsidence on the soil and water loss in the arid and semi-arid desert region，the temporal and spatial variation of soil moisture and the variation law of soil physical properties (soil bulk density，soil particle size distribution)，water cycling process (water infiltration，soil evaporation) of sandy land were studied in Bulianta coal mining area located at the southeast Mu Us desert，China.The experiment was conducted in one area experiencing mining subsidence and the other undisturbed control area 100 meters away from mining working face.The results show that，compared with the undisturbed control area，the mining subsidence changed soil moisture conditions in water recovery period，and increased soil moisture variability in 60-80 cm soil layer，but the difference between the subsidence area and the control area did not reach a significant level;the mining subsidence increased the coarse silt particles (0.01-0.05 mm) and decreased the fine clay particles (<0.001 mm);the subsided area was higher at initial infiltration rate and faster to reach a steady infiltration，while the undisturbed control area was higher at a steady infiltration rate，with little differences;the mining subsidence increased the infiltration depth and reduced the water holding capacity of the upper layer，and increased soil evaporation at the same time，which is not helpful for the soil and water conservation;and the final correlation analysis indicated that the mining subsidence enhanced the relevant degree of correlations between soil moisture and affecting factors.