采煤塌陷对土壤水分损失影响及其机理研究

Influences of Coal Mining Subsidence on Soil Water Loss and Its Mechanisms

摸清采煤塌陷对土壤水分作用是塌陷区退化生态系统恢复、重建的前提。根据相似可比原则,应用空间对比法研究毛乌素沙地东南缘井工矿——补连塔0～100 cm层土壤含水量对采煤塌陷的响应,探索半干旱风沙区采煤塌陷地土壤水分的空间变化,为困难立地土地复垦提供理论指导。试验结果如下：煤矿井工开采形成的裂缝（隙）加剧了土壤水分损失,造成塌陷区含水量明显降低,3个试验样地的土壤水分损失量顺序：2005年塌陷区〉2004年塌陷区〉未塌陷区。试验样地土壤含水量垂直变化表现为塌陷后0～60 cm层含水量明显下降（P〈0.01）;空间变化表现为塌陷后坡底和丘间低地含水量明显下降（P〈0.01）。开采塌陷加剧土壤水分损失主要是由于塌陷造成土壤非毛管孔隙增多,促进了土壤水分垂直蒸发;塌陷裂缝（隙）的发育增大了土壤水分侧向蒸发;同时塌陷错落面的形成也增大了土壤水分蒸发量。

Research on the influences of coal mining subsidence on soil water is the basis of ecosystem restoration and reconstruction in subsiding area.Water content variation of Bulanta coal mining area in southeast Mu Us sand land was analyzed by using spatial contrast method.The results showed coal mining subsidence aggravated soil water loss,caused water content of subsidence area to decrease significantly,especially from 0 cm to 60 cm,in bottom and depression of dune.Increase in the non-capillary spaces caused by coal mining subsidence accelerated soil water vertical evaporation,development of crevice caused by coal mining subsidence accelerated soil water horizontal evaporation,formation of subsiding plane also caused soil water evaporation to increase,which was the reason of coal mining subsidence aggravating soil water loss.