平原地区采煤沉陷区非饱和带水分特征及影响因素研究

Study on the water characteristics and influencing factors of unsaturated zone in mining subsidence area in plain area

基于安徽淮北市某矿采煤沉陷区,建立野外原位试验场,通过监测沉陷区非饱和带土壤水势、水位、降水量变化,并结合野外采集的土样测试结果,就地下水位、蒸发、降水、以及开采沉陷过程等因素对比分析沉陷区与非沉陷区土壤水分变动。结果表明:降水、蒸发条件的改变对非饱和带土壤水分分布影响较大,而在降水、蒸发条件基本相同的情况下,沉陷区30 cm以下非饱和带土壤含水率规律呈现先减小后增大,该现象主要是由于采煤后地面沉陷对土壤产生一定的扰动,竖直方向上裂隙增加,土壤持水率下降,沉陷稳定后,相对地势较低的沉陷区开始汇水使得土壤含水率上升。

Based on the mining subsidence area of a mine in Huaibei,Anhui,a field in-situ test field is established. By monitoring the soil water potential,water level and precipitation in the unsaturated zone of the subsidence area,and combining the soil samples collected in the field,the groundwater level,evaporation,precipitation,and mining subsidence are compared and analyzed in the subsidence area and the non subsidence area. Change of soil moisture in the region. The results show that the change of precipitation and evaporation conditions has a great influence on the soil water distribution in unsaturated zone,but under the same conditions of precipitation and evaporation,the soil moisture content of the unsaturated zone below 30 cm in the subsidence area decreases and then increases. This phenomenon is mainly due to the disturbance of the ground after coal mining. The cracks in the vertical direction increased,and the soil water holding capacity decreased. After subsidence,the soil water content increased as compared with the lower subsidence area.