陕北采煤沉陷区土壤水分入渗和蒸发特征研究

Study on the characteristics of soil moisture infiltration and evaporation in the coal mining subsidence area of coal mines in northern Shaanxi

土壤水分是制约矿区生态环境恢复的重要因素,采动地裂缝对土壤水分变化的影响规律和机理成为当前的研究热点.为了揭示沉陷区不同尺度的地裂缝、植被类型及土质对土壤水分入渗和蒸发的影响规律,本试验以陕北柠条塔矿区的小尺度(宽度<5 cm)、中尺度(宽度为5~10 cm)、大尺度(宽度>10 cm)地裂缝、柠条和油蒿、沙土和黄土为研究对象,采用双环入渗仪和微型蒸发器法分别对其周围土壤水分入渗和蒸发特征进行测定,计算土壤水分的入渗速率和平均蒸发量.结果表明:采动地裂缝增大周围土壤水分的入渗速率和蒸发量主要表现为水平方向上的差异,即随着水平距离的增加而减弱.裂缝宽度越大,水平影响范围越大.相对于油蒿,柠条更能改善土壤水分的入渗能力,减少土壤水分的散失.陕北煤矿区沙土的土壤水分入渗速率和蒸发量高于黄土,土质也是影响土壤水分的入渗和蒸发特征的重要因素.土壤总孔隙度、非毛管孔隙度、土壤容重是影响土壤水分入渗和蒸发能力的主要影响因子.研究采煤沉陷区对土壤水分入渗和蒸发的影响规律,对维持矿区生态系统稳定性和可持续性具有重要意义.

Soil moisture is an important factor limiting the ecological restoration of mining areas,and the influence law and mechanism of mining ground fractures on soil moisture changes has become a current research hotspot.In order to reveal the influence of different scales of ground cracks,vegetation types and soil quality on soil moisture infiltration and evaporation in the sinkhole area,this experiment took small scale(width<5 cm),medium scale(width 5—10 cm)and large scale(width>10 cm)ground cracks,caragana korshinskii and oil artemisia,sand and loess in the caragana korshinskii tower mining area in northern Shaanxi Province as the research objects,and used the double-ring infiltration meter and micro-evaporator method to measure the soil moisture infiltration and evaporation characteristics around them respectively.The infiltration and evaporation characteristics of the surrounding soil moisture were measured using a double-ring infiltration meter and a micro-evaporator,and the infiltration rate and average evaporation of soil moisture were calculated.The results show that the infiltration rate and evaporation of soil moisture around the increasing fracture in the mining area mainly show the difference in horizontal direction,that is,it decreases with the increase of horizontal distance.The larger the crack width is,the larger the horizontal influence range is.Compared with Artemisia oleifera,caragana korshinskii can improve the infiltration capacity of soil water more and reduce the dissipation of soil water.Soil water infiltration rate and evaporation of sandy soils in coal mining areas of northern Shaanxi are higher than those of loess soils,and soil quality is also an important factor affecting the infiltration and evaporation characteristics of soil water.Total soil porosity,non-capillary porosity and soil bulk weight are the main factors affecting the infiltration and evaporation capacity of soil water.It is important to study the influence of coal mining subsidence area on soil water infiltration and evaporation to maintain the stability and sustainability of mining ecosystem.