大柳塔采煤塌陷区土壤含水量的空间变异特征分析

通过研究采煤塌陷区土壤水空间分布及动态变化特征,查明了采煤塌陷对土壤含水量的影响,这对矿区生态环境保护、塌陷区土地复垦等具有重要指导意义。以大柳塔双沟采煤塌陷区为试验区,利用传统统计学和地统计学方法分析了采煤塌陷条件下的包气带土壤水空间变异特征。研究结果表明:由于采煤塌陷造成塌陷区土壤层位在垂向上倒置、重组,引起土壤粒度、容重、孔隙度等土壤物理特性的改变,使塌陷区土壤含水量比非塌陷区显著降低,在不同深度层（0~60 cm）分别减少14.2%~21.9%;在垂向分布上塌陷区土壤水分也表现出较强的变异性,其离散系数在不同深度（0~60 cm）与非塌陷区的差值在19.2%~50%之间。根据试验区0 cm、20 cm、40 cm、60 cm四个层面土壤含水量的Kriging插值等值线图显示,土壤含水量低值区均位于塌陷区内的塌陷坑部位,证明地表的地裂缝、塌陷坑、塌陷洞等塌陷形态对土壤持水能力的影响颇为显著。采煤塌陷区土壤含水量降低、空间变异性增强直接导致了地表植被生存环境的恶化,地表景观被严重破坏。

Spatial Variation of Soil Moisture Content in Mining Subsidence Areas of DaLiuta,Shenmu County,Shannxi Province

It is significant for environment protection and land reclamation to find out the influence of mining subsidence to soil moisture content by study the distribution and spatial variation of soil moisture content.This paper takes Shuanggou mining subsidence of Daliuta in Shenmu County,Shannxi Province as the test area to analysis the spatial variation of soil moisture content characteristic of coal mining subsidence by methods of traditional statistics and geostatistics.We set 69 sampling sites at the test area and collect 7 soil moisture content values at each site by TDR（Time Domain Reflectometry）.Then we use the drying method to revise the original data obtained by TDR.The analytic results indicated that： soil physical characteristics of granularity,bulk density and porosity of mining soil changed due to converting and recomposing of soil layer vertically.So that,soil moisture content of mining subsidence more significantly reduced than that of natural soil by 14.2 % to 21.9% at the depth of 0 to 60cm.And the vertical variability of soil moisture content of subsidence was also stronger than that of natural soil with the coefficient of variation tended to be19.2% to 50% higher at all depths in the subsidence area than that of the native area.The Kriging contour maps of soil moisture content in the depth of 0,20,40 and 60cm of the test area showed that low value of soil moisture content lies in the collapse crater of subsidence area.It proved that soil moisture retention capability has been influenced remarkably by those subsidence configurations such as ground fissures,collapse pit or collapse cave in the ground surface.Soil moisture content reduction and enhancing in spatial variation directly resulted in the deterioration of vegetation living conditions.Furthermore,the ground landscape was also badly destroyed.