黑河流域地下水电导率空间分异特征及影响因素研究

黑河流域是我国西北干旱区的第二大内陆河流域,地下水电导率γ的研究对保护流域地下水资源,减少流域生态环境的破坏具有重要的现实意义.通过对黑河流域地下水γ的空间变化及其与主要离子的关系进行分析,结果表明:1)整体上,上游浅层及深层地下水γ均较低,明显低于中下游地区,中游浅层地下水γ明显高于深层地下水,下游浅层与深层地下水γ差异不大;2)从区域上来看,中游干流地区浅层地下水γ沿流程呈增加趋势,中、下游沿河道附近浅层地下水γ高于距河道较远地区,上游及中游山前平原地区深层地下水γ较低,明显低于中游细土平原地区,下游居延海—中蒙边界地区与狼心山—额济纳旗城河道附近地区的深层地下水γ存在明显差异;3)地下水γ与各主要离子的关系表明,上游山区地下水γ主要受到Na~+、Cl~-浓度的影响,中、下游地区地下水γ主要受到Na~+、Cl~-和SO_4~(2-)浓度的影响.此外,中游距河道较远地区的深层地下水γ以及下游沿河道附近的浅层及深层地下水γ均受到了农业灌溉活动的影响.

Spatial differentiation characteristics and impact factors of groundwater conductance in the Heihe River basin

Heihe River is the second largest inland river basin in arid regions of northwest China.Study on groundwater conductance of the Heihe River basin has important significance in protecting its groundwater resource and reducing destruction of ecological environment. Characterization of spatial variation of groundwater conductance and its relation with maj or ions revealed that shallow and deep groundwater in the upper reaches showed low conductance values, lower than in the middle and lower reaches. Shallow groundwater in the middle reaches showed higher conductance than deep groundwater,but there was little difference between shallow and deep groundwaters in the lower reaches.Regionally,conductance of shallow groundwater in main stream of the middle reaches increased along the flow path.In the middle and lower reaches,shallow groundwater samples near the river channel had higher conductance than samples far away from the river channel.Conductance of shallow and deep groundwaters of the upper reaches and piedmont plain were lower,significantly lower than in the fine soil plain area of the middle reaches.In the lower reaches,deep groundwater conductance along the river channel from Langxin Mountain to Ej ina city was significantly different from areas from Juyan Lake to China-Mongolia border region.Relationship between groundwater conductance and maj or ions revealed that groundwater conductance in mountainous area of the upper reaches was mainly due to Na+ and Cl-,but mainly attributed to Na+,Cl- and SO2-4 in the middle and lower reaches. In addition,samples of deep groundwater in the middle reaches far away from the river channel and samples of shallow and deep groundwater near river channel in the lower reaches were also affected by agricultural irrigation activities.