运用氧稳定同位素研究黑河中游盆地地下水与河水转化

Exchange of Groundwater and River Water in a Basin of the Middle Heihe River by Using δ^(18)O

在西北干旱区内陆河流域盆地, 地表水与地下水转化频繁, 研究地表水与地下水转化对于有效地开发利用水资源和预测地下水环境的变化具有重要的意义. 运用地下水和地表水中稳定同位素δ18O值存在明显差异的特点, 在黑河中游盆地沿不同河段地表水和地下水现场取样, 进行同位素分析.结果表明: 在黑河中游盆地绿洲灌溉区, 农田灌溉严重影响了地下水和地表水之间的转化, 导致地下水补给地表水的增加. 运用质量守恒原理, 定量分析了黑河中游盆地黑河地下水与地表水转化的转化量, 为正确评价和合理利用水资源奠定了基础.

In arid regions of western China, water resources come from mountain watersheds and disappear in the desert plains. The exchange of surface water and groundwater takes place two or three times in a basin. It is essential to analyze the interaction between groundwater and surface water, so as to use water resources effectively and predict the change in the water environment. The conventional method of analysis, however, measures only the flow of a stream and cannot determine groundwater seepage accurately. Because of the distinct difference of {δ^(18)O} between groundwater and surface water, the method of using {{}^(18)O} was examined as an indicator for analyzing the interaction. With the addition of the mass balance equation, the composite proportion of different mixing components can be calculated. A conclusion was drawn from the computed result that, in the oases of the middle Heihe River, flood irrigation on vast farmlands has made a great impact on the transform between groundwater and surface water. The irrational irrigation has caused some problems, such as environmental deterioration and land subsidence.