太原盆地地下水系统水化学-同位素特征研究

Study on the Geochemistry-isotope Characteristics of the Groundwater Systems in Taiyuan Basin

太原盆地孔隙水与周边岩溶水、砂岩裂隙水有密切的水力联系。本文应用示踪元素均衡分析的方法对盆地地下水系统之间的转化关系进行了定量研究。结果表明,太原市区以北地区主要接受岩溶水补给,其补给量占总补给量的30%以上。盆地东侧大部分地区以裂隙水补给为主,其中文水东南至平遥一带裂隙水补给量最高,占总给量的60%以上;应用环境同位素分析方法对盆地孔隙水的起源与更新能力进行了研究分析。指出含水层埋藏深度在50m以内的浅层水,主要接受大气降水和地表水的补给,更新周期在60年以下,更新能力较强;含水层埋深在50—200m之间的为混合水,是深层古水与浅层现代水混合形成,与现代水交换比例在40%以上,更新能力较强;含水层埋深在200m以下的,为深层古水,更新能力较差。

There are closer relations among pore groundwater system, Karst groundwater system and fissure groundwater system in Taiyuan basin. In the paper, the method of the equilibrium analysis of the major trace element was used in the quantitative study on the exachanging relationship of the groundwater systems in Taiyuan basin. The results showed that the pore groundwater in the northern parts of Taiyuan city mainly received the recharge resources of Karst groundwater which accounts for more than 30 percent of the whole recharge resources. A lot of eastern parts of the basin mainly received recharge sources of fissure groundwater, and in the areas from the southeast part of Wenshui to Pingyao the recharge amount was the highest which accounts for more than 60 percent of the whole recharge resources. The isotopic methods were applied on the the study of the origination and renewbility of the pore groundwater in the basin. It concluded that the shallow groundwater of the aquifers which buried within 50m depth mainly received the recharge of precipitation and surface water, its circulation period was less than 60 years old, and its renewbility was more powerful. The groundwater buring in the depth from 50m to 200m was the mixing groundwater which included the shallow modern groundwater and the deep ancient groundwater. The moderm groundwater accounted for more than 40 percent of the whole mixing groundwater, and its renewbility was powerful. The groundwater buring under more than 200m was the deep ancient groundwater and its renewability was weak.