太原东山岩溶水系统锶元素分布特征及其指示意义

Distribution characteristics and indicative significance of strontium elements in Dongshan karst water system of Taiyuan City

东山岩溶水系统是兰村泉域的重要组成部分,查明其补径排关系,对兰村泉域水资源开发利用与保护有重要的指导意义。根据地形地貌、地质构造和地下水流场,将东山岩溶水系统划分为补给区、强径流带、径流带、转换带和汇水区,在此基础上,采集了岩溶水样品,分析了Sr^2+含量及87Sr/86Sr比值,并对系统内岩溶水中Sr^2+质量浓度及87Sr/86Sr比值在不同水文地质分区中的分布情况及其成因进行了分析研究。结果表明:从补给区到汇水区Sr^2+质量浓度逐渐增加,局部地段因降水的稀释作用有所降低;东山岩溶地下水中的87Sr/86Sr比值呈现出明显的不均一性,其仅与水-岩相互作用有关,与径流条件无关;在东山岩溶水系统内,岩溶水Sr^2+浓度场与TDS场具有高度的相似性,系统可划分为杨兴河岩溶水子系统和乌河岩溶水子系统。

Dongshan karst water system is an important water source in Lancun spring region.Finding out its supplement,runoff,and drainage mechanism is of great significance to the development,utilization and protection of the water resources in this region.Based on the topography,geological structure and groundwater flow field,this system is divided into five areas,which are recharge area,strong runoff area,runoff area,conversion area and catchment area.Water samples were collected accordingly and the distribution and genesis of Sr^2+concentration and the ratio of87 Sr/86 Sr in these five hydrogeological areas were analyzed.The results show that the mass concentration of Sr^2+increases gradually from the recharge area to the catchment area,and decreases in some partial areas due to the dilution of precipitation.The87 Sr/86 Sr ratio in Dongshan karst groundwater shows an obvious heterogeneity,which is only related to water rock interaction,not to runoff condition.In Dongshan karst water system,the Sr^2+concentration field is highly similar to the TDS field.This water system can also be divided into Yangxinghe karst water subsystem and Wuhe karst water subsystem.