天津浅层地下水海水入侵的水化学特征及氧同位素示踪研究

Hydrochemical Characteristics and Oxygen Isotope Tracing Study of Shallow Groundwater Seawater-Intrusion in Tianjin

本研究通过对天津浅层地下水进行取样调查,研究与海水入侵相关的水化学因子,并进行筛选分析,归纳天津地区浅层地下水中水质咸化的水化学特征,并以此判定天津地区浅层地下水中不同程度的入侵均有发生.在原有咸水区的基础上,运用18 O同位素手段开展地下水物源示踪,氧同位素δ值整体表现由陆至海方向呈逐渐增加趋势.最终通过同位素特征测算地下水海水混合比例,进而划分天津现代海水入侵区,并评估海水入侵的强度等级,归纳适用于天津地区现代海水入侵的判定方法.

In this paper,the shallow groundwater in Tianjin had been sampled and investigated,and the hydrochemical factors related to seawater intrusion were studied and analyzed.The hydrochemical characteristics of the salty water in shallow groundwater in Tianjin area were summed up,and judged that different degrees of invasion of shallow groundwater occur.At the same time,Using 18 O isotope method to trace groundwater provenance,the oxygen isotope value increases gradually from land to sea.Finally,the mixing ratio of groundwater and seawater were estimated by isotope characteristics,which divided the area of modern seawater intrusion on the basis of the original saline water area,evaluated the intensity level of seawater intrusion,and sumed up the method of determining modern seawater intrusion which applied to Tianjin.