论文部分内容阅读
海水入侵是沿海地区主要环境地质问题,分析沿海地下水和河水水化学特征,对圈定海水入侵范围及判断影响程度具有重要意义。通过在福建长乐市海水入侵含水层和闽江口海水上溯区采取23件水样进行室内常规离子测试,获得了海水入侵(上溯)区水中主要离子含量。利用海水稀释线分析主要离子与Cl离子之间的相对变化,对比离子实际浓度与理想浓度的差异,分析海水入侵对水化学变化的影响。研究结果显示,随着海水与淡水混合,水化学类型从海水到淡水依次为Na—Cl型水——Na—Cl·HCO3型水——Na·Ca—HCO3·Cl型水——Ca—HCO3型水;引起水化学类型和TDS变化的主要因素为Na+和Cl-的增加;Ca2+、Mg2+高于海水稀释线和理想浓度线,Na+、K+在海水稀释线和理想浓度线上下跳跃:Br-/Cl-与海水稀释线吻合较好,可以作为判断海水入侵范围的依据。
Seawater intrusion is a major environmental and geological problem in the coastal area. Analyzing the chemical features of the groundwater and river water is of great significance for delineating the extent of the seawater intrusion and judging the degree of influence. By using 23 water samples in the seawater intrusion aquifer of Changle city in Fujian Province and the upstream area of seawater in Minjiang River estuary to conduct routine indoor ion tests, the main ions in the seawater intrusion (upstream area) were obtained. The seawater dilution line was used to analyze the relative changes between the main ions and the Cl ions. The difference between the actual ion concentration and the ideal ion concentration was analyzed to analyze the influence of seawater intrusion on the chemical change of water. The results showed that with the mixing of seawater and freshwater, the types of water chemistry from seawater to freshwater were Na-Cl water-Na-Cl · HCO3-Na · Ca-HCO3 · Cl water-Ca-HCO3 Type water. The main factors causing the change of chemical type and TDS were Na + and Cl-; Ca2 + and Mg2 + were higher than seawater dilution line and ideal concentration line; Na + and K + were jumping below seawater dilution line and ideal concentration line; Br- / Cl- and seawater dilution line is good, can be used as a basis to determine the extent of seawater intrusion.