赣南红层地区地下水水化学特征及成因分析

为研究赣南红层地区地下水资源及保障区域供水安全，基于水文地球化学理论，运用数理统计、Pipper三线图、Gibbs模型、水化学平衡法、同位素示踪法和离子比例系数法等方法，分析了研究区地下水水化学特征及主要离子来源。结果表明：研究区地下水水化学类型以HCO₃-Ca、HCO₃-Ca·Na为主，主要阳离子和阴离子分别为Ca²⁺和HCO^-₃;氢氧同位素特征显示研究区地下水起源于大气降水，Sr同位素主要来源于硅酸盐岩和碳酸盐岩风化的混合。地下水中石膏、岩盐、白云石、方解石和硅酸盐岩均处于未饱和状态。影响研究区地下水离子组成的是硅酸盐岩和碳酸盐岩的风化溶解作用，碳酸盐岩风化溶解控制区以方解石溶解为主。地下水在径流过程中存在阳离子交换作用，阳离子交换以地下水中的Ca²⁺、Mg²⁺置换围岩矿物的Na⁺、K⁺为主，人类活动对地下水离子组成的影响较小，其中工矿活动的影响大于农业活动和生活污水排放。

Hydrochemical Characteristics and Genetic Analysis of Groundwaterin Red-Bed Area of South Jiangxi Province

In order to study the groundwater resources and ensure the safety of regional water supply in red bed area of south Jiangxi Province, based on hydrologic geochemistry theory, using mathematical statistics, Piper diagram, Gibbs model, hydrochemical equilibrium, isotope tracing and ion ratio method, this paper analyzes the hydrochemical characteristics and main ion sources of groundwater in the study area.SThe results show that the chemical type of study area is mainly HCO3-Ca, HCO3-Ca.Na, the main cations and anion are Ca2+ and HCO3-^; the characteristics of hydrogen and oxygen isotopes indicate that the groundwater in the study area originates from the precipitation,Sr isotopes are mainly derived from the weathering mixing of silicate and carbonate rocks. Gypsum, rock salt, dolomite, calcite and silicate in groundwater are in an unsaturated state, the weathering and dissolution of Silicate Rock and carbonate rock are the main factor on the ion composition of groundwater in the study area, calcite dissolution is dominant in the weathering and dissolution control area of carbonate rocks. Groundwater run-off process exist cation exchange, the cation exchange mainly involves Ca²+ ^{and Mg2}+ ^{in groundwater replacing Na}+ ^{and K+ in surrounding rock minerals}, the influence of human activities on the ion composition of groundwater is small, and the influence of industrial and mining activities is greater than that of agricultural activities and domestic sewage discharge.