浅层地下水水文地球化学特征及其演化规律——以淮北东部典型乡镇为例

Hydrogeochemical Characteristics and Evolution Law of the Shallow Groundwater—Taking the Typical Towns in Eastern Huaibei as an Example

摘要: 为研究淮北东部典型乡镇浅层地下水水文地球化学特征及其演化规律，采集研究区浅层地下水样品33组，综合运用数理统计水化学图解(Gibbs)图、离子比例系数、氯碱指数等方法，开展了地下水的水文地球化学特征及其演化规律相关研究。结果表明：研究区浅层地下水呈弱碱性(pH均值7.82)，TDS变化范围为46~752 mg/L⁻¹ (均值287.45 mg/L⁻¹)，整体属于优质淡水。优势阳离子和优势阴离子分别为Na⁺和$HC{O}_3^{-}$ 。地下水化学组分主要受岩石风化–溶解作用控制，水岩作用以硅酸盐岩矿物风化和碳酸盐岩矿物风化溶解。此外，氯碱指数(CAI)负值占多数，该阳离子交替吸附作用是引起地下水中Na⁺富集的重要水文地球化学作用。研究成果可为淮北地区地下水资源可持续开发利用和保护提供参考。

Abstract: In order to study the hydrogeochemical characteristics and evolution law of the shallow groundwater of typical towns in Eastern Huaibei, this study collected thirty three shallow samples. The mathematical statistics, hydrochemical map, ion ratio, and alkaline indices were conducted for grasping the hydrogeochemical characteristics and evolution law of the shallow groundwater. The results showed that the shallow groundwater belonged to the weak alkaline (the average value was 7.82), the content of TDS varied from 46 mg/L⁻¹ to 752 mg/L⁻¹ (the mean value was 287.45 mg/L⁻¹), and the aquifer belonged to the high quality fresh water. The dominant cation and anion were Na⁺ and $HC{O}_3^{-}$ , respectively. The hydrochemical components are controlled by the rock weathering-dissolution, containing the weathering-dissolution of the silicate mineral and the carbonate mineral. In addition, the major alkaline indices were negative, indicating that the enrichment of the aquifer’s Na⁺ was affected by the cation exchange absorption. The research findings can provide reference for the sustainable development and protection of groundwater resources in Huaibei area.