长江流域安庆段浅层地下水水化学特征及控制因素

浅层地下水为安庆市居民生活用水和工农业生产用水的主要水源，是维持社会经济可持续发展和区域生态环境的重要基础保障.为深入研究安庆市浅层地下水的水化学特征及控制因素，采集了196组浅层地下水水样，综合运用Piper三线图、Gibbs图、离子比值和数理统计方法对安庆市地下水的水化学特征及控制因素进行研究，定量评估不同来源对地下水水化学组分的贡献.结果表明，安庆市浅层地下水呈弱碱性，pH值在5.84～8.38，均值为7.21； ρ（TDS）介于47～1 620 mg·L^-1，均值为324.21 mg·L^-1，阴阳离子主要以HCO₃^-和Ca²⁺为主，水化学类型为HCO₃-Ca型.地下水水化学组分受岩石风化溶滤作用、阳离子交替吸附作用、矿物溶解和沉淀以及人类活动综合影响.Ca²⁺、Mg²⁺和HCO₃^-主要来源于碳酸盐岩和硅酸盐岩的风化溶解作用，Na⁺、Cl^-和SO₄^2-受工业活动和生活污水的排放、K⁺和NO₃^-受农业活动的影响.APCS-MLR受体模型分析进一步揭示地下水水化学组分主要有地质因子、工业因子、农业因子和未知源这4种来源，其贡献率分别为45.35%、14.19%、25.38%和15.08%.地质因子是浅层地下水水化学组分的重要来源，人类活动则加剧了地下水水化学的演变.

Hydrochemical Characteristics and Control Factors of Shallow Groundwater in Anqing Section of the Yangtze River Basin

Shallow groundwater is the main source of water for living and industrial and agricultural production in Anqing City, which is an important basic guarantee to maintain the sustainable development of the social economy and regional ecological environment. In order to further study the water chemical characteristics and controlling factors of shallow groundwater in Anqing City, 196 groups of shallow groundwater samples were collected. A Piper diagram graph, Gibbs chart, ion ratio, and mathematical statistics were comprehensively used to study the water chemical characteristics and controlling factors of groundwater in Anqing City, and the contribution of different sources to the water chemical components of groundwater was quantitatively evaluated. The results showed that the shallow groundwater in Anqing City was weakly alkaline, with pH values ranging from 5.84 to 8.38, with an average value of 7.21. The TDS ranged from 47 to 1 620 mg·L^-1, with an average of 324.21 mg·L^-1. HCO₃^- and Ca²⁺ were the main anions, and the water chemical type was HCO₃-Ca type. The chemical components of groundwater were affected by rock weathering leaching, cation alternating adsorption, mineral dissolution and precipitation, and human activities. Ca²⁺, Mg²⁺, and HCO₃^- were mainly derived from the weathering dissolution of carbonate and silicate; Na⁺, Cl^-, and SO₄^2- were affected by industrial activities and domestic sewage discharge; and K⁺ and NO₃^- were affected by agricultural activities. The APCS-MLR receptor model analysis further revealed that the chemical components of groundwater were mainly geological factors, industrial factors, agricultural factors, and unknown sources, and their contribution rates were 45.35%, 14.19%, 25.38%, and 15.08%, respectively. Geological factors were important sources of hydrochemical components of shallow groundwater, and human activities aggravated the evolution of groundwater hydrochemistry.