泰安市旧县水源地水化学特征及成因分析

Hydrochemical characteristics and formation mechanism of water source area in Jiuxian County, Tai’an City

地下水是北方地区重要的供水水源,近年来随着城市化进程加快及人类活动影响,地下水水化学特征日趋复杂,识别水源地地下水水化学特征、成因机制对于合理开发利用地下水资源,保障当地社会经济可持续发展与生态安全具有重要意义。在地下水样品采集的基础上,运用数理统计、相关性分析、Piper三线图、Gibbs图以及地下水主要离子比值等多种方法,分析泰安市旧县地下水水化学特征及成因机制。结果表明:研究区内地下水化学类型多样,孔隙水以HCO_(3)-Ca、HCO_(3)+SO_(4)-Ca型为主,岩溶水以HCO_(3)-Ca型、HCO_(3)-Ca+Mg型、HCO_(3)+SO_(4)-Ca型、HCO_(3)+SO_(4)-Ca+Mg型为主;区内孔隙水和岩溶水水化学组成主要受自然和人为因素的双重作用控制,地下水主要离子组分受水岩相互作用影响,离子主要来源于岩盐中的文石、方解石、白云石的溶解,阳离子交换作用较弱;人为活动影响导致地下水中Cl−、NO_(3)^(−)浓度增加。

The groundwater in the northern region of China is an important source for water supplement.In recent years,with the acceleration of urbanization and the impact of human activities,the hydrochemical characteristics of groundwater have become increasingly complex.It is important to identify the hydrochemical characteristics of groundwater in the water source areas and the cause mechanisms for the rational development and utilization of groundwater resources and for the insurance of local socio-economic sustainable development and ecological security.Based on the collection of groundwater samples,the mathematical statistics,correlation analysis,Piper three-line diagram,Gibbs diagram,and the ratio of groundwater main ions were applied to analyze the chemical characteristics and genetic mechanism of the groundwater in Jiuxian County,Tai'an City.The results showed that the chemical types of groundwater in the research area were diverse.The pore water was mainly HCO_(3)-Ca,HCO_(3)+SO_(4)-Ca type,and the karst water was HCO_(3)-Ca,HCO_(3)-Ca+Mg,HCO_(3)+SO_(4)-Ca,and HCO_(3)+SO_(4)-Ca+Mg type.The chemical composition of pore water and karst water in the area was mainly controlled by both of the natural and human factors.The main ionic components of groundwater were affected by the interaction of water and rock.The ions mainly came from the dissolution of carbonate rock,calcite,and dolomite,and the cation exchange effect was weak.Moreover,the increase of the concentration of Cl−and NO_(3)^(−) in groundwater was due to human activities.