苏南地区地下水化学特征及演化分析  

Hydrogeochemical characteristics and evolution of groundwater in southern Jiangsu

作　　者：龚亚兵 龚绪龙[1,2] 许书刚 唐鑫[1,2] 苏东 吴夏懿 GONG Yabing;GONG Xulong;XU Shugang;TANG Xin;SU Dong;WU Xiayi(Geological Survey of Jiangsu Province,Nanjing,210049;Key Laboratory of Earth Fissure Geological Disaster,Ministry of Natural Resources,Nanjing,210049)

机构地区：[1]江苏省地质调查研究院,南京210049 [2]自然资源部地裂缝地质灾害重点实验室,南京210049

出　　处：《地质论评》2022年第6期2207-2218,共12页Geological Review

基　　金：部省合作项目“苏南现代化建设示范区综合地质调查(苏财建[2016]140号)”的成果。

摘　　要：苏南地区深层地下水禁采距今已20年,水动力场和地下水环境发生了较大变化,结合2009年和2019年两期地下水采样测试数据,综合统计分析、Piper图、Gibbs模型、氯碱指数和离子相关关系等方法分析了不同层位地下水水文地球化学及其演化特征,探讨了水化学组分的来源及形成演化。结果表明:潜水水化学类型以HCO_(3)^(-)-Na+·Ca^(2+)型为主,孔隙I承压水水化学类型以HCO_(3)^(-)-Ca^(2+)·Mg^(2+)型为主,深层承压水以HCO_(3)^(-)Na^(+)·Ca^(2+)型为主,不同时期各层位优势阳离子和阴离子未发生变化,水化学类型向复杂趋势演变,地下水化学组分主要受岩石风化、阳离子交换吸附作用和人类活动的影响,其中潜水和I承压水—岩作用以硅酸盐岩和碳酸盐岩作用为主,深层承压水以硅酸盐岩和蒸发盐岩为主。研究结果可为苏南地区地下水资源开发和管理提供科学依据。Under the background of the ban on deep groundwater extraction in the 20th anniversary,great changes have taken place in the groundwater environment in southern Jiangsu.Based on comprehensive statistical analysis,Piper diagram,Gibbs diagram,chlor-alkali index,ion correlation and other methods,this paper reveal the evolution process of the formation of groundwater at different aquifer in 2009 and 2019.The results show that the chemical type of shallow water is mainly HCO_(3)^(-)-Na+·Ca^(2+)type,the chemical type of confined pore water is mainly HCO_(3)^(-)-Ca^(2+)·Mg^(2+)type,and the deep confined water is mainly HCO_(3)^(-)-Na+·Ca^(2+)type.The predominant cations and anions of each aquifer in different periods did not change,and the hydrochemical types evolved to a complex trend.The chemical composition of groundwater is mainly affected by rock weathering,cation exchange adsorption and human activities. Among them, phreatic and I confined water—rock interactions are mainly silicaterocks and carbonate rocks, and deep confined water is silicic acid. Among them, the water—rock interactionsprocess in shallow groundwater and I confined groundwater are dominated by silicate rocks and carbonate rocks, thedeep confined water are dominated by silicate rocks and evaporative salt rocks. The research results can provide ascientific basis for the development and management of groundwater resources in southern Jiangsu.

关 键 词：苏南地区 地下水 水化学特征 演化 形成机理 

分 类 号：P641.3[天文地球—地质矿产勘探]