地质论评2025，Vol.71Issue(4)：1250-1264,15.DOI:10.16509/j.georeview.2024.12.022
渭河上游散渡河流域苦咸地下水形成机制
Formation mechanism of brackish groundwater in the Sandu River basin,upper reaches of the Weihe River
摘要
Abstract
Objectives:Sandu River basin in the upper reaches of the Weihe River is a well-known distribution area of brackish groundwater in the Loess Plateau.The social and economic development of the region is constrained by the issue of"pollution induced water shortage".Make an intensive study of the formation mechanisms in brackish groundwater is of great significant to the rational development and utilization of groundwater resources,as well as ensuring drinking water safety. Methods:In this paper,it takes the water chemical detection data collected from 26 sites in the middle and southern parts of the San Du River basin as the research foundation.The hydrochemical analysis,correlation analysis,ion ratio analysis and mineral saturation index analysis were investigated to identify the hydrochemical characteristics and ion sources of groundwater in the Sandu River Basin,and discuss the formation mechanism of brackish groundwater. Results:The results show that phreatic water of river valley was generally brackish water,the average values of total dissolved solids(TDS)mass concentration and SO42-mass concentration are 5599.7 mg/L and 1973.1 mg/L,respectively,in the research area.In addition,the distribution of brackish water is closely correlated with the meizoseismal area of"Tongwei earthquake"in history.The phreatic water of loess is a recharge area for regional groundwater in the study area,with a short and intense circulation pathway,and better water quality than the phreatic water of river valley.The TDS mass concentrations are 839.6～1237.6 mg/L. Conclusions:① The hydrochemical compositions of groundwater mainly come from the weathering and dissolution of gypsum and halite;② lixiviation is the main controlling factor for the formation of brackish goundwater in the study area,followed by cation exchange,but evaporation and human activities have a slight impact;③ the increase in soluble salts in valley deposits and changes in the conditions of groundwater runoff caused by the Tongwei earthquake is the root cause.关键词
苦咸水/离子来源/水岩作用/咸水成因/散渡河流域Key words
brackish water/ion sources/interaction of water-rock/salinization mechanism/Sandu River Basin引用本文复制引用
张彦林,李积玉,赵成,李春亮..渭河上游散渡河流域苦咸地下水形成机制[J].地质论评,2025,71(4):1250-1264,15.基金项目
本文为甘肃省地矿局2022年度创新资金项目(编号:2022CX21)、甘肃省自然资源厅青年人才团队项目(编号:202310)和甘肃省陇原青年英才项目的成果. This study was supported by the innovative fund project of Gansu Bureau of Geology and Mineral Resources in 2022(No.2022CX21),the Youth Talent Team Project(No.202310)of Department of Natural Resources of Gansu Province and the Gansu Longyuan Young Talent Project （编号:2022CX21）
