大沽河下游地区地下咸水的水化学特征及成因  

Hydrochemical Characteristics and Origins of Salt Groundwater in the Lower Reaches of Dagu River

作　　者：刘贯群[1,2,3] 朱利文 孙运晓 LIU Guan-Qun;ZHU Li-Wen;SUN Yun-Xiao(The Key Laboratory of Marine Environmental Science and Ecology,Ministry of Education,Ocean University of China,Qingdao 266100,China;College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China;Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学海洋环境与生态教育部重点实验室,山东青岛266100 [2]中国海洋大学环境科学与工程学院,山东青岛266100 [3]中国海洋大学山东省海洋环境地质工程重点实验室,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2019年第5期84-92,共9页Periodical of Ocean University of China

基　　金：国家重点科技计划项目(2016YFC0402810)资助~~

摘　　要：大沽河下游地区存在大面积咸水体,为了查明咸水体盐分的来源,揭示地下水咸化机理,于2017年4、8和10月在大沽河下游地区采集地下水样品,对其进行研究。现场原位监测地下水的水位、水温、电导率和总溶解性固体等,并采集水样进行主要水化学离子测定。用数理统计法、吉布斯图解法、主要水化学离子比值法以及卤族元素比值法对地下水样进行综合分析,分析地下水化学分布特征,识别出地下咸水的盐分来源;并结合古地理、地质和水文地质资料,研究其咸水形成机理。结果表明:(1)研究区由西北向东南方向,TDS和Cl浓度均逐渐升高,水质由淡水逐渐向盐水转化,地下水的优势阴离子类型沿着HCO_3型→HCO_3·Cl型→Cl·HCO_3型→Cl型变化,大部分地区的阳离子以Na^+占主导地位。(2)研究区内地下淡水受到岩石风化-溶滤和蒸发浓缩的共同影响,地下咸水的形成主要受到与海水的混合作用控制,还受到阳离子的交换吸附和矿物溶解作用的影响。(3)综合Br/Cl和I含量,证实了研究区存在着海相沉积地层的溶解作用,这是研究区东南部地下咸水的重要盐分来源。There is a large area of salt groundwater in the lower reaches of Dagu River. In order to identify the sources of salt groundwater and reveal the salinization mechanism of groundwater, groundwater samples were collected in April, August and October,2017. Based on analysis of field measurement data (including the water lever, water temperature, conductivity and total dissolved solid), hydrononomic ion ratio, Gibbs diagram and halogen elements of various water samples, it is concluded that the groundwater hydrochemistry distribution characteristics. Then combining paleogeographical environment and geological data, we can reveal the genetic mechanism of salt groundwater. The results suggest that:(1) from the northwest to southeast of the study area, the concentrations of TDS and Cl gradually increase, and the water quality changes from freshwater to salt water. The dominant anion types of groundwater are along HCO 3→HCO 3·Cl→Cl·HCO 3→Cl changes, Na + is the major cation in most regions.(2) The fresh groundwater in the study area is affected by the combination of rock weathering, leaching and evaporation. The formation of salt groundwater is mainly controlled by the mixing action with seawater, and is also affected by the cation exchange adsorption and mineral dissolution.(3) The combination of Br/Cl and I content confirms the existence of marine dissolved sediments in the study area, which is an important salinity source for salt groundwater in the southeast of the study area.

关 键 词：地下咸水 大沽河下游 水化学特征 盐分成因 

分 类 号：X523[环境科学与工程—环境工程]