汾河流域浅层地下水水化学和氢氧稳定同位素特征及其指示意义  

Hydrochemical and Isotopic Characteristics in the Shallow Groundwater of the Fenhe River Basin and Indicative Significance

作　　者：刘鑫 向伟 司炳成 LIU Xin;XIANG Wei;SI Bing-cheng(Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Ministry of Education,Northwest A&F University,Yangling 712100,China;Department of Soil Science,University of Saskatoon,SK S7N 5A8,Canada)

机构地区：[1]西北农林科技大学旱区农业水土工程教育部重点实验室,杨凌712100 [2]萨斯喀彻温大学土壤学系,加拿大萨斯卡通市S7N5A8

出　　处：《环境科学》2021年第4期1739-1749,共11页Environmental Science

基　　金：国家自然科学基金项目(41877017,41630860);西北农林科技大学基本科研业务费(2452017317)。

摘　　要：汾河流域是黄河的第二大支流,本文利用Piper三线图、Gibbs模型、主成分分析法、相关矩阵和正向演替模型等方法,分析了汾河流域浅层地下水的水化学和氢氧稳定同位素分布特征及其控制因素,揭示了流域水循环及水质演化过程.结果表明,汾河流域地下水属弱碱性和微硬水;优势阴阳离子分别为HCO^(-)_(3)和Ca^(2+);地下水水化学类型以Mg-Ca-HCO_(3)和Mg-Ca-ClSO_(4)为主,水质整体较好,Ⅰ~Ⅲ类水占比超94%.地下水δD和δ^(18)O平均值分别为-70.2‰和-9.6‰,与7~9月降水同位素值相似,指示地下水可能主要来源于该时期的降水,并发现地下水补给方式(优势流和活塞流)存在一定的空间变化.岩石风化是地下水溶质的主要来源(87%),而大气输入和人类活动相对较小,分别占8%和5%.在岩石风化中,硅酸盐岩、蒸发盐岩和碳酸盐岩对地下水溶质的贡献相当,分别占32%、28%和26%.本研究结果可为促进可持续开发利用汾河流域地下水资源提供依据.The Fenhe River basin is the second largest tributary of the Yellow River.Piper diagrams,Gibbs,PCA,correlation analysis and forward derivation modeling were used to analyze the distribution characteristics and the controlling factors of the groundwater chemistry and stable isotopes in the Fenhe River basin,which revealed the water cycle and water quality evolution process.The results indicated that the groundwater is a weakly alkaline,micro-hard water,the dominant anions and cations are HCO^(-)_(3)and Ca^(2+),the major groundwater types are Mg-Ca-HCO_(3)and Mg-Ca-Cl-SO_(4),the groundwater quality is good,and more than 94%of the samples belong to classesⅠ-Ⅲ.The average values ofδD andδ^(18)O of the Fenhe River groundwater are-70.2‰and-9.6‰,which are similar to the isotope values of the precipitation from July to September,indicating that the groundwater may have originated from this period and that the groundwater recharge mode(dominant flow and piston flow)has a spatial variation.Rock weathering is the dominant source of ions in the groundwater,with an average contribution of 87%,while the contributions of atmospheric input and human activity are 8%and 5%,respectively.For rock weathering,silicate,evaporate,and carbonate rock contribute equally to the groundwater solutes,accounting for 32%,28%,and 26%,respectively.The results of this study provide the basis for promoting the sustainable development and utilization of groundwater resources in the Fenhe River basin.

关 键 词：水化学 氢氧稳定同位素 黄河流域 黄土高原 地下水 汾河 

分 类 号：X523[环境科学与工程—环境工程]