极端干旱气候下赣江下游及支流流域地下水硝酸盐污染特征及来源  

Characteristics and sources of nitrate pollution in groundwater of lower reaches and tributaries of Ganjiang River under extreme drought climate

作　　者：何景媛 张茹星 丁水波 李思维 李东阳[3] 马志飞 HE Jingyuan;ZHANG Ruxing;DING Shuibo;LI Siwei;LI Dongyang;MA Zhifei(Jiangxi Provincial Coal Geological Exploration Research Institute;Key Laboratory of Poyang Lake Environment and Resource Utilization,Ministry of Education,College of Resources and Environment,Nanchang University;Chinese Research Academy of Environmental Sciences)

机构地区：[1]江西省煤田地质勘察研究院 [2]南昌大学资源与环境学院,鄱阳湖环境与资源利用教育部重点实验室 [3]中国环境科学研究院

出　　处：《环境工程技术学报》2025年第1期111-119,共9页Journal of Environmental Engineering Technology

基　　金：江西省技术创新引导类计划项目(2023KDG01008);国家自然科学基金项目(41907168)。

摘　　要：为研究极端干旱气候对地下水硝酸盐(NO_(3)^(−))污染特征及来源的影响,对比分析赣江流域下游及支流地下水在极端干旱前和干旱期间的地下水化学特征、NO_(3)^(−)空间分布及来源。结果表明:2022年极端干旱年研究区地下水NO_(3)^(−)浓度为0~73.89 mg/L,平均值为6.58 mg/L,总体低于正常年(2021年);极端干旱年和正常年研究区内丰水期和枯水期地下水类型为HCO_(3)-Ca型和少量的Cl-Ca·Mg型,正常年和极端干旱年水化学组分主要受岩石风化作用,其NO_(3)^(−)高值点分部偏向于大气降水区域,硝酸盐的变化主要受外界直接影响;极端干旱年丰水期和枯水期NO_(3)^(−)的空间分布高值区面积和程度低于正常年,长期干旱造成地下水补给来源减少,NO_(3)^(−)受岩盐溶滤、排泄和反硝化作用影响,且人畜粪便和生活污水贡献增强。In order to study the influence of extreme drought climate on the characteristics and sources of nitrate pollution in groundwater,the groundwater chemical characteristics,spatial distribution and sources of nitrate were compared before and during extreme drought in the lower reaches of Ganjiang River Basin and its tributaries.The results showed that the NO_(3)^(−)content of groundwater in the study area in the extreme drought year of 2022 was 0-73.89 mg/L,with an average value of 6.58 mg/L,which was generally lower than that in the normal year(2021).In the study area in 2021 and 2022,the groundwater types were mainly HCO_(3)-Ca type and a small amount of Cl-Ca·Mg type in the wet and dry seasons.The hydrochemical components in the normal year and the extreme drought year were mainly affected by rock weathering,and the points with high nitrate values tended to be in the atmospheric precipitation region,indicating that the nitrate changes were mainly directly influenced by the outside world.The spatial distribution of nitrate in the wet and dry seasons in the extreme drought year was lower than in the normal year in terms of high-value area and degree.Long-term drought resulted in the reduction of groundwater recharge sources.The nitrate content was affected by rock salt leaching,excretion and denitrification,with increased contribution from human and animal feces and domestic sewage.

关 键 词：极端气候 地下水 NO_(3)^(−) 空间分布 污染来源 

分 类 号：X523[环境科学与工程—环境工程]