赣抚平原东北部地下水硝酸盐浓度变化特征及成因  

Variability in spatiotemporal groundwater nitrate concentrations in the northeast Ganfu Plain

作　　者：何佳汇 毛海如 薛洋 廖福 高柏[4] 饶志 杨扬 刘媛媛[4] 王广才[1] HE Jiahui;MAO Hairu;XUE Yang;LIAO Fu;GAO Bai;RAO Zhi;YANG Yang;LIU Yuanyuan;WANG Guangcai(State Key Laboratory of Biogeology and Environmental Geology/MOE Key Laboratory of Groundwater Circulation and Environmental Evolution,China University of Geosciences(Beijing),Beijing 100083,China;Beijing Institute of Geo-Engineering,Beijing 100048,China;China Water Investment Co.,Ltd.,Beijing 100053,China;School of Water Resources&Environmental Engineering,East China Institute of Technology,Nanchang 330013,China;Geological Environment Monitoring Institute of Jiangxi Geological Survey and Exploration Institute,Nanchang 330006,China)

机构地区：[1]中国地质大学(北京)生物地质与环境地质国家重点实验室/地下水循环与环境演化教育部重点实验室,北京100083 [2]北京市工程地质研究所,北京100048 [3]中国水务投资有限公司,北京100053 [4]东华理工大学水资源与环境工程学院,江西南昌330013 [5]江西省地质调查勘查院地质环境监测所,江西南昌330006

出　　处：《地学前缘》2024年第3期360-370,共11页Earth Science Frontiers

基　　金：国家自然科学基金重点项目(42030705)。

摘　　要：赣抚平原地下水硝酸盐含量较高,但目前对地下水水化学组分(特别是硝酸盐)浓度的季节变化特征及其影响因素的研究还较少。本文通过采集赣抚平原东北部枯、丰水期地下水样品,运用水化学图解法、自组织神经网络(SOM)、空间自相关分析及反向水文地球化学模拟等方法,对研究区地下水化学组分(特别是硝酸盐)浓度的时空变化及硝酸盐来源进行研究。研究结果表明,研究区地下水化学类型以Cl·NO_(3)-Ca型、HCO_(3)-Ca型为主,人类活动的输入是引起地下水化学空间分布差异的主要因素。NO-3浓度较高以及季节变化较大的地区均集中于南昌下游。NO-3浓度低值区和季节变化的低值区主要分布在西部、东南部的山区以及赣江三角洲下游。地下水NO-3浓度的空间分布特征和季节变化特征与地下水径流特征、氧化还原环境和土地利用类型有关。地下水中NO-3主要来源于工业、生活污水,农业化肥对地下水NO-3的影响也不可忽视。反向水文地球化学模拟结果定量揭示了地下水径流过程中所受水岩作用和人类活动的影响。Groundwater in the Ganfu Plain exhibits high NO-3 concentrations,yet few studies have investigated the seasonal variations and influencing factors of groundwater chemistry,particularly NO-3 concentrations.In this study,groundwater samples were collected in the northeast region of the Ganfu Plain during both dry and wet seasons.The study aimed to explore the spatiotemporal variations in groundwater chemistry,focusing on NO-3 concentrations,and the sources of NO-3 in groundwater using hydrochemical diagrams,Self-Organizing Map(SOM),spatial autocorrelation analysis,and an inverse geochemical model.The results indicate that the primary groundwater types in the study area are Cl·NO_(3)-Ca and HCO_(3)-Ca.Human activities emerge as the key factor driving spatial variations in groundwater chemistry.Regions with elevated NO-3 concentrations and significant seasonal variations are predominantly located in the lower reaches of Nanchang.Conversely,areas with lower NO-3 concentrations and seasonal variations are primarily situated in the western and southeastern mountainous regions and the lower reaches of the Ganjiang River Delta.The spatial distribution and seasonal variability of groundwater NO-3 concentrations in the study area are influenced by groundwater runoff conditions,redox environments,and land use patterns.Industrial and domestic sewage are identified as the main sources of NO-3 in groundwater,with the impact of fertilizers on NO-3 concentrations also warranting consideration.The results from the inverse geochemical model provide quantitative insights into the effects of water-rock interactions and human activities on groundwater quality during groundwater movement processes.

关 键 词：地下水 硝酸盐污染 时空变化 水化学演化 

分 类 号：P641.12[天文地球—地质矿产勘探] X523[天文地球—地质学]