华南沿海地区地下水硝酸盐分布特征及来源识别——以珠海市为例  

Distribution characteristics and source identification of nitrate in the underground water of coastal areas of South China:A case study of Zhuhai City

作　　者：何军[1,2] 黎义勇[1,2] 吴盼 曾敏[1,2] 陈晨 赵信文[1,2] HE Jun;LI Yiyong;WU Pan;ZENG Min;CHEN Chen;ZHAO Xinwen(Wuhan Center of China Geological Survey,Wuhan Hubei 430205,China;Key Laboratory of Eco-hydrogeological Process of River and Lake Wetlands in Changjiang Reaches,China Geological Survey,Wuhan Hubei 430205,China)

机构地区：[1]中国地质调查局武汉地质调查中心,湖北武汉430205 [2]中国地质调查局长江河湖湿地生态水文地质过程重点实验室,湖北武汉430205

出　　处：《中国地质调查》2025年第1期98-108,共11页Geological Survey of China

基　　金：中国地质调查局“粤港澳大湾区资源环境承载能力监测评价(编号:DD20221729)”;珠海市财政项目“珠海市城市地质调查(含信息化)(编号:MZCD-2201-008)”联合资助。

摘　　要：沿海地区农业、工业、生活和海水养殖多重作用下的人类活动可能会导致地下水硝酸盐污染,为查明我国华南沿海地区地下水硝酸盐的分布特征及其来源,以典型的沿海城市珠海市为例,综合运用数理统计、离子关系比值、主成分分析等方法研究不同类型地下水水化学及硝酸盐、亚硝酸盐和氨氮的分布特征,识别地下水硝酸盐来源。结果表明。研究区地下水以弱酸性水为主,深层承压水电导率明显高于浅层地下水,主要的地下水化学类型为Ca^(2+)·Mg^(2+)-HCO_(3)^(-)型和Na^(+)-Cl^(-)·SO_(4)^(2-)型。松散岩类孔隙承压水的溶解性无机氮(dissolved inorganic nitrogen,DIN)组成以NH+4为主,其他类型地下水以NO_(3)^(-)为主。个别水样的硝酸盐和亚硝酸盐超标,丘陵台地区和山间沟谷地区水样的硝酸盐浓度相对较高。研究区18.01%的地下水样品氨氮超标,高氨地下水主要分布于滨海平原区。硅酸盐、硫酸盐矿物的风化作用、蒸发作用和海水混合作用是控制研究区地下水化学特征的主要因素。地下水硝酸盐主要来源于大气降水和人类活动,其中碎屑岩类孔隙裂隙水、花岗岩变质岩裂隙水和孔隙潜水中的硝酸盐主要来大气降水和农业活动,松散岩类孔隙承压水和碳酸盐岩裂隙岩溶水中的硝酸盐则来自于生活污水和养殖废水。研究成果可为华南沿海地区地下水开发利用与保护提供科学依据。Nitrate pollution could present in the underground water due to the human activities like agriculture,industry,residents and mariculture in coastal areas.In order to find out the distribution characteristics and sources of nitrate in the underground water of the coastal areas of South China,the authors in this paper took a typical coastal city-Zhuhai as an example.The mathematical statistics,ion ratio and principal component analysis were adopted to study the distribution characteristics of water chemical,nitrate,nitrite and ammonia nitrogen,and the sources of nitrate in the underground water.The results show that the underground water is mainly weak acid,and conductivity of deep confined underground water is obviously higher than that of shallow underground water.The chemical type of underground water is mainly Ca^(2+)·Mg^(2+)-HCO_(3)^(-) and Na^(+)-Cl^(-)·SO_(4)^(2-) type.The dissolved inorganic nitrogen(DIN)of pore confined groundwater in loose rocks is mainly composed of NH+4,and the DIN of other types of underground water is mainly NO_(3)^(-).Nitrate and nitrite exceed the standard in sporadic water samples,and the concentration of nitrate is relatively high in the water samples of hilly areas and intermountain valleys.The ammonia nitrogen of 18.01% underground water samples in loost rocks exceeds the standard,and the high concentration ammonia nitrogen water samples are mainly distributed in the coastal plain area.The chemical characteristics of underground water in the study area is mainly controlled by the weathering,evaporation and seawater mixing of silicate and sulfate minerals.Nitrate in the underground water is mainly from atmospheric precipitation and human activities.Nitrate in clastic pore fissure groundwater,granite metamorphic rook fissure groundwater and pore unconfined groundwater mainly comes from atmospheric precipitation,and agricultural activities.Nitrate in pore confined groundwater in loose rocks and carbonate fissure karst water comes from domestic sewage and mariculture wastewater.Th

关 键 词：滨海地区 地下水 硝酸盐 水化学 成因 

分 类 号：P534.46[天文地球—古生物学与地层学] P618.76[天文地球—地质学]