洞庭湖区浅层地下水水质指标空间分异及其控制因素研究  

Spatial Variation of Quality Indices of Shallow Groundwater in the Dongting Lake Area and Their Control Factors

作　　者：危润初[1,2,3] 曹阳 唐仕明 尹欧 欧阳琦 鲁涛 刘长明 WEI Runchu;CAO Yang;TANG Shiming;YIN Ou;OUYANG Qi;LU Tao;LIU Changming(School of Hydraulic Engineering,Changsha University of Science and Technology,Changsha 410004,Hunan,P.R.China;Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province,Changsha 410004,Hunan,P.R.China;Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province,Changsha 410004,Hunan,P.R.China;Hunan Institute of Geological Survey,Changsha 410004,Hunan,P.R.China;402 Geological Prospecting Party,Hunan Bureau of Geology and Mineral Resources Exploration and Development,Changsha 410007,Hunan,P.R.China)

机构地区：[1]长沙理工大学水利工程学院,湖南长沙410004 [2]水沙科学与水灾害防治湖南省重点实验室,湖南长沙410004 [3]洞庭湖水环境治理与生态修复湖南省重点实验室,湖南长沙410004 [4]湖南省地质调查院,湖南长沙410004 [5]湖南省地质矿产勘查开发局四〇二队,湖南长沙410114

出　　处：《湿地科学》2022年第1期1-14,共14页Wetland Science

基　　金：国家自然科学青年基金项目(41602264);湖南省自然科学青年基金项目(2020JJ5572和2018JJ3270);长沙理工大学“双一流”科学研究国际合作拓展项目(2019IC08);湖南省水利厅重点科研项目(XSKJ2019081-09)资助。

摘　　要：利用1258个地下水水样的水质指标数据,对洞庭湖区浅层地下水水质指标空间分异及其控制因素开展了研究。从地下水系统、氧化还原环境和第四纪沉积物物源角度,剖析了浅层地下水水质指标空间分布的内在影响因素。研究结果表明,洞庭湖区浅层地下水7个水质指标的空间分布都呈现出一定的规律性,自洞庭湖区外围至湖盆腹地,浅层地下水中的氨氮、铁元素、溶解性总固体和化学需氧量含量逐渐增大,硝酸盐氮含量的空间分布规律则与之相反,锰元素含量的空间分布独具特点,水体pH的分布呈现出西北—东南单向减小特征;洞庭湖区大范围浅层地下水中的氨氮、铁元素和锰元素含量超过Ⅲ类地下水该指标的限值,在洞庭湖区外围的零星区域,浅层地下水中的硝酸盐氮含量小幅度超标,其溶解性总固体和化学需氧量含量仅在大通湖附近的局部区域略超标;洞庭湖区的基底构造对浅层地下水系统的整体空间格局有重要影响,主要体现在对“四口”水系地下水系统、澧县盆地地下水系统、赤山隆起-大通湖地下水滞留区等的控制作用;独特的受构造格局控制的地下水系统格局宏观上决定了地下水化学场的空间分布;受地下水系统格局控制的浅层地下水水体的氧化还原电位对硝酸盐氮、氨氮、铁元素、锰元素和化学需氧量含量的空间分布有重要影响,平原区浅层地下水水体的氧化还原电位较低是氨氮、铁元素和锰元素含量大范围超标的主要原因;洞庭湖区浅层地下水的pH“西北—东南单向递减”的分布特征主要受湖区第四纪沉积物物源的空间差异的影响。The 1258 sampling wells of the shallow groundwater evenly distributed in the Dongting Lake area were used to analyze the spatial variation of water quality indices,and the internal influencing factors were analyzed from three aspects of groundwater system,redox environment and source characteristics of Quaternary sediments.The results showed that the concentration or value of each index of the shallow groundwater of the Dongting Lake area presented a certain spatial distribution law.The concentrations of ammonia nitrogen,total iron,total dissolved solids and chemical oxygen demand gradually increased from the periphery to the hinterland of the lake basin,while the concentration of nitrate nitrogen showed an opposite trend.The concentration of manganese element increased at first and then slightly decreased,and pH of the shallow groundwater showed a unidirectional decrease from northwest to southeast.The concentrations of ammonia nitrogen,total iron and manganese element exceeded the upper limits of gradeⅢgroundwater specified by the standard for groundwater quality of China(GB/T 14848-2017)in a wide area in the Dongting Lake area,while the concentration of nitrate nitrogen exceeded the standard of gradeⅢgroundwater only in the peripheral sporadic areas.The concentrations of total dissolved solids and chemical oxygen demand only slightly exceeded the standard of gradeⅢgroundwater in some small areas near the Datong Lake.In the large area of the southeast of the lake area,the pH of the shallow groundwater was lower than the lower limit value of the standard of gradeⅢgroundwater.The basement topography of the lake area had an important influence on the overall spatial pattern of groundwater system in the Dongting Lake area,which determined the formations and patterns of the sub-groundwater systems,including Lixian Basin groundwater system,Chishan uplift-Datong Lake groundwater detention system,etc.The spatial pattern of groundwater system in the Dongting Lake area determined the spatial distribution of the h

关 键 词：洞庭湖 浅层地下水 水质指标 空间分异 构造格局 沉积物 

分 类 号：P641.3[天文地球—地质矿产勘探]