2017-2022年洱海水体营养状态的时空变化趋势及其成因分析  

The spatiotemporal variation and potential causes for the nutrient status of water in Lake Erhai from 2017 to 2022

作　　者：华兆晖 李锐 杨智 文紫豪 单航 丑庆川 张霄林[1] 曹特[1] Hua Zhaohui;Li Rui;Yang Zhi;Wen Zihao;Shan Hang;Chou Qingchuan;Zhang Xiaolin;Cao Te(Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,P.R.China;Yunnan Institute of Water&Hydropower Engineering Investigation,Design Co.,Ltd,Kunming 650000,P.R.China;Yunnan Institute of Water&Hydropower Engineering Investigation,Design and Research,Kunming 650000,P.R.China;University of Chinese Academy of Sciences,Beijing 100049,P.R.China)

机构地区：[1]中国科学院水生生物研究所,武汉430072 [2]云南省水利水电勘测设计院有限公司,昆明650000 [3]云南省水利水电勘测设计研究院,昆明650000 [4]中国科学院大学,北京100049

出　　处：《湖泊科学》2024年第6期1639-1649,共11页Journal of Lake Sciences

基　　金：国家自然科学基金项目(32101319,32071574,31930074);中国博士后科学基金项目(236070)联合资助。

摘　　要：洱海是云贵高原重要湖泊,近年来经历了多次污染和治理。2017年以来,洱海全流域开展高水平保护治理,外源污染和水质发生了时空变化。为分析洱海水质的影响因素,于2017-2022年在洱海8个主要湖湾以及北部、中部、南部3个湖心水域进行连续6年的逐月水质监测,重点分析了总氮、总磷和叶绿素a浓度以及透明度4项水质指标,并用综合营养状态指数(TLI)法评价水体的富营养化程度。结果表明,1)洱海水体富营养化程度呈北高南低趋势,与外源污染物主要经由北三江入湖有关。2)2017-2022年,南部水域富营养化程度逐年降低,中部水域氮、磷浓度呈降低趋势,北部水域氮、磷浓度略有升高,表明中部和南部治理成效优于北部。3)洱海富营养化程度在汛期高于非汛期,北部水域富营养化程度的季节变异高于中部和南部水域。4)洱海北片区及汛期污染控制尤其是水体磷控制是洱海治理需要关注的重点问题。Lake Erhai is an important lake on the Yunnan-Guizhou Plateau,which has experienced pollution and treatment in recent years.Since 2017,the high-level protection and management have been carried out in the entire Lake Erhai basin,resulting in spatiotemporal changes in the external pollution and water quality.To analyze the influencing factors of external pollution on the water quality of Lake Erhai,this study conducted monthly water quality monitoring in eight major bays,as well as in the central of the northern,middle,and southern parts of Lake Erhai from 2017 to 2022.The concentrations of total nitrogen,total phosphorus,chlorophyll-a and water transparency were measured in the water column.The eutrophication was evaluated by the trophic level index(TLI).The results showed that:1)The TLI decreased from the northern area to southern area,in agreement with the higher nutrients input of rivers in the northern part of the lake.2)During the period from 2017 to 2022,the trophic index decreased significantly in the southern area of Lake Erhai and decreased slightly in the middle area,while increased in the northern area,indicating that the pollution control was more effective in the southern and middle areas than in the northern area.3)the trophic index was higher in the wet season than in the dry season,and the seasonal variation of TLI was higher in the northern area than in the middle and southern areas.4)It is important for the control of phosphorus input into the lake,particularly for the northern area of Lake Erhai basin and/or in the flooding season,as well as the phosphorus concentration in the lake water.

关 键 词：洱海 水质 富营养化 综合营养状态指数 水环境治理 

分 类 号：X524[环境科学与工程—环境工程]