人民长江2025，Vol.56Issue(12)：60-69,10.DOI:10.16232/j.cnki.1001-4179.2025.12.006
滇池富营养化问题综合诊断
Comprehensive diagnosis on eutrophication in Dianchi Lake
摘要
Abstract
As one of the severely eutrophic lakes in the Changjiang River Basin,Dianchi Lake faces long-term challenges in water quality improvement and ecological restoration.To accurately diagnose its current eutrophication status,this study systemati-cally examined the spatiotemporal characteristics from 2021 to 2023 and interannual trends of key water quality and trophic level indicators in Dianchi Lake—namely chlorophyll-a,total phosphorus(TP),total nitrogen(TN),and oxygen-consuming organ-ic pollutants(represented by CODMn).The trophic level of Dianchi Lake was assessed using the single-indicator method based on chlorophyll-a,and the quantile method was applied to determine nitrogen and phosphorus reference conditions.The results in-dicated that:① from 2021 to 2023,the water quality of Dianchi Lake was predominantly Class Ⅳ to worse than Class Ⅴ,with TP,TN,and CODMn being the main parameters exceeding the standards.The average TP concentrations in Caohai and Waihai Lake were similar,measuring(0.067±0.001)mg/L and(0.064±0.004)mg/L,respectively.In contrast,the average TN concentra-tion in Caohai Lake((4.19±1.10)mg/L)was significantly higher than that in Waihai Lake((1.54±0.09)mg/L).The av-erage CODMn concentration in Caohai Lake((4.09±0.66)mg/L)was lower than that in Waihai Lake((6.67±0.66)mg/L).The average chlorophyll-a concentrations in Caohai and Waihai Lake were(106±22)μg/L and(77±6)μg/L,respec-tively.From March to December each year,both the mean and median chlorophyll-a concentrations across all areas exceeded the severe eutrophication threshold of 30 μg/L.During January and February,chlorophyll-a concentrations were relatively lower across the entire lake,with an average of 29 μg/L.②Dianchi Lake was in a state of severe eutrophication,with most areas experi-encing algal blooms throughout the majority of the year.TN concentrations were lower during the wet season compared to the dry season,while TP and CODMn concentrations were higher during the wet season.Over the past decade,nitrogen,phosphorus,and ox-ygen-consuming organic pollutant levels in Dianchi Lake have shown a significant declining trend,reflecting notable achieve-ments in pollution control.The effectiveness of TP control has been greater than that of TN control,and the nitrogen-to-phos-phorus ratio has exhibited an upward trend.The current average N/P ratio in Dianchi Lake is 37,indicating excessive levels of ni-trogen,phosphorus,and oxygen-consuming organic pollutants relative to the requirements for algal growth.Water pollution pre-vention and control should continue to be strengthened,and the control of TN should not be overlooked.The key to reducing nitro-gen and phosphorus pollution in the lake lies in controlling the pollutant loads from its inflow tributaries.Nitrogen and phosphorus control targets for key monitoring sections of these tributaries should be established from the perspective of the aquatic ecological security of Dianchi Lake.关键词
富营养化/氮磷/叶绿素a/叶绿素a单指标法/分位值法/氮磷基准/滇池Key words
eutrophication/nitrogen and phosphorus/chlorophyll-a/single-indicator method based on chlorophyll-a/quantile method/nitrogen and phosphorus reference conditions/Dianchi Lake分类
资源环境引用本文复制引用
娄保锋,段友爱,黄杰,袁赛波,杨超,余明星..滇池富营养化问题综合诊断[J].人民长江,2025,56(12):60-69,10.基金项目
国家重点研发计划项目(2023YFC3205600,2023YFE0102400) （2023YFC3205600,2023YFE0102400）
