长江科学院院报2025，Vol.42Issue(9)：58-66,9.DOI:10.11988/ckyyb.20240741
滇池水质时空变化及富营养状况分析
Spatiotemporal Variation in Water Quality and Eutrophication Status of Dianchi Lake
摘要
Abstract
[Objective]Dianchi Lake,an important freshwater lake in Southwest China,has experienced increas-ing water quality degradation and eutrophication in recent years due to urbanization and agricultural activities.Most existing studies primarily focus on interannual variations,with limited understanding of seasonal variation and spa-tial heterogeneity.This study aims to:(1)reveal the spatiotemporal distribution patterns of water quality in Dianchi Lake using the Water Quality Index(WQI)method;(2)evaluate eutrophication dynamics using a logarithmic power-function universal index;and(3)identify key driving factors to provide scientific support for targeted reme-diation strategies.[Methods]Using daily water quality data from 2021 to 2023 at ten nationally controlled monito-ring stations in Dianchi Lake,the WQI-incorporating six indicators(TP,TN,CODMn,NH3-N,DO,and turbidi-ty)—was employed to classify water quality levels.Eutrophication Index(EI)calculated using the logarithmic pow-er function model including Chl-a,TN,TP,and CODMn,was applied to evaluate eutrophication levels.Spatial pat-terns were depicted using Kriging interpolation in ArcGIS,and correlation analysis was conducted to identify the major influencing factors.[Results]1)Spatiotemporal characteristics of WQI:(a)regarding temporal variations,the mean WQI was 65.03(ranging from 31.33 to 82.67),with"moderate"water quality prevailing.Water quality was poorest in summer(only 16％rated"good"),primarily due to high temperatures accelerating organic decom-position,leading to decreased DO(8.40 mg/L)and increased CODMn(6.29 mg/L).Water quality was best in win-ter.(b)In terms of spatial variations,the average WQI in Caohai(68.96)was significantly higher than that in the Waihai(64.01),attributed to nutrient absorption by wetland vegetation.Severe pollution accumulation was ob-served in the central Waihai(e.g.,Guanyinshan monitoring station)due to limited water exchange.2)Dynamics of EI:(a)for seasonal patterns,eutrophication was most severe in spring,with an average EI of 55.166,and 16.8％of the area reached a"moderate eutrophication"level,due to runoff inputs during the peak agricultural fer-tilization season.Summer exhibited the greatest variation in EI(38.102-87.603),accompanied by frequent algal blooms.(b)In light of spatial differentiation,EI values in Caohai were generally higher than those in Waihai,par-ticularly at Duanqiao and the center of Caohai,where direct urban sewage discharge was significant.In northern Waihai,areas such as Luojiaying exhibited higher eutrophication levels due to intensive human activities.3)Key driving factors:(a)WQI was strongly positively correlated with DO(+0.492),and negatively correlated with NH3-N(-0.485)and CODMn(-0.358),indicating that organic pollution primarily drove water quality variation.(b)EI was mainly influenced by TP(with a weight of 0.230)and Chl-a(0.326),suggesting that phosphorus control and algae management were crucial for mitigating eutrophication.[Conclusions]Dianchi Lake exhibits pro-nounced seasonal and spatial heterogeneity in both water quality and eutrophication.In summer,nonpoint source pollution should be strictly controlled,while in spring,agricultural fertilization should be limited.The ecological restoration experiences in Caohai could be extended to Waihai,and enhanced water circulation is needed in the deep-water central zone.This study innovatively integrates the WQI and EI models,establishing a replicable meth-odological framework for dynamic assessment of eutrophic lakes,and emphasizes the need for long-term monitoring data to refine management strategies.关键词
水质评价/时空变化/富营养状况/综合水质指数(WQI)/滇池Key words
water quality evaluation/spatiotemporal variation/eutrophication status/water quality index(WQI)/Dianchi Lake分类
资源环境引用本文复制引用
沈春颖,左黔,程乖梅,何士华..滇池水质时空变化及富营养状况分析[J].长江科学院院报,2025,42(9):58-66,9.基金项目
国家自然科学基金项目(52069009) （52069009）
