滇池近20年水环境变化趋势与影响因素分析

利用2001—2020年滇池水质监测数据，研究其水环境时空变化特征。结果表明：滇池水质呈现波动变化趋势，TN波动区间较大，呈现雨季＜旱季的变化趋势。TP年内变化3—6月呈现增长趋势，空间上滇池北部TP值整体较高。Chl-a年内变化7—10月出现明显提升。IMn波动区间较大，空间上滇池南部呈现IMn值较高且稳定。NH3-N年内2—11月整体呈现连续下降趋势。2001—2020年滇池TLI整体呈现波动降低；空间上呈现由北向南递减，草海区域富营养化较为严重。滇池Chl-a与TN、TP、水温、pH值及降雨量呈现正相关性，与水位和透明度呈现负相关性。

Analysis of Water Environment Change Trend and Influencing Factors in Dianchi Lake in Recent 20 Years

Based on the water quality monitoring data of Dianchi Lake from 2001 to 2020, the temporal and spatial variation characteristics of water environment were studied. The results showed that the water quality of Dianchi Lake showed a fluctuating trend. The fluctuation range of TN was large, and the variation trend showed TN was lower in rainy season than in dry season. The annual variation of TP showed an increasing trend from March to June. TP in the northern part of Dianchi Lake was generally high. The annual variation of Chl-a increased significantly from July to October. IMn fluctuation range was large. IMn was high and stable in the south of Dianchi Lake. NH3-N showed a continuous downward trend from February to November. From 2001 to 2020, the overall fluctuation of TLI in Dianchi Lake decreased. TLI decreased from north to south in space. The eutrophication was more serious in Caohai area. Chl-a was positively correlated with TN, TP, water temperature, pH value and rainfall, and negatively correlated with water level and transparency.