2000-2019年阳澄湖水质变化趋势分析

Analysis of Water Quality Change Trend of Yangcheng Lake From 2000 to 2019

根据阳澄湖2000-2019年的水质监测数据,分析了总磷、总氮对水质的影响,以及水质富营养状况的年际变化趋势。结果显示,与2000年相比,阳澄湖水质明显好转,主要超Ⅲ类指标总磷、总氮浓度总体呈波动下降趋势,但近几年水质稳定在Ⅳ类,改善不明显;2011年以来,总氮月度变化特征呈明显波浪型周期变化,阳澄西湖水质较差,东湖较好;从2015年起,各湖区总磷浓度均有不同程度上升,各湖区总氮波动趋势减弱;阳澄湖总体处于轻度富营养状态,各湖区在2006-2012年富营养指数呈明显下降趋势,2014年以后西湖富营养指数呈明显下降趋势,中湖和东湖富营养指数变化趋势较为一致,总体呈波动趋势。

Based on the water quality monitoring data of Yangcheng Lake from 2000 to 2019,this paper mainly analyzed the impact of total phosphorus and total nitrogen on water quality,as well as the inter-annual change trend of the water quality and eutrophication of Yangcheng Lake.The results showed that compared with that in 2000,the water quality of Yangcheng Lake improved significantly,and the main indicators,total phosphorus and total nitrogen,displayed fluctuating decline.However,the water quality has been stabilizing at categoryⅣin recent years,and the improvement was not obvious.Since 2011,the monthly changes of total nitrogen have been showing obvious wave-like periodic changes.The water quality of the western area is relatively bad and the eastern area is relatively good.Since 2015,the total phosphorus concentration in each area has been increasing in various degrees.The fluctuating trend of total nitrogen in the whole lake weakened.Yangcheng Lake is generally in a mild eutrophication state,and the eutrophication index of each area declined significantly during 2006-2012.After 2014,the eutrophication index of western area showed a significant downward trend,while that of the middle and the eastern area showed a relatively consistent and fluctuating trend.