阳澄西湖入湖河道水质时空变化特征

Spatial and temporal variation characteristics of water quality in rivers flowing into West Yangcheng Lake

基于2007—2019年阳澄西湖入湖河道逐月水质监测数据,分析了阳澄西湖入湖河道水质时空变化特征。结果表明:阳澄西湖入湖河道呈现出氮磷营养盐春季含量较高的特点;氨氮、总氮和高锰酸盐指数年均质量浓度整体呈下降趋势,2019年比2007年分别下降78.7%、47.9%和34.8%;总磷年均质量浓度2015年后有较大幅度下降,2015—2019年均值比2007—2014年均值下降45.3%;阳澄西湖主要入湖河道中,水质较差的是蠡塘河和白荡,主要污染因子为氨氮、总磷及总氮。

Based on the monthly water quality monitoring data of rivers flowing into West Yangcheng Lake from 2007 to 2019, the spatial and temporal variation characteristics of water quality in rivers flowing into West Yangcheng Lake were analyzed. The results show that the rivers flowing into West Yangcheng Lake had the characteristic of high content of nitrogen and phosphorus nutrients in spring.The annual average mass concentration of NH3-N, TN and permanganate index showed overall downtrend with the decline rate of 78.7%, 47.9% and 34.8% respectively in 2019 compared with 2007. The annual average mass concentration of TN declined considerably after 2015. The annual average value from 2015 to 2019 declined by 45.3% compared with that from 2007 to 2014. Water quality in Litang River and Baidang were the worst among rivers flowing into West Yangcheng Lake with the main pollution factors of NH3-N, TP and TN.