Based on the monitoring data of total phosphorus in"three cities and one district"of Dongting Lake from 2021-2023,the temporal and spatial changes of total phosphorus concentration in Dongting Lake were analyzed.The results showed that:From 2021-2023,the total phosphorus content of the water quality monitoring section in the lake area showed a steady and positive trend,among which the total phosphorus content in the west Dongting Lake reached the standard better,with an average annual total phosphorus concentration of 0.046～0.049 mg/L,and the total phosphorus content in the East Dongting Lake region was higher,with an average annual total phosphorus concentration of 0.058～0.069 mg/L.From 2021-2023,the average annual total phosphorus content of the four estuary of the Yangtze River and the lake surrounding rivers(Miluo River and Xinqiang River)into the lake estuary was significantly higher than that of the four rivers of the Yangtze River,and the total phosphorus content of the lake estuary showed a downward trend in general,but the total phosphorus content of the Zijiang Lake estuary in 2023 increased to different degrees than that of the previous two years.In order to achieve accurate control of total phosphorus pollution in Dongting Lake,it is suggested to make up for the construction of flow monitoring points in the river section entering the lake and the key trans-boundary sections,strengthen the control of agricultural non-point source pollution in Dongting Lake area and the dynamic monitoring of water quality in the lake outlet.
关键词
洞庭湖/总磷/入湖河流
Key words
Dongting Lake/total phosphorus/rivers flowing into lakes
万方数据