The 24th IAHR-APD Congress (24th IAHR-APD Congress)

277 / 2024-02-28 22:29:09

Research on the Diversion and Confluence Relationship between Dongting Lake and Changjiang River under Extreme Water Conditions

Extreme water conditions; Hydrological conditions; the diversion of three outlets; the confluence of Dongting Lake

Subtheme 1: Water-related Hazard and Risk Reduction > Topic 1: Water Hazard Under Climate Change

In order to research the diversion and confluence relationship between Dongting Lake and Yangtze River under extreme water conditions in 2022。 This paper used the hydrological data of three outlets and Dongting Lake confluence stations from 1956 to 2022,to analyze the changes. In 2022, the diversion volume of the three outlets of Jingjiang River still showed a decreasing trend. Due to extreme water conditions, the diversion volume of the three outlets was only 27.62 billion cubic meters, with a diversion ratio of only 7.5%. The most severe reduction in diversion ratio occurred in August and September; The confluence of Dongting Lake is 228.9 billion cubic meters, with a confluence ratio of 40.68%. The most severe decrease in confluence ratio occurred in October and November. The impact of the three channel diversion is more significant, with a decrease of 22.29 billion cubic meters compared to the average from 2003 to 2021, further reducing the Yangtze River inflow to Dongting Lake and exacerbating the trend of water supply shortage in the Dongting Lake area.