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

116 / 2024-02-07 16:18:16

Analysis and Countermeasure Study on Low-Water Situations in the Middle and Lower Reaches of the Yangtze River after the Operation of the Three Gorges Project

middle and lower reaches of the Yangtze River; drought situation; changing trends; countermeasures

After the construction of the Three Gorges and other reservoirs, significant adjustments have been observed in the water-sediment processes, leading to prolonged and large-scale erosion and incision processes in the middle and lower reaches of the Yangtze River. Consequently, leading a certain impact on the low-water situation. This paper analyzes the changing patterns of low-water conditions in the middle and lower reaches of the Yangtze River following the operation of the Three Gorges Project, utilizing field-measured data, and proposes strategic approaches. The research findings indicate that although erosion and incision in the middle and lower reaches of the Yangtze River have led to a decline in water levels during low-flow periods, the compensating effect of the reservoir group has resulted in elevated water levels at all other stations except for Sandouping. Based on the latest predictions, the total erosion and incision volume in the Yichang to Datong River section during the period of 2020-2062 is estimated to be 42.85 billion m³. Against the backdrop of continued erosion and incision of the riverbed, water levels in the main channels of the middle and lower reaches of the Yangtze River during low-flow periods are expected to continue to decline. To mitigate the adverse effects of riverbed incision on low-water conditions, strategies are proposed, including upgrading and improving water intake projects, enhancing joint reservoir scheduling schemes, and establishing emergency water source areas. The research findings can serve as a reference for future defense against drought situations in the Yangtze River basin.