Study on water replenishment operation strategy of Three Gorges Reservoir in extremely dry year 2022

In 2022 ,the changjiang River Basin encountered a basin - wide drought with the sharp shift from abundant to scarce inflow. The upstream reservoir group with the Three Gorges Reservoir as the core lacked the support of research on water replenishment scheduling during the dry period. In order to investigate the water replenishment operation strategy of the Three Gorges Reservoir during the dry period ,firstly the operation practice of the upstream reservoirs in 2022 was reviewed. Then the relationship between the water level at each control site and the Three Gorges Reservoir discharge during the dry period was analyzed. After that ,the water operation trial method was adopted to study the water storage target and the guarantee of water supply of the Three Gorges Reservoir under different water conditions and operation parameters. Finally ,a strategy of water replenishment opera- tion of the Three Gorges Reservoir was proposed for the extreme dry year. Then this strategy was verified by the typical dry year 2006 . Results showed that it is more reasonable for the Three Gorges Reservoir to discharge 6 000 m3 /s under 40% ~ 50% less incoming water ,6 500 ~ 7 000 m3 /s under 30% less incoming water ,and 7 000 ~ 7 500 m3 /s under 10% ~ 20% less incoming water. Accordingly ,the Three Gorges Reservoir can provide " basic guarantee " for downstream water supply targets in the case of extra unfavorable inflow , " limited guarantee " for downstream water supply targets in the case of relatively unfavorable inflow , " full guarantee " for downstream water supply targets in generally unfavorable inflow conditions. The research findings can provide a reference for the water replenishment operation of the Three Gorges Reservoir during extreme dry years.