Abstract: In recent years, the issue of refilling cascade reservoir group in the upper Yangtze River at the end of flood season has become increasingly prominent. Ensuring flood control safety while raising the reservoir water level and facilitating a smooth connection between flood control and reservoir refill operations is of particular importance. Using power generation and water utilization rate as evaluation criteria, we investigated the strategy of in-advance water refill during flood season (July to August) for cascade reservoirs in lower Jinsha River, namely Wudongde, Baihetan, Xiluodu, and Xiangjiaba. The findings indicate the following: 1) In normal (50%), low (75%), and extremely low (90%) inflow conditions, the reservoir water level for Wudongde and Baihetan should be raised in advance as much as possible, with priority given to Wudongde. Specifically, regardless of whether the inflow in August is normal or low, if the inflow in July is normal, the water level of Wudongde should be raised above 960 m as a priority. On the other hand, if the inflow in July is low, the water level of Wudongde should be raised above 954 m as a priority. 2) For Xiluodu, regardless of the inflow conditions, it is advisable to raise the reservoir water level as much as possible, while ensuring it does not exceed 585 m.

Key words: in-advance refill strategy, lower Jinsha River, cascade reservoirs, flood control storage, comprehensive benefits