Analysis of joint operation of the lower Jinsha River and Three Gorges cascade reservoirs in the 2024 flood season

To further enhance the joint operation capability of the cascade reservoirs of the lower Jinsha River and the Three Gorges, and improve the comprehensive utilization level of basin water resources, this study inversely analyzed the joint operation process of the cascade reservoirs during the 2024 flood season and impoundment period. It quantified the benefits of the measures such as the overall use of flood control storage capacity of the Jinsha River downstream cascade reservoirs, the optimized regulation of outflow from the Three Gorges Reservoir, and the joint optimized scheduling of the cascade reservoirs. Results show that facing the complex inflow conditions (i.e. “drought-flood abrupt alteration”) in the 2024 flood season, under the scientific regulation of the Changjiang Water Resources Commission of the Ministry of Water Resources, the cascade reservoirs scientifically responded to three numbered floods, intercepting 13.45 billion cubic meters of floodwater in the main flood season, thereby robustly ensuring flood control safety. In the impoundment period, through refined impoundment operations, the available water volume of the cascade reservoirs reached 33.3 billion cubic meters by the end of December, which was 2.7 billion cubic meters more than the same period in 2023, laying a solid foundation for water supply in the dry season. Additionally, the joint scheduling reduced water abandonment by 8.3 billion cubic meters and increased power generation by 7.3 billion kilowatt-hours, significantly improving beneficial effects. The joint optimal scheduling practices of the cascade reservoirs in 2024 provide valuable references for optimizing operational strategies of basin-controlled reservoir systems and achieving multi-objective collaborative regulation.