Study on Watershed Ecological Water Replenishment Coupling Hydrodynamic and Reservoir Operation

In order to develop an ecological operation strategy that combines cross-basin water transfer and reservoir ecological management, this study investigates the corresponding theoretical framework and methodological approach. A novel optimization model that couples hydrodynamic with reservoir dispatch for ecological water replenishment is proposed. Using the Yongding River ecological operation project as a case study, various scenarios of Yellow River water diversion are analyzed to assess the satisfaction of ecological water demands and associated costs in the downstream channel of the Guanting Reservoir. The results show that: 1) For ideal ecological flow process, suitable ecological flow process, and minimum ecological flow process in the downstream river channel of Guanting Reservoir, the minimum values are 8.67 m3/s, 4.46 m3/s, and 1.66 m3/s respectively, and the maximum values are 49.82 m3/s, 33.69 m3/s, and 8.37 m3/s respectively. 2) The coupling model is applied to the ecological water replenishment project of Yongding River and achieves satisfying effects. The ecological guarantee degree can be increased by 48.8% when the cost of water replenishment is doubled and the Yellow River water is used for ecological water replenishment. 3) According to the water storage situation of Guanting Reservoir, the satisfaction of ecological water demand and the cost of water replenishment are comprehensively considered. In order to ensure the water supply of the Beijing section of Yongding River, two ecological water supply schemes are recommended, and the ecological guarantee degree of the two schemes can reach more than 90%. The research results provide new ideas and methods for the development of ecological water replenishment programs for Yongding River in the future, and also have important reference value for the development of ecological water replenishment programs for other water-scarce rivers.