Research on multi-reservoir joint scheduling and dynamic correction method: A case study of Yarkant River Basin

Abstract

[Objective] To address the challenges of multi-objective coordination, high hydrological uncertainty, and limited adaptability of conventional static schemes in water resource scheduling of the Yarkant River Basin, a dynamic correction method for multi-reservoir joint scheduling is proposed to achieve dynamic coordinated scheduling between mountain and plain reservoirs, improve the flexibility and reliability of water resource scheduling, and provide a scientific basis for integrated management of inland river basins in arid regions. [Methods] A “planning-forecast-feedback” dynamic correction framework was established.(1) Based on a linear programming model, the multi-objective optimization problem was defined, including objective such as regional water supply guarantee rate, reservoir storage recovery rate, and ecological release volume.(2) Monthly-scale river inflow was predicted through rolling forecasts using the Prophet time-series model, and the constraints were dynamically updated by integrating actual inflow and forecast result.(3) The linear programming model was solved on a monthly rolling basis to adjust the reservoir scheduling schemes in real time. Taking the Yarkant River Basin as a case study, hydrological, meteorological, and operational data from the mountain reservoir(Artashi hydropower station) and 33 plain reservoirs were integrated. Historical simulations(1961—2020) and scenario analyses in typical years(dry and wet years) were conducted, and the impact of runoff forecast errors on the scheduling effectiveness was evaluated. [Results] The dynamic correction strategy showed robust performance in historical simulations. The optimal and baseline schemes achieved the objective of ecological release(≥330 million m³) from the Heiniyazi section to the Tarim River in 59 years and 50 years, respectively, with regional water supply guarantee rates exceeding 86% in all years. In the dry year(1963) and wet year(1977), water supply guarantee rates reached 88% and 98% respectively, and the release objective were fully met. When runoff forecast errors reached 25%, water supply guarantee rate decreased significantly to 78%, while the scheme maintained stable effectiveness with errors below 25%, indicating that the current forecast error(22%) in the mainstream of the Yarkant River could support the practical requirements of dynamic scheduling. [Conclusion] The results show that proposed dynamic correction framework effectively mitigates the conflict between hydrological uncertainty and rigid scheduling by coupling runoff forecasting with rolling optimization, significantly enhancing the adaptability of multi-objective water resource scheduling. The joint scheduling of mountain and plain reservoirs can balance the demands for power generation, irrigation, and ecological water supplementation, while the accuracy of monthly-scale runoff forecast is critical to the reliability of dynamic schemes. The method provides a technical pathway for refined scheduling of complex reservoir systems in arid regions. Future work should further integrate hydrological process-based models to improve long-term forecast accuracy.

Keywords

dynamic correction scheduling / multi-reservoir joint scheduling / Yarkant River Basin / runoff forecasting / multi-objective optimization / water resources / arid regions / inland river basins