Development and Application of Reservoir Operation Method Based on Pre-Release Index for Control of Exceedance Floods

The pre-release operation has the potential to enhance the ability of a reservoir to manage exceedance floods. However, the mechanisms for the initiation and termination of such operations are unclear, and a clear method for calculating the pre-release water amount at each time step of the scheduling phase is lacking. To address this, the framework and mathematical expression for a pre-release index are proposed herein, and a refined pre-release scheduling model is developed based on the pre-release indices and their thresholds. Then, the proposed pre-release operation model is applied to the Shuifumiao Reservoir in the Lianshui River Basin in Hunan Province, China. The simulation results demonstrate that the refined pre-release scheduling model can effectively prevent exceedance floods, ensuring the safety of flood control without compromising the effectiveness of water supply safety. The proposed model provides a valuable framework and tool for enhancing the ability of reservoir operators to manage flood events and improve overall flood control safety.