A Forecast-Based Operation(FBO) Mode for Reservoir Flood Control Using Forecast Cumulative Net Rainfall

With advance of up-to-date hydrology measuring and forecasting system, reservoir operations are no longer required to be as conservative as they once were. The incorporation of flood inflow and weather forecasts allows for greater flexibility in the management of reservoir space and inherently increases opportunities for acquiring additional water supply and reducing flood risks effectively advance. In this paper, taking Ankang Reservoir as an example, a forecast-based operation (FBO) mode for flood control is developed with cumulative net rainfall in the real-time rolling prediction as the primary indicator and the water level in the reservoir as the auxiliary indicator. Based on the accuracy of flood forecasting data, FBO rules for reservoir flood control are formulated by using the stepwise regulation method considering the actual situation of Ankang Reservoir. For verification, a flood routing simulation is conducted for designed and typical flood processes with different recurrence intervals using the formulated rules. The results show that the maximum flood level is lower than for conventional regulation and that the duration of the maximum discharge under the forecast operation mode is slightly shorter than the conventional discharge, which indicates that the flood risk is reduced to some extent by applying the formulated FBO rules and, correspondingly, demonstrates the merits and applicability of implementing FBO mode for Ankang reservoir.