Abstract In recent years, the increasing frequency of extreme precipitation events has resulted in severe flooding worldwide. This problem is particularly pronounced in small and medium-sized rivers discharging into the sea, where tidal backwater effects, sediment deposition, and aquaculture encroachment have greatly reduced their flood conveyance capacity. To address this issue, this study develops a one-dimensional hydrodynamic model for the estuarine section of the Biliu River based on measured cross-sectional data and simulated design flood scenarios. The model is used to evaluate the river’s flood conveyance capacity under current conditions. Water level observation stations are established to monitor the dynamic water level process in real time, enabling a quantitative assessment of flood risk. For the vulnerable reaches, two targeted mitigation measures – channel dredging and shoreline restoration – were proposed and evaluated through hydrodynamic simulations to enhance flood conveyance capacity and support future flood control planning. The estuarine reach of the Biliu River, which is notably affected by tidal backwater, sediment deposition, and aquaculture activities, is selected as a case study. The results demonstrate that the standardized approach proposed here can serve as a valuable reference for assessing flood conveyance capacity and developing flood control strategies in the estuarine sections of the Biliu rivers.
Zhang et al. (Thu,) studied this question.