Hydrological-Hydraulic Flood Simulation For Carey Island Under Different Design ARI

Abstract

Periodic monitoring of environmental changes is crucial for effective flood risk management. Shifts in factors such as land use, annual rainfall patterns, and sea-level rise can significantly increase the potential for flooding. In response to these challenges, this study employs the HEC-HMS and HEC-RAS models to simulate the hydrological and hydraulic conditions of the Carey Island catchment. The objective is to analyze the island’s vulnerability to fluvial flooding under current and future environmental scenarios. The results obtained the maximum discharge of 91.5 m³/s at Basin 116 for 3 hr rainfall simulation while the maximum discharge of 75.1 m³/s at Basin 116 for 6 hr rainfall simulation. According to flood simulation results under various discharge scenarios, the narrow river cross-section and limited flow capacity are the main causes of the minor flooding that occurs at lower discharges and the significant upstream flooding that occurs as discharge 500 m³/s.