A method for simulating coastal inundation and inland flooding by integrating inland hydrology with ocean hydrodynamics
摘要
Traditional flood models often address either coastal or inland flooding separately, making comprehensive flood prediction challenging. This study presents an integrated framework that combines coastal and inland hydrodynamics, including tides, storm-surges, waves, and river flooding, to improve flood prediction in deltaic regions. The framework links the HEC-RAS 2D model with the tightly coupled ADCIRC + SWAN model to simulate flood inundation extents. The Brahmani-Baitarani River delta in Odisha (India) and the Bay of Bengal serve as the study areas for simulating tides, surges, waves, and inland flooding. The ADCIRC + SWAN model was calibrated and validated for cyclones Fani (2019) and Yaas (2021), using wind and pressure data from Climate Forecast System Version 2 (CFSv2) and European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis 5 (ERA5). Model performance in predicting water surface elevations was excellent, with Nash–Sutcliffe Efficiency (NSE) values of 0.97–0.99 and errors within 8–18 cm. Flood extent for cyclone Yaas, simulated with HEC-RAS 2D, was validated against Sentinel-1 SAR imagery which showed good agreement. The integrated ADCIRC-SWAN-HEC-RAS 2D framework provides a robust tool for predicting flood dynamics in deltaic regions, enabling better disaster management for areas prone to cyclonic storm tides and inland pluvial flooding.