Flood risk assessment due to cyclone induced dike breaching on coastal areas of Bangladesh

Abstract. Bangladesh, one of the most disaster-prone countries in the world, has a dynamic delta with 123 polders protected by earthen dikes. Cyclone induced storm surges cause severe damages to these polders by overtopping and breaching the dikes. Nineteen major tropical storms hit the coast in last 50 years and storm intensity is predicted to increase due to climate change. The present paper presents an investigation of the inundation pattern in a protected area behind dikes due to floods caused by storm surges and identifies possible critical locations of dike breaches. Polder 48 in the coastal region, also known as Kuakata, was selected as the study area. A HEC-RAS 1D–2D inundation model was developed to simulate inundation under different scenarios.…