Bangladesh is a country of natural calamities and Bangladesh coast is very vulnerable to cyclone surges. Due to long and shallow continental shelf and funnelling shape of the coast, surges are used to concentrated and amplified at the northern part of the Bay. The project concerns the reassessment of the delineation of High Risk Area in the ‘Multipurpose Cyclone Shelter Programme’ study (MCSP 1994). The modelling study is to provide the hydraulic calculations of cyclone induced surge heights on the coastal areas. The result of these calculations together with other consideration form of the basis for the assessment of the delineation of the High Risk Area.

The study included 14 severe cyclones occurred during 1960 to 1995. The same set of cyclones, but shifted half a tidal cyclone (6 hour) was assumed for another 35 years period. In total, 28 cyclones representing 70 years of cyclone climate in Bangladesh has been simulated using one and two-dimensional model. In the simulation all the existing embankments and polders have been considered. Impact of these embankments and polders on the depth and extent of inundation has also been investigated by Geographical Information System (GIS). The inundation at every location caused by cyclone is calculated by mathematical modelling. The outputs so the model was used to delimate the high risk area. Subsequently the inundation are analysed statistically for 1:10, 1:20, 1:25, 1:35, 1:50, 1:100 years return period.