a cyclone induced storm surge forecasting model for the coast of bangladesh with application to the cyclone `sidr'

the coast of bangladesh has a specialty in terms of high bending and many off- shore islands. incorporation of the coastline and island boundaries properly in the numerical scheme is essential for accurate estimation of water levels due to surge. for that purpose a numerical scheme consisting of very fine mesh is required along the coastal belt, whereas this is unnecessary away from the coast. in this study, a fine mesh scheme covering the coastal belt and islands has been nested into a coarse mesh scheme covering up to 15 n latitude in the bay of bengal. for the existence of so many small and big islands and also for high bending of the coastline along the meghna estuary, a very fine mesh scheme for the region between barisal and chittagong is again nested into the fine mesh scheme. a vertically integrated model is developed in cartesian coordinate system to solve the shallow water equations using semi- implicit finite difference technique for computing surge associated with storms. the developedsystem is applied on a severe cyclonic storm ’sidr’ that hit bangladesh on 15th november, 2007. the computed water levels are found to be in good agreement with those observed.