M. Mizanur Rahman - Shahjalal University of Science & Technology, Sylhet ۳۱۱۴, Bangladesh Bangladesh Department of Mathematics
G. Chandra Paul - University of Rajshahi, Rajshahi-۶۲۰۵, Bangladesh Bangladesh Department of Mathematics
A. Hoque - University of Rajshahi, Rajshahi-۶۲۰۵, Bangladesh Bangladesh Department of Mathematics

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 ۱۵ 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 ۱۵th November, ۲۰۰۷. The computed water levels are found to be in good agreement with those observed.

Bay of Bengal, shallow water model, finite difference method, Cyclone Sidr, water level