A CYCLONE INDUCED STORM SURGE FORECASTING MODEL FOR THE COAST OF BANGLADESH WITH APPLICATION TO THE CYCLONE `SIDR'

Subject Areas : International Journal of Mathematical Modelling & Computations

M. Mizanur Rahman ¹ , G. Chandra Paul ² , A. Hoque ³

1 - Shahjalal University of Science & Technology, Sylhet 3114, Bangladesh Bangladesh Department of Mathematics
2 - University of Rajshahi, Rajshahi-6205, Bangladesh Bangladesh Department of Mathematics
3 - University of Rajshahi, Rajshahi-6205, Bangladesh Bangladesh Department of Mathematics

Received: 2016-04-12 Accepted : 2016-04-12 Published : 2011-03-21

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

Abstract :

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.