A study of tides and storm surges in offshore waters of the Meghna estuary using a finite element model

Abstract

Tropical Cyclones which develop in the Andaman Sea and the Bay of Bengal during the inter monsoon months (April-May, October-December), move either westwards affecting the east coast of India or recurve to the north or northeast and eventually cross the coast of Bangladesh or Myanmar. Extensive damage is caused to the life and property by the storm surge as much of  the coastal land around the Bay of Bengal is densely populated. The damage caused by a cyclone induced surge depends to a considerable extent on whether the surge peaks at or close to high tide.

The main purpose of the present study was to develop a combined time-surge model for the off-shore waters in the Meghna estuary.

It seems clear that the strong, predominantly southward current measured at Site A, south of Sandwip Island, has substantial magnifying and delaying effect on tidal elevation and current. But the areal extent of this modification of the tide is unknown at present. Further, it is impossible to say whether the fast southward current forms a narrow jet or a broad current many kilometers wide, but it is important to know which is the case before the effect can be modelled satisfactorily.