Storms in the Bay of Bengal
The Bay of Bengal is one of the major centres of the world for breeding of tropical storms. These storms are known as cyclones over the Indian Ocean and southwestern Pacific, as typhoons over the northwestern Pacific, and as hurricanes over the Atlantic. Cyclones over the Bay of Bengal usually move westward, northwestward, or northward and cross the east coast of India or Bangladesh (Fig. 23). When this happens, it brings strong winds and high rainfall to the coastal region, causing loss of life and damage to property.
Compounding the damage is the occurrence of a “storm surge” that often accompanies a storm. The surge is primarily piling up of water due to the strong storm winds. This raises the mean water level in the coastal zone, whose magnitude is dependent on the strength of the winds. It is not unusual for this rise to be a metre for many cyclones, and 2-3 metres for major cyclones. With mean water levels being elevated, and with strong winds generating high waves, storm surges lead to immense loss of life and property. The particularly strong cyclone (also called supercyclone) of October 1999 caused a loss of over 10000 lives and huge property loss in Orissa. Of the 34 reported storm surges with loss of life of 5000 or more around the world, 26 have occurred in the Bay of Bengal. A storm surge in 1970 in Bangladesh caused 500,000 deaths. The rather flat topography of Bangladesh makes it particularly vulnerable to storm surges.