Impact

Impact Severe tropical cyclones cause considerable damage to life, property and agricultural crops. The prin­cipal dangers posed are (a) fierce winds, (b) torrential rains and associated flooding, and (c) high storm tides (combined effect of storm surge and tides).

While gales and strong winds as well as torrential rain cause sufficient havoc to property and agriculture, loss of human life and cattle is mainly due to storm surges. If the terrain is shallow and shaped like a funnel, like that of Bangladesh-much of the exposed land is just about at the mean sea level or even less-storm surges get enormously amplified;.Coastal inundation due to a combination of high tide and storm surge can cause the worst disaster.

Tropical Cyclones in the Indian Ocean and Bay of Bengal Regions The frequency, intensity and coastal impact of cyclones vary from region to region. Interestingly, the frequency of tropical cyclones is the least in the north Indian Ocean regions of the Bay of Bengal and the Arabian Sea; they are also of moderate intensities. But the cyclones are deadliest when they cross the coast bordering north Bay of Bengal (coastal areas of Orissa, West Bengal and Bangladesh). This is mainly due to storm surges (tidal waves) that occur in this region inundating the coastal areas.

Tropical cyclones over the Bay of Bengal occur in two distinct seasons, the pre-monsoon months of April-May and the post-monsoon months of October-November. On an average, in fact, almost half a dozen tropical cyclones form in the Bay of Bengal and the Arabian Sea every year, out of which two or three may pe severe. Out of these, the stormiest months are May, June,' October and November. Compared to the pre-monsoon season of May-June, when severe storms are rare, the months of October and No­vember are known for severe cyclones.

'Tropical cyclones in the Bay of Bengal are more frequent than in the Arabian Sea. There could be three reasons fqr this-(i) waters in the Bay of Bengal are comparatively shallow; (ii) the coastline along the Bay of Bengal is more complicated; and (iii) more number of rivers
drain into the Bay of Bengal than into the Arabian Sea.