A study of the cyclonic storms incident on the different sections of the coast around the Bay of Bengal

Abstract

The study covers all the storms/severe storms incident on the different sections of the Bay coast during 1877-1980. The series of storms/severe storms have been examined for trend, changes in mean frequency and changes in the ratio of severe storms to storms incident on each section of the Bay coast, the east India coast and the whole Bay coast. The mean annual frequency of storms incident on Bangladesh coast shows a highly significant increase during the period 1965-80. For the severe storm series for the Andhra Pradesh, the Bangladesh,  the east India and the Bay coasts, mean annual and mean post-monsoon season frequency shows a highly significant increase in the same period. Possible causes have been given for the highly significant increase in the incidence of storm/severe storms. Locations of the origin of storms reaching different sections of the Bay coast have been brought out. The number of storms which form over each of the different sectors of the Bay and of these, the numbers which reach each of the sections of the Bay coast have been indicated. The frequency of 0, 1, 2, 3, etc storms in a year/season are found to be consistent with the Poisson probability model. Finally, mean annual frequency has been estimated for the next 50-year period and using this mean, frequencies of 1, 2, 3, 4 etc storms in a year have been worked out on the basis of the Poisson probability model. These frequencies may be useful for planning funds to mitigate the hardship of the people affected by storm havoc or for evolving a suitable insurance scheme for the benefit of the areas liable to storm havoc.