Distribution of Deep Water Wave Power Around the Indian Coast Based on Ship Observations

Abstract

The ship reported swell data published in the Indian Daily Weather Reports for the period from 1968 to 1983 are compiled for the seas around India which are divided into 10 grids each of 5° latitude and 5° longitude. The percentage distribution of wave power in different directions over a year for each grid is presented. The annual mean wave power along the Indian coast varies from 11.4 to 15.2 KW per metre length of wave crest with a maximum of 15.2 KW for the regions off south Kerala and south Tamilnadu coasts and a minimum of 11.4 KW off the Andhra coast. Computation based on the measured waves of one year duration show that the annual mean wave power available in the grids 3 and 9 is lower and is only about 53 and 77 percent respectively of the annual mean wave power computed based on ship reported wave data. About 55 to 65 percent of the annual total wave power is contributed during the southwest monsoon period from June to September. Wave power available in February, March and April in general is the lowest. Wave activity is found to be high both during the southwest and the northeast monsoons along the east coast bordering the Bay of Bengal whereas it is confined predominantly to the southwest monsoon period in the case of the west coast bordering the Arabian Sea.