Interannual and seasonal variations in nearshore wave characteristics off Honnavar, west coast of India

Abstract

Interannual and seasonal variations in nearshore surface wave parameters over a period of three years (March 2008 - March 2011) were examined based on the measured wave data at 9 m water depth off Honnavar, west coast of India. Significant wave height up to 4.3 m was observed during the summer monsoon with an average value of 1.7 m. Predominant wave spectral energy density was within 0.05 - 0.25 Hz and directional spreading was narrow (directional width less than 20 degrees) for high waves (significant wave height more than 2 m). Average annual wave power per unit width was the same (6.2 kW m sup(-1)) in different years. Yearly average wave parameters were also the same during different years. Even though the average wave parameters are the same in different years, for estimating the wave height having different return periods, data covering a large period are required