A parametric wave prediction model based on Time delay concept

Abstract

Parametric wind-sea relationships for prediction of significant wave height (Hs) and zero-upcrossing period (Tz) for slight to moderate sea states have been presented in this paper based on the analysis of time series wind and wave data collected off west coast of India in March 1986. Wave measurements are made by deploying Data well wave rider buoy from an oceanographic research vessel Gaveshani. Observations revealed a series of growing and decaying phases of sea state with wind speeds ranging from 0 to 11.5 m/s .The characteristic feature of the proposed parametric model is the introduction of 'Time-delay' concept in place of wind duration limit. A time-lag of 6 hr is noticed between wind speed and wave height and same has been incorporated in this model which enables forecasting seas at 6-hourly synoptic time intervals. Model comparison is made and the predicted values of Hs and Tz closely agree with the recorded wave observations. Results show that the present method yields significant wave height prediction with an r.m.s. difference of 0.12 m for the observed Hs ranging from 0. 6 to 2.3m.