Effect of Different Wind Inputs in the Evaluation of Design Waves

摘要

The evaluation of design significant wave height (Hs) is often carried out on the basis of a numerical wave model forced by long-term wind data. For this purpose, alternative wind data sets are available. In this study, we have tried to understand the extent of variations in the 100-year or design Hs when three different wind data sets were employed. Two out of these were of reanalysis type, and the third one belonged to a regional climate model. We forced a numerical wave model with these wind data and simulated waves for around 30 years at a series of locations spread along the 7,000-km-long coastline of India. The simulated wave heights were fitted to generalized Pareto distribution on the basis of the peak-over-threshold method. A comparison of resulting design Hs showed that generally such wave heights were in agreement, with a few exceptions. The differences across any two given data sets appeared to have been overshadowed by uncertainties associated at various stages of statistical fittings. It therefore appears that the climate model-based wind can be conveniently used in studies related to climate change impact on waves and other ocean parameters requiring projected wave conditions. The results of this study also indicated that the methods adopted for distribution fittings are more influential than the choice of wind input.