ESTIMATION OF EXTREME WAVE CONDITIONS FROM HINDCAST SIMULATIONS WITH APPLICATION TO THE WAVE CLIMATE ALONG FRENCH COASTS

摘要

A numerical wave data-base has been built by hindcasting sea-state conditions over a period of 23 years and 8 months, from 1979/01/01 to 2002/08/31, using the TOMAWAC spectral wave model, driven by wind fields from the ERA-40 meteorological reanalysis produced by the ECMWF. The resolution of the finest model's grid is about 2 to 3 km along the French coasts of Atlantic ocean, English Channel and North Sea. From this data-base, synthetic charts representing mean and severe wave conditions over the European continental shelf are established. A statistical analysis of extreme wave heights is also carried out assuming that the wave climate is stationary. The so-called peak over threshold (POT) approach is applied and a chart of estimates of 50-year return spectral significant wave height is obtained. The results are compared with those obtained considering a block maxima approach. Finally potential trends in the regional wave climate are investigated over the period 1979-2002.