BIVARIATE ANALYSIS AND JOINT EXCEEDANCE PROBABILITIES OF EXTREME WAVE HEIGHTS AND PERIODS

摘要

In the present paper significant wave heights and concomitant peak wave periods are analyzed at a Dutch station in the North Sea. Different bivariate models are utilized to produce contours of equal probability density as well as return level contours for return periods commonly used in the design of flood defence structures. Some of the models used are the bivariate log normal, the bivariate log-normal with correction for skewness, a parametric distribution based on transformations to normality and the bivariate logistic model, which belongs to the family of extreme value distributions.An approach based on copulas is also examined and compared with the results of the previously implemented bivariate distributions, with respect to (a) their probability densities and (b) the estimated bivariate return levels. The comparisons among the different models concentrate mainly on their ability to correctly describe the data and on their behavior when extrapolation is of interest.