Joint Probability Distribution of Significant Wave Height and Peak Wave Period Using Gaussian Copula Method

Abstract

In this study, the joint probability distribution was estimated using the significant wave height-peak wave period data observed for 3 years for 3 stations along the coast of Korea, and an environmental contour line drawing was performed. For accurate estimation, an optimal probability distribution model was calculated for each wave parameter, and the Kolmogorov-Smirnov test and Kullback-Leibler divergence were used for the distribution fit test. Using each estimated optimal probability distribution, a Gaussian copula function was applied considering the correlation between the two wave parameters. As a result of the analysis, it was found that the significant wave height was suitable for the ‘Log-normal’ and ‘3-P Weibull’ distributions, and the peak wave period was suitable for the ‘Log-normal’ distribution. Then, as a result of correlation analysis between significant wave height and peak wave period at all points, it was confirmed that there was a significant correlation. As a result of performing environmental contour line drawing through this, observation data exceeding 3-year recall were found to be less than 1.0% of the total data. In addition, the environmental contour line calculated through the Gaussian Copula showed a limit to reproduce the area where no wave exists as a concave tendency appeared.