Extreme Value Analysis of the Ocean Wave around the Gulf of Thailand in Trat, Phetchaburi, and Surat Thani Provinces

Abstract

The purpose of this study was to analyze an appropriate model from the extreme value theory for the data of wave height in the ocean around a shoreline on the Gulf of Thailand in the Trat, Phetchaburi, and Surat Thani provinces. The data were collected weekly between 2007 and 2019. Two distributions we employed to compare the data of wave height were Generalized Extreme Value and Generalized Pareto distribution. We employed the Maximum Likelihood Estimate to estimate parameters for Generalized Extreme Value and used Peak Over Threshold for GPD to anticipate the Return Level of the wave height in the ocean in the next two years, five years, ten years, and twenty years, which we used Akaike’s Information Criterion as the selection criteria for the model. The results revealed that the data of the wave height in the ocean around the shoreline of three provinces, which collected weekly were suitable for GPD. From the results, we were able to use it as a guideline to plan an arrangement and prevent coastal areas from erosion of all five areas, including nearby areas. Also, it even helps to prevent the environment and ecosystems around the coast.