Soheil Saeed Far1 and Ahmad Khairi Abd. Wahab1,21Faculty of Civil Engineering, Universiti Teknologi Malaysia (UTM), 81310, Skudai, Johor Bahru, Malaysia 2Center for Coastal & Ocean Engineering, Research Institute for Sustainable Environment, UTM, Jalan Sultan Yahya Petra, 54100, Kuala Lumpur, Malaysia
Received: 16 Jun 2016 – Accepted for review: 06 Jul 2016 – Discussion started: 07 Jul 2016
Abstract. Two extreme wave analysis models, namely Peaks-Over-Threshold (POT) and Generalized Pareto Distribution (GPD), were developed in order to improve the POT model and highlight merits and limitations of the two models. Studies have shown that the POT model was not equipped with a suitable approach to determine a true threshold value. This paper proposed an approach to specify the most suitable threshold value for the POT model, which is called Hybrid method. In addition, until now the MIR (minimum ratio of residual correlation coefficient) criterion has been used as a goodness-of-fit method in the POT model. However, the examinations on the method represented that MIR is not always a stable approach in determining true distribution function. This paper proposed an alternative approach instead of the MIR criterion method, it is called Norm of Residuals, and its credibility was examined by the Chi-Square test. The results drawn from this study also demonstrated that the Hybrid method completely matched with the POT model, and the threshold obtained by this method is credible, moreover, the Norm of Residuals method is completely stable in determining the best fitting distribution for the POT model.
Saeed Far, S. and Abd. Wahab, A. K.: Evaluation of Peaks-Over-Threshold Method, Ocean Sci. Discuss., doi:10.5194/os-2016-47, in review, 2016.