Sensitivity Study of Sea State Parameters in Correlation to Extreme Wave Occurrences

摘要

Sea states are commonly described by significant wave height and zero-crossing or peak period. Additional parameters can be chosen in many different ways. The list published in 1986 by the International Association for Hydraulic Research, and augmented in 1997 is an extensive reference from which to choose. It defines more than 120 parameters, and thus several questions arise:rnHow should one select a small number of parameters to represent the sea state climate from their distributions ? How robust is the estimation of those parameters ? Can some parameters from that list or others be related to some special statistical properties of the sea state, such as the occurrence of rogue waves ?rnThe present paper is an attempt to provide at least partial answers to those questions. In a first stage a choice is made of some parameters, by reference to the literature and to theoretical results. In a second stage, a number of cases where extreme waves were observed are taken for the basis of the study. Then, the natural (aleatory) variability of the selected parameters is established for those sea states and their relevance to characterize the risk of occurrence of extreme waves is investigated. Lastly, recommendations and analysis priorities are suggested, from the comparison of observed results with the computed ranges, for the most relevant parameters to be used for dangerous sea states characterization.