Ανάλυση Παράκτιων Καταιγίδων για την Eφαρμογή τους στο Σχεδιασμό των Λιμενικών και Παράκτιων Έργων

Μαρτζίκος, Νικόλαος; Martzikos, Nikolaos

dc.contributor.author	Μαρτζίκος, Νικόλαος	el
dc.contributor.author	Martzikos, Nikolaos	en
dc.date.accessioned	2021-12-06T10:44:37Z
dc.date.available	2021-12-06T10:44:37Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/54141
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.21839
dc.rights	Αναφορά Δημιουργού 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by/3.0/gr/	*
dc.subject	Παράκτιες καταιγίδες	el
dc.subject	Συζεύξεις	el
dc.subject	Προσομοίωση	el
dc.subject	Μοντελοποίηση	el
dc.subject	Περίοδος επαναφοράς	el
dc.subject	Coastal storms	en
dc.subject	Copulas	en
dc.subject	Simulation	en
dc.subject	Modelling	en
dc.subject	Return periods	el
dc.title	Ανάλυση Παράκτιων Καταιγίδων για την Eφαρμογή τους στο Σχεδιασμό των Λιμενικών και Παράκτιων Έργων	el
dc.title	Analysis of Coastal Storms for their Application in Harbours and Coastal Structures Design	en
dc.contributor.department	Εργαστήριο Λιμενικών Έργων	el
heal.type	doctoralThesis
heal.classification	Ακτομηχανική	el
heal.classification	Παράκτια Μηχανική	el
heal.classification	Coastal Engineering	en
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2021-07-19
heal.abstract	The sea-level rise and the increase of storms severity are the major effects of climate change in coastal areas. Their impacts are of great importance for millions of people who live and work in coastal communities, also affecting the ports functionality and many other economic activities. In conjunction with the sea level, the astronomical and the meteorological tide, coastal storms cause extreme wave runup and overtopping phenomena in ports and coastal structures. Consequently, coastal storms threaten the reliability of infrastructure, the urban areas with coastal flooding, and the coasts from erosion. The above reasons depict the importance of coastal storms analysis and its necessity before any technical study in coastal engineering. Such analyses provide valuable information for risk reduction, coastal management, harbour and coastal structures design. Coastal storms as multivariate extreme events require a detailed multivariate analysis of many variables. A coastal storm analysis is accomplished by studying the wave height, the wave period, the duration, the calm period, and the storm energy, which are considered “coastal storm parameters” since they define a coastal storm event. The range of coastal storm parameters and how they are interrelating draw a rough outline of wave climate during coastal storm events. The analysis of these parameters is used to understand the coastal storm characteristics, their severity and improve their modelling. The theory of copulas can be applied for coastal storm modelling, as it has already been implemented for other multivariate events in hydrology and finance. This thesis focuses on the modelling of coastal storms through copulas, and secondly, in order to apply the proposed methodology, analyses 4008 coastal storms in the Mediterranean Sea, studying the activity of coastal storms in the last decades. More specifically, this thesis: a) describes the dependency of wave height (H) and the wave period (T) during a coastal storm investigating the best fit bivariate copulas, b) simulates the coastal storms in a given location applying a five-dimensional C-Vine copula, and c) estimates the return periods of coastal storms by using two- to five-dimensional copulas. In addition, for the description of energy, a comparison of coastal storm energy with energy flux is accomplished and the shape of coastal storms is also investigated. The dependency of H and T is investigated among 40 copula families for 4008 coastal storms, presenting the two best-selected copulas and their properties. Three algorithms based on works of De Michele et al. (2007), Aas et al. (2009), and Stöber and Czado (2017) developed into five dimensions and compared for their efficiency in coastal storms simulation. To estimate the return periods, up to five-dimensional copulas are used for any combination of important coastal storm parameters. Moreover, the thresholds of coastal storm parameters, their identification, the frequency of their occurrence and the description of their characteristics are presented. The Tawn and the Joe copulas are the most frequent best-selected bivariate copulas for modelling H and T during a coastal storm. The C-Vine copulas can be used to simulate the coastal storms efficiently and estimate high-dimensional return periods with extreme characteristics. The flexibility of C-Vines to describe better the tail dependencies makes this class of copulas an effective tool for coastal storm modelling. In addition, it can be said that Mediterranean coasts face around 10-14 coastal storms per year, with most of them occurring in winter. Their average duration is shorter than 30 hours, and 25% of them are consecutive events that hit twice a location in less than a day. Furthermore, the wave period and the main direction present no remarkable fluctuations during a coastal storm. The sharpness of coastal storms is not related to the wave period or the direction and they are not reaching their peak faster than they decay. This thesis describes the use of copulas for the modelling of coastal storms. Besides, through a thorough analysis of Mediterranean coastal storms, a deeper understanding of coastal storm severity is pursued, gaining knowledge about their past activity in order to be prepared in the future and protect the coastal areas. Consequently, all this information is helpful for their application in harbours and coastal structures design.	en
heal.sponsor	This doctoral thesis was implemented through a scholarship by State Scholarships Foundation (IKY), co-financed by Greece and the European Union (European Social Fund-ESF) through the Operational Programme «Human Resources Development, Education and Lifelong Learning» in the context of the project «Strengthening Human Resources Research Potential via Doctorate Research» (MIS-5000432).	el
heal.advisorName	Τσουκαλά, Βασιλική	el
heal.advisorName	Tsoukala, Vasiliki	en
heal.committeeMemberName	Tsoukala, Vasiliki
heal.committeeMemberName	Memos, Constantine	el
heal.committeeMemberName	Prinos, Panagiotis	el
heal.committeeMemberName	Karlis, Dimitris	el
heal.committeeMemberName	Soukissian, Takvor	el
heal.committeeMemberName	Katsardi, Vasiliki	el
heal.committeeMemberName	Nikoloulopoulos, Aristeidis	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Πολιτικών Μηχανικών	el
heal.academicPublisherID	ntua
heal.numberOfPages	251
heal.fullTextAvailability	false