Morphodynamic modelling of a wave-dominated tidal inlet : the Albufeira lagoon

• Main Author: Dodet, Guillaume
• Other Authors: LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Université de La Rochelle, André Fortunato, Xavier Bertin
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2013
• Subjects: Western Iberia Margin; Wave-current interactions; North-Atlantic Oscillation; Wave climate variability; Ephemeral inlet dynamics; Data analysis; Regional wave modelling; Morphodynamic modelling; Marge ouest-ibérique; Interactions vague-courant; Modélisation morphodynamique; Modèle régional de vagues; Analyse de données; Dynamique des embouchures tidales éphémères; Variabilité du climat de vagues; Oscillation Nord-Atlantique; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Houle; Lagoon Inlet; North Atlantic; North Atlantic oscillation
• Online Access: https://tel.archives-ouvertes.fr/tel-01127011; https://tel.archives-ouvertes.fr/tel-01127011/document; https://tel.archives-ouvertes.fr/tel-01127011/file/2013LAROS413.pdf

Wave-dominated tidal inlets are very dynamic coastal systems, whose morphology is continuously shaped by the combined action of the waves and the tides. The rapid morphological changes they experience impact directly their ecological and socio-economic environments. In order to implement adequate regulations for the sustainable management of tidal inlets, systematic environmental studies are necessary. The main objective of this PhD research work is to gain a better understanding of the physical processes that control the morphological evolutions of an ephemeral tidal inlet in Portugal - the Albufeira Lagoon inlet - based on the analysis of hydrodynamic and topographic data and on the results of a newly developed morphodynamic modelling system. The processes that impact the dynamics of the inlet at short time-scales, particularly those related to wave-current interactions, are investigated through the application of the modelling system to the inlet. The seasonal modulations of the wave climate and mean sea level strongly affect the sediment dynamics of the inlet and contribute to the natural closure of the inlet during the winter period. Long-term processes are also investigated based on a 65-year hindcast of mean wave parameters at regional and local scales. The large inter-annual variability of the wave climate and the associated longshore sediment transport – both correlated to the North-Atlantic Oscillation – are proposed to explain the differences in the morphological behaviour of the inlet-lagoon system at pluri-annual time-scales. Les embouchures tidales dominées par la houle sont des systèmes côtiers particulièrement dynamiques dont la morphologie est continuellement remodelée par l’action des vagues et de la marée. Les rapides évolutions morphologiques auxquelles elles sont sujettes impactent directement leurs environnements écologiques et socio-économiques. Afin de mettre en œuvre des réglementations adaptées à la gestion durable des embouchures tidales, des études environnementales systématiques ...