Video monitoring of sandbar-shoreline response to an offshore submerged structure at a microtidal beach
BOUVIER, Clément
Bureau de Recherches Géologiques et Minières [BRGM]
Environnements et Paléoenvironnements OCéaniques [EPOC]
Bureau de Recherches Géologiques et Minières [BRGM]
Environnements et Paléoenvironnements OCéaniques [EPOC]
BOUVIER, Clément
Bureau de Recherches Géologiques et Minières [BRGM]
Environnements et Paléoenvironnements OCéaniques [EPOC]
< Réduire
Bureau de Recherches Géologiques et Minières [BRGM]
Environnements et Paléoenvironnements OCéaniques [EPOC]
Langue
EN
Article de revue
Ce document a été publié dans
Geomorphology. 2017-07-20, vol. 295, p. 297-305
Résumé en anglais
In early 2013, an 800-m long and 12-m wide submerged breakwater with its crest in 2-m depth was implemented at the wave-dominated barred beach of Sète, SE France, to fight against erosion and submersion hazards. Daily video ...Lire la suite >
In early 2013, an 800-m long and 12-m wide submerged breakwater with its crest in 2-m depth was implemented at the wave-dominated barred beach of Sète, SE France, to fight against erosion and submersion hazards. Daily video images from April 2011 to April 2016 covering an alongshore distance of 3.5 km are used to analyse the response of both the sandbar(s) and the shoreline to the structure implementation. Results show that the breakwater had a profound impact on the nearshore system, both shoreward of the structure and well away from it alongshore. A progressive rotation and linearisation of the sandbar was observed shoreward of the submerged breakwater. This resulted in the splitting of the sandbar adjacent to the structure during a net offshore sandbar migration event driven by a severe storm in December 2013. The typical formation of a salient or tombolo was not observed. Instead, shoreline coupled to the sandbar geometry, which resulted in a slight seaward migration of the shoreline in front of the structure. Overall, this study highlights that the role of the sandbar is critical to shoreline response to the implementation of breakwaters on barred beaches.< Réduire
Mots clés en anglais
Nearshore bars
shoreline change
submerged structure
shoreline-sandbars coupling
Project ANR
Processus cross-shore et longshore combinés en morphodynamique littorale - ANR-14-ASTR-0004