Secular shoreline response to large-scale estuarine shoal migration and welding
Language
EN
Article de revue
This item was published in
Geomorphology. 2023p. 108972
English Abstract
The 14.5-km North-Médoc coast, southwest France, is a high-energy mesoto macro-tidal environment adjacent to the largest estuary in Europe. Over the last centuries, this coastline has locally suffered periods of severe ...Read more >
The 14.5-km North-Médoc coast, southwest France, is a high-energy mesoto macro-tidal environment adjacent to the largest estuary in Europe. Over the last centuries, this coastline has locally suffered periods of severe erosion, threatening coastal infrastructures and requiring the progressive implementation of coastal structures and, more recently, localized beach nourishments. This contribution combines 84 years (1937-2021) of shoreline data from various sources, 118 years (1903-2021) of shallow water bathymetric surveys and historical photographs. Results show that, averaged in both time and space, the coast eroded by-0.6 m/yr over the last 84 years, but with a large alongshore and temporal variability. Erosion is locally peaking at-5.2 m/yr, while accretion is restricted to a remote 2.5-km and locally peaks at 5.4 m/yr. A salient characteristic of shoreline evolution is the alternation of rapid erosion ( 20 m/yr) periods over relatively short intervals (≈ 10 years) and across limited alongshore distances (e.g. couple ofRead less <
English Keywords
Coastal erosion
Estuary mouth
Shoal welding
Bathymetric control
Multidecadal variability
ANR Project
Comprendre et prévoir l'évolution contemporaine du traite de côte dans un contexte de changement climatique par assimilation de données satellite dans les modèles hybrides - ANR-21-CE01-0015