Medium-term survey of rapid morphodynamic evolution of a gravel barrier spit during storm event (Sillon de Talbert in Brittany, France)

Over the last decades, the spit experienced landward migration by rollover process reaching 1.1 m/yr at least since 1930, with a maximum retreat rate of 1.35 m/yr affecting the proximal section. This evolution has led during the 70’s and 80’s to the construction of coastal defence structures (frontal dyke, riprap and groin) to stabilize the spit. In 2001, management of the Sillon de Talbert was transferred to a public service (Conservatoire du Littoral), which adopted a different strategy in terms of coastal management. At the same time, a topo morphological survey was undertaken to analyze and quantify both crossshore and longshore morphosedimentary processes of the spit. This monitoring began in 2002 and are still ongoing. It is based on yearly DGPS field measurements and/or aerial drone stereoscopic photography.