Modifications morphodynamiques et phénomènes rétroactifs en baie de Saint-Michel-en-Grève (Côtes-d'Armor) (Morphodynamic changes and feedback processes in the Saint-Michel-en-Grève bay, Cotes-d'Armor)

摘要

Two technical operations concerning the mechanical opening of the channel rivers of the Yar and the Roscoat in the Saint-Michel-en-Grève bay were carried out between 1998 and 1999. These operations were undertaken in order to eliminate the confluence of the two rivers on the shore and to allow the fill up of a large depression which was located on the upper part of the beach, just behind the confluence. The fill up of the depression brought important morphodynamic changes inducing feedback phenomenon such as dune erosion located on each side of the rivers. A monitoring based on topographic measurements allowed to analyse and quantify these processes.