The Senegal river mouth migration

Abstract

The Senegal River presents one of the most dynamic river mouths in the world. It has shown a very fast migration in the last 12 years, as a result of an artificial channel. This new inlet was made in October 2003 over the Langue de Barbarie. In that year, the heavy rains originated a flood all along the river, so that the authorities had no other choice to open a new inlet through the sand spit to facilitate the river discharge. The original channel dimensions were 4 m wide, 200 m long and 1.5 m deep, and it was located approximately 7 km south of Saint Louis. The pressure of the river water flowing at very high speed originated the quick channel widening. Since then the morphodynamic change in this area has been very fast. Few months after the opening, the artificial channel evolved to form the new river mouth, and the ancient mouth was naturally closed due to the weakness of the river flow and the strong longshore drift. Nowadays the mouth dimensions are very large, reaching nearly 6 km in width. The coast facing this new mouth is completely expossed to wave action and therefore it suffers very strong coastal retreat.