Mouncef SEDRATI, Laboratoire Geo-Ocean UMR 6538, Université Bretagne Sud, France
Kader BA, Université Cheikh Anta Diop, Senegal
Mouhamadoul Bachir DIOUF, Université Cheikh Anta Diop, Senegal
Ibrahima DIOUF, Université Cheikh Anta Diop, Senegal
The southern coast of Senegal (Petite Côte Sénégalaise) is caractrised by a succession of large sand spits with contrasting morphological evolution and anthropisation degree. The sand spits of Mbodiène and Joal located on either side of Joal Point reflect this situation, with the first spit (Mbodiène) relatively untouched by massive human occupation and the second (Joal) further south, which is considered one of the largest fishing ports in Senegal and is almost completely urbanised. This paper deals with an evaluation of the erosion hazards and coastal risk assessment together with the discussion of erosion management issues at both sand spits. For this work, we have computed a Coastal Sensitivity Index (CSI) at 1-km spatial scale for Mbodiène and Joal sand spits taking into consideration coastal characteristics (geomorphology, shoreline changes, coastal elevation, beach slope, bathymetry), coastal forcings (sea level rise, mean tidal range, significant wave height), and socio-economic characteristics (coastal population density, land use) as indicators. The study revealed that the southern high density urbanized sand spit (Joal) is characterised by the highest risks, followed by some central areas with a significant erosive focus. On the contrary, the northern sand spit (Mbodiène) more morphologicaly dynamic, with wither beaches and developed dunes systems highlights the lowest risk level. These results could be useful in the development of adaptation strategies to increase the resilience of this coastal zone and then be extended to the management of the entire Senegalese coast characterized by numerous sand spits.
Mots clés : Coastal vulnerability|Coastal management|Sand spit|Mbodiene-Joal|Senegal
A105147YF