Shoreline Changes on the Wave-Influenced Senegal River Delta, West Africa: The Roles of Natural Processes and Human Interventions
Fiche du document
2017
- handle: 10670/1.z1mdsn
- hal: hal-01708511
- doi: 10.3390/w9050357
Ce document est lié à :
info:eu-repo/semantics/altIdentifier/doi/10.3390/w9050357
info:eu-repo/semantics/OpenAccess
Mots-clés
ERA hindcast waves longshore sediment transport Senegal River delta Langue de Barbarie spit delta vulnerability river-mouth migration spit breachingSujets proches
Sénégal Fleuve Fleuve Sénégal (River)Citer ce document
Mamadou Sadio et al., « Shoreline Changes on the Wave-Influenced Senegal River Delta, West Africa: The Roles of Natural Processes and Human Interventions », Archive Ouverte d'INRAE, ID : 10.3390/w9050357
Métriques
Partage / Export
Résumé
The Senegal River delta in West Africa, one of the finest examples of " wave-influenced " deltas, is bounded by a spit periodically breached by waves, each breach then acting as a shifting mouth of the Senegal River. Using European Re-Analysis (ERA) hindcast wave data from 1984 to 2015 generated by the Wave Atmospheric Model (WAM) of the European Centre for Medium-Range Weather Forecasts (ECMWF), we calculated longshore sediment transport rates along the spit. We also analysed spit width, spit migration rates, and changes in the position and width of the river mouth from aerial photographs and satellite images between 1954 and 2015. In 2003, an artificial breach was cut through the spit to prevent river flooding of the historic city of St. Louis. Analysis of past spit growth rates and of the breaching length scale associated with maximum spit elongation, and a reported increase in the frequency of high flood water levels between 1994 and 2003, suggest, together, that an impending natural breach was likely to have occurred close to the time frame of the artificial 2003 breach. Following this breach, the new river mouth was widened rapidly by flood discharge evacuation, but stabilised to its usual hydraulic width of