Coastal zone of The Gambia and the Abidjan region in Côte d'Ivoire: sea level rise vulnerability, response strategies, and adaptation options

Abstract

The aerial videotape-assisted vulnerability analysis (AVVA) technique was combined with various data sets to assess the vulnerability of the coastal zone of The Gambia to sea level rise. Land loss due to inundation, flooding, and erosion was estimated. Costs of damage and population at risk were also evaluated. Only historical data and maps were used to assess the vulnerability of the coastal zone of the Abidjan region of Cote d'Ivoire to sea level rise. Results show that with a 1 m sea level rise the whole of the capital city of Banjul will be under mean sea level in the next 50 to 60 yr as a greater part of the city is below 1 m. The mangrove systems on St. Mary's Island, Kombo St. Mary, and the strand plains in the north bank will be inundated. About 1950 billion Dalasis (US $ 217 million) worth of land will be lost. The most appropriate response would be to protect the whole of the coastline of Banjul, the shoreline area from the Banjul cemeteries to Laguna Beach Hotel, the infrastructure at Sarro, and the hotel complex at Cape Point. Innovative sand management, repair of the damaged groins, and construction of dikes, breakwater structures, revetments, and low-cost seawall are some of the shoreline stabilization and hardening techniques suggested for the protection of this area. For the Abidjan region, the same response strategies should be used. Adaptation responses identified for both regions include public awareness, increase in height of coastal infrastructure, urban growth planning, wetland preservation and mitigation, and development of a coastal zone management plan.