Coastline evolution monitoring and estimation - a case study in the region of Nouakchott, Mauritania

Since the construction of a harbour, Port de l'Amitie, an important importation gate for Nouakchott, northwestern Africa in 1987, the previous coast dynamic equilibrium has been destroyed and thus a significant littoral geomorphologic change has occurred, which has produced a severe degradation of the littoral and urban environment. This research is focused on coastline evolution monitoring and its potential change estimation by remote sensing techniques using multitemporal Satellite pour l'Observation de la Terre (SPOT) images and Markov chain analysis. It is the objectives of the study to measure and estimate the coastal current hydrodynamics, coastline evolution rates, harbour life-span and to provide useful reference for the local authorities to make decisions for their future coastal management. The results show that the north beach of the harbour has extended by 0.92km(2) (92 ha) from 1989 to 2001 and the accretion will probably reach its maximum limit in about 13 years +/- 6 months (in 2014-2015) while the harbour will gradually arrive at the end of service. The south sandbar has been eroded by 1.34km(2) (134 ha) and the coastline has retreated landwards by 362m at the maximum point. Another 0.91km(2) of land will be eroded in the next 10 years from 2001 to 2011. This erosion has caused several inundations to the suburb and urban areas, provoking a deterioration of the urban environment.