ASSESSMENT LAND DEGRADATION USING OPTICAL REMOTE SENSING AND GIS IN SALOUM ESTUARY, SENEGAL

The present study aims at assessing consequences of salinization during the last three decades in this estuary with regard to land, biodiversity and water degradation. In this respect, Landsat images (1984, 1992, 1999 and 2010) were used to investigate regional time series land use/land cover. These were classified into six land-use/land-cover types: water bodies, high mangrove, low mangrove, denuded and salty soils (locally called “Tan”), savannah/rainfed agriculture and forestland. Change detection analysis of land and mangrove degradation was assessed using GIS techniques. Spectral analysis indicated that from 1984 to 2010, mangroves and savannah/rainfed agriculture are converted to “tan” (denuded and salty soils). In addition, these results showed that significant changes in land-use/land-cover occur within the whole estuary system and reflecting therefore environmental degradation, such as land desertification and salinization, and vegetation degradation which reflect the advanced of salinit