Impacts of climate change on the Senegalese coastal zones: Examples of the Cap Vert peninsula and Saloum estuary

Following a first study made to assess the impacts of sea level rise on the Senegalese coastline (Dennis et al., 1995), this vulnerability and adaptation (V&A) study tried to determine the impacts of climate change on two representative coastal zones, the Cap Vert peninsula and the Saloum estuary as well as potential adaptation options. The Intergovernmental Panel on Climate Change (IPCC) Methodology (Carter et al., 1994), completed by the United Nations Environment Programme (UNEP) Handbook (Feenstra et al., 1998), were used together with different models (like the Bruun rule, the FEFLOW model), geographical information system and economic data to determine the physical and socio-economic impacts of different climate change scenarios on these coastal zones. Land losses are expected due to sea level rise that will enhance coastal erosion and increase inundation levels, the second phenomenon being responsible for most of these losses, especially in low lying areas like the Saloum estuary (27% of the total area lost with a 1m inundation level). The combination of sea level rise and decreased precipitation will increase the salt water intrusion in a number of coastal aquifers, especially around Dakar and in the Saloum estuary. Population at risk of inundation in the Cap Vert peninsula could represent between 1 and 12% of the total population of this area. Economic values at risk were estimated by considering socio-economic scenarios and discount rates. For a 1m inundation level by 2050, this could represent (for the two areas) 14.1% of the actual Gross Domestic Product. While housings represent more than 90% of this value in the Cap Vert peninsula, in the Saloum estuary, it is the agricultural production which represents the dominant form of value at risk (55%). Only two adaptation options, protection works (sea walls and groins) and afforestation of littoral dunes, were evaluated and costed. For a 1m inundation level by 2050, this will represent 7.3% of the actual Gross Domestic Product. The main result of this study is the demonstration that protection costs will be lower than economic value at risk contrary to the results of the previous study. This is mainly attributed to the consideration of socio-economic scenarios and a better economic evaluation of the goods and services at risk of inundation.