地球科学と気候変動ジャーナル

抽象的な

Temporal Variabilities of the Climate along the Mauritanian Coast over the Last Decades

Anne Littaye, Sidi Mohamed Boba and Sidi Cheikh Ould Ahmed

Climate conditions affect all socio-economic spheres due to changes in the natural environment either in a geomorphological aspect or natural resources and biodiversity. The Sahelo-Saharan region has been subject to a very large number of climate studies after the main hazard of the 20th century that is called the “Great Drought” . Studies that focused on Mauritania and more specifically on its marine and coastal area, are very few whereas the government policies on this coastal area have been on the increase. The challenges of development are crucial such as the sustainability of the fishing sector, natural resources and infrastructure, for example the projects of two new on-going harbor. Another issue is the biodiversity world heritage that is present in this coastal area and perhaps in future, will be the tourism sector. Flood prevention for Nouakchott city which also represents a national challenge that has been subject to studies.

Several climate parameters have been studied with an ecological approach. The aim was to identify the different temporalities of variation of climate in the perspective to compare with environmental changes. The study parameters have been selected with regard to their link with marine or coastal processes. The data used are from the synoptic weather stations of Nouadhibou and Nouakchott managed by the National Meteorological Office, ONM. The study period covers the four to seven last decades according the availability of data series. This period allows one to characterize the current situation and then, discuss the future at short to medium termes when regarding the projections from the Inter-governmental Permanent expert group for Climate Change and the national results reshaped by the ONM. This multi-decadal time scale corresponds to the one giving for strategy of development.

The periodic and cyclic temporalities of variation have been revealed dominant. The air temperature is the only parameter which shows a long-term trend. The current deficit in easterly-wind appears to be the cause of the drastic increase in the vulnerability of the coast and islands to natural hazards. Such a situation has already occurred in the 1970s but the concerns about consequences have totally changed with development patterns and the advances in scientific knowledge.

The seasonal to multi-decadal time scales of the study bring new insights on the current situation. The results also clarify certain on-going changes in environment.