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 Printable version |
Evolution of the quaternary water table level in Senegal's Niayes region (1958-1994): Relationship with climate and human activities |
Science et changements planétaires / Sécheresse. Volume 21, Number 2, 97-104, avril-mai-juin 2010, Article de recherche
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 Résumé
Article gratuit
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Author(s) : Lazar AA Aguiar, Michelle Garneau, Anne-Marie Lézine, Pascal Maugis |
Summary : The main objective of this study is to examine the variability of groundwater level over the past 50 years in the Niayes region of Senegal and identify possible links with the climate and human activities. The analysis of the water table morphology from multi-temporal piezometric maps shows that the biggest piezometric depletions were recorded in the 1970's and 1980's with a gradual decline averaging almost −0.51m every ten years. At the intra-annual scale, the piezometric variations are more substantial at the end of the rainy season. The 1974 water balance analysis suggests that natural causes are the main water withdrawal factors with over 96% of water outlet among which 90% is lost through evapotranspiration. The water extracted for human activities represents no more than 4% of all water leaving the Niayes' water system. However, the evolution of the groundwater level is also controlled by human activities, mainly through hydraulic infrastructures (dams) in the northern sector of the Niayes where the water level fell by only 0.11 mm between 1984 and 1994, despite the continuing rainfall deficits of the 1980's and 1990's. |
Keywords : anthropic factor, climate, ground water, hydrogeology, rainfall, Senegal |
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