%0 Conference Proceedings
%9 ACTI : Communications avec actes dans un congrès international
%A Leduc, Christian
%A Favreau, G.
%A Marlin, C.
%A Dray, M.
%T Comparison of recharge estimates for the two largest aquifers in Niger, based on hydrodynamic and isotopic data
%S Tracers and modelling in hydrogeology
%C Wallingford
%D 2000
%L fdi:010022486
%G ENG
%I AIHS
%K AQUIFERE ; NAPPE PHREATIQUE ; HYDRODYNAMIQUE ; ECOULEMENT ; INFILTRATION ; ANALYSE ISOTOPIQUE ; FACTEUR ANTHROPIQUE ; DENSITE DE POPULATION ; UTILISATION DU SOL ; EAU SOUTERRAINE ; PRECIPITATION ; VARIATION SAISONNIERE ; VARIATION ANNUELLE ; BASSIN SEDIMENTAIRE ; LAC ; MODELISATION ; ETUDE COMPARATIVE
%K ZONE ARIDE ; ZONE SEMIARIDE ; NIGER ; TCHAD LAC
%K NIAMEY REGION ; IULLEMMEDEN BASSIN VERSANT
%N 262
%P 391-399
%U https://www.documentation.ird.fr/hor/fdi:010022486
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_7/b_fdi_55-56/010022486.pdf
%W Horizon (IRD)
%X The hydrodynamic and isotopic characteristics of the two largest phreatic aquifers in Niger have been studied. Even though the climate, geomorphology and vegetation seem similar, these aquifers differ. In the Iullemmeden basin, a seasonal fluctuation of the water table during the rainy season is combined with a significant long-term rise due to a change in land use ; isotopes (18O, 2H, 3H, 14C) show a median renewal rate of between 0.1% and 0.2%. In the Lake Chad basin, seasonal fluctuation is much rarer and the long-term trend is of stability or even a small decline of the water table due to the drying up of the Lake Chad ; isotopes indicate a median renewal rate of between 0.1% and 0.06%. In both cases, the large difference between the extreme values underlines the great variation in time and space of the recharge. (Résumé d'auteur)
%B TraM'2000 conference
%8 2000/05
%$ 062EVAEAU02