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Desconnets Jean-Christophe, Taupin Jean-Denis, Lebel Thierry, Leduc Christian. (1997). Hydrology of the HAPEX-Sahel central super-site : surface water drainage and aquifer recharge through the pool systems. In : Goutorbe J.P. (ed.), Dolman A.J. (ed.), Gash J.H.C. (ed.), Kerr Y.H. (ed.), Lebel Thierry (ed.), Prince S.D. (ed.), Stricker J.N.M. (ed.). HAPEX-Sahel. Journal of Hydrology, 188/189, p. 155-178. ISSN 0022-1694.

Titre du document
Hydrology of the HAPEX-Sahel central super-site : surface water drainage and aquifer recharge through the pool systems
Année de publication
1997
Type de document
Article
Auteurs
Desconnets Jean-Christophe, Taupin Jean-Denis, Lebel Thierry, Leduc Christian
In
Goutorbe J.P. (ed.), Dolman A.J. (ed.), Gash J.H.C. (ed.), Kerr Y.H. (ed.), Lebel Thierry (ed.), Prince S.D. (ed.), Stricker J.N.M. (ed.) HAPEX-Sahel
Source
Journal of Hydrology, 1997, 188/189, p. 155-178 ISSN 0022-1694
The hydrology of the Sahel is characterised by the degradation of the drainage network, resulting in the lack of large watersheds over which the spatial integration of the hydrological processes could be studied. The main hydrological units are small endoreic areas, measuring a few hectares to a few square kilometres and the surface runoff is collected into pools. A detailed investigation of the role of these pools in the hydrology of the HAPEX-Sahel Central Super-Site was carried out from 1991 to 1993. The first results of this investigation are presented. A typology in three classes of the endoreic systems (valley bottoms ; sinks, plateaux) is proposed. The behaviour of one representative pool in each class is analysed, showing that the partition between evaporation and deep infiltration depends on the level of filling of the pools. The bottom of the pool is clogged by clay deposits, which prevent infiltration. Above a threshold varying between 1 and 2 m most of the water stored in the pool after runoff infiltrates, contributing to the recharge of the aquifers. On a seasonal basis, deep infiltration accounts for less than 50% of the water collected by the plateau pool, and more than 80% for the valley bottom pools. Almost all the water running off to the sink pools infiltrates rapidly and deeply into the ground. The valley pools (both valley bottoms and sinks) appear to be the major contributors to the recharge of the upper aquifer. The proportion of the HAPEX-Sahel Central Super-Site water balance that is taken by the deep infiltration from the pools varies greatly depending on the temporal distribution of rainfall. Whereas similar seasonal rainfalls were recorded in 1991 and 1992, it is estimated that 5% of the water precipitated over the valley pool watershed infiltrated towards the aquifer in 1991 and 20% in 1992. This difference is explained by a very irregular time distribution of precipitation in 1992, most of the major rainfall events being observed over a short period during the intensive observation period... (D'après résumé d'auteur)
Plan de classement
Dynamique de l'eau à l'interface sol-plante-atmosphère [062MECEAU02]
Descripteurs
BILAN HYDROLOGIQUE ; ENDOREISME ; PLUVIOMETRIE ; INFILTRATION ; EVAPORATION ; NAPPE PHREATIQUE
Description Géographique
ZONE SAHELIENNE
Localisation
Fonds IRD [F B010010999]
Identifiant IRD
fdi:010010999
Contact