Evolution de l'écoulement d'un petit bassin-versant sahélien en lien avec les changements d'usage des sols

2014

Article référencé dans le Web of Science WOS:000346588200006

Amogu Okechukwu, Esteves Michel, Vandervaere J. P., Abdou M. M., Panthou G., Rajot Jean-Louis, Yero K. S., Boubkraoui Stéphane, Lapetite Jean-Marc, Dessay Nadine, Zin I., Bachir A., Moussa I. B., Maiga O. F., Gautier E., Mamadou I., Descroix Luc

Hydrological Sciences Journal = Journal des Sciences Hydrologiques, 2014, 60 (1), p. 78-95 ISSN 0262-6667

Land-use changes have been significant these last decades in West Africa, particularly in the Sahel region; in this area, climatic and demographic factors have led to a rise in cropped areas in recent decades causing strong changes in the water cycle and in river regimes. This study compares the rainfall-runoff relationships for two periods (1991-1994 and 2004-2011) in two small and similar neighbouring Sahelian catchments (approx 0.1 km(2) each). This allows identification of the different hydrological consequences of land-use/land-cover change, particularly the fallow shortening and the consequent degradation of topsoil. The main land surface change is a 75% increase in crusted soil area. Runoff increased by more than 20% on average between the two periods while flood duration decreased by 50% on average. However, runoff values remained largely constant in the lower part of the northern basin due to a strong increase in in-channel infiltration. Editor D. Koutsoyiannis; Associate editor T. Wagener

Hydrologie [062] ; Pédologie [068]

NIGER ; SAHEL

Fonds IRD [F B010063605]

fdi:010063605