Quantification des flux d'érosion éolienne au cours d'une transition champ-jachère au Sahel (Banizoumbou, Niger)

Abstract

In the Sahel, under 500 mm of annual rainfall, wind erosion is an important factor leading to the degradation of the environment. It causes soil losses and reduces soil productivity. This work, conducted in the southwestern Niger, aims at quantifying wind erosion fluxes using BSNE sand traps. The study was conducted, from 2006 to 2014, on a plot first in cultivation, then set in fallow. It emerges that the cultivated areas are very sensitive to erosion, particularly at the beginning of the rainy season (May-July), when more than 90 % of the fluxes are recorded. Once the plot in fallow, the progressive densification of the vegetation cover caused a sharp reduction of fluxes. Compared to the results obtained during the cultivated period, they decreased by 28 % in the first year of fallowing and by 94 % in the fifth.

Keywords

• wind erosion
• Sahel
• Niger
• field
• fallow
• pluriannual monitoring