%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Ide, I.
%A Toure, A. A.
%A Rajot, Jean-Louis
%A Marticorena, B.
%A Adamou, S. N.
%A Pierre, C.
%A Hassane, B.
%A Garba, Z.
%T Wind erosion dynamics associated with land use on sandy soils under heavy anthropogenic pressure (Southwestern Niger)
%D 2025
%L fdi:010094274
%G ENG
%J Land Degradation and Development
%@ 1085-3278
%K aeolian flux ; land-cover ; livestock grazing ; Sahel ; wind erosivity
%K NIGER ; AFRIQUE SUBSAHARIENNE ; SAHEL
%M ISI:001516619800001
%P [14 ]
%R 10.1002/ldr.70037
%U https://www.documentation.ird.fr/hor/fdi:010094274
%> https://www.documentation.ird.fr/intranet/publi/2025-08/010094274.pdf
%V [Early access]
%W Horizon (IRD)
%X Heavy anthropic pressures and rainfall crises have led to land degradation and increased the intensity of wind erosion in arid areas. This erosion transports soil particles and associated nutrients and contributes to the degradation of cultivated and grazed land. The aim of this study is to assess the intensity of wind flux in relation to land use on the Namaro dune ridge, with sandy soils representative of south-western Niger in central Sahel. Its surface is essentially dominated by millet fields and rangelands. The methodological approach consisted in monitoring soil cover by vegetation on a rangeland and a millet field, meteorological parameters (rainfall, wind speed, and direction) and associated wind erosion flux over two annual cycles. Precise, concomitant measurements of saltation and wind speed were used to determine wind erosion threshold velocity for both land uses. Wind erosion flux was measured using sand traps (BSNE) and saltation detectors: sensit and saltiphone. The potential wind erosion flux was also determined. The two land uses show the lowest land cover at the end of the dry and the beginning of the rainy season when the winds are strongest. It appeared that the millet field is at all times more covered by vegetation than the rangeland. This difference can be explained by the high grazing pressure on the dune complex, which is maintained throughout the year. As a result, the threshold velocity, which is always lower on the rangeland, was 6.1 m s-1 compared with 7.3 m s-1 on the millet field. From July to December, as vegetation developed, threshold velocities increased, reaching 9.6 and 11.1 m s-1, respectively, on the grazing land and the field. In agreement with the vegetation cover, dust uplift potential and threshold velocities, horizontal erosion flux and saltation were at least two times greater on the rangeland than on the millet field. This is the first time in the Sahel that measurements have shown that rangelands can be more erodible than cultivated fields for the same weather conditions. For better rangeland soil management, it will be necessary to control grazing pressure with an implication of local people. It is also important to minimize grazing pressure during the rainy season. During this period, high grazing pressure will result in poor vegetation cover and soils that are more susceptible to wind erosion from the start of the dry season.
%$ 068 ; 021