Barchan dune mobility in Mauritania related to dune and interdune sand fluxes - Université de Rennes Accéder directement au contenu
Article Dans Une Revue Journal of Geophysical Research Année : 2007

Barchan dune mobility in Mauritania related to dune and interdune sand fluxes

Résumé

[1] We present a 1 year study of 50 dunes in a small field of barchan dunes in Mauritania. We documented the morphological evolution of the dunes and their migration rates and measured at 10 min intervals the interdune sand transport, the wind strength, and its direction for the same interval of time. The dune heights H0 range between 2 and 5 m, and their celerity c is found to be well approximated by the standard migration law: c = Q0/H0, with Q0 ≈ 50 m3/m yr. From both the interdune sand flux and the migration rate of the dunes we were able to estimate the spatially averaged sand flux at the dune crest as well as the bulk sand flux associated with the mass of sand transported by the dune. We found that the sand flux at the crest was about 3 times greater than the interdune mass transport rate, whereas the bulk sand flux was surprisingly of the same order as the interdune flux. Moreover, we analyzed carefully the interdune sand transport data, which can be well described by the Sorensen law. The cumulative mass of sand transported during moderate wind events within 1 year was much greater than that transported during strong wind events.

Dates et versions

hal-00905995 , version 1 (19-11-2013)

Identifiants

Citer

Dah Ould Ahmedou, A. Ould Mahfoudh, Pierre Dupont, Ahmed Ould El Moctar, Alexandre Valance, et al.. Barchan dune mobility in Mauritania related to dune and interdune sand fluxes. Journal of Geophysical Research, 2007, 112, pp.F2. ⟨10.1029/2006JF000500⟩. ⟨hal-00905995⟩
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