A model of Barchan dunes including lateral shear stress
Institute for Computer Applications 1, University of Stuttgart, Pfaffenwaldring 27, 70569, Stuttgart, Germany
2 Departamento de Física, Universidade Federal do Ceará, 60455-970, Fortaleza, Brazil
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Published online: 31 January 2005
Barchan dunes are found where sand availability is low and wind direction quite constant. The two dimensional shear stress of the wind field and the sand movement by saltation and avalanches over a barchan dune are simulated. The model with one dimensional shear stress is extended including surface diffusion and lateral shear stress. The resulting final shape is compared to the results of the model with a one dimensional shear stress and confirmed by comparison to measurements. We found agreement and improvements with respect to the model with one dimensional shear stress. Additionally, a characteristic edge at the center of the windward side is discovered which is also observed for big barchans. Diffusion effects reduce this effect for small dunes.
© EDP Sciences/Società Italiana di Fisica/Springer-Verlag, 2005