Simulations of binary collisions of barchan dunes : the collision dynamics and its influence on the dune size distribution

Large dune fields can overrun for instance infrastructures lying in the way of their motion. Unidirectional wind fields and low sand availability give rise to single barchan dunes moving in the direction of wind. They can interact by directly exchanging their sand through collisions. This kind of interaction plays a crucial role in the evolution of barchan dune fields, for instance on the selection of a characteristic dune size. Simulations of dune collisions with lateral offset are studied systematically and described by general phenomenological rules. Moreover, simulations with a simplified model without sand flux considering only collisions show that the sizes of sand dunes in such a scenario follow a Gaussian distribution with a well defined characteristic size.

[1]  H. Herrmann,et al.  A continuous model for sand dunes and its application to barchan dunes , 2008 .

[2]  Bruno Andreotti,et al.  Barchan dune corridors: Field characterization and investigation of control parameters , 2006, cond-mat/0609120.

[3]  S. Douady,et al.  Collision of barchan dunes as a mechanism of size regulation , 2005 .

[4]  P. Claudin,et al.  Field evidence for surface-wave-induced instability of sand dunes , 2005, Nature.

[5]  H. Herrmann,et al.  Breeding and solitary wave behavior of dunes. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[6]  N. Endo,et al.  Collision Dynamics of Two Barchan Dunes Simulated Using a Simple Model , 2004, cond-mat/0403312.

[7]  H. Herrmann,et al.  A model of Barchan dunes including lateral shear stress , 2003, The European physical journal. E, Soft matter.

[8]  N. Endo,et al.  Observation of the whole process of interaction between barchans by flume experiments , 2004 .

[9]  K. H. Andersen,et al.  Corridors of barchan dunes: Stability and size selection. , 2003, Physical review. E, Statistical, nonlinear, and soft matter physics.

[10]  H. Herrmann,et al.  Minimal model for sand dunes. , 2001, Physical review letters.

[11]  H. Herrmann,et al.  Continuum saltation model for sand dunes. , 2001, Physical review. E, Statistical, nonlinear, and soft matter physics.

[12]  Hans J. Herrmann,et al.  The shape of the barchan dunes of Southern Morocco , 2000 .