Barchans are dunes of high mobility which have a crescent shape and propagate under conditions of unidirectional wind. However, sand dunes only appear above a critical size, which scales with the saturation distance of the sand flux [P. Hersen, S. Douady, and B. Andreotti, Phys. Rev. Lett. 89, 264301 (2002); B. Andreotti, P. Claudin, and S. Douady, Eur. Phys. J. B 28, 321 (2002); G. Sauermann, ...

The Libya-4 desert area, located in the Great Sand Sea, is one of the most important bright desert CEOS pseudo-invariant calibration sites by its size and radiometric stability. This site is intensively used for radiometer drift monitoring, sensor intercalibration and as an absolute calibration reference based on simulated radiances traceable to the SI standard. The Libya-4 morphology is compos...

The Shinnecock Inlet on the south shore of Long Island, New York, has experienced chronical erosion at down-drift beaches which require periodic nourishment to stabilize local shoreline. potential sand borrow site is selected outside inlet with minimum impact natural bypass process inlet. Supported by US Army Corps Engineers (USACE) District, a numerical sediment transport modeling study presen...

Solutions to Monge-Kantorovich equations, expressing optimality condition in mass transportation problem with cost equal to distance, are stationary points of a critical-slope model for sand surface evolution. Using a dual variational formulation of sand model, we compute both the optimal transport density and Kantorovich potential as t → ∞ limit of evolving sand flux and sand surface, respecti...

This paper shows that the location of the shoreface bank reefs along the northeastern and eastern coasts of Brazil, in a first order approximation, seem to be controlled by the deficit of sediment in the coastal system. The sediment transport pattern defined by a numerical modeling of wave refraction diagrams, representing circa 2000 km of the northeastern and eastern coasts of Brazil, permitte...

The present study aimed to identify threshold shear stresses to cause benthic invertebrates to drift in boundary shear layers. Laboratory experiments were carried out in a small tilting flume, 10 cm wide and 3 m long with a closed recirculation system and a fixed sand bottom of uniform grain size. Benthic invertebrates from different orders (Achaeta, Gastropoda, Crustacea, Ephemeroptera, Odonat...