We investigate flow separation in the air flow over transverse sand dunes. CFD simulations of the air flow over differently shaped dunes are performed. The length of the recirculation region after the brink of the dune is found to depend strongly on the shape of the dune. We find that the nondimensionalised separation length depends linearly on the slope of the dune at the brink within a large ...

The Conservation Estate, administered by the Department of Conservation (DOC), contains areas of land of undetermined conservation value. These include coastal lands, obtained and managed by the Government of the day for other than conservation purposes. One such purpose was to stabilise coastal sand dunes where drifting sands presented a hazard to adjacent railway lines or roads. The Sand Drif...

Running performance depends on a mechanical interaction between the feet of an animal and the substrate. This interaction may differ between two species of sand lizard from the Mojave Desert that have different locomotor morphologies and habitat distributions. Uma scorparia possesses toe fringes and inhabits dunes, whereas the closely related Callisaurus draconoides lacks fringes and is found o...

Despite being a harsh environment, sand dunes are rich in invertebrates, with about 30% (188 species) of the British spider fauna represented (Duffey, 1968), and 53 species being strongly associated with coasts (Ratcliffe, 1977). Arachnologists have examined spider communities in relation to the seral succession of plant communities on sand dunes (e.g. Lowrie, 1948; Barnes, 1953; Perttula, 1984...

Most studies of active aeolian processes on Mars have focused on dust [1], i.e., particles -1 [tm in diameter that are transported in suspension by wind. The presence of sand dunes on Mars [2-8] indicates that larger grains ( >60 _tm, transported primarily in saltation) are also present. Although indirect evidence suggests that some dunes may be active [9], definitive evidence is lacking. Nonet...

Wind erosion is considered a major global environmental problem. Dust storms from the migration of sand dunes can seriously damage civil, industrial, and agricultural areas and a method to stabilize these sand dunes is mulching. The present study investigates the feasibility of using organic wastes of Press mud and Dunder with clay for the production of environmentally-friendly mulches. Sandy s...

Insect prey of the Namib golden mole congregate beneath clumps of grass scattered among the sand dunes of the Namib Desert. In the presence of the light winds that typically blow over the Namib Desert, these grass clumps emit low-amplitude vibrations that are transmitted through the sand. While foraging in the sand-swimming mode (a few centimeters below the surface of the sand), some moles appa...