In India, family Bignoniaceae is represented by 21 genera and about 25 species including the non indigenous ornamental plants. The genera of Tecomella are a monotypic genus shrub/tree of the arid zone region in India. The natural stands of Tecomella undulata are restricted to the western parts and a few to southeastern parts of Pakistan. The species has been identified as an important for envir...

Basically, sand dunes are patterns resulting from the coupling of hydrodynamic and sediment transport. Once grains move, they modify the surface topography which in turns modifies the flow. This important feedback mechanism lies at the core of continuous dune modelling. Here we present an updated review of such a model for aeolian dunes, including important modifications to improve its predicti...

A circular crater, about 4 kilometers in diameter and located at 24.2 degrees N, 26.4 degrees E, was discovered in Landsat images among the linear dunes of the Great Sand Sea, Egypt. The crater has a sharp and crenulated rim crest, a terraced wall, a discontinuous inner structure (approximately 1.6 kilometers in diameter), and a few rim blocks. Its morphological and morphometric characteristics...

The linear stability analysis of the equations governing the evolution of a flat sand bed submitted to a turbulent shear flow predicts that the wavelength λ at which the bed destabilises to form dunes should scale with the drag length Ldrag = ρs ρf d. This scaling law is tested using existing and new measurements performed in water (subaqueous ripples), in air (aeolian dunes and fresh snow dune...