The aim of this work is to analyse barchan dunes migration patterns and their effect on urban agricultural areas in Ain Salah region southern Algeria. A supervised classification Landsat images over a 13 years period (2005, 2009, 2013 2017) was applied create land cover maps which were used for spatiotemporal monitoring by dune feature changes. results show that sand covered area has increased ...

The spatio-temporal evolution of a downsized model for a desert dune is observed experimentally in a narrow water flow channel. A particle tracking method reveals that the migration speed of the model dune is one order of magnitude smaller than that of individual grains. In particular, the erosion rate consists of comparable contributions from creeping (low-energy) and saltating (high-energy) p...

We apply a model for sand dunes to calculate formation of dunes on Mars under the present Martian atmospheric conditions. We find that different dune shapes as those imaged by Mars Global Surveyor could have been formed by the action of sand-moving winds occuring on today’s Mars. Our calculations show, however, that Martian dunes could be only formed due to the higher efficiency of Martian wind...

Abstract The current study deals with textural, mineralogical, and geochemical characteristics of the barchan dune sands Abu Muharak belts in Kharga Depression. is longest belt Western Desert Egypt. Sand samples from 37 sites were texturally, petrologically, chemically analyzed. Our goals to interpret provenance terms grain size, petrology, geochemistry correlate these data proposed source such...

A widening variety of applications is diversifying geomorphometry (digital terrain modelling), the quantitative study of topography. An amalgam of earth science, mathematics, engineering and computer science, the discipline has been revolutionized by the computer manipulation of gridded terrain heights, or digital elevation models (DEMs). Its rapid expansion continues. This article reviews the ...

In this study, we extend the mechanistic equilibrium saltation model of Ashida and Michiue (1972) for nearly horizontal sand beds to the case of spatial nonequilibrium sand transport, which allows us to calculate sand transport rates over varying mildly-sloped topographies. Our model incorporates a generalized description of the reduction of the Shields stress within the saltation layer due to ...