Wind forces and related saltation transport

摘要: The effect of several wind characteristics on sand transport was studied in three experiments north Burkina Faso, West Africa. first experiment is used to analyse the relation between speed and shear stress fluctuations across height. second study these with saltation for fourteen convective storms, registered during rainy seasons 2002 2003. sampling time two storms. third relates turbulent structures four storms transport. Wind measurements were undertaken sonic anemometers sediment measured by saltiphones. frequency either 8 or 16 Hz. frame reference rotated according a triple rotation. Horizontal showed (fairly) good correlation height because at both sensors affected same vortices. coefficients ranged from 0.42 (when distance 1.75 m) 0.92 0.25 m). instantaneous Reynolds' had weakest (correlation coefficient 0.05 m 0.56 sensors), momentum 2 above soil surface transported different eddies than those close ground. This also explains fairly horizontal components compared poor correlations saltation. An increase did not have much impact up periods about 30 s. However, this interval would be too coarse describe vertical component adequately. classification moments into structures, sweeps, ejections, inward outward interactions, that mean flux higher sweeps interactions ejections interactions. Also, occurred more often