THE ROLE OF DESERT SHRUB SIZE AND SPACING ON WIND PROFILE PARAMETERS

Abstract

Wind flow above desert surfaces is modified by shrubs, which slow the wind by friction. This study examines the effect of shrub size and spacing on the shape of wind profiles measured above shrubs at sites in the Mojave and Sonoran Deserts. The profile data were reduced to determine the values of the profile parameters, which are the zero plane displacement, d, and aerodynamic roughness parameter, z0. The results show that d is above the tops of the shrubs and z0 is small, indicating that the wind is effectively skimming over the shrubs and encountering little friction from the ground surface and the shrubs. No discernible pattern in the variation of d with shrub spacing is found, though z0 decreases with shrub spacing in a manner consistent with previous studies.