Aeolian sediment transport through large patches of roughness in the atmospheric inertial sublayer

Abstract

Roughness influences the flux of wind‐driven sand transport. In this paper, we report on sediment transport measurements for four different surface roughness configurations composed of the same size (solid) roughness elements in the atmospheric inertial sublayer. Results of these tests indicate that sediment transport rates through patches of roughness in the atmospheric inertial sublayer are to a large extent controlled and scale proportionally with the roughness density (λ = n b h / S , where n is number of elements of breadth b and height h in area S ) of the surface. However, element size apparently increases the magnitude of the reduction beyond that attributable to λ. A sediment transport model that incorporates the effect of shear stress partitioning appears to predict reasonably well the effect of roughness on sand transport in the cases where the roughness elements are ≤0.10 m in height. However, when the dimensions of the roughness itself are equivalent to or are greater than the range of saltation lengths (vertical and horizontal), additional interactions of the elements with the saltation cloud appear to reduce the transport efficiency.