Surface Roughness Parameter Estimated with a Drag Technique

Abstract

The surface roughness parameter, z0, can be estimated with different techniques. These techniques are analyzing the mean wind profile, estimating the surface drag coefficient and using the universal functions according to the Monin-Obukhov similarity theory. The first two techniques mentioned have been applied over more or less homogeneous terrain. As a result, it appears that the drag method is very sensitive to shear stress measuring errors and to local changes and irregularities in terrain.