Mean Wind Profiles and Change of Terrain Roughness

Information is presented on the wind structure in established flow over terrains with various roughness characteristics (open water, open terrain, suburban terrain, towns, centers of large cities). Based on recent results of theoretical and experimental meteorological studies a simple procedure is then proposed, enabling the designer to assess the effect upon the mean wind profile of a roughness change upwind of the structure under consideration. The procedure, which is approximate but adequate for structural engineering purposes, is then illustrated in a numerical example.