Regional roughness of the landes forest and surface shear stress under neutral conditions

✍ Scribed by Marc B. Parlange; Wilfried Brutsaert

• Publisher: Springer
• Year: 1989
• Tongue: English
• Weight: 696 KB
• Volume: 48
• Category: Article
• ISSN: 0006-8314
• DOI: 10.1007/bf00121783

✦ Synopsis

Mean wind velocity profiles were measured by means of radio-windsondes over the Landes region in southwestern France, which consists primarily of pine forests with scattered villages and clearings with various crops. Analysis of neutral profiles indicated the existence of a logarithmic layer between approximately .z -4 = 67(*18)z, and 128(*32)z, (z is the height above the ground, z0 the surface roughness and do the displacement height). The upper limit can also be given as zdo = 0.33 (kO.l8)h, where h is the height of the bottom of the inversion. The profiles showed that the surface roughness of this terrain is around 1.2 m and the displacement height 6.0 m. Shear stresses derived from the profiles were in good agreement with those obtained just above the forest canopy at a nearby location with the eddy correlation method by a team from the Institute of Hydrology (Wallingford, England).