Relationship between shelterbelt structure and mean wind reduction

Optical porosity is the important structural feature of two-dimensional (2-D) artificial fences and narrow shelterbelts, but not for 3-D, or wide shelterbelts. To determine the important features of wide shelterbelts, we measured the mean wind speed around eight natural shelterbelts of various widths Wand total area densities Ad. Our results show that the product of Wand Ad, but not Wor Ad alone, is useful for predicting the wind sheltering around fully 3-D shelterbelts. There was a strong negative correlation (p < 0.01) between W x Ad and the minimum relative wind speed. Also, the shelter distance generally increased with increasing W x Ad. (c) 2007 Elsevier B.V. All rights reserved.