WIND REDUCTION DOWNWIND FROM A SAVANNA WOODLAND EDGE

Traditionally known wind protection of a sparse tree canopy has been q uantified by experiments in a savanna woodland edge. On the basis of t he data a simple model is formulated for average wind reduction within such canopies. At a grid of points wind speeds were determined at two heights along lines perpendicular to the wind. Average wind speeds fo r these lines reduce approximately linearly into the woodland, paralle l to the wind flow, until they become almost constant (saturation redu ction). Airflow around single trees was studied for more understanding of these results. Preservation or regeneration of trees, in arrays su itable for the intended farming system, should be encouraged for wind protection in planning and developing crop land.