Abstract
The effect of windbreak on wind erosion control was studied by model experiment in a wind tunnel. Three types of windbreak (Simple forest, Shrubs, Complex forest) and eight kinds of complex forest type windbreak were experimented as the models. Shrubs roughened the roughness of surface layer and enlarged the drag coefficient of tree trunk layer. Consequently the wind speed at the windward fringe was reduced and the recovery of wind speed in the windbreak was controlled, furthermore wind speed reduced much exponentially in the windbreak. As a result, it clarified that the complex forest type windbreak was a highly effective windbreak rather than simple forest and shrub type windbreak. Type4 windbreak showed the best effect on the reduction of wind speed to the point of 5H at leeward side, although the wind speed showed a tendency of quick recovery at the back of windbreak in this type. Type1 windbreak seemed to be beteer as a windbreak because of the uniformity of accumulation of drifting sand although Type8 windbreak was the best from the point of catchable effect of drifting sand. We conclude through the experiment that Type1 windbreak arranged trees and shrubs on alternate rows could be selected as the most desirable windbreak for erosion control in the desert area.
