Simulation of Windbreaks for Wind-Erosion Control in a Wind Tunnel

Wind barriers can control wind erosion by reducing the travel distance of wind across a field. The wind speed can be reduced by more than 50% at a leeward distance of 20 times barrier height H (Skidmore, 1986). The efficiency of a windbreak can be evaluated in terms of the ratio between the mean wind speed of the air current as obstructed by a wind barrier and the mean wind speed of the undisturbed air at a given height and distance windward or leeward from the windbreak. The objectives of this wind-tunnel study were the simulation and scaling of vegetative windbreaks (stem + canopy) and to evaluate their efficiency in reducing wind speed. Five single-row windbreaks, each with a different stem porosity and canopy porosity were tested. Also windbreaks consisting of different elements (2 and 3 rows) were scaled. Possible zones of deflation and deposition were determined from wind-speed measurements and compared with experimental wind-tunnel data of sand transport.