Abstract
Wind-blowns and that is transportedo ver a flat sand surface is normallyc oncentratedto a layer near the surface. However, c onsiderablea mounto f wind-blowns and may cross over wind-breakst hat are several metersh igh and be transportedi nland. At present, t here is no comprehensiveth eory to describet his phenomenon. Based on simple field measurementso f the vertical distributiono f wind-blowns and transporta nd a tracer experimentd isplayingt he flow pattern around non-permeablefe nces, i t was observedt hat wind-blowns and transportedd ownwindi s entrained into the local current generated around the wind breaks. The sand is lifted high up in the air and crosses over the wind breaks. To verifyt hese observations, a wind tunnel experimento f sand crossingo ver a non-permeablef ence was carried out. The experiment provided evidence that the local current stirred the motion of blown sand near the fence and increased the amount of sand crossing over the fence.
