干旱区生态环境知识资源中心

Seasonal dustfall was collected in the Cele Oasis at southern Tarim Basin, China, to study the oasis microclimate effect on the spatial distribution of dust deposition. The deposition rates and grain-size parameters were analyzed for each season. In spring, when there is no significant microclimate effect, the deposition rates decreased from the windward margin to the downwind margin. In summer and autumn, when there is a significant microclimate effect, the deposition rates increased slightly from the windward margin to the downwind margin of the oasis, similar with the annual dust deposition pattern. The differences in the dust deposition pattern between seasons indicate that dust deposition is greatly enhanced in the center and downwind directions of the oasis during floating dust days in summer and autumn when there is a significant oasis microclimate effect. Therefore, it can be inferred that the background wind blowing the cold-wet center away from the geometric center of the oasis may be a key factor affecting the dust deposition pattern. The natural dust deposition pattern during winter is uncertain due to deposition from anthropogenic sources. Our results suggest that the dust deposition in the Cele Oasis is affected by a mechanical obstruction effect due to rough surfaces and by an oasis microclimate effect.