乌兰布和沙漠不同土地覆被类型粒度特征及空间分异

对中国沙尘暴源区之一的乌兰布和沙漠进行系统采样，分析不同土地覆被类型的地表沉积物粒度特征及其空间分异规律。结果表明：乌兰布和沙漠地表沉积物以中沙和细沙为主，平均粒径为2.84 φ。沙漠地表沉积物的粒度特征在不同土地覆被类型和不同空间存在明显的分异规律，表明该沙漠的地表沉积物粒度分布是由物源、地形和搬运营力共同作用的结果。乌兰布和沙漠内部最可能成为沙尘暴尘源的有沙漠中部的盐碱地、东北部的耕地和广泛存在于沙漠中的沙丘。根据不同区域的土地覆被类型因地制宜地选取先锋植物种群改善区域地表覆盖状况和地表沉积物粒度组分，是该区域尘源治理的主要手段。

The Spatial Variation and Grain Size Character of Different Land Cover Types in the Ulanbuh Desert

The paper is based on the systematic sampling of the Ulanbuh Desert, one of the source areas of dust storm in China, and the grain size characteristics and spatial variation of surface sediments between different land cover types in the desert are analyzed. It is concluded that most of the grain size of surface sediments in the desert are medium and fine sand, and the average particle size is 2.84 φ. According to different land cover types and different spatial distribution laws, the grain size distribution of the surface sediments in the desert was the result of the interaction of the sediment source, the terrain and the carrying capacity. The saline alkali land in the middle of the desert, the farming land in the northeast and the sandy land in the desert should be the sources of the sand dust. Therefore, according to the different land cover types in the Ulanbuh Desert, to set up suitable models of initial plant population structure is the main method to control desertification.