北京郊区不同土地利用类型起沙起尘的特征研究

沙尘天气分沙尘暴、扬沙、浮尘三种，北京扬沙天气的沙尘源以就地起沙为主。为有效地进行北京地区的防沙治沙，在2003和2004年连续两年的春季里，对北京郊区不同土地利用类型进行了起沙起尘的实地观测，同时对各土地类型进行了土壤采样，分析了土壤的粒度特征。得到的初步结论为：京郊地区裸露地表的起沙风速为6m／s左右，不同土地利用类型起沙起尘特性有很大不同，在同等风速条件下，可起沙性从大到小分别为翻耕地、留茬地、经济林地、荒地、防护林地和草地。不同土地利用类型起沙特性不同表明，调整土地利用结构是北京防沙治沙的重要途径。

Study on the Characteristics of Blown Sand-dust on the Surface of Different Land Use Type in Beijing Outskirts

Sand-dust weather can be divided into dust storm, sand blowing and dust haze. The sources of sanddust during sand blowing weather mainly come from Beijing outskirts. For effectively combating sand blowing in Beijing region, we have finished a series of field observations of sand blowing on different utilizing land types in Beijing outskirts during the spring of 2003 and 2004. At the same time, soil samples of each type of land were collected, and the samples were analyzed in the lab later. The primary conclusion is that wind velocity to blow sand on bare land surface in Beijing outskirts is about 6m/s, and the characteristics of sand blowing are quite different to each land using type. Under the condition of the same wind velocity, sand blowing intensity of each type of land in the order of degree is ploughed land, land with crop residue, orchard land, unused land, forest land and grassland. Different land use types have different sand blowing properties, which indicates that adjusting land use structure is an important method to control sand blowing in Beijing.