文摘
The regional characteristics of dust storm events including dust storm, blowing dust and floating dust in China have been studied by using the data from 701 meteorological observation stations during 1954–2000. The results are as follows: in China, there are two main areas (the South Xinjiang Region and the Hexi Region) where dust storm events happen the most frequently. The spatial distributions of the three types of dust storm events are different. Dust storms mainly occur in the arid and semiarid areas in Northern China. Blowing dust and floating dust not only occur in those areas, but also in neighboring areas. Compared with dust storm and blowing dust, the floating dust very seldom occurs in high-latitude areas. The frequencies of dust storm events decreased generally during 1954–2000. However, they have gradually increased since 1998. The interannual variations of dust storm events showed some characters including two cycles of 3–4 and 11–12 years. The annual changes of the dust storm events were characterized by a strong unimodal distribution with spring maximum. The daily variation of the dust storm occurrence was remarkable, most of dust storms happened in the afternoon, especially between 18:01–21:00LST. The areas of dust storms could be divided into seven sub-regions. The most frequent areas of dust storms and floating dust were in the South Xinjiang Region, but that of blowing dust was in the Hexi Region. Their maximum interannual variance also happened in both areas. Dust storm events generally occurred most frequently in April in most parts of China, but it happened a little earlier in the Qinghai-Xizang Region and a little later in the Xinjiang Region. The months in which dust storm events occurred more frequently were relatively concentrated in the Northeastern Region and Hetao Region, but were relatively dispersed in the Xinjiang Region.