Chinese Study Of The Basic Characteristics Of Dust Storms In The Past 30 Years

With the data published on Surface Meteorological Monthly Bulletin and Surface Chart during 1971 - 1999, the temporal-spatial distribution of floating-dust, blowing-sand and sandstorms(FBS) are analyzed on the basis of the atmospheric process case study. Furthermore, their tracks, source lands, incidences and weather types are determined in assistance with GIS. The results show: In rencent 30 years,the number of FBS's days is decreased in the most northern parts of the country. FBS occurred frequently in spring and early summer, especially in April.The gales have great influence on the sandstorms. According to their source lands, the sandstorms were classified into two types, i.e. the inner-source and extra-source. The source lands of inner-source sandstorms are mainly in the Taklimakan Desert and its surrounding areas in southern Xinjiang,southern part of the Junggar Basin in northern Xinjiang,Hexi Corridor in the west of Gansu Province.the dry deserts of Inner Mongolia and the Qaidam Basin in Qinghai. For the extra-source sandstorms, they always intrude China across the north and west tracks.The sandstorms are classfied into 5 weather types. There is a close tie between the sandstorms and the surface meteorological factors.