According to the data of ground - based observation from 1951 to 2008 at Dunhuang national standard climate station, the spatio - temporal change of sand - dustweather in Dunhuang area was analyzed. The result reveals that the sand - dust weather obviously decreased. It occurred most frequently in the 1950 s, and in a year, it occurred most in sp ring and least in autumn. The annual wind days decrease and wind speed becoming smallwere the main reasons for sand - dustweather reduction in Dunhuang area. Meanwhile, the circulation causing sand - dustweather there was classifyed in the paper. Amp le resources of sand - dust and regional effects p rovide essentialmaterial conditions for sand - dustweather occurrence.

Based on the basic observationaldata and automaticweather station data, a regionalheavy dust storm occurred onApril29,2009 inHexiCorridorwas analyzed from the causes of the synopticmeteorology, physics quantity fields and so on.The results show that itwas a duststorm thatcaused by the gale behind the cold front, and ithappened in the zone ofstrong pressure gradient. Groundmeteorological elements had a strong response to the outbreak of the dust storm, which can be used as a reference for forecast of dust storms. Therewas an obvious upwardmotion in the outbreak area ofduststorm with the lower level convergence and the high-leveldivergence. The frontogenesis function and helicity indicated the area of dust storm verywel.l