Based on FY-2 infrared images and the reanalysis data for six hours of NCEP(1°×1°),the heavy dust storm process occurred on 13 April 2007 in the middle west part of Hexi corridor is analyzed,particularly the cloud head of the descending jet was tracked and the gravitational instability,conditional symmetric instability and conditional instability are diagnosed in detail.

Based on the past research works we theoretically analyzed the formation mechanism of heavy dust storm and discussed the action of atmospheric strong advection to heavy dust storm (black wind).

In this paper the heavy sandstorms are that whose shortest visibility is less than 500 m, and the severe sandstorms less than 200 m.

This paper statistically analyzed the data of gale and duststorms from 1960 to 2004 observed at the six weather stations in Zhangye City in central Hexi Corridor during the past 45 years,then analyzed in detail the space-time distribution and forming cause of gale and duststorm weather,and has concluded their formative atmospheric circulation situation characteristics and influencing system.