Based on the meteorological data of dustweather, the dailymean temperature and p recip itation inMinqin in sp ring from 1976 to 2005, the temporal and spatial characteristics of dustweather and relations between dustweather and weather conditions, water resources as well as human activitieswere analyzed. The results show thatmost of the dustweather occurred from noon to evening and lasted for 1 to 2 hours, and it p resented decreasing trend. Dust weather has negative correlation with p recip itation in Minqin area in sp ring. Itwas also revealed that the special geographical location, the significant reduction of Shiyang River runoff and population growth and so on resulted in more dustweather in sp ring.

By using the data of 20 meteorological stations from 1971 to 2004，the region distribution and its climatecharacteristic of heavy fog along the first - class highway in Gansu province were analyzed. The results show that heavy fog occurring along the highway presents not only obvious regional difference，but marked yearly，seasonal，day and night，and local changing characteristics. So the different forecast service periods for heavy fog in different sections of the highway are put forward，so as to provide the basis for heavy fog forecast along the first - class highway in Gansu province