Abstract: For understanding the changes of atmospheric pollutants during the dust weather in Lanzhou, The hourly monitoring data of the national atmospheric environment monitoring network system from 2016 to 2017 were selected to analyze the interannual variation trend of particulate matter. Combination with the ground meteorological parameters, using Hysplit model calculation, analysis the process of particulate matter sources and transmission, potential source area. The results show that the dust weather is mainly affected by three types of air masses, namely, The northwest, East by north short range transmission and Northern Inner Mongolia masses. Among them, the northwest air mass has a long duration, the highest extinction coefficient and significant deterioration of ambient air quality. The other two types of air masses affect the dust weather for a short duration, which facilitates the diffusion of pollution Before the occurrence of dust weather, PM₁₀ is positively correlated with gaseous pollutants; during the process of dust weather, PM₁₀ is negatively correlated; after sand dust weather, PM₁₀ becomes positively correlated again. In spring, the potential distribution of particulate matter is relatively concentrated, mainly from the Hexi corridor in the northwest of Lanzhou, and the PSCF value is greater than 0.7. In the winter, the potential source areas are widely distributed, and the PSCF value is mainly concentrated in the range of 0.7-0.9. The large contribution area to PM₁₀ is concentrated in the southeast of Xinjiang, and the contribution value is 240-320 μg·m^-3.

Key words: dust weather, backward trajectory, Lidar observation, potential source area