关键词: 沙尘天气, 空气质量, 西安市

Abstract: Based on the data of Xi'an Meteorological Observing Stationfrom 1971 to 2003 and the data from the Environmental Monitoring Station including daily average concentration of SO₂, NO₂ and PM₁₀ from 2001 to 2003 and hourly PM₁₀ concentration in a heavy pollution case occurred on March, 2002 in Xi'an city, the temporal distribution characteristics of sand-dust events and their influence on air quality of Xi'an City were analyzed.The results are as follows: In Xi'an City, sand-dust events had a tendency of decrease in the past more than 30 years, but it increased obviously from 2000 to 2002.Most of sand-dust events mainly took place in spring especially in April, mean occurrence days in April accounted for 22.6% of all sand-dust days of a year.The influence of sand-dust events on air quality of Xi'an City is remarkable.Server sand-dust events could lead to heavy air pollution in Xi'an City.They could make the average growth rate of PM₁₀ concentration to reach 12.1% during March and April.During the case of server sand-dust storm, hourly PM₁₀ concentration could increase by 0.585 mg·m^-3, maximum PM₁₀ concentration reach 0.970 mg·m^-3.Server sand-dust storm usually cause heavy air pollution event in Xi'an City.

Key words: sand-dust event, air quality, Xi'an City