城市大气中SO2、TSP、NO2的时空变化特性

以长沙市2001年大气监测数据为基础，对长沙市区大气污染现状及SO2，NO2和TSP分别与大气降水酸度之间的关系和三者的时空变化特征进行了研究．结果表明：长沙市区的大气污染现状达到警戒水平．SO2与降水酸度线性模型的回归系数为-0．5448，表明降水pH值随SO2浓度的增加而降低。TSP与降水酸度的回归模型呈二次分布，对降水pH值的作用决定于组成TSP的颗粒物粒径，而NO2对降水pH值的作用不大．长沙市区大气污染以春冬两季最为严重．SO2，NO2和TSP浓度分布以火车站最高，其次是伍家岭；作为清洁对照点的马坡岭站点的大气环境质量达到国家环境质量二级标准，NO2浓度则达到国家环境质量一级标准．

Spatial and Seasonal Variation of SO_2, NO_2 and TSP in Urban Atmosphere

The present status of Changsha urban atmosphere and the relationships between pH value of rainfall and SO_2, NO_2, TSP concentration were studied, and the temporal and seasonal characteristics of the three pollutants were analyzed based on the atmospheric monitoring data in Changsha urban in 2001. It is indicated that the present atmospheric status of Changsha reached the alerting level. The regression coefficient of the model of SO_2 and pH value, which was -0.5448, proved that pH value decreased along with the increase of SO_2 concentration but the coefficient of NO_2 and pH value was low. The function between TSP and pH value of rainfall belonged to the size of the major particles. The severest pollution seasons were spring and winter in 2001. The strongest concentration of SO_2, NO_2 and TSP in Changsha city occurred in the train-station and followed by was Wujialing station. Mapoling as the clean-comparison station where atmospheric quality reached the second_grade standard of the Ambient Air Quality Standard and NO_2 arrived the first_grade standard.