被动采样监测重庆主城SO_2和NO_x的空间分布特征

Characterizing Spatial Patterns of SO_2 and NO_x in Chongqing Urban Area by Passive Sampling

利用被动采样技术在重庆市主城区117个网格内连续测量SO2和NOx的浓度,测量周期为1 a。采用聚类分析获取SO2和NOx的空间分布特征。结果表明:SO2和NOx平均浓度为51.81μg/m3和34.93μg/m3;通过SO2和NOx被动采样数据与自动监测数据的相关性分析,发现二者的相关系数r2分别为0.838和0.860;在垂直高度上的浓度分布情况上,SO2分布层出现了一个中间污染层,NOx的分布随着高度递增,浓度减小;在水平方向的浓度分布情况上,SO2主要集中在重庆主城区的正南方和东北方向,主要是受工业源的影响;NOx主要集中在重庆市主城区的正南方,主要受工业源和交通源的影响。

Concentrations of SO2 and NOx were measured by passive sampling within 117 grids in Chongqing urban area for one year. Spatial distributions of SO2 and NOx were obtained by clustering analysis. Results showed that the mean concentrations of SO2 and NOx were 51.81 μg/ms and 34.93 μg/m3 respectively; passive sampling data and automatic monitoring data of SO2 and NO~ was used for correlation analysis, and it was found that the correlation coefficient, r2, of both were 0.838 and 0.860 respectively. In the vertical direction, there was a middle layer for SO2, but the concentration of NOx decreased with altitude increasing. In the horizontal direction, the concentration of SO2 showed the highest levels in the south and the northeast of Chongqing urban area due to the industrial source, the concentration of NOx showed the highest levels in the south due to the industrial source and traffic source.