Pollution characteristics of particulate matter and interpolation analysis of its spatial distribution in the Beijing area

The 1-hour average mass concentration of particulate matter from March to May 2013 obtained from monitoring stations was used to characterize the concentration variation of particulate matter with time scale and its regional distribution in the Beijing area. The mass concentrations of PM_2.5 and PM₁₀ were studied to find out their seasonal variation characteristics, and their spatial resolution was improved. Based on that, the possible factors and pollution sources of particulate matter were then preliminary discussed. The results show that there are a periodical variation and a significant correlation on the average mass concentration of particulate matter from March to May in the Beijing area. Interpolation results on the particulate concentration distribution by using MATLAB spatial interpolation tools have certain precision to extrapolate and reveal the regional pollution characteristics. According to analysis, the main factors affected particulate concentration in the Beijing area are cold front and snowfall in late winter, dust and wind in spring, rainfall and hot-humid weather in early summer, and so on. The particulate concentration distribution shows an overall trend of high in the south and low in the north, and the pollution sources are very likely caused by local anthropogenic sources as well as the transmission of surrounding area. The conjoint analysis on time series and spatial interpolation of particulate concentration has significance for further research of the time-space relationship of particulate matter, and it also provides a method for understanding regional pollution characteristics.