A Study on Spatial-temporal Distribution Characteristics of PM2.5 Concentrations in Nanjing during 2012-2016

Abstract

Spatial-temporal distribution characteristics of PM2.5 concentrations in Nanjing is explored based on the PM2.5 data obtained by 9 automatic air quality monitoring stations in the city during 2012-2016.The results show that: 1)PM2.5 concentrations were in a downward trend in the recent 5 years, but there were still some over-standard conditions in individual years; 2) among the different types of monitoring stations, the highest PM2.5 concentrations were obtained at the traffic stations, followed by the urban stations, the control station, and the suburban stations successively; 3) from the perspective of temporal distribution, the highest PM2.5 concentrations were observed in winter, followed by spring, autumn, and summer successively; 4) monthly average PM2.5 concentrations followed a U-shaped distribution on the whole; 5) from the perspective of spatial distribution, PM2.5 concentrations in the recent 5 years had the characteristic of being higher in the north and central region and lower in the south; 6) there were significant positive correlations between PM2.5 concentrations and NO2 and SO2 concentrations, indicating that precursors have significant influence on PM2.5 concentration.