Geographical Characteristics of PM2.5, PM10 and O3 Concentrations Measured at the Air Quality Monitoring Systems in the Seoul Metropolitan Area

In this study, we investigated the relationships between the air quality (PM2.5, PM10, O-3) concentrations and local geographical characteristics (terrain heights, building area ratios, population density in 9 km x 9 km gridded subareas) in the Seoul metropolitan area. To analyze the terrain heights and building area ratios, we used the geographic information system data provided by the NGII (National Geographic Information Institute). Also, we used the administrative districts and population provided by KOSIS (Korean Statistical Information Service) to estimate population densities. We analyzed the PM2.5, PM10, and O-3 concentrations measured at the 146 AQMSs (air quality monitoring system) within the Seoul metropolitan area. The analysis period is from January 2010 to December 2020, and the monthly concentrations were calculated by averaging the hourly concentrations. The terrain is high in the northern and eastern parts of Gyconggi-do and low near the west coastline. The distributions of building area ratios and population densities were similar to each other. During the analysis period, the monthly PM2.5 and PM10 concentrations at 146 AQMSs were high from January to March. The O-3 concentrations were high from April to June. The population densities were negatively correlated with PM2.5, PM10, and O-3 concentrations (weakly with PM2.5 and PM10 but strongly with O-3). On the other hand, the AQMS heights showed no significant correlation with the pollutant concentrations, implying that further studies on the relationship between terrain heights and pollutant concentrations should be accompanied.