Impact of land-cover layout on particulate matter 2.5 in urban areas of China

Urbanization in China is closely connected with ambient particulate matter 2.5 (PM2.5). However, the potential for altering PM2.5 through the urban landscape characteristics is uncertain. In this study, we analyzed the urban PM2.5 pollution situation for 2014–2016 and investigated the impact of landscape factors on urban PM2.5 in China at the city level. All the prefecture-level cities were stratified by urban population size into small (medium (500,000–1,000,000), and large (>1,000,000), and the other second-level administrative cities were assigned as ‘other’ cities. The multivariate regression model including both urban landscape factors and social-economic variables explained 70.0%, 32.8%, 19.2%, and 12.4% of the arithmetic mean PM2.5 concentration (AMC-PM2.5) for the other, small, medium, and large cities, respectively. With regard to the configuration of land cover, agricultural activity is a major contributor of PM2.5 pollution, for which the explanatory power ranged from 7.6% (for the large cities) to 64% (for the other cities). In addition, grassland aggregation also has a limited but negative effect on urban PM2.5 pollution, despite the negligible effect on dry deposition. Overall, these findings likely reflect the interaction between urban air quality and urbanization, and will have implications for air quality control strategies.