Impact of Urban 3D Morphology on Particulate Matter 2.5(PM_(2.5)) Concentrations:Case Study of Beijing,China

Urban particulate matter 2.5(PM_(2.5)) pollution and public health are closely related, and concerns regarding PM_(2.5) are widespread. Of the underlying factors, the urban morphology is the most manageable. Therefore, investigations of the impact of urban three-dimensional(3D) morphology on PM_(2.5) concentration have important scientific significance. In this paper, 39 PM_(2.5) monitoring sites of Beijing in China were selected with PM_(2.5) automatic monitoring data that were collected in 2013. This data set was used to analyze the impacts of the meteorological condition and public transportation on PM_(2.5) concentrations. Based on the elimination of the meteorological conditions and public transportation factors, the relationships between urban 3D morphology and PM_(2.5) concentrations are highlighted. Ten urban 3D morphology indices were established to explore the spatial-temporal correlations between the indices and PM_(2.5) concentrations and analyze the impact of urban 3D morphology on the PM_(2.5) concentrations. Results demonstrated that road length density(RLD), road area density(RAD), construction area density(CAD), construction height density(CHD), construction volume density(CVD), construction otherness(CO), and vegetation area density(VAD) have positive impacts on the PM_(2.5) concentrations, whereas water area density(WAD), water fragmentation(WF), and vegetation fragmentation(VF)(except for the 500 m buffer) have negative impacts on the PM_(2.5) concentrations. Moreover, the correlations between the morphology indices and PM_(2.5) concentrations varied with the buffer scale. The findings could lay a foundation for the high-precision spatial-temporal modelling of PM_(2.5) concentrations and the scientific planning of urban 3D spaces by authorities responsible for controlling PM_(2.5) concentrations.