The application of a land-use regression model to investigate the effect of urban greenbelts on ambient PM10 and PM2.5 mitigation during seasons of light and heavy pollution

Abstract

Greenbelts located close to traffic pollution sources can significantly attenuate air pollution by intercepting and assimilating the pollutants on a lasting basis. However, the impact of greenbelts can be affected by neighbouring land use. This paper investigated the effects of urban greenbelts on the mitigation of ambient PM₁₀ and PM_2.5 in Wuhan, China using a land-use regression (LUR) approach. Traffic-related pollution emissions had a crucial impact on PM₁₀ and PM_2.5 levels. The effect of greenbelts on PM₁₀ and PM_2.5 mitigation can be decreased by adjacent traffic pollution sources, but enhanced by increasing the width of the greenbelt. In addition, meteorological factors had a variable impact on PM levels during the seasons of light and heavy pollution. According to the LUR model, the combined effects of the greenbelt, traffic PM sources and meteorological factors were characterized by the threshold impact of greenbelt width on PM mitigation, with a width of 40 m having a significant and positive effect on PM levels. In addition, these effects varied with thresholds in different pollution conditions, and were less evident in the heavily polluted season. The combined effect of urban greenbelt on PM reduction should be explored in real-life conditions, which will have important practical significance for urban planning and construction.