Distribution characteristics of submicron particle influenced by vegetation in residential areas using instrumented unmanned aerial vehicle measurements

The increasing knowledge in the distributions of air pollutants influenced by vegetation could facilitate reducing human exposure in residential areas. However, the distribution patterns of submicron particles (PM1) in residential areas have not been clearly recognized, particularly for vertical distribution at high altitudes, which are closely associated with the exposure level of residents living in high-rise buildings. Thus, instrumented un-manned aerial vehicles (UAVs) are used to characterize the vertical distribution of PM1 concentrations in near-road residential areas, including sites with dense, porous, and no vegetation barriers. Results show that PM1 concentrations present unimodal distributions vertically at all scenarios with vegetation barriers, and the highest concentration in the vertical direction appears near the vegetation canopy, rather than on the ground. The particle mitigation under the influence of vegetation is weak in near-road residential areas, and the concentrations behind dense vegetation and porous vegetation decrease by 10.1% and 4.9%, respectively. Moreover, computational fluid dynamics simulations verified by field measurement are conducted to investigate the effects of vegetation density and height on PM1 distribution. Effective countermeasures are proposed to support urban planning and design to alleviate air pollution in residential areas.

Automated summary

The distribution patterns of PM1 concentrations in residential areas with vegetation barriers, particularly at high altitudes, have been investigated using instrumented UAVs. The results show that the highest PM1 concentration appears near the vegetation canopy, rather than on the ground. The particle mitigation under the influence of vegetation is relatively weak, with concentration reductions of 10.1% and 4.9% behind dense and porous vegetation, respectively. Computational fluid dynamics simulations are conducted to study the effects of vegetation density and height on PM1 distribution. Effective countermeasures are proposed for urban planning and design to alleviate air pollution in residential areas.