Dispersion of traffic derived air pollutants into urban parks

Research output: Conference Papers (RGC: 31A, 31B, 32, 33)Abstractpeer-review

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Original languageEnglish
Publication statusPublished - Oct 2017


TitleCASANZ 2017
LocationBrisbane, Queensland
Period15 - 18 October 2017


Scarce land resources in dense cities means that small urban parks are important as a leisure and amenity resource for the urban population. However, streets with heavily traffic often surround these fragmented parks and increase the potential user exposure to air pollutants from vehicles. There is a sharp gradient in air pollutant concentrations away from the roadside, which leads to heterogeneous personal exposure within parks. Thus we need to understand dispersion of pollutants into parks and the rate at which concentration decays. Although previous research on the dispersion of pollutants from roads and line sources provides some guidance, these are often situations free of obstructions or under more rural conditions.

This makes such field measurements and modelling simulations somewhat different from conditions found in the urban parks in crowed cities. In particular, the length scale is much smaller and dispersion takes place over tens rather than hundreds of meters. Here we report measurements of PM2.5 and black carbon concentrations in some urban parks surrounded by streets and with radius around 50 m in Hong Kong. Concentrations decreased rapidly within a comparatively short distance from the roadside and by 15 m reached as relatively constant values across the core of the parks. We also measured the effect of surface meteorological parameters on concentration decay rate. Observations of changing concentration away from the boundaries of urban parks were also explored using an advection-diffusion equation under assumptions of short length scales and rapid changes in eddy diffusivity with distance. We use the observations and modelled predictions of concentrations to consider variations in the exposure of park occupants and the implications it might have for the design of small urban parks.

Research Area(s)

  • advection-diffusion equation, eddy diffusivity, urban environments, roadside pollution

Citation Format(s)

Dispersion of traffic derived air pollutants into urban parks. / XING, Yang; BRIMBLECOMBE, Peter.

2017. Abstract from CASANZ 2017, Australia.

Research output: Conference Papers (RGC: 31A, 31B, 32, 33)Abstractpeer-review