Near-field geometry effects on urban street canyon measurements for model validation Online publication date: Fri, 18-Jul-2003
by Stilianos Rafailidis
International Journal of Environment and Pollution (IJEP), Vol. 14, No. 1/2/3/4/5/6, 2000
Abstract: Selection of numerical urban pollution dispersion models for regulatory purposes entails reliable prior validation against either physical modelling or field measurements. It is shown that an asymmetric geometry of the urban street canyon, in which measurement takes place, induces persistent gradients in pollution dispersion within it, irrespective of the wind vector meandering above the roofs. This influences field measurements taken there and, depending on canyon aspect ratio and roof geometry, favourable or unfavourable ventilation regions develop, on an annually-averaged basis. Therefore, inappropriate placement of the sampling probe can lead to systematic under or over-predictions of actual air quality. Proper consideration of the potential influence of the near-field on pollution dispersion guarantees that the campaign's results remain free of systematic bias and, therefore, appropriate for regulatory model testing and validation. The repercussions of these findings for urban air quality monitoring are identified and discussed.
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Environment and Pollution (IJEP):
Login with your Inderscience username and password:
Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.
If you still need assistance, please email subs@inderscience.com