Pollutant concentrations predicted by a steady state Gaussian plume model

Abstract

This article describes a computer program that estimates air pollutant concentrations in the vicinity of an elevated point source. The program is intended to be used in screening applications, i.e. applications where it is necessary to make a rapid analysis of a number of scenarios in order to identify situations where there may be cause for concern. The program uses a steady state Gaussian plume model and is based, with a number of exceptions, on Turner’s workbook. It is capable of calculating concentrations in cases of straightforward advection-diffusion, i.e. with a very high mixing layer, as well as in cases of fumigation or multiple reflections. The atmospheric stability classification is done with a scheme which applies to Highveld conditions. Both plume rise and plume spread are calculated using formulas established by Briggs. The effect of topography on the plume trajectory is taken into account in a rudimentary manner.