Air pollution modelling for the greater Cape Town region

Includes bibliography.Limited research on dispersion modelling for the Cape Town metropolitan area has been undertaken. This thesis deals with air-pollution aspects in relation to dispersion modelling, as well as with the input requirements and application of a dispersion model in the Greater Cape Town region. An EPA approved Gaussian plume model, the Industrial Source Complex Short Term 2 (ISCST2), was chosen for the pollution simulation. The model requires one point meteorological measurements and can accommodate multiple point, line and area sources. Meteorological data used in the study were collected from D. F. Malan airport for the years 1991 and 1992. However, required parameters, such as the mixing height and the atmospheric stability class, are not readily available and thus needed to be calculated. Three methods for determining the mixing heights and three methods for determining atmospheric stability class were used in the model and the accuracy for each combination was assessed. Appropriate emission information for use with dispersion modelling is not available for the Greater Cape Town area. Therefore, the compilation of an emission inventory formed a considerable part of this study. Emission data from the large industries was collected with the collaboration of the Cape Town City Council's Air Pollution Control and of the Air Pollution Group of the Western Cape Regional Services Council. The rest of the sources (i.e. residential, vehicular and industrial), were grouped into areas, and their emissions were based on their fuel consumption