SENSITIVITY OF GAUSSIAN PLUME MODEL TO DISPERSION SPECIFICATIONS

Variations in computed ground-level pollutant concentrations resulting from different sigma schemes in a Gaussian plume model have been inve stigated. Deviations from a standard calculation may be as large as or ders of magnitude and are mostly associated with Pasquill-Gifford-Turn er classes pertaining to active diffusion (classes A through D) in the rural case and to poor diffusion (classes E and F) in the urban one. The implications of these results as regards impact assessment studies are briefly discussed.