A MODIFIED GAUSSIAN PLUME DISPERSION MODEL SUITABLE FOR THE CLIMATE OF SAUDI ARABIA.

摘要

This dissertation is aimed at developing special methods of classifying stability and estimating standard deviations of plume concentration in the horizontal and vertical direction, (sigma)(,y) and (sigma)(,z), respectively, so that Gaussian modeling techniques can be adapted specifically to the conditions found in Saudi Arabia. A data base consisting of 50 SF(,6) tracer dispersion experiments conducted in the eastern province of Saudi Arabia during the period from January 27, 1979 to May 7, 1980, was available for this purpose. The terrain was an arid, flat, desert area. Observed SF(,6) concentrations were compared initially with those calculated using the standard Gaussian plume dispersion model. Several methods and the available results from the tracer data base have been used to specify stability and to obtain a modified set of dispersion coefficient values for use in standard Gaussian plume dispersion models that are especially suitable for the climate of Saudi Arabia. For neutral conditions of turbulence, it was found that the (sigma)(,y) and (sigma)(,z) relationships were similar to those of Pasquill and Gifford, as might be expected. However, for both stable and unstable conditions, where the conditions found in Saudi Arabia are much more extreme than usually occurs in the United States or Britain, the expression derived for the (sigma)(,y) and (sigma)(,z) dispersion coefficients were different from those typically available from other experimental programs in other climatic regimes. The results of the present research should be generally applicable to dispersion modeling programs in other hot, desert environments.