Sensitivity of plume descriptors of a Gaussian plume model to deposition and source elevation

Plume descriptors, constituting the first four moments of the concentration distribution, have been obtained for a Gaussian deposition plume model. An alytical expressions for the plume descriptors (centroid, variance, skewnes s and kurtosis) for point source ground-level and elevated releases are der ived from a solution to the advection-diffusion equation accounting for dep osition at the ground surface. A sensitivity analysis has been carried out to investigate the effect of deposition velocity and source height on the p lume descriptors. For the particular case of a fully reflected Gaussian plu me from a ground-level source, the centroid and the standard deviation have been found to vary as square root of downwind distance whereas skewness an d kurtosis are independent of downwind distance, the approximate values bei ng 0.995 for skewness and 3.87 for kurtosis.