ABSTRACT
This chapter describes methods of estimating airborne pollutant concentration distributions associated with various emission sources. The most widely used dispersion model to compute pollutant concentration profiles is the Gaussian plume model for single or multiple source pollution problems. The effect of eddy motion is important in diluting concentrations of pollutants. Eddies exist in different sizes in the atmosphere, and eddies most effective in dispersing the plume are those about the size of the plume. Temperature change with altitude has great influence on the motion of air pollutants. By simple consideration of mass continuity, it is possible to keep track of the transport and accumulation of pollutants to calculate the concentration in each box. Box model techniques, which can take into account nonlinear interactions among different species arising from chemical reactions, have been used in longer-range dispersion computations. An unstable condition is favorable for pollutant dispersion.
