ABSTRACT
The primary inputs to a dispersion model consist of emission information and meteorological data. The emission information consists of the coordinates for the location of the source, the physical stack height, the inside stack top diameter, the stack exit velocity, and the stack temperature. First, by using analytical geometry, the downwind distance and the crosswind distance of the receptor from the source are determined. The major computation that is done within this loop is the calculation of plume rise and effective plume height for this source for the meteorological condition for this hour. Prior to entry to this loop, general setup of the run is accomplished, including selection of various options such as using urban or rural dispersion parameters and the reading of source information and provision for receptors. Although the basic output from most models consist of hourly concentrations at the receptors, many of the models contain considerable code to do “bookkeeping.”.
