IMMISnet - Concept

Program concept
IMMISnet is a Gaussian multi-source dispersion model for calculating the spatial extent of concentration levels of air pollution. Treated as a stationary process, the model describes the dilution and transport of pollutants from point, line or area sources, using a Gaussian normal distribution. Gaussian dispersion models are instruments that have been tried and tested for many years for dealing with climatological concentration problems within the framework of plans for maintaining air quality, or planning permit procedures, in line with the German Technical Directive on Air Pollution Control (TA-Luft 1986).

On the basis of the Gaussian smoke plume equation, the model calculates concentration contributions from the emissions of all the area, line or point sources considered. Statistical parameters, such as the mean annual value or the percentile of cumulative frequency, are calculated for each of the defined receptors from the individual concentrations determined for all the hours of a year. In addition, IMMISnet can prepare all the background input data for microscale street canyon models.