Keywords: atmospheric dispersion models, environmental impact assessment, EU regulatory models, European Union, model evaluation, air pollution, environmental pollution, modelling
Comparison of six Gaussian dispersion models used for regulatory purposes in different countries of the EU
The environmental impact of industrial emissions from stacks of 30m, 80m and 150m have been compared using five Gaussian models that are routinely used for regulatory purposes in one or more member states of the EU. The models are: IFDM (Belgium), PLUIMPLUS (the Netherlands), AUSTAL86 (Germany), OML (Denmark) and ISCST2 (several countries). All models are run with the same meteorological input data for the year 1985. The observations along the 120m high meteorological tower in Mol, completed with the synoptic observations in Kleine Brogel and the radio soundings of Brussels, are used. The comparison is based on the yearly average, the 98-percentile of the hourly averages and the maximum hourly average concentrations. The largest values for these parameters differ by a factor of up to 3. The spatial distribution of the calculated impact can also be very different for the considered models. These differences are almost entirely due to the use of different turbulence typing schemes and the associated dispersion parameters. A sixth model studied in this paper is IMMPROG (Switzerland, Belgium). Although this model is based on the same principles as the AUSTAL86 model, the differences between the models are considerable.