Keywords: atmospheric dispersion models, Germany, environmental impact assessment, modelling, air pollution, environmental pollution
Dispersion modelling in Northrhine-Westphalia: regulations, guidelines and pragmatic approaches
In Germany the only regulation concerning dispersion modelling is found in Annex C of the Technical Instructions on Air Quality Control (TA Luft). It prescribes a Gaussian plume model but does not consider features such as wet deposition, dynamic plume rise and transport in structured terrain. Several VDI Guidelines have been formulated to harmonize handling of those features. However, concerning dispersion modelling in the vicinity of a source where the influence of buildings has to be taken into account, no general proposal has been made. As there are several models to calculate flow and concentration fields in the vicinity of buildings, first steps have been made in the State of Northrhine-Westphalia to find a pragmatic approach for using these models to determine annual means and percentiles. Thereby the number of different meteorological situations to be considered has to be reduced. The resulting coarser classification of wind speed, wind direction and stability classes must be based on the available meteorological frequency distributions.