Atmospheric dispersion modelling with AERMOD for comparative impact assessment of different pollutant emission sources in an alpine valley

High-resolution simulations are performed with the AERMOD dispersion model to assess the impact on air quality in the area surrounding the town of Vipiteno, in the Alps, from the main pollutant sources: the Brenner motorway, the town of Vipiteno, three major industrial plants and a big parking lot. The combination of terrain complexity and specific emission sources makes the air pollution load particularly critical for such a valley environment. AERMOD is run with a spatial resolution of 25m and fed with specific meteorological data and emission factors, modulated according to hourly and seasonal emission patterns. The resulting annual means of NO2 and PM10 concentration are validated against measurements from a local air quality station and then compared with the limits set by legal provisions. Finally, the contributions of single sources are analysed, highlighting their relative relevance to the pollution load of the area.