An integrated spatial and temporal analysis of anthropogenic emission sources, prepared at an hourly level and on a 15 × 15 meter grid, coupled with the Lagrangian dispersion model GRAMM/GRAL, an effective tool for assessing the impact of primary emission sources on air quality. The subalpine city of Ljubljana was selected as the study area. The emission inventory included sectors that contribute the most to emissions of NOx, PM10, PM2.5, NMVOC, and NH3. The total estimated annual emissions for Ljubljana in 2021 amounted to 1,935 tons of NOx, 393 tons of PM10, 315 tons of PM2.5, 1,847 tons of NMVOC, and 168 tons of NH3. Spatial analysis showed that NOx concentrations are mainly concentrated along major roads, with some high concentrations coinciding with locations of industrial facilities. Emissions from traffic are also evident in the maps of PM and NMVOC emissions. PM10 and PM2.5 emissions are primarily associated with residential areas, mainly due to the use of wood in small-scale combustion. NH3 emissions coincide with agricultural land use. NMVOC emissions are concentrated in commercial zones, where solvent use is more frequent. To assess the reliability of the emission inventory, a comprehensive validation and verification were carried out. A comparison of the inventory with those of other European countries was conducted, taking into account area and population density, along with a detailed uncertainty analysis. Verification was performed by comparing GRAMM model wind fields at five measurement locations using statistical analysis (R, MB, NMB, and RMSE). Measurement results and observed values of PM and NOx were also statistically analyzed at three monitoring sites (Bežigrad, Celovška, and Vič). The statistical comparison between modeled and observed concentrations indicates moderate agreement for PM10 and stronger agreement for NOx. At the Vič location, a source apportionment analysis using the PMF method was also conducted in 2023, showing similar source contributions compared to the emission inventory. Overall, the results of this study improve the understanding of pollutant dispersion dynamics and provide a scientific basis for decision-making aimed at improving air quality and protecting public health.
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