# Odor Impact Assessment via Dispersion Model: Comparison of Different Input Meteorological Datasets
## 3 Results and Discussion
### Separations Distances  
Figure 6 illustrates, for both domains, the direction-dependent separation distances for the three reference concentration values specified in the Italian guidelines (i.e., 1 ou\({}_{E}\)/m\({}^{3}\), 3 ou\({}_{E}\)/m\({}^{3}\), 5 ou\({}_{E}\)/m\({}^{3}\)). These separation distances represent contour lines (isopleths), varying according to direction, of an ambient concentration threshold. The left graph refers to both point sources and the right graph to area source.  
In very few cases, separation distances were found to be below 50 m, which is the distance of the first discrete receptor from the emission source. In such instances, a minimum separation distance of 25 m was considered.  
First, focusing on the results of the point source, in the left part of Figure 6, the separation distances obtained for the Italian site (left) with the three different input meteorological settings appear almost overlapped. The same behavior is observed for the Cuban domain (right). In particular, for the \"HYBRID\" and \"OBS\" simulations, the lines are even closer,  
Figure 6: Direction-dependent separation distances considering the Italian domain and the Cuban one for the point source (left graph) and area source (right graph).  
overlapping in different sectors, with few discrepancies in the main direction of the wind, particularly in the SW direction in the Cuban domain.  
The separation distance related to 5 oue/m\({}^{3}\) in the Italian domain achieves a maximum value of roughly 100 m along the prevalent wind directions (E and W). Lines for 3 ou\({}_{\rm E}\)/m\({}^{3}\) are relatively close, ranging from 100 m to 200 m. The greatest value in the main wind directions (E and W) is 400 m when the distance refers to 1 ou\({}_{\rm E}\)/m\({}^{3}\).  
For the Cuban domain, the separation distance associated with 5 ou\({}_{\rm E}\)/m\({}^{3}\) reaches a maximum of about 150 m. Lines for 3 ou\({}_{\rm E}\)/m\({}^{3}\) reach 300 m, whereas lines for 1 ou\({}_{\rm E}\)/m\({}^{3}\) reach 600 m. All of these values are obtained along the predominant wind direction (SW).  
In conclusion, as previously discussed for the odor contour maps, the point source impacts simulated with different meteorological input data appear largely comparable.  
As observed in the discussion regarding odor impact maps, separation distances with different meteorological input data (Figure 6) exhibit greater discrepancies for both domains when simulated for area sources compared to point sources. Specifically, in the case of area sources, the lines tend to converge and overlap across different sectors in the \"HYBRID\" and \"OBS\" simulations, with some discrepancies noted in the Cuban domain, possibly attributable to a higher percentage of invalid data.  
The separation distance of 5 oue/m\({}^{3}\) in the Italian domain achieves its greatest value in the main east direction at roughly 150 m for \"NO-OBS\" simulations and 250 m for the \"OBS\" and \"HYBRID\" modes. The separation distance for 3 ou\({}_{\rm E}\)/m\({}^{3}\) is approximately 300 m for \"NO-OBS\" and 400 m for \"OBS\" and \"HYBRID\". Finally, with a reference value of 1 oue/m\({}^{3}\), the maximum separation distances for \"NO-OBS\" and \"OBS\"/\"HYBRID\" are 500 m and 800 m, respectively.  
Simulated separation distances for the \"OBS\" and \"HYBRID\" modes in the Cuban domain differ more with respect to the point source. The 5 oue/m\({}^{3}\) line has a range of 150 m for \"NO-OBS\" and 200 m for the \"OBS\" and \"HYBRID\" mode. In the major SW direction, the separation distance of 3 oue/m\({}^{3}\) is 200 m for \"NO-OBS\" and 300 m in the other situations. The maximum distance for lines with 1 ou\({}_{\rm E}\)/m\({}^{3}\) is, hence, 600 m for \"NO-OBS\" lines and 800 m for \"OBS\"/\"HYBRID\" lines, respectively.  
In conclusion, in the case of the area source, as previously revealed by the odor impact maps, \"NO-OBS\" results appear slightly underestimated compared to the \"OBS\" and \"HYBRID\" simulation.