The emission variability maps were used for carrying out a
preliminary evaluation of the areas of representativeness of some
selected air quality monitoring stations existing in the studied
domains. A qualitative criterion was used for the evaluation. From
the natural breaks classification, the first three classes (in ascending
order) were defined to represent an acceptable range of variability
and so to include the area of representativeness. We chose the three
lowest classes among the ten coming from the natural breaks
classification method, applied to the emission variability maps,