I am checking the CLC data 2000-2006 in excel at NUTS3levels.
Regarding transport areas (a sum of roads, airports and ports), there are some NUTS3 levels that do not have any transport area whatsoever, (so the sum is equal to 0; e.g. AT124, AT125, BG425, DE218), while there are some (e.g. DE242, DE249, PT168, ITD54) that show an increase between 2000 to 2006 from 0 to some hectares of transport areas.
How is it possible? If the transport areas in 2000 are 0, does it mean that the transport areas (roads, airports or ports) at that time were not captured because they are below the 25 ha threshold? Or shall I treat these data as missing?
Thank you very much if you can help me with this.