In land use conflicts green areas tend to loose to grey areas like roads and parking lots. Green areas are important for recreation, for children playing, and have significance for human health and quality of life. Green areas also have significance for what plants and animals that can survive in the urban landscape. Some cities have vast green areas within their municipality borders, while other city municipalities are restricted to the urban area only. It is therefore not very interesting to compare a percentage of green areas versus grey areas with other cities.
Meaningful information is obtained by studying map series of land use in the same city over time.