This booklet is only about vegetation. In fact, there is nothing else shown on the maps then vegetation in urban areas. This might seem boring at first. But suddenly, there are patterns. Patterns that look familiar, can be recognized. I call this pattern the "green fingerprint" of a city. The small polygons representing parks, riverbanks, or avenues with trees on both sides shape the cities in the same way streets and buildings on usual maps do.
The greener a city, the easier is it to actually recognize it on the vegetation map. Man-made contructions like airports and highways can be discovered in some urban areas. And some curved shapes can only be formed by a river.