Investigate the surface of your home town.
Walk through one area using a town map for orientation.
How much of the surface is covered with streets, buildings, or concrete?
Are there parks and open spaces and how large are they?
Make a black and white copy of your town map and colour in the parks and the non-built up areas in green and the built up area in red.
Calculate (in percent) how much of your town is built up and how much of the natural surface still exists.