Torstai 22.7.2021 klo 13:25 - Mikko Nikinmaa
“Hot down, summer in the city…” Town building has traditionally maximized the concrete housing and the asphalt streets and parking lots. The area allocated to trees and parks has usually been minimized. This has two major consequences. First, the temperatures in the towns without green areas can be up to 5-10oC higher than in parks. Second, the rainwater cannot be removed from the asphalt streets leading to flooding whenever heavy rain sets in. If the town is at the coast, and the vegetation and floodplains in the coastline have been removed, any rise of water level will cause flooding.
All of these problems could be remedied. First, instead of building towns for cars, they should be built for people. The streets should be boulevards with trees between the car lanes and pavements. Further, the proportion of land that is park in towns should be maximized. This would both decrease the temperature and combat floods, as the water would be sucked in soil. To decrease the temperature further, apartment blocks could have green roofs. The park areas and green roofs would also increase insect diversity.
With regard to coastal towns, one should have green area between the town and the sea. No wonder that mangrove forests grow by the seaside in the tropics. They effectively prevent coastal floods, but have been cut down and replaced by concrete and asphalt. Also, overall human handling of rivers, drying of marshes etc. almost always cause reduced retention of water, with the result that floods become more severe and droughts set on more rapidly.
The above changes in town and watershed planning are both possible and necessary. It should be quite obvious given the floods in Germany and China and heat waves in American West. One cannot but wonder, why towns are planned for cars and not for people.