Below are satellite and photographic images of three classic urban basins (or bowl-shaped valley cities, Katmandu, Nepal; Lubango, Angola; and Tegucigalpa, Honduras. There are a number of cities around the globe that sit in basins surrounded by mountains, including Mexico City, La Paz, Tecate, and Caracas, but few are as symmetrically rounded as these three. Granted, few, if any, natural geographic landforms are uniformly shaped, but these three come about as close as one could imagine to representing a bowl.
Katmandu and Tegucigalpa are surrounded by higher peaks that Lubango, but this Angolan city is my favorite example of an urban basin. The subtleties of Lubango’s surrounding rim topography (see photo at top of blog post) are such that it really does appear to be a shallow, smooth bowl. The two other bowls have a rugged rim surrounding them.
For urban planners, a key aspect of basin cities is how pollutants can become trapped in the bowl-shaped valley leading to health and environmental concerns. Current and long-term planning efforts must include methods for mitigating and off-setting current problems in these areas, while also promoting those land use and transportation alternatives that enhance community-wide health, as well as environmental stewardship and sustainability.