ABSTRACT
Urbanization may well be a major force for reducing the human degrading impact on the environment. Serious as urban problems are, it seems inevitable that urbanization will continue until the entire world is 78–80 percent urbanized. Urban areas are usually defined by administrative boundaries— the number or proportion of people living in administrative areas that are defined as urban. Satellite images of Bangkok taken in 1985 and 1989 were computer-enhanced to show change of land from rural to urban uses. Urban areas imply densely packed buildings, roads and public structures, or a ‘built-up’ area. Cities can be conceived of as living systems, driven by basic metabolic processes. Urban impacts on the environment extend considerably beyond the transformation of land. Cities and towns demand resources from outside, and empty their wastes beyond their own boundaries. The high concentrations of people in these restricted spaces greatly amplify all human impacts.
