ABSTRACT
The natural environment of a metropolitan region may be taken to consist of the surrounding air mantle, watercourses, large landscape features, climate and weather, soil conditions, and the associated biological systems. Human activities in such a region influence the quality of this natural environment in various ways—usually for the worse. But at a cost, often at a large cost, these adverse impacts can be controlled and managed so as to maintain environmental standards. In some instances, environmental circumstances can be improved; for example, artificial landscape features such as lakes may be created which are more attractive than the natural landscape.
