The pattern and extent of cities, roads, agricultural land, and natural areas within a watershed influences infiltration properties, transpiration rates, and runoff patterns, which in turn impact water quantity and quality.

This map presents the distribution of urban areas as judged by satellite images of nighttime lights for 1994 - 95. Because more urbanized watersheds tend to have greater impervious areas as well as higher quantities of urban and industrial pollution, this map also shows greater pressure on freshwater systems.

This map shows that highly urbanized watersheds are concentrated along the east coast of the United States, Western Europe, and Japan, with lesser concentrations in coastal China, India, Central America, most of the United States, Western Europe, and the Persian Gulf (Revenga et al. 2000.)