08/20/2017
Interesting info: What is an urban area?
An urban area may be defined by the number of residents, the population density, the percent of people not dependent upon agriculture, or the provision of such public utilities and services as electricity and education.
Some countries define any place with a population of 2,500 or more as urban; others set a minimum of 20,000. There are no universal standards, and generally each country develops its own set of criteria for distinguishing urban areas.
The United States uses a population density measure to define urban with a minimum population requirement of 2,500. The classification of metropolitan includes both urban areas as well as rural areas that are socially and economically integrated with a particular city.
http://www.prb.org/Publications/Lesson-Plans/HumanPopulation/Urbanization.aspx
