SAP Technical Guidelines: Cities and Climate Change
Traditionally, cities are defined as large human settlements, with no one standardized definition applied internationally. Frequently, national governments have criteria they use to define urban areas. These criteria can vary to include aspects such as administrative boundaries, living conditions or population density. Another approach is what is termed “urban agglomeration”, which considers the extent of an urban area, or sometimes, that of a built-up area, to identify a city’s boundaries.