Human Settlements
Human settlements are clusters where people live and work. The domain covers rural and urban forms, site and situation, patterns and urban hierarchy.
Core rules
- Site is the actual ground occupied, such as a floodplain, hilltop or road junction; situation is the settlement's position relative to surrounding features.
- Rural patterns include compact or nucleated, dispersed, linear, rectangular and radial.
- Urban functions include administration, trade, industry, transport and services.
- Hierarchy terms include town, city, metropolis, conurbation and megacity (10 million or more).
- Rank-size rule: the nth city's population is approximately the largest city's population divided by n. A primate city is disproportionately larger than the second city.
Worked example
If the largest city has 4 million people, rank-size predicts the second at 4/2 = 2 million and the third at 4/3 ≈ 1.33 million. If the second actually has 3.5 million, the system is primate rather than rank-size, suggesting concentrated urban growth.
Traps
Do not confuse site with situation. Rural settlements are not exclusively agricultural; they may be mining or fishing villages. Do not call any large city a megacity: the threshold is 10 million. A conurbation is a merged urban area, not a single administrative city.