Rank Size Rule Settlement
Learning outcomes • To understand what the rank Size rule is and the pattern that it tries to outline
Rank Size Rule • This is an attempt to find a numerical relationship between population size of settlements within an area such as a country or county • Settlements are ranked in descending order of population size, with the largest city first
Assumptions • The 2nd ranked city will have 1/2 the population of the 1st • The 3rd ranked city will have 1/3 population of the 1st • The 4th ranked city will have a ¼ population of the 1st ranked city
Example • The largest city has a population of 1,000,000 • The 2nd largest city: 1,000,000/2= 500,000 • The 3rd city: 1,000,000/3= 333,333 • The 4th city: 1,000,000/4= 250,000 • And so on….
Formula • This allows us to express the rank size rule as: • Pn= Pl /n (or R) • Pn= The population of the City • Pl= The population of the largest city • N (or R)= The rank size of the city • See graph Page 404/405 Brazil e.g.
Variations from the Rank Size Rule • It is rare to find a close correlation between the city size of a country and the rank size rule
Primate City • This is found where the largest city (often the capital) completely dominates a country or region • The population size will be many times greater than that of the 2nd or 3rd city
Example of Primate City: Buenos Aires • Populations in thousands: • Buenos Aires: 10,990 • Cordoba: 1198 • Rosario: 1096 • Mendoza: 775 • La Plata: 640 • San Miguel de Tucuman: 622
Binary Distribution • Occurs where there are 2 very large cities of almost equal size within the same country. One may be the capital and the other a major port or industrial centre • Examples: Spain- Barcelona and Madrid
Exceptions to the rule • Rank size rule is more likely to operate in a country that is developed or urbanised for a long time • Large in size • Stable economic and political organisation • Primate distribution is likely to occur in countries that are small, less developed and only recently urbanised