urban hierarchy consists of a form of organization between cities, where large urban centers influence medium and small cities.
This hierarchy is formed mainly based on the economic diversification of urban centers, making those with less development dependent and subordinate to the most developed.
It is also through the urban hierarchy that the national space is organized, in terms of the influence of certain urban centers on others. It works as an indicator of the importance of a city, which is not always dependent on its size, but on other influencing factors, such as the dynamics of goods, people, services and information that it has, for example. The urban hierarchy can have a regional, national or world scale.
The urban hierarchy is related to the ranking of cities, from the smallest to the one with the largest population. Within the urban hierarchy, cities can change their position, since there are population transfers between cities, causing them to vary in position.
Brazilian urban hierarchy
In Brazil, the urban hierarchy follows the model proposed by IBGE (Brazilian Institute of Geography and Statistics): Metropolises, Regional Capitals, Sub-Regional Capitals, Zone Centers and Local Centers. In other countries around the world, however, the classification patterns of the urban hierarchy can vary, mainly according to the structure of these nations.
The urban hierarchy is formed by national metropolis, which are the big cities; at regional metropolises, which are cities that exert a polarization over an extensive region; regional capitals, which are cities that polarize a smaller or less important area in terms of population; regional centers, which are cities polarized by regional capitals and that polarize a large number of local cities, and local cities, which are small cities that exert influence in a small area, where rural or semi-urban housing patterns predominate, such as villages, for example.
See also: meaning of Urban area.
Urban hierarchy and urban network
The concept of urban hierarchy is based on the notion of urban network, which would be a integrated set of cities that establish economic, social and political relations among themselves.
Urban networks are the result of the processes of urbanizationobserved in all countries, where there is a grouping of cities that are integrated at different scales. As a matter of fact, it is from this differentiation of levels of development of urban networks that the concept of hierarchization of urban centers emerges.
Currently, urban networks can be classified into: megalopolises (global cities), metropolises, medium and small cities.
