Spanish Urban System: Hierarchy, Functions, and Influence Areas
Spanish Urban System
1. The Size of Cities
The population size of cities is one of the bases of the urban hierarchy. It is established according to the rank-size rule, which relates the population of a city and its range in larger demographic areas. The Spanish system corresponds to seven metropolitan areas. Including Madrid, which has the largest population and ranks number one in the system. Barcelona has a much larger size than what usually corresponds to the second city in a national system, so there is an abrupt jump between it and the third-largest agglomeration, Valencia, followed by Seville, Bilbao, Malaga, and Zaragoza.
The spatial distribution of urban agglomerations by size features two main characteristics:
a) In the peninsula, large cities form a semi-ring in the periphery, surrounding an inner space with low urbanization, whose center is the largest urban agglomeration in the country: Madrid. The growth in these metropolitan areas has contributed to shaping territorial lines:
- The northern axis is discontinuous and presents difficulties of articulation due to the absence of central Atlantic metropolitan areas. Galicia and inland cities depend on it and the Cantabrian axis (Oviedo, Gijon, Aviles, the Basque Country, and Pamplona).
- The Mediterranean axis extends from Girona to Cartagena.
- The Andalusian urban network is available along a double axis: the Guadalquivir valley and the coastal axis.
- The Ebro Valley corridor serves as a communication route between the Cantabrian and the Mediterranean regions, with Zaragoza as its main city.
b) Large metropolises are concentrated in the Northeast, where five of the seven agglomerations are located.
2. The Functions of Spanish Cities
The functions performed by cities are another factor that determines their position in the urban system. Functions are understood as socio-economic activities that cities play outward, not aimed at internal city service.
- Primary Cities: They have a specialization in primary sector activities. Stain and Murcia stand out in Andalusia.
- Secondary Cities: These cities are specialized in industry and construction.
- Tertiary Cities: These cities are specialized in tertiary services.
Urban Relations in the Spanish System
Relations between cities in a system can be unidirectional or reciprocal. The Spanish system is characterized by the following features:
- Madrid maintains intense relations with the other metropolises.
- Barcelona has a more general influence, although weak, and intense in the eastern sector.
- The northeast quadrant has five principal metropolises that maintain close relationships, especially Madrid and Barcelona.
- In the rest of the system, the degree of integration is incomplete. The smaller and more disconnected area is the one around Portugal, except for Galicia.
Spanish Urban Hierarchy
The following are the categories:
A) Metropolises: These are cities in the top hierarchy of the urban system with a population of over 250,000 inhabitants. They perform specialized functions, and the remaining cities are diversified.
- National Metropolises: Madrid and Barcelona. Their metropolitan areas’ population exceeds 4 million inhabitants, and they have more diversified functions. Their area of influence extends throughout the national territory, and they are linked to other metropolises.
- Regional Metropolises: Valencia, Seville, Bilbao, Malaga, and Zaragoza. They have a population between 500,000 and 1.5 million inhabitants. They have a regional area of influence and maintain strong relationships with national metropolises.
- Second-Order Sub-Metropolises: Cities such as Valladolid, Oviedo, Murcia, and Alicante. They maintain intense capital relations with corresponding regional capitals.
B) Medium Cities: Most province capitals are not included in the preceding paragraphs. Their population is around 250,000-500,000 inhabitants. They have tertiary functions and are endpoints with a dense bus network.
C) Small Towns/Villages: They have a small population of fewer than 50,000 inhabitants. Their functions are less specialized: administrative and commercial. They are transport nodes for the region, and their area of influence is county-level.
The Urban Area of Influence
For their services to the outside, cities are considered central places that supply goods and services to an even more extensive area, called the area of influence. This area will be greater the more diverse and specialized urban functions are. Christaller’s central place theory classifies cities according to the variety and quality of functions they offer and their hexagonal area of influence. A village would influence an area of six villages, a town would have a catchment area of six towns, etc., until reaching the highest-ranking cities. The result is an organized territory as a hexagonal grid formation by the area of influence of each central place.
- Madrid is the principal central place, and its influence extends throughout Spain.
- In the periphery, nuclei of influence are located: Barcelona, Valencia, Seville, and Bilbao.
- A Coruña and middle-distance cities like Burgos, Zaragoza, Murcia, and Granada are mid-range, followed by nuclei of minor influence.