Understanding Urban Development: Concepts, Networks, and Systems
The Urban Development Concept
Urbanization is the phenomenon by which cities grow rapidly in number, population, and surface area. Lifestyles characteristic of cities are extended to large areas. A traditional interpretation considers only demographic, economic, and geographical factors, but a more advanced approach includes cultural aspects.
Different Rhythms of Urbanization
It is estimated that by 2020, three-quarters of the world’s population will be urban, and one in four people will live in cities of over a million inhabitants. The urbanization process has been particularly rapid in Latin America. The cities with the highest number of inhabitants are Tokyo, Mexico City, Sao Paulo, New York, Mumbai, and Shanghai. Besides having high birth rates, cities constantly expand, creating areas with makeshift housing called favelas (Brazil), villas miserias (Argentina), or bidonvilles (Africa).
Urban Networks
Cities are not isolated but exist within a territory, relating to other cities. This interconnectedness—economic, social, cultural, and political—causes cities within a country to acquire complementary and differentiated functions, forming a hierarchical set of centers.
Descriptive Theory
The central place theory, formulated by German geographer Walter Christaller in 1933, is a descriptive model. It posits that a city’s primary function is to provide goods and services to its surrounding territory. The number, size, and distribution of cities have a logical explanation based on the relationship between the supply of goods and services and the population, size, and characteristics of their influence areas. Central place theory explains the hierarchical levels of cities based on their specialization, determined by a minimum level of demand for profitability. The gravity model, inspired by Newton’s law, explains the relationship between cities in an urban network and their influence areas. Larger cities have greater influence, and this influence decreases with distance. Examples in Catalonia include the Tarragona-Reus and Terrassa-Sabadell combinations. Another important model is the economic base theory, which introduces a new variable to explain a city’s economic momentum. Industries export a significant part of their production to their areas of influence.
Urban Systems
Urban networks are dynamic systems where exchanges between different nuclei drive development. These systems comprise various elements: land and real estate, productive infrastructure and services, mobile elements, communication and transportation networks, and legal frameworks. Assessing an urban system’s development requires understanding its integration level and the flow of exchanges (people, goods, information, etc.) between its nuclei. The capitalist free-market economy is characterized by the concentration of means of production in the hands of a minority. This trend of socio-economic structures achieving global reach is called globalization. Economic globalization involves reorganizing cities’ roles and creating hierarchies.
The Different Functions of Urban Spaces
Urban Regions
Urban regions are areas with dense urban networks where cities and urban areas are nearly continuous, separated by few agricultural or forested areas. Urban regions can be of three types:
- Metropolitan Area: A large city and surrounding smaller cities forming a system with intense exchanges of people, goods, and communications.
- Conurbation: A large urban area with multiple central cores of equal or similar importance, potentially with different functions.
- Megalopolis: A series of conurbations and metropolitan areas interacting to form an extensive urban area, where transport and communication networks are crucial.
Metropolitan Governance
Within a metropolitan area, there are areas with diverse characteristics and functions. Sometimes, the physical separation between two cities is merely the distance between two sidewalks. This proximity and the many links often lead to local government entities sharing powers with larger councils (e.g., municipal corporations or commonwealths) to coordinate services like transport and sanitation. Europe has some significant metropolitan administrative entities.
The City as a Center of Power
The world’s economic power centers are always located in urban areas due to historical reasons.