Urban Development and Evolution: From Pre-Industrial to Contemporary Cities
1. Urban Population Dynamics
1.1. The Rise of Urban Populations
Traditional societies were primarily rural, while modern society is fundamentally urban. In 1900, only 10% of the global population resided in cities. By 2003, this figure reached 48%, and it is projected to hit 61% by 2030. Megacities like Tokyo, Mexico City, New York, São Paulo, and Mumbai continue to expand, with urban populations, particularly in Asia and Africa, expected to increase significantly.
1.2. Uneven Urbanization
Urbanization is most advanced in developed nations. The growth of cities in these regions throughout the 19th and 20th centuries was driven by industrialization and rural-to-urban migration. Currently, cities in developed countries are experiencing slower growth, with internal migration nearly ceasing, though international immigration contributes to some expansion. Conversely, urbanization in developing countries is accelerating, rising from 27% to 42% between 1975 and 2003. This rapid growth is fueled by substantial rural-urban migration, often leading to uncontrolled urban expansion and challenges related to poverty and inadequate housing.
2. 19th-Century Urban Evolution
2.1. The Pre-Industrial City
Pre-industrial cities were compact, with travel primarily on foot or horseback. Narrow, winding streets were enclosed by walls. Buildings were typically low-rise, with homes and workplaces often combined. Merchant streets specialized in specific goods, and the city center housed political and religious power.
2.2. The Industrial City
The first industrial revolution brought trams and trains, enabling urban expansion. City walls were demolished, and growth followed tram lines, creating a tentacular shape. Economic activities concentrated in the center, excluding industry. Planned neighborhoods with grid layouts emerged around the historical core, while working-class neighborhoods developed with less organized layouts and poorer housing.
3. The Contemporary City
3.1. The 20th-Century City
The automobile further expanded cities, creating a dispersed, oil-spot pattern. New industries located in peripheral areas, and road transport surpassed rail. Highways fueled metropolitan area growth, comprising a central city and surrounding municipalities. These municipalities became dynamic, with new residential areas and industrial zones. This led to a more dispersed urban form.
3.2. Internal Structure of the Current City
A. The City Center
The center is the most representative area, hosting economic activity, leisure, and cultural venues. Multifamily dwellings predominate, and the population tends to be older with a higher proportion of foreign-born residents. Public transport is crucial due to traffic congestion.
B. The Periphery
The periphery is dynamic and diverse, with extensive residential areas offering cheaper housing and a younger population. It also houses economic activities, including industry, which requires large land areas. Industrial parks, technology centers, business parks, shopping malls, and entertainment centers are common features.
4. Urban Challenges
4.1. Transport and Mobility
Cities face transport challenges, with heavy private car use. Solutions include promoting public transport, pedestrian zones, and bike lanes.
4.2. Pollution
Industry, heating systems, and vehicles contribute to air pollution, impacting public health, vegetation, and monuments. Cities also grapple with water and noise pollution from transport and industry.
5. City Systems and Territorial Organization
5.1. Urban Hierarchies
Cities within a territory are interconnected, forming systems. Larger cities offer more specialized services and have wider catchment areas. Global cities influence the world economy (e.g., New York, London, Tokyo). National cities play key roles within their countries (e.g., Madrid, Barcelona). Regional cities and towns maintain regional balance, and small towns offer basic services.
5.2. Functional Specialization
Some cities specialize in particular activities. Large cities are often multifunctional, while smaller ones may have more focused roles.
5.3. Structure and Morphology of Urban Systems
Effective territorial organization requires a balance in city sizes and distribution. Macrocephalic systems have one disproportionately large city. Polycentric systems have multiple competing large cities. Concentrated systems have urban areas clustered in one part of the territory, while dispersed systems have cities spread more evenly.