Cities Across the World

Historical Context & the Rise of Global Urbanization

The story of cities is the story of human civilization itself. The earliest permanent settlements emerged in the Fertile Crescent roughly 10,000 years ago, following the Neolithic Revolution when agriculture allowed populations to concentrate. Over millennia, urbanization spread outward from these hearths of urban development to encompass civilizations across Mesoamerica, the Indus Valley, East Asia, and the Mediterranean. Each wave of city-building reflected the cultural, economic, and environmental conditions of its era, producing urban forms that still shape the landscapes we observe today.

The modern acceleration of urbanization, however, is historically unprecedented. While only about 3% of the world's population lived in cities in 1800, the Industrial Revolution triggered massive rural-to-urban migration in Europe and North America, fundamentally restructuring economies and landscapes. By 2007, the United Nations declared that more than half of humanity resided in urban areas for the first time. Today, that figure exceeds 56% and is projected to reach nearly 70% by 2050, with the most dramatic growth concentrated in the cities of the Global South — Africa, South Asia, and Southeast Asia.

Understanding these historical patterns raises a central question for AP Human Geography: How do cities in different world regions differ in their spatial organization, growth processes, and urban challenges, and what models help us explain those differences? This lesson examines the dominant urban models and regional typologies that geographers use to analyze cities across the globe.

Core Principles of Global Urban Structure

Geographers have developed several foundational principles to explain how cities are organized internally and why urban morphology varies from one world region to another. While classic North American models such as the concentric zone model, the sector model, and the multiple nuclei model provide useful starting points, global urban geography demands additional frameworks that account for colonial legacies, informal economies, religious and cultural zoning, and the dynamics of rapid industrialization.

Visual Comparison: Regional City Models

The diagram below illustrates three of the most frequently tested regional city models on the AP Human Geography exam: the Latin American City Model (Griffin-Ford), the African City Model (de Blij), and the Southeast Asian City Model (McGee). Each model highlights how colonial history, economic development, and cultural traditions produce distinctive spatial patterns.

In the Latin American city model, the CBD anchors the center, and a commercial spine of elite residences, upscale retail, and modern infrastructure extends outward — often toward the airport or university. Surrounding this spine is a zone of maturity (middle-class housing), while the periphery is dominated by squatter settlements and industrial uses. This stands in sharp contrast to the typical North American pattern, where wealth increases with distance from the CBD. The African model reflects the legacy of European colonialism: a CBD often located near a former colonial administrative area, with distinct ethnic neighborhoods, mining or industrial zones, and large informal satellite townships on the periphery. The Southeast Asian model adds the concept of an alien commercial zone — typically a Chinese or Indian merchant district — reflecting the region's history of international trade networks.

How Urban Structure Develops: Driving Forces

Urban structure is not random; it emerges from the interplay of several interconnected forces. Understanding these mechanisms enables geographers to explain why a city in Buenos Aires looks fundamentally different from one in Nairobi or Bangkok, even though all three are rapidly urbanizing. The AP exam frequently asks students to identify the processes that produce observed spatial patterns, so a mechanistic understanding is essential.

Colonialism and Imposed Urban Plans

European colonial powers frequently laid out cities according to grid plans with clear spatial separations between the European quarter, indigenous neighborhoods, and commercial districts. In Africa, the dual-city structure — a modern colonial core alongside a traditional African settlement — persists in cities like Nairobi and Lagos. In Latin America, the Spanish Laws of the Indies dictated a central plaza flanked by a cathedral and governmental buildings, a pattern visible in virtually every major city from Mexico City to Santiago.

Economic Globalization and Land Markets

The concept of bid-rent theory — which posits that land values decline with distance from the CBD and that different land uses compete for central locations — applies with modifications to cities worldwide. In many Global South cities, however, the relationship is complicated by informal land markets where squatters occupy land without formal title, by government ownership of land, and by the influence of global capital flows that can produce enclaves of luxury development adjacent to extreme poverty.

Transportation Networks and Urban Form

Transportation infrastructure profoundly shapes city structure. North American cities developed around the automobile, producing low-density suburban sprawl, while European cities retain compact cores dating to the pedestrian and streetcar eras. In the Global South, the juxtaposition of modern highways, informal transit networks (matatus, jeepneys, tuk-tuks), and pedestrian-oriented traditional cores creates layered, polycentric urban forms. The McGee model of the Southeast Asian city, for instance, explicitly includes desakota zones — mixed rural-urban landscapes along transportation corridors where agriculture, manufacturing, and residential uses coexist.

Cultural and Religious Influences

The Islamic city model demonstrates how cultural values shape urban form. Traditional Islamic cities feature a central mosque, a suq (market) adjacent to it, and residential quarters organized by ethnicity or sect with narrow, winding streets that prioritize privacy. These organically developed patterns contrast sharply with the geometric regularity of colonial or industrial-era Western cities.

Detailed Breakdown of Regional City Models

The AP Human Geography exam expects students to identify, describe, and compare city models from multiple world regions. The following table and diagram provide a systematic comparison of the key models you are most likely to encounter.

The wealth gradient diagram reveals a critical distinction that the AP exam tests repeatedly. In North American cities, suburbanization was driven by middle-class and affluent residents seeking larger homes, automobile-dependent lifestyles, and racial homogeneity, producing wealthier peripheries. In contrast, Latin American elites historically clustered near the colonial plaza and along the commercial spine, leaving peripheral zones to lower-income in-migrants from rural areas. European cities maintain wealthy cores partly because of strict historic preservation laws, high-quality public transit, and cultural preference for urban living. Understanding these contrasting gradients is fundamental to correctly applying the right city model to an exam scenario.

Worked Example: Identifying a City Model from a Description

AP Human Geography free-response questions frequently present a description of a city and ask you to identify the model, explain its features, and compare it to another region. The worked example below walks through the analytical process step by step.

Strengths and Limitations of Regional City Models

While regional city models are indispensable analytical tools, they are generalizations and cannot capture the full complexity of any individual city. The AP exam occasionally asks students to evaluate the utility of these models, so understanding their strengths and limitations is important for earning full marks on free-response questions.

Connections to Advanced Urban Theory

The regional city models covered in this lesson connect to broader theoretical frameworks that AP Human Geography students should be aware of, even if the exam does not test them at the same depth. These advanced concepts provide intellectual scaffolding for understanding ongoing urban transformations.

As you continue into college-level geography or urban studies, you will encounter increasing skepticism toward rigid model-based thinking. Contemporary scholars emphasize the relational nature of cities: rather than existing as self-contained spatial units, cities are nodes in global networks of trade, migration, information flow, and political power. The concept of world cities (or global cities) — advanced by scholars like Saskia Sassen — highlights how places like London, Tokyo, New York, and increasingly Dubai, Shanghai, and São Paulo function as command centers for the global economy, regardless of the regional model their physical layout might resemble. For the AP exam, remember that these advanced ideas are best deployed as nuance in free-response essays rather than as standalone answers.

Practice Problems

Summary: Cities Across the World