Unit 6 Overview: Cities & Urban Land-Use

7 min read•june 18, 2024

Riya Patel

AP Human Geography 🚜

320 resources

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The “Why of Where” for Cities

Geographers have developed models to better understand the different distribution patterns of cities within a country or region. Knowing the difference between rank-size rule 🥇🥈🥉 and primate cities 💪 is crucial to fully understand these distribution patterns. Some countries and regions have cities of all sizes spread out somewhat evenly (like the United States). In contrast, others have one dominant city where the majority of wealth 💲 and services are concentrated (like Mexico City).

Rank-Size Rule

The rank size rule is a statistical relationship that describes the size distribution of cities within a country or region. According to the rank size rule, the population of a city is inversely proportional to its rank in the size distribution. In other words, the largest city (ranked first) is typically much larger than the second-largest city, which is in turn much larger than the third-largest city, and so on.

This relationship can be described mathematically as:

P(n) = K/n

Where P(n) is the population of the nth ranked city, and K is a constant.

The rank size rule has been observed in many countries around the world and is often used to study urbanization and the size distribution of cities. However, it should be noted that the rank size rule is not a strict law and there are many exceptions to it.

Primate Cities

A primate city is a city that is significantly larger than any other city in its country or region and that plays a dominant role in the economic, cultural, and political life of the area. Primate cities are often the capital cities of their countries and are major centers of trade, finance, and other forms of economic activity. They are also often centers of cultural exchange and are known for their diverse populations and advanced infrastructure. Examples of primate cities include London, Paris, Tokyo, and New York.

Christaller’s Central Place Theory is probably the most important urban model in developing an understanding of the distribution of different-sized settlements within a region. Using the concepts of threshold and range, the model helps geographers determine why certain services are found in nearly all settlements (gas stations ⛽), regardless of size, while other high-level services (professional sports arenas ⚽⚾🏀🏈) are only found in larger cities.

🎥 Watch: APHUG - Site & Situation Factors in Urban Geography

Unit Preview (Try to answer these questions!)

Why are cities located where they are?
How does a country’s level of development influence how cities are structured?
Why do cities in different parts of the world experience similar challenges?
Why aren’t the largest cities found in the most powerful countries?
Why do people move to and from cities?
Why do so many people in the United States live in suburbs?
Why are racial minority groups clustered in large cities in the United States?

Urbanization & Suburbanization

At this point in history, humans 👪 have settled the vast majority of the earth’s surface. Geographers break these settlements into three primary categories—urban (cities with lots of people), suburban (residential areas just outside cities), and rural (farm-based settlements far away from cities).

Urbanization refers to the process of population movement from rural areas to urban areas, and the resulting increase in the proportion of a country's population living in urban rather than rural areas. This process is important because more than half of the world’s 7+ billion people now live in urban areas. Understanding where modern cities are growing fastest and why this process affects people worldwide is critical in fully understanding the significance of urban geography.

Suburbanization refers to the process of the population shift from urban to suburban areas, often motivated by the desire for more space and a lower cost of living. This trend has been observed in many countries around the world and has had a number of social, economic, and environmental impacts. Some of the factors that have contributed to suburbanization include the availability of affordable housing, the development of transportation infrastructure, and the growth of the service sector and white-collar jobs. In the United States, this process has been accelerating since World War II. 💨

Although people move for many reasons, the following components of the suburban lifestyle draw many urbanites to these communities: more space, less traffic, and pollution, decreased crime rates, and lower population densities, to name a few. 🏡🚙🌳

📚 Read: APHUG - The Origins & Influence of Urbanization

🎥 Watch: APHUG - Why So Many Suburbs Look the Same

Distribution of Cities

The distribution of cities refers to the way that cities are geographically located and distributed within a country or region. Cities are typically located in areas that are conducive to economic development and growth, such as areas with access to resources, transportation networks, and markets.

The distribution of cities can vary widely depending on the country or region. Some countries, such as the United States, have a more decentralized pattern of city distribution, with a number of large cities located throughout the country. Other countries, such as China, have a more centralized pattern of city distribution, with a few large cities dominating the country's economic and political life.

Factors that can influence the distribution of cities include geography, transportation networks, natural resources, and economic and political policies. The distribution of cities can also be affected by historical and cultural factors, such as the legacy of colonialism or the influence of specific religions or cultures.

Here are a few examples of the distribution of cities within different countries or regions:

United States: The United States has a decentralized pattern of city distribution, with a number of large cities located throughout the country. Some of the largest cities in the United States include New York, Los Angeles, Chicago, Houston, and Philadelphia.
China: China has a more centralized pattern of city distribution, with a few large cities dominating the country's economic and political life. Some of the largest cities in China include Shanghai, Beijing, and Tianjin.
Europe: The distribution of cities in Europe is somewhat more evenly dispersed than in other regions, with many medium-sized cities located throughout the continent. Some of the largest cities in Europe include London, Paris, Berlin, and Madrid.
Africa: The distribution of cities in Africa is highly varied, with some countries having a few large cities and others having a more dispersed pattern of city distribution. Some of the largest cities in Africa include Cairo, Lagos, and Kinshasa.

Image Courtesy of Wikipedia Commons

📚 Read: APHUG - The Size & Distribution of Cities 🎥 Watch: APHUG - Urban Challenges

Growth of Cities

The locations of the world’s largest cities have changed over time due to increased economic development 💰💲💵💸 and globalization. 🌎 The largest cities in the world—megacities (10+ million population) and metacities (20+ million population)—are mostly located in low and medium-developed regions.

Some examples of these large cities include Tokyo, New York, Mexico City, Mumbai, and Shanghai. These cities are often centers of economic activity and are known for their high levels of innovation and cultural diversity. However, they can also face challenges related to overpopulation, traffic congestion, pollution, and the strain on resources and infrastructure.

In contrast, the most economically advanced countries and regions (United States, Western Europe) have a much smaller share of these types of settlements than in the past. The increased number of large urban settlements in less developed regions has created many challenges for leaders at varying scales of government while simultaneously increasing the interactions of these countries with wealthier states around the world. Although megacities and metacities are on the rise in less developed regions, global cities—ones with political, 📜 economic, 💲and cultural influence 👪👲👳 far beyond their own boundaries—are found primarily in the most highly developed countries.

🎥 Watch: APHUG - Urbanization and the Rise of the Megacity

City Models

In addition to the urban models that analyze distribution patterns within a country or region, geographers have also created urban land use models to better understand patterns within individual cities. The earliest models were based on North American cities in the first half of the 20th century (using the city of Chicago) and focused on a central business district (CBD) at the heart of the city where most commercial activities took place. 🏢💳👔💼💲As the economy became more advanced and people started to move, new urban models were developed to incorporate suburbanization that began in the 1950s. 🏡 The most recent urban models reflect the development of “edge cities” in the urban periphery, as more people and businesses have relocated to settlements outside the central city.

In addition to the North American urban models, several others were developed for less developed countries, which include the Latin American, African, and Southeast Asian City Models. While they all differ in some ways, each of these models reflects the influence of previous European colonizers and the adverse effects of rapid rural-to-urban migration occurring in the past half-century due to globalization. 🏙🏃

Urban Problems

The unit concludes with a careful examination of challenges within cities at different scales and locations throughout the world. Although not an exhaustive list, the following are challenges found in most urban areas throughout the world, regardless of economic development level:

Poverty—large numbers of people unemployed, reliant on government aid, and/or working in jobs without a livable wage.
Decaying infrastructure—roads, bridges, power, and sewage systems.
Housing shortages—for all social classes, but especially lower-income individuals and families.
Displacement of families following urban renewal efforts—including government housing projects and gentrified neighborhoods.
Homelessness—lack of affordable housing, and limited services for the homeless and impoverished.
Limited services (food, medical, education, etc.) for lower-income individuals and families.
Racial and ethnic discrimination—segregated neighborhoods, displacement of racial minorities due to gentrification, presence of food deserts in poor regions.
Crime—theft, homicide, and gang violence.
Pollution—including air (factory and vehicle emissions), water, waste disposal, and noise pollution.
Urban sprawl—the rapid expansion of suburban communities, which leads to a reduction in farmland, increased traffic congestion, etc.