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Human Geography Unit 6: Cities and urban land-use patterns and processes

Cities grow and organize space in patterns that geographers explain with urban models and theories.

Covers: Origins and influences of urbanization, cities across the world, urban hierarchies, urban models, density and infrastructure, urban sustainability, urban challenges

Study guide

Urbanization is the growth of the share of people living in cities. Early cities formed in agricultural hearths with food surpluses. Today, most people live in urban areas, and growth is fastest in developing countries. Megacities have over 10 million people, and world cities (global cities) like New York, London and Tokyo are hubs of finance and culture. Suburbanization moved people to the edges of cities, aided by cars and highways, leading to urban sprawl and edge cities. Boomburbs are rapidly growing suburbs.

Cities form urban hierarchies. Christaller's central place theory explains the spacing of cities by the services they offer, with each service having a threshold (minimum customers needed) and range (distance people will travel). The rank-size rule says the nth largest city is 1/n the size of the largest. A primate city is more than twice as large as the next largest city and dominates the country, like Paris or Bangkok. The gravity model predicts interaction between places based on population and distance.

Urban models describe city structure. The Burgess concentric zone model has rings around a central business district (CBD); the Hoyt sector model has wedges along transportation lines; and the Harris and Ullman multiple nuclei model has several centers. Other models include the Latin American city model (with a spine and wealthy sector), the Southeast Asian city model (with a port zone) and the African city model (with multiple CBDs). Challenges include redlining (denying loans in minority neighborhoods), blockbusting, gentrification, squatter settlements, filtering and inadequate infrastructure. Bid-rent theory explains why land is most expensive near the CBD. Smart growth and new urbanism promote walkable, mixed-use, transit-oriented development to make cities sustainable.

Metacities, sometimes called hypercities, have more than 20 million people, such as Tokyo, Delhi and Shanghai. Cities grow through rural-to-urban migration, driven by jobs, services and farm mechanization, and through natural increase among city residents. World cities are defined by their economic and political influence, not by population size. The galactic city, or peripheral, model shows a metro area as a central city ringed by a beltway, with suburbs, office parks and edge cities growing at highway interchanges. Joel Garreau coined 'edge city' for these suburban business nodes. They grew because highways and commuter rail made outlying areas easy to reach.

Migrants supply labor for construction, service and high-skill jobs, start businesses and add consumers, which boosts a city's economy. Fast inflows can also strain housing, schools and services and expand the informal economy. Infrastructure such as transit, roads, water, sewer, electricity and internet shapes who can reach jobs, schools and health care. Neighborhoods without good infrastructure, often poor or informal settlements, have fewer economic opportunities and worse health.

Critics argue that new urbanism and smart growth can raise property values and rents, which speeds up gentrification and pushes out lower-income residents. They also say these designs can feel artificial or be too costly to build widely. Large cities concentrate high-paying finance, tech and government jobs, educated workers and investment (agglomeration). Their GDP per capita is often far above the national average, especially in developing countries where rural areas remain poor.

Key ideas

• Urbanization is fastest in developing countries today.
• Central place theory explains city spacing through threshold and range.
• Primate cities dominate their countries.
• Urban models describe how land use is arranged in cities.
• Smart growth and new urbanism aim to make cities sustainable.

Formulas and rules

Common mistakes

• Confusing threshold (minimum customers) with range (maximum travel distance).
• Mixing up the Burgess (rings) and Hoyt (sectors) models.

Words to know

Urbanization

Growth in the share of people living in cities.

Megacity

A city with more than 10 million people.

World city

A global hub of finance, culture and politics.

Suburbanization

Movement of people to areas outside central cities.

Urban sprawl

Low-density development spreading outward.

Edge city

A large business and retail center on a city's edge.

Central place theory

Christaller's theory explaining the spacing of cities.

Threshold

The minimum number of customers a service needs.

Range

The maximum distance people will travel for a service.

Rank-size rule

The nth largest city is 1/n the size of the largest.

Primate city

A city more than twice the size of the next largest.

Gravity model

Interaction depends on population size and distance.

Concentric zone model

Burgess model of rings around the CBD.

Sector model

Hoyt model of wedges along transportation lines.

Multiple nuclei model

Harris and Ullman model with several centers.

Bid-rent theory

Land costs more near the city center.

Redlining

Denying loans in minority neighborhoods.

Gentrification

Wealthier people moving into and renovating poorer neighborhoods.

Squatter settlement

Informal housing on land residents don't own.

New urbanism

Design promoting walkable, mixed-use neighborhoods.

Sample practice questions

13 more questions like these, from level 1 to 5, are in the practice set.