Cities & Urban Land Use
What this unit covers
The topics below follow the published Human Geo course framework for Unit 6. This unit is worth 12–17% of the exam, so budget your time against that rather than against how long the unit takes to teach.
Lessons in this unit
- Urbanization & City Systems13 min · 3 objectivesExplain urbanization, suburbanization, and the growth of world cities · Apply the rank-size rule, primate cities, and central place theory · Distinguish world/global cities, megacities, and metacities
- Internal Structure of Cities15 min · 3 objectivesCompare the Burgess, Hoyt, and Harris–Ullman urban models · Explain bid-rent theory and the location of the CBD · Apply the Latin American, African, and Southeast Asian city models
- Urban Challenges & Sustainability14 min · 3 objectivesAnalyze urban challenges: sprawl, segregation, and informal settlements · Explain gentrification, urban renewal, and their social effects · Evaluate smart growth, New Urbanism, and sustainable city strategies
Every term in Unit 6
All 18 terms we publish for Cities & Urban Land Use, with definitions. Reading them through is the fastest way to find the ones you cannot define — then drill those in cram mode until you can produce them without the prompt.
- Christaller's central place theory
- Settlements form a hierarchy of nested hexagonal market areas, with larger centers offering higher-order goods and being fewer and further apart.
- Urbanization
- The growing share of population living in cities, driven by rural-to-urban migration and natural increase, fastest today in the developing world.
- Site and situation for cities
- Site explains why a city began where it did; situation explains why it grew, since connectivity determines whether it becomes a node.
- Megacity and metacity
- A megacity exceeds ten million people; a metacity twenty million. Most growth in this class is now outside Europe and North America.
- World city
- A city commanding global finance, culture and decision-making — London, New York, Tokyo — whose influence exceeds its national importance.
- Range and threshold
- The range is how far people will travel for a good; the threshold is the minimum market needed to sustain it. Together they set how many of each service a region supports.
- Rank-size rule and primate city
- The rank-size rule says the nth city is 1/n the size of the largest. A primate city dominates disproportionately, often reflecting colonial history.
- Concentric zone model
- Burgess: CBD at the center, then transition, working-class, residential and commuter zones. Based on 1920s Chicago and assumes uniform growth outward.
- Sector model
- Hoyt: growth along transport corridors produces wedges rather than rings, so higher-income sectors extend outward along desirable routes.
- Multiple nuclei model
- Harris and Ullman: cities develop around several specialized centers rather than one, which fits car-dependent cities better than the older models.
- Latin American, African and Southeast Asian city models
- Griffin-Ford has an elite spine from the CBD with peripheral squatter settlements; African models show three CBDs from colonial layering; McGee centers on a former colonial port.
- Bid-rent theory
- Land value falls with distance from the center, so competing uses sort themselves by what they can pay — which explains why retail outbids housing downtown.
- Suburbanization and sprawl
- Outward low-density growth driven by cars and cheap land, raising infrastructure cost per person and consuming farmland.
- Gentrification
- Wealthier residents moving into a lower-income neighborhood, raising property values and investment while displacing existing residents.
- Urban redevelopment and renewal
- Public efforts to rebuild declining areas. Mid-century versions often demolished functioning communities in the name of blight removal.
- New Urbanism and smart growth
- Mixed-use, walkable, transit-oriented design intended to counter sprawl. Criticized for producing expensive developments that exclude those they claim to serve.
- Urban sustainability challenges
- Traffic congestion, air and water quality, waste disposal, heat islands, affordable housing and infrastructure maintenance.
- Squatter settlements
- Informal housing on land the residents do not own, common in rapidly urbanizing states where formal housing supply cannot keep pace.
What examiners penalize here
- Keep the three North American models distinct by their shape: **Burgess = rings** (concentric zones), **Hoyt = wedges** (sectors along transport lines), **Harris–Ullman = multiple nodes** (no single center). One word each — rings, wedges, nodes — anchors the answer.
Practice Human Geo
Our practice bank is drawn from across the whole course rather than filtered to one unit, which is closer to how the exam asks anyway — it will not tell you which unit a question is testing.
Questions about this unit
How much of the AP Human Geography exam is Unit 6?
Unit 6, Cities & Urban Land Use, is worth 12–17% of the Human Geo multiple-choice section according to the published course framework. Across all 7 units that makes it a substantial share — heavier than an even split would give it.
What topics are covered in Human Geo Unit 6?
Cities & Urban Land Use covers Urban models, Infrastructure, Urban challenges and Sustainability. We publish 18 terms with definitions for this unit, all of them on this page.
How should I study Human Geo Unit 6?
Read the 3 lessons below first — about 40 minutes — then drill the 18 terms in cram mode until you can produce each definition from memory rather than just recognize it. Recognition is what makes a unit feel finished when it is not. Finish with practice questions and read the explanation for every one you get right by elimination as well as the ones you miss.
All 7 units of AP Human Geography
Unit names, topics and exam weights follow the published College Board course framework for AP Human Geography. AP® is a trademark registered by the College Board, which does not endorse this site.