AP HUG Unit 6 Terms and Definitions

(Urban) Annexation

The legal process by which a city expands its boundaries by absorbing adjacent unincorporated land or territory from surrounding areas.

Basic Business

A business that generates income from outside the local economy — it brings new money into the region. These are the 'export' industries of a city or region.

Bid-Rent Theory

A geographic economic theory that describes how the price and demand for real estate changes as distance from the CBD increases. Businesses near the CBD can afford to pay the most rent; as distance increases, land value/rent decreases.

Borchert's Transportation Epochs

A model by John Borchert describing how American cities developed through distinct eras of transportation technology, each shaping urban form differently: (1) Sail-Wagon (pre-1830), (2) Iron Horse/Steam Rail (1830-1870), (3) Steel Rail (1870-1920), (4) Auto-Air-Amenity (1920-1970), (5) High-Technology (1970-present).

CBD (Central Business District)

The commercial and business core of a city. Features: tallest buildings, highest land values, most accessible location, daytime population peak, offices, retail, entertainment, government offices. Lacks: residential housing (expensive), heavy industry, large parking lots. In the US, many CBDs have declined due to suburbanization; European CBDs remain more vital due to historic walkable design.

Central Place Theory (CPT)

Developed by Walter Christaller (1933). Explains the size, number, and distribution of cities/towns. Central places provide goods and services to surrounding hinterlands. Larger places offer higher-order goods; smaller places offer lower-order goods. Predicts a hexagonal market area pattern on a flat, uniform plain.

Commercial Area (Zoning)

A zoning designation that allows retail stores, restaurants, offices, and service businesses. Separates commercial uses from residential and industrial zones.

Concentric Zone Model (Burgess)

Proposed by Ernest Burgess (1925) based on Chicago. Cities expand outward from the CBD in concentric rings: Zone 1 = CBD; Zone 2 = Zone of Transition (mixed industry/old housing); Zone 3 = Working-class housing; Zone 4 = Middle-class residential; Zone 5 = Commuter/suburban zone.

Counterurbanization

The movement of people and businesses from cities to rural areas or small towns, reversing urbanization trends. Often driven by improved transportation, remote work, and desire for lower costs/more space.

Economic Base

The primary industries and businesses that drive a city's or region's economy by bringing in external income. Divided into basic (export) and non-basic (local service) sectors.

Enclosure

(Historical) The process in Britain (15th-19th centuries) where common agricultural land was 'enclosed' into private property, forcing rural farmers off the land and contributing to rural-to-urban migration and urbanization.

Edge City

A large node of office, retail, and entertainment development that has emerged on the suburban fringe of a major metropolitan area. Has more jobs than bedrooms. Developed near highway interchanges.

Exurb

A community beyond the suburbs — farther out from the city, often rural or semi-rural in character, but connected to the metropolitan area by commuters. Lower density than suburbs, even more auto-dependent.

Density Gradient

The change in population or building density from the center of a city outward. Traditionally, density was highest at the CBD and decreased with distance. Modern cities may show a 'density valley' near the CBD if it has been suburbanized.

Favela

An informal/squatter settlement in Brazil, typically built on steep hillsides or urban fringe areas, characterized by self-built housing, lack of formal infrastructure, and social marginalization.

Filtering

The process by which housing passes from higher-income groups to lower-income groups over time as the housing ages and its desirability (and price) declines.

Food Desert

An urban or rural area with limited access to affordable and nutritious food, typically lacking supermarkets or grocery stores within reasonable distance. Often found in low-income neighborhoods.

Galactic City / Peripheral Model

Developed by Chauncey Harris (1997). Describes the post-suburban metropolis with a CBD surrounded by suburbs, edge cities, boomburbs, exurbs, and airport/highway nodes, all connected by a beltway. Resembles a galaxy with clusters around a core.

Gentrification

The process of renovating and improving a district so that it conforms to middle-class taste, typically displacing lower-income residents. Often involves wealthier, usually younger, residents moving into older urban neighborhoods.

Gravity Model

Based on Newton's law of gravitation — predicts that interaction between two places is proportional to the product of their populations and inversely proportional to the distance between them. Larger and closer places interact more.

High-Order Services (CPT)

Goods and services that people are willing to travel long distances for because they are specialized, expensive, or purchased infrequently. Require large thresholds and have large ranges.

Hinterland

The surrounding region that a central place (city or town) serves. The area from which a city draws its customers, workforce, and resources.

Historic Preservation

Efforts to protect, conserve, or restore historically or architecturally significant buildings and districts. Can conflict with redevelopment and gentrification pressures.

Latin American City Model

Describes the internal structure of Latin American cities, shaped by colonial history. Features: CBD at the center (with a main plaza/cathedral), spine of commercial development leading to a mall, elite residential sector along the spine, inner-city slums (disamenity zones/favelas), and squatter settlements on the periphery.

Low-Order Services (CPT)

Goods and services that people buy frequently and are not willing to travel far for. Small range and threshold. Found in small towns and neighborhoods.

Megacity

A city with a population of more than 10 million people. Increasingly found in the Global South (periphery/semi-periphery).

Megalopolis

A chain of closely spaced metropolitan areas that have merged into one massive urban corridor. Jean Gottmann coined the term in 1961.

Metacity

A city with a population of more than 20 million people. Extremely large, complex urban agglomerations, mostly in the Global South.

Metropolitan Area

A large city and the surrounding suburbs, towns, and communities that are functionally integrated with it (commuting, economic ties, etc.). Broader than just the city itself.

MSA (Metropolitan Statistical Area)

A US Census Bureau designation for a core urban area of at least 50,000 people plus adjacent counties that are socioeconomically tied to the urban core (commuting patterns, etc.).

Multiple Nuclei Model

Developed by Harris and Ullman (1945). Cities don't have just one center — they develop around multiple nodes (nuclei), each with a specialized function: CBD, industrial district, university area, airport zone, etc.

Municipal / Municipality

A city, town, or other locality that has its own local government. The formal legal entity of a city or town with the power to tax, regulate, and provide services.

New Urbanism

An urban design movement that promotes walkable, mixed-use, transit-oriented neighborhoods with diverse housing types. Reaction against suburban sprawl and car-dependency. Emphasizes community, public space, and sustainable design.

Node

(Old term) A point of intersection or concentration of activity — a focal point in a transportation network or urban area. A central place where routes converge.

Non-Basic Business

A business that serves the local population rather than attracting outside money. Recirculates money within the local economy but does not bring in new money.

Outsourcing

The practice of a company contracting work to an external firm, often in another country, to reduce labor costs. Why: lower wages, fewer regulations, lower taxes. Where: initially to Mexico, now heavily to India, Bangladesh, Vietnam, China.

Periodic Market

A market that is not open every day but rather occurs on a regular schedule (weekly, bi-weekly, etc.). Common in areas where demand is not sufficient for a permanent market.

Periphery

In World Systems Theory (Wallerstein), less-developed countries that supply raw materials and cheap labor to the core. Also refers to the outer areas of a city relative to the CBD.

Primate City

A city that is disproportionately large compared to other cities in the country and dominates in economics, politics, and culture. Often more than twice the size of the second largest city.

Primate City Rule

The rule stating that a country's largest city (primate city) is more than twice the size of the second largest city. Related to rank-size rule but shows an imbalance.

Primary Sector Services

Economic activities that extract raw materials from the natural environment. Agriculture, mining, fishing, logging, quarrying.

Public Transportation

Transportation systems operated for public use, typically by government. Includes buses, subways, light rail, commuter rail, and ferries. Reduces car dependency, pollution, and sprawl.

Public Housing

Government-owned and operated housing provided to low-income residents at subsidized rents. In the US, often high-rise towers that concentrated poverty; many have been demolished.

Range (CPT)

The maximum distance a consumer is willing to travel to obtain a good or service. Higher-order goods have larger ranges; lower-order goods have smaller ranges.

Rank-Size Rule

The principle that in a country with a well-developed urban system, the nth largest city will be 1/n the size of the largest city. Example: if city 1 = 10M, city 2 = 5M, city 3 = 3.3M, city 4 = 2.5M, etc.

Redlining

A discriminatory practice (1930s-1968) in which the federal government and banks denied loans and insurance to residents in minority neighborhoods (outlined in red on maps), preventing homeownership and wealth-building. Outlawed by the Fair Housing Act of 1968.

Residential Area (Zoning)

A zoning designation for land used for housing. Can be single-family, multi-family, or mixed residential. Excludes commercial and industrial uses (in traditional Euclidean zoning).

Secondary Sector Services

Economic activities that process and manufacture raw materials into finished goods. Manufacturing, construction, processing industries.

Sector Model (Hoyt)

Proposed by Homer Hoyt (1939). Cities grow outward in wedge-shaped sectors (not rings) from the CBD along transportation routes. High-income housing follows the best transportation routes and tends to stay in the same sector as the city grows.

Site

The absolute, physical location of a place — its local characteristics: topography, soil, water availability, climate. Why cities were built where they were built.

Situation

The relative location of a place — its position in relation to surrounding features, trade routes, and other places. Explains why cities grew large and remained important.

(Urban) Sprawl

The uncontrolled outward expansion of urban areas into surrounding countryside, characterized by low-density development, auto-dependence, strip malls, and dispersed land uses.

Squatter / Informal Settlement

A settlement built on land that the residents do not legally own or have permission to use. Structures are self-built, often lacking formal infrastructure (water, sewage, electricity). Found on the urban periphery of rapidly growing cities in the Global South.

Smart Growth / Smart Growth Policies

Urban planning principles that aim to concentrate growth in existing urban areas to avoid sprawl, reduce auto-dependence, promote transit, and preserve open space and farmland.

Suburbanization

The process by which populations and businesses move from the urban core to the suburbs. Driven by: automobile, highway construction (Interstate Highway Act 1956), FHA loans, cheap land, 'white flight.' Accelerated post-WWII in the US.

Sustainability

Meeting present needs without compromising future generations' ability to meet their own needs (Brundtland Commission, 1987). In urban context: reducing ecological footprints, energy use, pollution, and sprawl.

Tertiary Sector Services

Economic activities that provide services to consumers and businesses. Retail, healthcare, education, government, finance, tourism, transportation. The dominant sector in MDCs/HDCs.

Urban Hierarchy (of Settlements)

The ranking of settlements from smallest (hamlet, village) to largest (megacity, world city), based on population size and the range of functions/services provided. Higher-order places provide more services.

Urbanization

The process by which an increasing proportion of a country's population lives in cities. Driven by rural-to-urban migration and natural increase in cities. Historically tied to industrialization; now driven by economic opportunity in LDCs.

Urban Growth Boundaries (UGB)

Government-designated lines beyond which urban development is prohibited or severely restricted. Designed to contain sprawl and protect farmland/open space.

(Urban) Infrastructure

The physical systems that support urban life: roads, bridges, water/sewer systems, electrical grids, public transit, broadband, airports, ports. Quality and distribution directly affect economic development patterns.

Urban Renewal

Government programs to redevelop deteriorated urban areas, often involving demolition of older buildings and replacement with new development. Mid-20th century US programs often displaced minority communities.

Urban Structure Model

A theoretical diagram that explains how land uses are arranged within a city. Major US models: Concentric Zone (Burgess), Sector (Hoyt), Multiple Nuclei (Harris & Ullman). Non-US models: Latin American, African, Southeast Asian city models.

World / Global City

A city that functions as a major node in the global economic network. Characterized by: major financial centers, headquarters of MNCs, major airports, significant cultural influence, advanced business services (law, finance, consulting). Does NOT have to be a primate city.

Zone of Transition

Zone 2 in Burgess's Concentric Zone Model. Located just outside the CBD; historically a mix of light industry, warehouses, and deteriorating housing. Immigrants and low-income residents moved there because rent was cheap. Site of intense urban change — gentrification today.

Zoning / Zoning Ordinance

Laws that regulate land use by dividing a city or county into zones that specify what activities are permitted (residential, commercial, industrial, agricultural). Shapes urban form and separates incompatible uses.

Boomburb

A suburb that has grown rapidly into a large, sprawling city with more than 100,000 residents. Characterized by fast population growth and suburban form even at large size.

Blockbusting

A discriminatory real estate practice where agents convinced white homeowners to sell cheaply by stoking fears that Black families would move in, then selling to Black families at inflated prices. Outlawed by Fair Housing Act of 1968.

Brownfield

An abandoned, idled, or underused industrial or commercial site in a city or suburb where expansion or redevelopment is complicated by environmental contamination.

Greenfield / Greenbelt

Greenfield: previously undeveloped land on the urban fringe, often converted to development (contributing to sprawl). Greenbelt: protected open space (parks, farmland) around an urban area to limit sprawl.

Inclusionary Zoning

Zoning laws that require or incentivize developers to include a percentage of affordable housing units in new market-rate developments.

Infilling / Infill Development

The development or redevelopment of vacant or underused parcels within existing urban areas, rather than expanding outward. Counters sprawl and uses existing infrastructure.

Disamenity Zone

A high-poverty urban area in a disadvantaged location, often containing squatter settlements, steep slopes, flood-prone land, rail lines, landfills, or heavy industry. Areas of environmental injustice.

Slow-Growth Policies

Policies designed to limit or slow the expansion and growth of a city, typically by restricting building permits, limiting infrastructure expansion, or imposing impact fees.

Threshold (CPT)

The minimum number of customers (or market size) needed to support a business or service. Low-order services have small thresholds; high-order services have large thresholds.

Quaternary / Quinary Sector

Beyond tertiary: Quaternary = information, research, education, finance, high-tech services. Quinary = highest-level decision-making (executives, government officials, top scientists).

Southeast Asian City Model

Describes cities shaped by colonial port history. Features: port/commercial zone at the center (not a traditional CBD), surrounded by zones of different ethnic groups established during colonial rule (Chinese district, foreign commercial zone), with Western-style suburbs beyond.

African City Model

Describes African cities that often have three CBDs: a traditional one (pre-colonial), a colonial one (European-built), and a modern one. Surrounded by informal settlements, ethnic neighborhoods, and mining/industrial zones.