In Augment’s notes, a marked term shows its definition when you hover or tap it, and each page ends with the terms it introduces.
133 terms from Urban environments, each defined in a sentence or two, with the part of the syllabus where you first meet it.
A sudden, sharp event that threatens a city, such as a flood, earthquake, heatwave, terrorist attack, cyber attack or disease outbreak.
The presence in the atmosphere of gases or particles, from human or natural sources, at concentrations that harm human health, ecosystems or materials.
A scale that converts measured concentrations of several air pollutants into one number and category, used to tell the public how polluted the air is and what precautions to take.
Heat released into the atmosphere by human activities, such as vehicles, heating and air conditioning, industry and people’s own metabolism.
A theory (Alonso, 1964) that land users bid for sites according to the value of accessibility to them, so land values and land-use intensity fall with distance from the city centre.
A theory, put forward by Wilson and Kelling in 1982, that visible signs of disorder and neglect in an area encourage further antisocial behaviour and more serious crime.
Land that has previously been developed, such as a former factory, dock or railway yard, which may be derelict or contaminated and can be reused.
A model (1925, based on Chicago) of a city as five concentric rings around the central business district, in which housing quality and residents' wealth increase with distance from the centre.
A high-capacity bus system with dedicated lanes, stations with fare payment before boarding and frequent services, giving metro-like speed and reliability at lower cost.
A planned area of offices, research and light industrial buildings in a landscaped setting at the edge of a city, with good road or airport access and parking.
A residential area designed so that most households do not own or need a car, with streets reserved for walking, cycling and access, and any parking placed at the edge.
The commercial centre of a city, with the highest land values and accessibility, tall buildings, a concentration of offices, shops and services, and few residents.
Christaller's model (1933) of the size, number and spacing of settlements that serve their surrounding areas, in which higher-order centres with larger ranges and thresholds are fewer and further apart.
The movement of people or economic activity away from the centre of an urban area, such as suburbanisation and counter-urbanisation.
The movement of people or economic activity towards the centre of an urban area, such as rural–urban migration, gentrification and reurbanisation.
Migration in which people follow relatives, friends or neighbours who have already moved, relying on them for information, housing and work at the destination.
A slow-moving, long-term pressure that weakens a city over time, such as poverty, inequality, ageing infrastructure, water scarcity or sea-level rise.
An urban metabolism in which outputs such as waste, wastewater and heat are reused or recycled as inputs, so the city uses fewer resources and produces less waste.
A model of sector shift in which, as an economy develops, employment moves from the primary sector to the secondary sector and then to the tertiary and quaternary sectors.
A town or village, usually beyond the edge of a city, whose residents mostly travel to work in the city each day.
An urban form with relatively high residential density and mixed land uses, which reduces travel distances and the amount of land built on.
The transport of goods in standard-sized steel containers that can be moved between ships, trains and lorries without unpacking, which cut shipping costs and required large new port terminals.
A situation in which different stakeholders compete for the same urban land or disagree over how it should be used or changed, usually because they gain or lose differently from the change.
A roof with a light-coloured or reflective surface of high albedo, so that it absorbs less solar radiation and stays cooler than a conventional dark roof.
The net movement of people from large urban areas to smaller towns, villages and rural areas beyond the edge of the city.
A small area in which crime occurs much more frequently than in the surrounding area, identified by mapping recorded crimes.
An approach that reduces opportunities for crime by designing buildings and public spaces with natural surveillance, clear boundaries, good lighting and maintenance.
The systems and assets, such as energy, water, transport, telecommunications and health services, that are essential to a city’s functioning and whose loss would cause severe disruption.
A self-reinforcing sequence in which low income leads to poor housing, diet, health and education, which lead to low-paid work or unemployment, keeping income low and passing disadvantage to the next generation.
A theory of residential design, put forward by Oscar Newman in 1972, that crime falls where the layout of buildings and spaces gives residents a sense of ownership and the ability to watch over them.
The long-term decline of manufacturing industry, measured by its share of employment or output, in a city, region or country.
The loss of parks, gardens, wetlands, farmland and other vegetated areas within a city to building and paving.
A lack of access to the goods, services, resources and opportunities considered normal in a society, such as adequate housing, education, health care, work and a safe environment.
The gap between people, places or countries that have access to modern digital technology and the internet and those that have limited or no access.
The involuntary movement of residents or businesses out of an area because of rising rents and prices, redevelopment or eviction.
A system that supplies heat to many buildings from a central source, such as waste heat, biomass or a heat pump, through a network of insulated pipes.
The delivery of public services and information through digital channels, such as online applications, digital identity and electronic voting.
A city or urban district planned or redeveloped to minimise its ecological footprint, through renewable energy, efficient buildings, low-car transport, recycling, green space and compact, mixed-use development.
A concentration of offices, shops and entertainment that grows at the edge of a metropolitan area, usually around a motorway junction, far from the traditional city centre.
A residential area in which one ethnic or cultural group is concentrated and has its own businesses, places of worship and community institutions.
The removal of people from their homes or land against their will, without appropriate legal protection, consultation or compensation.
A residential area enclosed by walls or fences, with controlled entrances, private security and often its own services, that restricts access to residents and their guests.
The movement of higher-income households into a low-income, often inner-city area, renovating housing and changing its social character, which usually raises property values and displaces existing residents.
A city that is a major node of the global economy, concentrating the headquarters of transnational corporations, financial markets and advanced business services, with strong international connections.
A ring of protected open land around a city in which new building is strictly limited, to prevent urban sprawl and protect the countryside.
A planned network of natural and semi-natural features in a city, such as parks, street trees, green roofs, wetlands and rivers, managed to provide cooling, flood control, cleaner air and habitats.
A roof partly or wholly covered with vegetation and a growing medium, which insulates the building, absorbs rainfall and cools the surface through evapotranspiration.
Land that has not previously been built on, such as farmland or open countryside, often at the edge of an urban area.
A model (1980) of the Latin American city with a central business district and commercial spine lined by an elite sector, surrounded by zones of maturity, in situ accretion and peripheral squatter settlements.
A city or regional plan to reduce deaths and illness in heatwaves, combining early warnings, public information, cooling centres, protection of vulnerable groups and long-term cooling measures.
A cross-section of air temperature across an urban area, showing a steep rise (cliff) at the urban edge, a suburban plateau, a peak over the CBD and cooler sinks over parks and water.
Physical measures such as bollards, barriers, planters and street furniture placed to stop vehicles being driven into crowds or buildings.
A model (1939) of a city in which land uses form wedge-shaped sectors growing outwards along transport routes from the centre, with high-class housing in sectors away from industry.
Improving an informal settlement where it stands by providing infrastructure, services and secure tenure, instead of demolishing it and moving its residents elsewhere.
A measure from 0 to 100 of how unevenly two groups are spread across the districts of a city, equal to the percentage of either group that would have to move for both to be evenly distributed.
A composite measure that combines weighted indicators of several domains of deprivation, such as income, employment, health, education, crime and housing, to rank small areas from most to least deprived.
The increase in traffic that follows an increase in road capacity, because faster journeys encourage more and longer trips, so that congestion often returns.
A planned area of factories, warehouses and workshops, usually at the edge of a city near major roads, where firms share access roads and services.
The basic physical structures and networks a settlement needs to function, such as transport routes, water and sewerage pipes, power supply, waste facilities and telecommunications.
The use of sensors, communications and data to manage traffic and public transport in real time, for example through adaptive signals, live passenger information and road pricing.
A medium-sized city, usually of about 50,000 to 1 million people, that links rural regions with larger cities and holds a large and growing share of the world’s urban population.
A network of physical objects, such as sensors, meters, vehicles and appliances, connected to the internet so that they can collect and exchange data without human input.
The purpose for which an area of land is used, classified in towns and cities as residential, commercial, industrial, transport, open space, institutional or vacant land.
An urban metabolism in which resources flow into the city, are used once and leave as waste and pollution, with little reuse or recycling.
A defined urban area in which the most polluting vehicles are banned or must pay a daily charge, to reduce traffic emissions; London’s Ultra Low Emission Zone is an example.
Public transport that carries large numbers of passengers along fixed routes, such as metros, commuter railways, trams and bus rapid transit.
A model (1967) of the South-east Asian port city, centred on the port, with western and alien commercial zones, mixed land use, squatter areas, and industrial estates and market gardening at the edge.
An urban area with more than 20 million people, a term used by UN-Habitat for the very largest urban agglomerations.
An urban area with a population of one million people or more.
Development that combines housing, shops, offices, services and leisure in the same area or building, so that people can meet daily needs within a short distance.
A model (Harris and Ullman, 1945) of a city that grows around several separate centres, such as the central business district, industrial districts and outlying business districts.
The number of people moving into an area minus the number moving out, when arrivals exceed departures.
The economic activity of a city in the evening and at night, such as bars, clubs, restaurants, theatres and late transport, often associated with concentrations of crime and disorder.
The relocation of some of a company’s production or services to another country, either to its own facilities or to foreign contractors, usually where costs are lower.
A large shopping centre or group of stores at the edge of an urban area, usually near a motorway or ring road, with extensive free parking.
A scheme in which drivers leave their cars at car parks on the edge of a city and complete their journey to the centre by public transport.
Solid or liquid particles suspended in the air, classed by diameter as PM10 (up to 10 micrometres) and PM2.5 (up to 2.5 micrometres), which penetrate deep into the lungs and bloodstream.
The point within a central business district with the highest land values, usually the junction of the busiest shopping streets.
The growth of urban populations, housing and economic activities in the zone just beyond a city's formal boundary, often unplanned and mixing urban and rural characteristics.
A brownish haze formed when nitrogen oxides and volatile organic compounds, mainly from vehicle exhausts, react in strong sunlight to produce ground-level ozone and other secondary pollutants.
A settlement designed as a whole before it is built, with its street layout, land-use zones and services decided in advance by a government or developer.
Economic activities that extract raw materials directly from the natural environment, such as farming, fishing, forestry, mining and quarrying.
A town or city planned and built from the beginning on an undeveloped site, with its layout, infrastructure and technology designed in advance.
Knowledge-based economic activities, such as research and development, information technology, consultancy and financial services.
A rule stating that in a country's urban system the population of the city ranked n is one nth of the population of the largest city.
The inclusion of spare or duplicate capacity in a system, such as back-up power or alternative routes, so that it keeps functioning if one part fails.
The long-term improvement of a declining urban area through investment in its economy, buildings, infrastructure, environment and community.
The difference between the rent a property earns in its current, run-down state and the much higher rent it could earn if renovated, which makes gentrification profitable.
The spatial separation of different social groups, such as ethnic, religious or income groups, into different residential areas of a city.
A global network of cities, successor to the Rockefeller Foundation’s 100 Resilient Cities programme (2013–2019), that shares methods for planning urban resilience to shocks and stresses.
Adding new technology, materials or design features to existing buildings, infrastructure or urban areas to improve their performance, such as smart sensors, insulation or flood protection.
The growth of population and investment in the central and inner areas of a city after a period of decline, often through redevelopment, conversion of older buildings and gentrification.
Charging vehicles directly for using roads, often varying by place and time of day, to reduce congestion and raise revenue, as in congestion charges and Singapore’s Electronic Road Pricing.
The zone at the edge of a built-up area where urban and rural land uses meet and mix, such as farmland, retail parks, housing estates, airports and waste sites.
The region of the north-eastern and Great Lakes United States, including Detroit, Cleveland and Pittsburgh, that has suffered deindustrialisation and population decline since the mid-20th century.
A planned area of high-technology and research-based firms located near a university or research institute to benefit from its research, staff and graduates.
Economic activities that process raw materials into manufactured products, including construction and energy production.
The ranking of settlements in a region or country by population size or by the number and order of their services, from many small hamlets to a few very large cities.
An urban area that has experienced a substantial and sustained loss of population, usually because of economic decline and out-migration.
The physical characteristics of the land on which a settlement is built, such as relief, geology, water supply, drainage and protection from hazards.
The location of a settlement in relation to its surroundings, such as other settlements, transport routes, resources and the wider region.
The demolition of informal or substandard housing in an urban area, with or without rehousing its residents, usually to redevelop the land or remove perceived health and safety risks.
A city that uses digital technology, sensors and data analysis to manage its infrastructure and services, such as transport, energy, water and waste, more efficiently and improve residents’ quality of life.
An electricity network that uses digital communication, smart meters and automated control to balance supply and demand, integrate renewable sources and respond to faults.
A designated area in which a government applies different, usually more liberal, economic rules, such as lower taxes and fewer trade restrictions, to attract investment and promote exports.
A city designed, as in China’s national programme from 2015, to absorb, store, clean and reuse rainwater through green spaces, wetlands, permeable surfaces and green roofs instead of draining it rapidly away.
The unplanned expansion of a settlement as buildings and streets are added gradually by individuals and businesses, without an overall design.
A model (van den Berg and others, 1982) of the sequence of urbanisation, suburbanisation, counter-urbanisation and reurbanisation that a city region may pass through.
Migration in a series of stages, for example from a village to a nearby town, then to a regional city and finally to a major city.
The concentration of student households in a residential area near a university, usually in converted shared rental housing, changing the area's population, services and character.
The outward growth of an urban area and the movement of people and activities from the inner city to residential and commercial suburbs at its edge.
A layer of the atmosphere in which temperature increases with height instead of decreasing, so cooler, denser air near the ground is trapped beneath warmer air and pollutants cannot disperse upwards.
Economic activities that provide services to people and businesses, such as retail, transport, health care, education, entertainment and tourism.
A condition in which the volume of traffic on a road network exceeds its capacity, causing slower speeds, longer and less predictable journeys and queues.
A continuously built-up area with a high density of buildings and people, in which most residents work in non-agricultural activities; each country sets its own threshold of size, density or status.
A street between rows of tall buildings, in which radiation is trapped by repeated reflection between walls and wind speed is reduced.
An economic or social role that a settlement performs for its residents and surrounding area, such as administration, trade, manufacturing, port activity, tourism, education or finance.
An increase in the number of people living in an urban area, or in the area it covers, regardless of any change in the share of the population that is urban.
An estimate of the future size of an urban population, calculated from present data and assumptions about natural increase, migration and the reclassification of settlements as urban.
An urban area that is significantly warmer than the surrounding rural area, especially at night in calm, clear weather, because urban surfaces store heat, human activity releases heat and there is less evaporative cooling.
A model of the city as a system of flows, in which resources such as energy, water, food and materials enter, are used and transformed, and leave as products, wastes and emissions.
The small-scale climate of a city, in which temperature, humidity, precipitation, wind and visibility differ from the surrounding rural area because of urban surfaces, buildings and human activity.
The demolition and rebuilding of an urban area, often changing its land use, density and population, as part of a plan to regenerate it.
The capacity of a city’s people, communities, institutions, businesses and systems to survive, adapt and keep developing despite the chronic stresses and acute shocks they experience.
The uncontrolled spread of low-density urban development, especially housing and roads, into the countryside at the edge of a city.
A city viewed as a system of inputs such as people, water, energy and materials, stores, flows and outputs such as goods, waste and emissions, linked by infrastructure.
The idea that settlements form a continuous gradient from highly urban to highly rural, rather than two distinct categories, with density and urban functions decreasing outwards.
A public square built below the level of surrounding streets that is used for recreation in dry weather and temporarily stores stormwater during heavy rain, releasing it slowly.
The UN Population Division’s regular estimates and projections of urban and rural populations and city sizes for every country, the main source of global urbanisation data.
The ring next to the central business district in the Burgess model, where older housing is being replaced by commercial and industrial uses and is occupied by the poorest residents and newest migrants.
A planning control that divides an urban area into zones in which only specified land uses or types of building are permitted.
A lack of access to the social conditions and opportunities most people in a society enjoy, such as good health, education, secure housing, safety and social networks, often concentrated in particular urban areas.