Flashcards in 9 Contemporary Urban Environments Deck (68):
What is a megacity?
A city with a population of over 10 million people, e.g. London
What is a metacity?
A conurbation with a population of over 20 million people
What is urban growth?
The increase of the number of urban dwellers
What is urbanisation?
An increase in the proportion of a countries population that lives in towns and cities
What is urban sprawl?
The spread of an urban area into the surrounding countryside
What are the causes of urban growth?
Moving population due to; economic activity, government institutions, business and transportation, higher levels of education, better health, easier access to social services and greater opportunities for cultural and political participation.
What is the cause of natural population growth?
Because young people are moving to cities due to pull factors like education and jobs, cities have higher fertility rates than the surrounding rural area.
What are the push factors for rural-urban migration?
Issues with low precipitation and over-farming in rural areas meaning lack of stable income
Disease epidemics without adequate health care
Local farmers being driven off of their land for commercial use
Wars and civil strife
What are the pull factors for rural-urban migration?
Employment opportunities in factories and service industries
Economy from the informal sector
Better quality social provisions such as healthcare, education, entertainment an tourism
Perceived better quality of life from the media
What are the consequences of urbanisation?
Shortage of housing in LIC's (leading to slums)
Lack of affordable housing in HIC's
Lack of urban services and waste disposal
Unemployment and under employment
What are the negative impacts of urban sprawl?
Requires more roads and infrastructure which is less economically efficient to service
Causes habitat loss
More fuel consumption from commuters
Increases air pollution and causes urban heat island
Affects the water cycle because of more impermeable surfaces
Industry also moves out of town but this leads to homogenisation or clone towns
Why do LIC's have a shortage of housing as a result of urbanisation?
Because of high population density leads to a shortage of accommodation. This leads to inadequate housing with poor building regulations and lack of access to basic infrastructure like water, electricity and waste disposal
Why do HIC's have a shortage of affordable housing as a result of urbanisation?
Rising demand for accommodation has resulted in a dramatic increase in house prices/rental costs. This is caused largely by gentrification and the purchasing of properties by wealthy FDI's.
Why is the lack of urban services and waste disposal an issue as a result of urbanisation?
Because of the financial restraints in urban areas in LIC's it can result in a lack of basic services such as water, electricity and maintenance of infrastructure. This can lead to traffic congestion, polluted water, flooding and rapid spread of disease
What is the issue of unemployment and under employment as a result of urbanisation?
Since a high proportion of the people who move to cities are relatively young, there is pressure to create sufficient jobs. Unemployment is high so people find employment in the informal sector and frequently people are underemployed (not making full use of their skills)
Why are transport issues a problem caused by urbanisation?
Increased traffic in cities from urbanisation and suburbanisation, has created more congestion and pollution which damages human health and wastes billions of pounds in lost productivity
What is counter-urbanisation?
The movement of people from large urban areas to smaller urban areas or rural areas (NOT THE RURAL URBAN FRINGE)
What is decentralisation?
The movement of population and industry from urban centre to outlying areas
What is deindustrialisation?
The loss of jobs in the manufacturing centre
What is gentrification?
The buying and renovating of properties in run down areas by wealthier individuals
What is suburbanisation?
The movement of people from living in the inner city to living on the outer edges, which has been allowed by improved transport and communications - permitting commuting`
What is urban resurgence?
Regeneration of economy and structures, in an urban area that has suffered a period of decline
What are the negative effects of suburbanisation?
Increased social segregation due to wealthier people moving away from the poor
Diversion of funding away from inner cities to the suburbs to pay for new infrastructure and services
What causes counter-urbanisation?
Out-migration of young people seeking education or jobs
Decline of elderly through death
The in-migration of young to middle-aged couples with children
The in-migration of younger, affluent, commuters - raises house prices
What is an urban form?
The physical characteristics that make built-up areas, including the shape, size, density and organisation of settlements. Can be on a range of scales; from regional to urban neighbourhood.
What is an edge city?
A self-contained settlement which has emerged beyond the original city boundary and is a city in its own right.
What is a fortress landscape?
Landscapes designed around security, protection, surveillance and exclusion.
What is a world city?
Cities that have great influence on a global scale because of financial status and worldwide commercial power
What is urban morphology?
The spatial structure and organisation of an urban area - could originally be affected by physical factors such as relief and drainage but after industrialisation most industries were built near rivers to use water for energy and transportation.
Explain the bid-rent theory.
Very profitable large retailers are found on the PLVI (peak land value intersection) in the centre of the city where prices are greater
CBD is inhabited by retailers and commercial enterprises
Smaller retails are more likely to be found around the edge of the CBD
What are the characteristics of fortress landscaping?
Railings and fencing
Mosquito alarms that emit a high pitched noise that only young people can hear to prevent loitering
What is postmodernism?
The changes that took place in western society and culture in the late twentieth century, mainly concerned with art and architecture and marked the departure from conformity and uniformity of modernism.
What is cultural diversity?
The existence of a variety of cultural or ethnic groups within a society
What is diaspora?
A group of people with the same heritage or homeland who has settled elsewhere
What is economic inequality?
The difference between levels of living standards, income etc. across the whole economic distribution
What is social segregation?
When groups of people live away from the majority because of factors such as wealth, ethnicity, religion or age.
What is urban social exclusion?
Economic and social problems faced by residents in areas of multiple deprivation
What are the reasons for economic inequality?
Housing - by planning affordable housing and expensive housing on opposite ends of the city, wealthier people can also choose to live away from poorer people.
Changing environments - many houses that were built to house larger families in Victorian or Georgian times have been converted into apartments for low income people and former poor areas are being gentrified - forcing poor people out
Ethnic dimension - people suffering discrimination in the job market and may be either unemployed or employed in low-paid jobs, can only afford cheap housing
What are the seven dimensions of deprivation?
Health deprivation and disability
Education, skills and training
Barriers to housing and services
How can cities tackle poverty and inequality?
Enforcing a living wage or providing urban subsidy
Provision of schools beyond primary school in LIC's
Supporting low-skilled workers who want to develop their abilities by giving them opportunities
Access to affordable housing
Greater provision of public transport
Enforcing environmental standards to aid health
Why is there greater cultural diversity in cities?
Results highly from immigration and cities have more immigrants because;
Better employment opportunities
Cities are the first point of entry into a country
Cities house immigrant groups with same ethnicity
Ethnic shops and religious centres
What is a microclimate?
Small-scale variations in temperature, precipitation, humidity, wind speed and evaporation in an urban area.
What is particulate air pollution?
Air pollution formed by the release of particles and noxious gases into the atmosphere
What is photochemical pollution?
Exhaust fumes trapped by temperature inversions which in the presence of sunlight, creates a low level ozone
What is temperature inversion?
Temperature, unusually increases with height. As inversions are extremely stable conditions and do not allow convection, they trap pollution into the lower layer of the atmosphere.
What is urban heat island?
The zone around and above an urban area, which has higher temperatures than the surrounding rural areas.
The temperature range is greatest at night due to high heat storage capacity of building materials compared to vegetation (as vegetation cools surroundings)
What are the reasons for urban heat island?
Surfaces have higher albedo
Air pollution creates a dome and reflects outgoing radiation back to the surface
Water is disposed as quickly as possible through drains which reduces the urban moisture, and reduces evapotranspiration meaning more energy is available as heat
Heat from industries, buildings and vehicles using fuel
Why is urban heat island a problem?
Extreme heat in the summer can be a risk to health - more cases of heat stroke, asthma and organ damage
More air pollution from chemical reactions happening faster in heat
Increased water consumption
Earlier flowering times of plants resulting in longer hayfever season
Increased deterioration of historical buildings through heat involved weathering
What are the strategies to reduce urban heat island effect?
Cool surfaces with low albedo
Green roofs with plants (which naturally cool the air) on roofs for reducing precipitation run-off and filtering pollutants
Sky view factor - the openness between buildings in an open area which can remove heat faster
Lighter coloured cars which reflect heat
Why is there more rainfall in an urban area?
Urban heat island generates convection which results in rapid evapotranspiration
Low pressure of rising air draws surface winds in from the surrounding rural area which converges and rises over the higher urban canopy
City pollution which are hygroscopic (water attracting) and assist in raindrop formation
Cities produce large amounts of water vapour from industrial sources and power stations
What is channelling?
Wind redirected down long straight canyon-like streets where there is less friction
What is the venturi effect?
The squeezing of wind into an increasingly narrow gap resulting in a pressure decrease and velocity increase
How has the government aimed to reduce air pollution?
Clean air acts such as smoke free zones in London and local councils in the UK have to monitor pollution in their area and establish Air Quality Management Areas when levels are likely to be exceeded
Vehicle control and public transport
Locating industry downwind and higher chimneys to emit pollutants above the inversion layer
What are sustainable urban drainage systems (SUDS)?
Aims to reduce flooding, control flooding and provide amenity for the community.
Roofwater is collected in water butts for use in gardens, rain falling on roads or paths soak through permeable block paving where it is filtered and stored in the stown below
What are the impacts of increasing waste generation?
The costs of collecting are high which means in LIC's waste is not disposed of to a proper standard and is usually a city's single largest budgetary item
Environmentally, waste is a large source of methane and contributes towards water, ground and air pollution
Can be a health hazard if not disposed of properly
Running out of landfill space
What are the approaches to waste management?
Recycling and recovery such as manufacturing new products from recycled material, which can work out cheaper than manufacturing it from new material (also known as urban mining), for example; recycling old aluminium requires 95% less energy from doing it from virgin materials.
Trade of waste between countries (however this is an issue because it is often from high to low income countries)
Incineration (but this produces pollution and costs)
How can we manage water pollution?
Low impact development (LID) - aims to reduce run off by planting vegetation and having permeable surfaces
Legislation regulation and enforcement - charging polluters per unit and limiting amounts of controlled pollutants
Improvements to sewage and wastewater processing
Appropriate technology (such as a Janicki Omniprocessor)
What is a Janicki Omniprocessor?
Provides clean water in low income countries - boils raw sewer sludge, solids are incinerated producing steam that drives an engine, producing electricity for the system processor and local communities, and then the water left over is put through a cleaning system to produce drinking water.
What is dereliction?
The state of having been abandoned and become dilapidated
What threats does dereliction cause?
Has a negative impact on the surrounding area and crime rates tend to be higher.
Contamination from industrial processes can live on in the environment long after the industry that produced them is gone - posing a health threat.
What is a brownfield site?
A term used in urban planning to describe land previously used for industrial purposes or some commercial uses
What is a greenfield site?
An area of undeveloped land
What is land remediation?
The removal of pollution or contaminants from the ground which enables areas of derelict former industrial land to be brought back into commercial use
What is sustainable urban development?
Meeting the needs of the present without compromising the ability of future generations to meet their own needs. A sustainable city is one which provides employment, a high standard of living, healthy environment and fair governance for all its residents.
What is an ecological footprint?
The total area of productive land and water required to produce the resources a population consumes and absorb the waste produced
What is liveability?
The characteristics of a city which improve the quality of life for the people living there
What is urban resilience?
The capacity of individuals, communities, institutions, businesses and systems within a city to survive, adapt and grow, no matter what kinds of chronic stresses and acute shocks they experience.