Contemporary Urban Environments (mine)

Urbanisation

the process where the proportion of people living in towns and cities increases.

what are the causes of Urban Growth?

• natural population growth

• industrialisation

• rural-urban migration

how does natural population growth cause urban growth?

• young pop likely to migrate from rural areas → have children meaning the rates of natural increase are higher in cities.

• Traditionally younger adults live in urban areas due to the prospect of higher paid jobs, better education opportunities, and better social and cultural diversity.

• Between 2001 and 2011 the number of residents aged between 22-29 nearly tripled.

  • typical age that people have children. In London, the area between Clapham and Fulham has been termed ‘Nappy Valley’ due to the high number of young adults.

• Once, these young adults would have moved to the suburbs, however due to the rising costs in the suburbs they are choosing to stay within the city.

how does industrialisation cause urban growth?

• Sometimes considered as a pull factor for rural to urban migration → industrialisation of cities has been a large cause of urban growth.

• Many people are enticed into these urban areas due to the prospect of having a service or industry job, for example within a factory.

• These factory jobs bring notion of higher pay, better working conditions, and better social environments → result, younger adults will move to urban areas without their families in order to earn a wage to send back.

• Some factories e.g. China, will build dormitories for the staff. This provides them with housing, but also ensures that they are able to get into work.

how does rural to urban migration cause urban growth?

This is divided into push (centripetal) and pull (centrifugal) factors. Push factors are those that cause people to move away from rural areas, whereas pull factors attract them to urban areas. In low- income countries, push factors tend to be more important than pull factors.

push factors → largely due to poverty

• POPULATION GROWTH: means the same area of land has to support an increasing n of people, causing over-farming, soil erosion, low yields

• high levels of local diseases + inadequate medical provisions

• natural disasters like floods, tropical storms, earthquakes → people flee & don’t return

• war + civil strife → people flee there land

pull factors

• employment in factories/service industries → higher paid than in rural areas + increasing demand for unskilled labour in cities

• earning money from informal sectors → selling goods on the street/providing transport

• better q. social provisions → education, healthcare, entertainment, tourism

how muchhas population in urban areas increased?

• n. of ppl since 1945 has increased

  • 1950 → 30% lived in urban areas

  • 2014 → over 50% live in towns/cities

• developed world has seen slight pop increase as urbanisation began much earlier → industrial revolution people moved to cities to find work in mills and in factories

• in developing countries old cities afre expanding and new cities are being built e.g. Beijing pop went from 4.4 million in 1970 to 20.4 million in 2015

which processes affect pop of cities?

• urbanisation

• sub urbanisation

• conter urbanisation

• urban resurgence

Define urbanisation

• growth in proportion of ppl living in urban areas

• occurs due to migration & natural increase → birth rate = higher than death rate

• migrate to cities for better access to healthcare, schools & more jobs available

• migrants tend to be young adults → have kids → pop increases

what is a negative of urbanisation?

can result in shanty towns within developing countries → illegal settlements made of any available material

Define suburbanisation?

• movement of pop from city centres to city outskirts

• urbanisation = areas more densely pop + more expensive + people desire to move for more space → improved transport links allow this as people can just commute

what is a negative of suburbanisation?

• can lead to economic & ethnic segregation → patter of wealthier & poorer areas develop

• wealthy move to suburbs for better q. of life leaving behind poorer population

Define counter urbanisation?

• movement of people out of city into surrounding rural areas and villages

• improved transport links → people can commute to work

• improved communications e.g. internet → people can work from home

what is a negative of counter-urbanisation?

• people leave cities due to high property prices + overcrowding

• new housing esates built in rural areas to suppourt → house prices increase → local people can no longer afford area → age structure of area changes due to lack of affordability

Define Urban resurgence

• movement of people back into the city centre

• due to lack of jobs + new developments

• common in post-industrial countries like US/UK

• new shops/services open in the city as ppl move back → boosts local economy + creates jobs

what is negative of urban resurgence?

• Original residents may no longer be able to afford an area → forced to move somewhere cheaper

how has urbanisation led to the emergence of mega cities?

• mega city = urban area w over 10 million people

• 1950 only 2 → 2015 = 28

• develop due to rural-to-urban migration & natural increase → migrants move to cities experiencing rapid economic growth = rapid population increase

• dominate national + regional economies as companies build headquaters where there is a high concentration of skilled workers + transport links → e.g. internatinal airports

outline characteristics of world cities

• world cities global centres for finance, business & culture/

• they have ‘world’ influence e.g. London mostly in the developed world some in emerging economies like Rio De Janeiro

• since 1945, they have emerged as leaders of banking and finance → many banking companies like lloyds have their headquater located here

• they dominate national trade and regional economies in there areas

  • e.g. Tokyo influential to international trade in east asian nations

how do economic processes cause urbanisation

• people attracted to cities from potential job opportunities + jobs better paid

• urban pop increases → Businesses e.g. factories/shops grow in size → become more profitable → leads to more jobs + wage rises

• countries develop → Commercial farming overtakes subsistence farming as primary method of food production → decline in agriculture pushes more people towards cities

how do social processes cause urbanisation

• cities have higher living standards than rural areas → better access to healthcare + education attracts people

• migration of people increases mix of social backgrounds → people more tolerant of eachother + creates a more welcoming environment encouraging more ppl to come

• social segregation may also occur

how do technological processes cause urbanisation?

• factories emerge in cities → Urban areas become hotspots for technological advancements

• e.g. Manchester in the 19th century the first industrialised city in the world → nicknamed cottonopplis because of its cotton processing factories

• areas with large n. of high-tech industries have emerged e.g. Silicon Valley in California → attract people offering highly paid specialised jobs

how do political processes cause urbanisation?

• urban growth → increased inequalities → new ‘working class’ emerges made up of people who work in manufacturing industries

• new political movements emerge to represent the ‘working class’ population → political reform focuses on issues affecting urban life

  • e.g. poor sanitation, quality of housing, working conditions in factories

how do demographic processes cause urbanisation?

• cities become larger + wealthier → attract migrants from all over the world → urban areas become more ethnically & culturally diverse → new areas emerge → e.g. Chinatown NY

• young people attracted by jobs → + entertainment like bars/clubs → choose to stay and raise families in the city so cities tend to have younger populations in rural areas

which changes have developed countries undergone?

• deindustrialisation

• rise of service economy

• decentralisation

how have countries faced change through deindustrialisation

• 1960s developing nations (singapore, Taiwan etc) became industrailised

• countries able to produce goods ar lower prices to europe/north america due to low labour costs

• 1970s developed world struggled to compete with products being manufactured within the developing world → entire industries (steel in sheffield) collapsed → led to mass unemployment and poverty

• UK deindustrialisation caused unemployment to rise above 3 million in 1983 → highest rate of unemployment since ww2

how have countries faced change through the rise of service economy?

• 1980’s service industries like banking/retail began to expand and dominate western economies

• these industries were responsible for majority of economic growth in developed countries since deindustrialisation

how have countries faced change through decentralisation?

• land prices in cities increase → businesses/shops/offices forced to relocate to suburbs

• led to rise of out of town retail parks

• has caused city centre shops/buildings to close → led to buildings being abandoned, job losses and urban poverty

what was the purpose of urban policies

to regenerate citities

Urban Development Corporations (1980s) eg London Docklands

• Were set up to regenerate inner city areas

• Boards of the UDCs were made up of people from local business communities

• These people were encouraged to put money towards buying land, building infrastructure, and marketing to attract private investment

• Funding came from central governmen

what were the successes of urban development corporations?

• The docklands now contains some the world biggest banks including HSBC, Barclays and Merrill Lynch Bank of America

• There is now 14 million square feet of office and retail space. Many buildings include a canteen, gym, etc

• which helps businesses attract staff

• In 2000 only 28,000 people worked there compared to 105,000 people now working there

what were the failures of urban development corporations?

• The property-led approach did little to tackle social problems.

• local people complained they had little involvement in the process and, in the London Docklands, locals did not tend to benefit from the new housing and jobs created

City Challenge (1990s)

eg Hulme City Challenge partnership, Manchester

• A scheme where cities had to compete with each other for government regeneration grants

• Cities with the best scheme got a grant

• A local authority led scheme, forming partnerships between the private sector, local communities, and the local authority

• Strategies focused on helping social, economic, an environmental problems in run down areas in the city

what were successes of the city challenge?

• The fact that local authorities had to bid for funding was judged to have resulted in more successful regeneration schemes 

• City challenge gave equal importance to buildings, people and values 

• 1997 data revealed that the city challenge had improved over 40,000 houses, created 53,000 jobs and reclaimed 2000 ha of derelict land

what were failures of the city challenge?

• Resources were thinly spread over large areas.

• Areas which had previously received government funding based on need, no longer received funding because their bid was unsuccessful.

• Money was lost preparing bids by local authorities who did not win funding

Partnership Schemes - New Deal for Communities/City Deals (2010-present) eg Devonport or Manchester ‘Working Well’ pilot

or Birmingham’s Big City Plan (Changing Places)

• First wave of deals were completed in 2012, covering the eight largest English cities outside London

• Second wave was completed in 2014 and covered 14 largest English cities and wider areas

• This allows cities to: take responsibility for decisions affecting their area, designing strategies to help businesses, create economic growth, and deciding how public money should be spent

what were the successes of partnership schemes?

• The city deal approach to infrastructure funding has proven successful in

  • delivering increased economic activity,

  • infrastructure funding

  • and development certainty in a number of cities and will continue to be rolled out across the United Kingdom

what were the failures of partnership schemes?

• Many employers feel that adult employment and skills funding streams remain too fragmented and project-specific to allow cities to integrate policy and delivery across sectors between partners.

• A number of barriers to further local integration of employment and skills delivery remain. This is due to the payment-by-results nature of the deals.

• This has resulted in funding for programmes and specific projects rather than creating more flexible, non-ring fenced funding sources

define urban form

the physical characteristics which make up a city inluding size, shape , population density and how the city is arranged

what are the physical factors affecting urban form?

• topography

• water

• natural resources

• land type

how is topography affecting urban form

• physical features influence growth of cities

• steep slopes → harder to build on + less accessible → poorer housing like slums may be built on them

• large flat areas encourage low density developments as theres lots of space to build

how does water affect urban form

• presence of lakes and sea limits urban growth in those areas→ cities can grow along the course of a river

• city centre shops + businesses located close to the waterfront rather than at geographical centre of the city

how does land type affect urban form?

• some ground surfaces are more expensive/difficult to build on

  • e.g. swamps & wetlands can limit urban growth

what are human factors affecting urban form?

• planning

• infrastructure

• land value

how does infrastructure affect urban form?

• new developments are built along transport links → e.g. motorways → leading to linear growth

what are the different land use patterns from cities in the developed world?

• tend to have a central business district → central zone of shops & businesses

• CBD surrounded by housing - houses increase in value away from city centre though land value highest in the city centre

• common for science parks and large shopping centres to be constructed due to availability of cheap land in semi rural areas → close to urban centres

land use patterns of cities in the developing world

• have CBDs = contain shops, entertainment services, offices

• CBD surrounded by housing which decreases in vlaue with distance away from the centre

• land value highest around city centre, wages high, residents wealthy, areas home wealthy immigrants

• land value low on the outskirts of cities → low cost, informal housing built there with limited access to services like clean water and electricity → most residents have poorly paid jobs + poverty levels are high

• industrial areas are located along transport links

what are town centre mixed developments?

• areas where land use is mixed

• resident, commercial & leisure uses are combined → luxury flats, offices, shops, entertainment facilities e.g. gym, bars, cinemas

• developments are planned by local councils with private investment

• aims to attract ppl back to city centres

what are cultural and heritage quaters?

• areas focusing on history or character of a city

• often home to theatres, art galleries, historical mueseums

• often developed by local councils to regenerate former industrial areas → attract visitros encouraging economic developement + creating jobs

what are fortress developments?

• developments (e.g. for residential/retail use) with lots of security such as CCTV guards and high walls → often located in suburban areas of large cities - only those with permission can enter

• designed to give a safe environment for families but divisive as only rich ppl can afford to live in or use them

what are gentrified areas?

• gentrification = when wealthy ppl move into rundown inner city areas and regenerate them by improving housing

• gentrified areas can have a large range of services + contain high-quality housing

  • e.g. shops + restaurants

  • poorer residents may be displaced as cost of living increases → leading to ethnic and social segregation

what are edge cities?

• new areas of offices, shops + leisure facilities developing close to transport links

• often contain housing but most people travel to them for work

• majority have developed since 1950/60s as car ownership has increased

• most common in USA

what are characteristics of post-modern western cities?

• multiple centres with different purposes > a single centre

• focus on tertiary and quaternary industry e.g. IT instead of secondary industry

• less uniform architecture → buildings have a wider range of styles

• prioritses asthetic of city over practical use

• higher social + economic inequality

• e.g. of post modernist architecture → the gherkin in London

define economic inequality

is the unequal distribution of money amongst a population

where/why are economic inequalities high

• in the developing world

• developing countries lack resources to support poorest pop

• wheras developed nations have welfare state which provide basic services and income for those who are struggling financially

what issues can economic inequality cause within cities?

• political & social unrest e.g. rioting

• a rise in drug use, crime & violence

• health problems e.g. cities with higher levels of economic inequalities have more malnourished children

define cultural diversity?

• wide mix of people from different ethnic and cultural backgrounds

what are the benefits of cultural diversity?

• can enrich a citi’s character

• increase tolerance

• cultural events and ethnic quarters within cities can increase tourists → boosting cities economy

what are issues cause by cultural diversity within cities?

• tensions between different groups → can lead to violence

• increased pressure on services → e.g. school may need extra staff for people unable to speak the native language

• minorities may feel isolated & under-represented politically

• social segregation → groups separate from each other

  • either voluntarily → e.g. religious groups settling close to their places of worship

  • or forced → e.g. many Roma people in Italy can’t access social housing, ending up in camps on city outskirts

what issues can social segregation cause in urban areas?

• lack on integration between different groups → can cause prejudice and discrimination

• people in some areas may have less access to education & jobs → widening inequalities

• segregation → can lead to anxiety → & have negative impacts on health and life expectancy

• in developing countries poorer areas may lack access to facilities → e.g. electricity, clean water, public transport → more likely to be close to industry and rubbish dumps affecting health and well-being

what strategies are there to reduce poverty and economic inequalities within urban areas?

• improving transport systems → makes it easier for urban poor to access jobs

• subsidising construction of affordable housing → can help less wealthy people buy properties

• introducing minimum wages → help to stabilise wage inequalities between the rich & poo

what strategies are there to encourage social and cultural integration in urban areas?

• govs can encourage political participation of minority groups → e.g. by sending postcards/messages encouraging them to vote → ensures minority groups have the opportunity to influence decision making

• govs can pass laws → e.g to prevent companies discriminating against employees on the basis of race

• new developments can include luxury homes and lower-cost housing reducing divisons between richnpoor

• communities can help ease racial tensions → e.g. by involving different groups in projects to clean off racist graffiti

define the term → urban heat island affect

• the phenomenon of urban areas being warmer than rural areas

what are UHI’s → Urban Heat Islands?

• urban areas with higher air temperatures than the surrounding rural areas

What is an example of a clearly defined UHI?

London

Where are the highest tempratures in UHI’s found?

• in industrial areas

• in most densley built up areas → e.g. CBD

define the term temperature sink:

• pockets of cool air above parks and bodies of water

define the term temperature plateau:

• Areas within the city with the same land use → generally have the same temp

define temperature cliffs:

• rapid temprature change when land use changes

what are the 4 main causes of UHI effect?

1. Absorption of heat by urban surfaces

2. Air pollution

3. Heat from human activity

4. Less evapotranspiration

How does the absorption of heat by urban surfaces cause the UHI effects?

• concrete, brick & tarmac surfaces absorb and store heat from the sun during the day

• they slowly release heat as a long wave of radiation → most noticeable at night when it warms the air

how does air pollution cause the UHI effect?

• air pollution from cars and factories, increased cloud cover over the city

• it also creates a pollution dome → a layer of pollution over the city

• both things trap ongoing heat radiation and reflect it back to the surface

How does heat from human activity cause UHI effect?

• cars, factories, offices, central heating, air conditioning units and people themselves all release heat

How does less evapotranspiration cause UHI effect?

• when it rains, water is quickly removed by drainage systems → so there’s little surface water to evaporate

• little vegetation = little transpiration

• evapotranspiration uses heat energy → less evapotranspiration = higher temperatures

How does UHI effect vary Diurnally?

• UHI effect is stronger at night

• urban daytime temps are 0.6 degrees warmer than surrounding rural areas → nightime temps can be 2-4 degrees warmer → because rural areas cool at night but urban areas dont cool as much as urban surfaces continue to release heat they’ve absorbed during the day

How does the UHI effect vary seasonally?

• stronger in Summer

• average winter temps → can be 2 deg warmer

• average summer temps → can be 5 deg warmer as there’s more solar radiation in summer so urban areas absorb more heat

• Stronger when theres Anticyclones → which cause clear skies and low winds → no clouds = more solar radiation reaches and hits the ground → low winds = mean warm air isn’t blown away

how are winds affected by buildings in Urban areas?

• average wind speed is lower in cities than in rural areas → because tall buildings create friction slowing down moving air

• areas where wind speed is 0 → as some areas are totally sheltered from wind by buildings

• canyon effect may happen → where powerful gusts of wind may be channelled down streets

whats the weather like in urban areas?

• more rain, fog & thunderstorms

• rains more often in urban areas than in surrounding countryside areas

what are the 2 main reasons for rain being more intense and their being more thunderstorms within urban areas?

• UHI effect = air in urban areas is warm & warm air can hold more water → warm moist air rises = called convectional uplift - as it rises it cools, water condenses & it rains → This type of rain is called convectional rainfall

• urban areas generate huge amounts of dust and pollution, these particles float around in the air acting as condensation nuclei → encouraging clouds to form> rather than allowing warm moist air to disperse

why is there less snow and frost in urban areas?

• doesnt snow often

• when it snows, snow melts faster → die tp it being warmer from UHI affect

• urban areas have fewer days of frost for the same reason

whats the most common form of pollution in urban areas?

• particulate pollution

• found in urban areas rather than rural areas

what are particulates?

• tiny pieces of solids and tiny droplets of liquids floating in the air

what do sources of particulates include?

• vehicle exhausts → approx 80% in urban areas from them

• burning of cigs/fuels → e.g. coal which produces fine + coarse particulates like sulfates, soot and ash

• construction/mining/quarrying → produce coarse e.g. tiny fragments of rock

• plants and mould → generate coarse particulates e.g. pollen

what are issues associated with particulates?

• can cause health problems

• coarser particulates filtered out by the nose + throat, finer can enter the lungs causing bronchitis, lung cancer, asthma, heart disease

which types of pollution can lead to photochemical smog?

• pollutants like hydrocarbons come from burning fossil fuels

• when these pollutants come into contact with sunlight, UV light causes them to break down into harmful chemicals → forming photochemical smog

• photochemical smog is a problem in many cities → LA, Mexico City, Barcelona, Beijing → more common in places with hot + sunny climates as theres more sunlight

• photochemical smog is linked to health problems → breathing difficulties, respiratory disorders = asthma & headaches

what are the different ways to reduce air pollution?

• congestion charges

• pedestrianisation

• public transport improvements

• legislation

• alternative fuels

how does congestion charging reduce air pollution?

• people charged if they use their vehicles in certain places at certain times

• reduces pollution → by reducing road traffic

  • in central london, congestion charging reduced traffic and emissions in the congestion zoneby around 15% in first year of operation

• some people may travel to the edge of these zone to prevent being charged → increasing traffic in these areas

• hard to enforced change due to large volume of the traffic

how does pedestrianisation reduce air pollution?

• vehicles restricted from entering certain places at certain times → reduces pollution by reducing road traffic

• cities have pedestrianised zones → London, Liverpool, Cardiff, Manchester

• it may lead to shops receiving less customers as people can only reach them on foot

how do public transport improvement help to reduce air pollution?

• cities have improved bus services → journeys cheaper, faster & more efficient → cities introduce bus lanes so buses dont get caught in slow moving traffic

• park and ride schemes → make it easier to access public transport

• public transport links can be expensive → metrolink cost over £1 billion

• new developments can cause problems → park and ride schemes can shift traffic to rural area

how does legislation help reduce air pollution?

• aim to reduce pollution by limiting emissions and setting air quality standards

• UK clean air acts of 1956 & 1968 reduce domestic pollution

  • by introducing smoke control areas → where only smokeless fuels can be burned

  • reduced industrial pollution → by introducing the use of tall chimneys

• Road vehicles regulations reduce exhaust emissions by ensuring cars pass emission tests in their MOT

• in UK local authorities can issue fines to people who leave their engines running unnecessarily

how do alternative fuels help reduce air pollution?

• petrol/diesel can be replaced with cleaner fuels that pollute less like biofuels from plants which produce lower particulate emissions

• electric vehicles have lower emissions because they run off of batteries> conventional fuel → but producing/disposing of batteries can cause environmental problems

why is infiltration low and surface runoff high in urban areas?

• urban areas are covered in impermeable surfaces → e.g. concrete/tarmac + urban structures designed to shed water quickly → means infiltration is low

• ground water feeds rivers → during drier periods → river discharge in urban areas is low

• precipitation is higher in urban areas than rural + storms more intense → increasing surface runoff

• run-off is funnelled through manmade pipes which transfers water to rivers and streams

• low infiltration rates + high surface run off means = water enters rivers quickly → short lag time + high peak discharge

what is catchment management?

• a way of managing rovers and improving drainage systems by looking at the whole river catchment + interactions between water & land

what does catchment management aim to do?

• reduce urban drainage issues

• minimise issues like flood, drought, erosion in sensitive areas

• improve river ecosystems

Which 2 main methods can be used to manage river catchments?

• hard engineering

• soft engineering

how can hard engineering be used to manage river catchments?

• hard engineering → manmade structures like dams, used to preven flooding and ensure constatnt water supplies

  • NEG: schemes = expensive, disrupt natural systems increasing erosion, can alter wildlife habitats → dams can prevent salmon migrating upstream to breed

how can soft engineering be used to manage river catchments?

• involves land use management, → e.g. planting trees to reduce flood risk, and water pollution & prevent building on floodplains

• can involve river restoration & conservation

• cheaper + can improve the local environment

• planning restrictions can limit the construction of new homes + businesses

• land use management is hard in areas already urbanised

example of catchment management schemes being destructive

• construction of Three Gorges Dam, CHINA

• flooded 13 cities + 140 towns

• forced 1.2 million to move

what is the aim of SUDS?

• to make urban drainage more sustainable

• aims to imitate natural drainage systems > chanelling water through pipes

which SUDS methods are used to decrease flooding, water pollution & drought in urban areas?

• vegetated trenches → lower flood risk - decrease runoff

• vegetated roofs → intercept rainfall + increase evapotranspiration → reducing flood risk

• containers of roofs of buildings → catch & store rainwater for reuse → helps to reduce drought risk