3.2.3.1 CUE>> Global patterns, significance and growth of urban areas Flashcards
Urbanisation
Urbanisation - increase in the proportion of people living in urban areas
Causes of urbanisation:
- Rural to urban migration —> happens due to push and pull factors
- Pull factors —> lack of services, lack of job opportunities
- Push factors —> better services, better job opportunities
- Natural increase (birth rate higher than death rate) —> many migrants in urban areas are young adults —> more likely to have children —> population increases further —> natural increase contributes to roughly 60% of urban growth
Urbanisation patterns:
- The number of people living in urban areas has increased dramatically since 1945. In 1950, 30% of people lived in urban areas. In 2014, just over 50% lived in towns or cities
Developed:
- Population has only increased slightly since 1945 —> urbanisation began much earlier in the developed world. e.g. during the industrial revolution
Developing:
- Urbanisation is happening at a quicker rate. For example, in Beijing, China, the urban population increased from 4.4 million in 1970 to 20.4 million in 2015
Consequences of urbanisation:
- Urban sprawl - spread of an urban area into the surrounding countryside
- More car dependant lifestyle leads to increases in fossil fuel consumption —> increases pollution —> impacts health/trigger different microclimate responses
- More houses —> impermeable surfaces —> flood risk increases
Shortage of housing in LICs:
- Leads to informal settlements —> these settlements have limited access to basic necessities and services —> more likely to be ill —> can’t go to work —> have to continue living in these settlements
- Dharavi slum —> people will build houses for themselves —> slum conditions are poor —> 1000 people sharing a toilet and approximately 14 people living in one room
Shortage of affordable housing in HICs:
- Urban planners have built sky scrapers —> small flats come with social problems —> many people in tokyo face issues with social interaction and spend vast quantities of time by themselves —> birth rate has decreased rapidly to 7.8 births per 1000 population —> creates an ageing population which creates issues —> less people working so less taxes —> less government spending on healthcare which the ageing population need
Lack of urban services:
- When more people move to cities, the demand for services increases —> lack of urban services due to high demand—> ill —> can’t go to work —> can’t pay tax
Unemployment:
- High proportion of people who move to cities are young —> lots of pressure on jobs —> some people unable to find one due to high proportion of people wanting a job
Deindustrialisation, decentralisation and urban resurgence
Deindustrialisation - decrease in the amount of manufacturing taking place (inner city areas suffer the most)
Causes of deindustrialisation in the UK:
- Cheaper labour and manufacturing costs in countries such as China
- Technological advancements —> automation reduces the need for manual labour
Example:
- Steel industry in sheffield collapsed —> caused mass unemployment with 3 million being out of work
Negatives of deindustrialisation:
- Deindustrialisation —> people unemployed —> less money to spend —> local shops and services get less income —> schools and shops etc start to close
- Deindustrialisation —> people unemployed —> less money to spend —> increase in burglary —> people move out of the area —> services and shops start to close
- Deindustrialisation —> industrial buildings become derelict —> increase in graffiti etc —> people move out of the area —> services and shops start to close
Rise of the service economy:
- Deindustrialisation has led to a rise in the service economy
- In 2015, the service sector accounted for 77% of the UKs economy
Urban resurgence - regeneration of an area after a period of decline (deindustrialisation) —> movement of people back into the city
How did they try regenerate areas after decline?
- Convert derelict buildings and industrial areas into houses
- Create new jobs
- Enhance the environment through the creation of open green spaces
Deindustrialisation and resurgence in Leeds?
- During the Industrial Revolution, Leeds developed into a major mill town —> In 1950, 55% of the Leeds workforce was employed in manufacturing but by 1960 this had declined to 35% —> jobs lost —> less income —> less money spent in goods/services so shops relocate —> decline of area
- Leeds Trinity opened in 2013 and transformed the centre —> attracted more people into Leeds
- Leeds arena opened —> attracts people into the city
Decentralisation - The movement of population, shops and offices away from urban areas to the suburbs
Causes of decentralisation:
- High costs in city centres cause businesses/offices to relocate to less expensive outskirts areas
- Improvements in transport links —> people can commute to work —> facilitates decentralisation
- Better communications —> allows businesses to operate from locations further from urban centres
Negatives of decentralisation:
- More car dependant lifestyle leads to an increase in fossil fuel consumption —> increases pollution —> impacts health/trigger different microclimate responses
- Attracts people to suburb areas —> less ppl in the city —> less demand for goods/services in the city —> city centre shops/services start to close —> urban decline
- Environmental impact —> deforestation to make space for businesses/offices etc
Regeneration policies
Regeneration policies:
City Challenge - Local authorities competed against each other for government funding to regenerate deprived urban areas
- The Manchester authority won the challenge with their proposal to regenerate Hulme
Issues in Hulme?
- Of the 5,500 dwellings in the Hulme area of Manchester, 98% were council owned
- There was a high number of single parents, and other people with social difficulties. There was some evidence that the local authority had used the area to dump some of its more unfortunate residents
- Perception of Hulme was bad so no one wanted to live there —> area went into decline
Redevelopment?
- 3,000 new homes were built (social - make area more attractive)
- The Moss Side Sports Centre was updated in 2002 and is now a modern facility widely used by the community (social - make area more attractive)
- The main shopping area was totally refurbished, including the addition of an ASDA supermarket (economic - jobs created) (social - make area more attractive)
- New road infrastructure was constructed —> easier to travel to places for work etc —> attracted more people into the area (economic)
Successes:
- Hulme’s population has grown by 3.3% since 1992
- Of the original goals of regeneration of Hulme, it is estimated that 80% of them have been achieved
- It was found that crime levels had gone down, with the police reporting a 40% reduction in crimes
Failings:
- Unemployment rates in 2003 remained 5-6x higher than the national average
- The bid was awarded based on the most attractive ideas rather than based on need (negative of city challenge)
- A lot of deprived areas didn’t receive any funding (negative of city challenge)
New deal for communities - 10 year strategies that were established to help the 39 most deprived regions of the country
Case study:
- Aston, inner city Birmingham —> identified as one of the 39 most deprived regions in the country
Issues in Aston?
- Poor health (poor diet inherited from the cultural background)
- High levels of unemployment —> in 2002, 36% of the working age population was unemployed —> predominantly muslim population —> lifestyle requirements such as friday afternoon prayers and english may not be their first language —> not easily employable —> if unemployed then no money —> area goes into decline
What was done?
- £4 million was spent on healthcare —> life expectancy is improving in Aston
- Health centre has introduced cooking clubs —> gives advice to people about healthier meals
- Project was set a target to help 400 unemployed people find work —> they managed to help around 1000 people through work experience programmes
Issues?
- The increased development in cities resulted in town centres being rundown —> more time and money centred on cities instead of towns —> moves the problem to another area
UDCs - In the 1980s, the government set up the UDCs to try and reverse inner city decline —> they set up the LDDC
- In the 19th century, Londons port was one of the busiest in the world but by the end of the 1950s, it was in significant decline with many of the docks derelict and abandoned
Why did the docks go into decline and why did the area go into decline?
- Containerisation —> few dockers were needed to lift containers from ships —> reduced demand for workforce —> fewer jobs in area —> travel further for work —> transport services to the rest of london were poor —> fewer people working —> less income —> less spent on goods and services —> shops started to close —> area went into decline
- Environmental quality of area was bad
Positives of LDDC:
Environmental:
- Planting of 200,000 trees
Economic:
- Unemployment had fallen from 14% to around 7%
- Transport improved —> docklands light railway —> carried 35,000 passengers a week —> improved accessibility
Social:
- 22,000 new homes built
- £100 million spent on health, education and job training
Issues of LDDC:
- Despite increased accessibility to jobs, dockers did not have the skills required
Enterprise Zones - In 1981, enterprise zones were established in areas with high unemployment —> they offered lower taxes to businesses and also eased planning restrictions
- High unemployment —> less money to spend on goods and services —> increase in burglary —> people move out of the area —> shops and services start to close —> area goes into decline —> enterprise zones
Positives?
- By 1990, the enterprise zones housed over 5000 companies, employing more than 125 000 people
Issues?
- Tax reductions encouraged many existing companies to move their premises and staff to the enterprise zones which limited the number of new jobs created
Example?
- The Metro Centre Gateshead (Newcastle) was established as an enterprise zone on an old industrial site (a power station) in which the land was bought for just £100,000 —> there were high levels of unemployment in Newcastle due to deindustrialisation
Megacity and world cities
Megacity - A city with over 10 million people
- In 1950, there were 2 megacities - tokyo and new york
- By 2014, there were 28 megacities
Why do megacities grow?
- Rural-urban migration and natural increase
Positives?
- Better access to education, healthcare and transportation
- Economic growth —> companies choose to build their headquarters in cities with a high number of skilled workers—> leads to economic growth —> on average megacities produce 2-3 times more GDP than other cities
- Cultural diversity —> lots of different cultures —> diversity attracts tourists/increased tolerance
Problems in megacities?
- More pollution —> impacts health
- More waste
- More congestion
- Shortage of housing
HICs:
- More money —> urban planners are often able to cope with pollution levels better e.g. by planting more trees, implementing more sustainable transport options, congestion charge
- Urban areas are growing much slower so controlling pollution levels is much more manageable
LICs (mumbai):
- Limited funding so issues like pollution are harder to address —> in 2015, the central pollution control board found that over half of india’s rivers were polluted —> impacts human health e.g. diseases like cholera spread —> affects ability to work and gain income
- Urban areas are growing at a faster rate so controlling pollution is harder
Shortage of housing
HICs (tokyo):
- Urban planners have built sky scrapers —> small flats come with social problems —> many people in tokyo face issues with social interaction and spend vast quantities of time by themselves —> birth rate has decreased rapidly to 7.8 births per 1000 population —> creates an ageing population which creates issues —> less people working so less taxes —> less government spending on healthcare which the ageing population need
LICs (mumbai):
- Dharavi slum —> people will build houses for themselves —> slum conditions are poor —> 1000 people sharing a toilet and approximately 14 people living in one room
A world city - a city that has political and financial influence over the whole world e.g. London and Sydney
- Most are in the developed world but some are in emerging economies e.g. Dubai and Rio de Janeiro
- The number of world cities is increasing. In 1950, the only world cities were London, Paris, Tokyo and New York. More recently, economic growth in oil-rich countries such as Nigeria has allowed cities such as Lagos to become contenders for world city status. These cities are increasingly important in global economics and business
- World cities are often the leaders in international trade. For example, Tokyo plays a big role in trade between East Asian countries. These cities have strong transport connections, making it easier for them to trade globally
- Since 1945, world cities such as London and New York have emerged as the leaders of banking and finance. Many banking companies, such as HSBC and Lloyds have headquarters in these cities
- World cities are generally home to prestigious universities
- Culturally diverse
- They tend to attract high numbers of people from other countries, including migrants, business visitors, students and tourists
Processes associated with urbanisation
Cities develop in lots of different ways as they urbanise:
Economic:
- Cities attract people from rural areas because they offer more job opportunities, and jobs are often better paid
- As the urban population increases, businesses grow in size and become more profitable. This leads to more jobs
Social:
- Cities tend to have higher living standards than rural areas, e.g. better access to healthcare and education
- The migration of people into urban areas increases the mix of people from different social backgrounds. This can make people more tolerant of others, creating a welcoming environment that attracts more migrants
Demographic:
- People from different social and cultural backgrounds migrate into the city, making cities more diverse
- Many young people are attracted by jobs and entertainment. They often choose to stay and raise families in the city, so cities tend to have a younger population than rural areas. Older people tend to move away from cities into the suburbs in search of a better quality of life, altering the demographic of urban areas
Political:
- Urban growth may lead to increased inequalities between rich and poor people. A new ‘working class’ emerges, often made up of people who work in manufacturing industries
- New political movements emerge to represent the ‘working class’ population e.g. voice their concerns on issues that affect urban life such as poor sanitation, quality of housing, working conditions in factories
Technological:
- Urban areas often become centres for technological advancement e.g. Silicon Valley
- New technology is often introduced into cities first as there is a higher demand for it e.g. the development of ‘Smart Cities’
Urban form
Urban form - The characteristics that make up a city including it’s size and shape, population density and how the city is arranged
Where were cities initially established?
- Good water supplies
- Fertile soil for growing food
- Natural resources (wood for fires)
- Good defensive positions (on top of a hill)
Human factors influencing urban form:
- Planning - urban expansion can be planned or unplanned. For example, a lot of urban growth in developing countries is caused by the unplanned expansion of slums
- Infrastructure - new developments are often built along transport links (e.g. motorways), leading to linear growth
- Land value - the highest value land is often found in the city centre, so profitable businesses (e.g. chain stores) normally locate there, while less profitable businesses (e.g. independent shops) may be found further from the centre
Physical factors influencing urban form:
- Topography - physical features often influence the growth of cities e.g. steep slopes are harder to build on and less accessible, so poorer housing (e.g. slums) may be built on them. Large flat areas encourage low density developments because there’s lots of space to build
- Water - the presence of lakes and seas limits urban growth in those areas
- Natural resources - rich resources (e.g. coal, metal) encourage growth in size and population of cities
- Land type - some ground surfaces are more difficult or expensive to build on than others e.g. swamps and wetlands can limit urban growth
Land use patterns in developed and developing countries:
- Cities in developed countries tend to have a Central Business District (CBD) — a central zone of shops and businesses.
- The CBD is surrounded by housing. Although land value tends to be highest in the city centre, houses generally increase in value with distance away from the centre
- Inner city areas have high land value, so housing is typically high density e.g. terraced housing. Wages are often low, and many residents live in relative poverty. The proportion of people from ethnic minorities tends to be high.
- Land value is lower in rural and semi-rural areas, so residential areas are less dense and have more open space
- Houses are usually larger and newer than those in inner city areas. Residents are generally quite wealthy and earn relatively high wages. The proportion of people from ethnic minorities tends to be low
- Cities in the developing world also have CBDs
- The CBD is surrounded by housing, which decreases in value with distance away from the centre
- Land value is highest around the city centre, so high-cost housing (e.g. luxury apartments) is built there. Wages are generally high, and residents are wealthy
- Surrounding the high-cost housing there is often a zone of medium-cost housing. It may have started as an informal settlement, but gradually the housing has been improved and some services have been provided
- Land value is very low on the outskirts of cities, so low-cost and informal housing is built there, often with limited access to services such as clean water and electricity. Most residents have poorly paid jobs and poverty levels are high
New urban landscapes:
Town centre mixed developments:
- Areas where land use is mixed
- Luxury flats, offices, shops and entertainment facilities can all be found in one place. This promotes sustainable living by reducing the need for extensive commuting e.g. covent garden, london
- Creates a diverse and inclusive living environment —> people of all ages and backgrounds etc —> greater social integration —> increased tolerance —> reduces social segregation
Cultural and heritage quarters:
- These areas focus on the history or character of a city e.g. the cultural quarter in Southampton includes the SeaCity Museum, which tells us about the city’s maritime history
- These areas are often home to theatres, art galleries and historical buildings
- They are often developed by local councils to regenerate former industrial areas. They attract visitors, creating jobs
Fortress developments:
- Developments with lots of security such as CCTV, guards and high walls
- Fortress landscapes have reduced crime levels e.g. in Hulme, homes and offices were built with large windows facing fields. This leads to fewer crime levels and attracts businesses/homeowners into the area. As a result, property prices increase. Only affluent people can afford to live here so rich people concentrated in one area. This widens inequalities
Gentrified areas:
- Gentrified areas are places where wealthier residents move into poorer, rundown areas and improve the housing e.g. Chapel Allerton, Leeds
- Pushes original residents out as cost of living increases. This leads to social segregation between rich and poor. The poor are concentrated in one area. Schools are likely to be below average in poorer areas. This leads to worse exam performance and widens inequalities
Edge cities:
- Urban areas that develop on the outskirts of cities
- This is because land is cheaper on the outskirts of cities
- For example, Las Colinas
Characteristics of post modern western cities:
- Multiple centres with different purposes e.g. technology, retail, heritage rather than a single centre for everything
- A focus on tertiary and quaternary sector
- Less uniform architecture —> buildings have a wide range of styles e.g. in London, buildings such as the Gherkin and Cheesegrater are examples of post-modern architecture
- High levels of diversity
- Higher social and economic inequality
- Planning prioritises the aesthetics of the city (how it looks) over practical use
Urban issues - economic inequality, cultural diversity, social segregation
- Economic inequality - the unequal distribution of money amongst a population
- Economic inequalities are higher in the developing world than in developed countries. This is because many developing countries lack the resources to support their poorest citizens, whereas most developed nations have welfare states which provide basic services and income for people who are struggling financially
Issues caused by economic inequality:
- Political and social unrest e.g. rioting
- A rise in crime, drug use and violence
- Health problems e.g. cities with higher levels of income inequality have more malnourished children
- Social segregation
Cultural diversity:
- Cities tend to be culturally diverse - they have a wide mix of people from different ethnic and cultural backgrounds
Benefits:
- Ethnic diversity can enrich a city’s character
- Increased tolerance
- Cultural events and ethnic quarters within a city can attract tourists, boosting the city’s economy
Issues:
- Tensions between different groups, sometimes leading to violence
- Increased pressure on services e.g. schools may need extra staff for pupils who can’t speak the native language
- Minority communities can feel isolated and under-represented politically
- Social segregation - this is when different groups are separated from each other e.g. poorer people or people from a particular ethnic background are concentrated in a specific area of a city
Social segregation:
- This can be voluntary e.g. followers of a particular religion may choose to settle close to their place of worship
- It can also be forced e.g. many Roma people in Italy can’t access social housing, so they end up in camps on city outskirts
Issues with social segregation:
- Lack of integration between different groups can cause prejudice and discrimination
- People in some areas may have less access to education and jobs, widening inequalities
- Segregation can lead to anxiety and 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
Strategies to manage urban issues:
Reduce economic inequalities:
- Improving transport systems can make it easier for the urban poor to access jobs
- Subsidising the construction of affordable housing can help less wealthy people to buy property
- Introducing minimum wages can help to stabilise wage inequalities between the poor and rich
- Governments can offer subsidies for new companies, increasing local employment opportunities
- In developing countries, many cities have introduced upgrading programmes for slum settlements e.g. Favela Bairro Project
Encourage integration:
- Governments can encourage political participation of minority groups e.g. by sending postcards and text messages encouraging them to vote. This ensures minority groups have opportunities to influence decision-making
- Governments 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 divisions between rich and poor
London case study:
- London has issues associated with economic inequality, cultural diversity and social segregation
- London is home to some of the richest and poorest people in the UK — this gap has widened since the 1980s
- The average annual income in Kensington and Chelsea is more than £130,000, but in Newham it’s less than £35,000. Low wages and few job opportunities in some areas mean that more than 25% of people in London live in poverty
- Many inner city areas e.g. Notting Hill, have been gentrified — this has forced poorer residents out of the area
- London is culturally diverse - more than 50% of the population is not white British. Proportions of ethnic minorities differ widely between boroughs - e.g. in Brent over 60% of people are not white British, whereas in Havering the proportion is only around 16%, suggesting that ethnic segregation is an issue
- Hate crime based on race and religion is a problem in London e.g. in the twelve months before July 2015, there were over 800 anti-Muslim incidents in the city
- Social segregation based on age and class is also an issue - London residents have less interaction with people of different age groups and classes than people elsewhere in the UK. This could lead some residents to feel isolated
Strategies to tackle these issues:
1. The London Living Wage is £13.85. This should increase income and social mobility in deprived areas
2. London mayor, Sadiq Khan, plans to build more affordable homes in London - this could allow less affluent people to remain in more expensive areas, reducing social segregation
3. The police are working to tackle hate crime e.g. by encouraging people to report it and offering support to victims
4. Some charities are calling for better access to English language classes for immigrants, and mentoring schemes to help recent immigrants adjust to life in the UK, with the aim of increasing integration between groups
UHI
Urban heat island effect - urban areas being warmer than surrounding rural areas
Temperature peak - the highest temperatures are found in industrial areas and in densely built up areas e.g. the CBD
Temperature sink - pockets of cool air are found above parks and bodies of water (e.g. rivers or ponds)
Temperature plateaus - areas within the city with the same land use generally have the same temperature
Temperature cliffs - temperature can change rapidly when land use changes e.g. from inner city housing to CBD high rise buildings
4 main causes of UHI effect?
Absorption of heat by urban surfaces:
- Surfaces in urban areas have low albedo and tend to be much less reflective so they absorb a lot of heat —> concrete, brick and tarmac surfaces absorb and store heat from the sun during the day. This heat is slowly released as long wave radiation at night
- Rural areas tend to have more grass —> greater albedo —> temperatures lower
Air pollution:
- Air pollution from cars and factories increases cloud cover and creates a ‘pollution dome’ (layer of pollution over the city) —> both of these trap outgoing heat radiation and reflect it back to the surface
Heat from human activity:
- Cars, factories, offices, central heating, air conditioning units and people themselves all release heat
- People release heat so cities with large populations will be warmer —> positive feedback loop —> people will turn air conditioning on —> releases hot air into atmosphere —> temperatures rise
Less evapotranspiration:
- When it rains, water is quickly removed by drainage systems —> less evapotranspiration —> less cooling effect from water —> higher temperatures
UHI day and night:
- The UHI effect is stronger at night
- Urban daytime temperatures are on average 0.6 °C warmer than surrounding rural areas but at night time, temperatures in urban areas can be 3-4 °C warmer than rural areas —> rural areas cool down at night, but urban areas don’t cool as much because urban surfaces continue to release heat that they’ve absorbed during the day
UHI seasonally:
- UHIE is stronger in summer
- Average winter temperatures can be 2°C warmer, but average summer temperatures can be up to 5°C warmer in urban areas —> there’s more solar radiation in summer so urban areas absorb more heat
- UHIE is stronger when there’s an anticyclone —> anticyclones cause clear skies and low winds —> if there are no clouds, more solar radiation reaches and hits the ground —> low winds mean warm air isn’t blown away
How can the UHI effect be managed?
- Increased vegetation —> plants absorb sunlight and reduce the amount of heat absorbed by buildings// trees also release moisture into the air through evapotranspiration —> cools the air down
- Implementing cool roofs —> reflects more sunlight and absorbs less heat than standard roofs —> less heat transferred into buildings —> reduces the need for air conditioning
- Urban design —> e.g. using lighter coloured materials for buildings and roads and creating more open spaces
- Energy efficient appliances —> less heat released by energy efficient appliances —> reduce overall heat production in urban areas
Urban drainage
- Urban areas are covered in impermeable materials e.g. concrete and tarmac. Many urban structures are designed to shed water quickly. This means that infiltration is low in urban areas
- Precipitation is higher in urban areas than in rural areas, and storms are more intense - this increases surface runoff
- Low infiltration rates and high surface runoff means that water enters rivers quickly. This gives a short lag time and high peak discharge
2 methods to manage urban drainage issues (manage river catchment):
- Hard engineering - this involves man-made structures such as dams, floodwalls and reservoirs, which are often used to prevent flooding and ensure a constant water supply. However, hard engineering schemes are often expensive and can disrupt natural systems
- Soft engineering - this uses knowledge of the river basin and its processes to try to work with nature. It involves land use management e.g. planting trees to decrease flood risk and water pollution, and preventing building on the flood plain. It can also involve river restoration and conservation. It is generally cheaper than hard engineering, and it can improve the local environment. However, planning restrictions can limit the construction of new homes and businesses, and land use management is hard in areas that are already urbanised
- Catchment management schemes can also be disruptive - e.g. construction of the Three Gorges Dam in China flooded 13 cities and 140 towns, forcing over 1.2 million people to move
SUDS:
- SUDS aim to imitate natural drainage systems, rather than channelling water through pipes and drains. They use several methods to decrease flooding, water pollution and drought in urban areas
- Vegetated trenches (swales) - increase interception of rainfall. This decreases runoff, which lowers flood risk. Increased infiltration also decreases the amount of pollutants entering watercourses
- Vegetated roofs - intercept rainfall and increase evapotranspiration, which reduces flood risk
- Containers on the roofs of buildings catch and store rainwater for reuse. This helps to reduce drought risk
- SUDS are more sustainable than traditional urban drainage methods because they work with the natural environment to improve drainage and water quality
Urban drainage case study
Cheong Gye Cheon is a natural river flowing west to east through the centre of Seoul
In 2003, a $281 million scheme was launched to restore the river —> highway concrete was dismantled to create a 5.8km green pedestrian corridor (increased vegetation)
Prior to the project, the river had been covered by a highway, which contributed to significant environmental problems such as traffic congestion, air pollution and flooding
Successes:
- Cheonggyecheon river has become a tourist attraction —> 18.1 million visitors by 2008 (economic)
- Removal of large numbers of cars and more pedestrianisation// increased vegetation —> -4.5% reduction in UHIE (environmental)
- Seoul is vulnerable to monsoon rains, which can lead to flooding. Restoring the river led to increased green spaces and less pavement, which allowed more water to infiltrate into the ground instead of running off the surface - reduced surface runoff - decreases flooding (environmental)
- Before the restoration, residents were more than twice as likely to suffer from respiratory disease as those in other parts of the city (social)
- School children have access to a valuable educational resource (social)
- By removing the highway and restoring the river, the city reduced air pollution and created green spaces. The presence of more vegetation and open water helped purify the air and make the city more liveable (-10% in air pollution) (social)
Failures:
- Expensive - $281 million
- The scheme gentrified the area —> more desirable place to live —> house prices increased —> forced 1000s of people to move away as they couldn’t afford increasing prices
- 80,000 tonnes of waste was generated from the project —> waste is expensive and difficult to get rid of —> may be left in other areas
- Although waste generated was recycled e.g. 100% of scrap iron and steel was recycled —> not possible for LICs due to insufficient funding —> water management only achievable in HICs
Waste in urban areas
In urban areas, waste is an issue as there is a limited amount of space in which to dispose of waste so it can become an environmental problem. The growing population in urban areas also emphasises the problem as there is a demand for more consumer goods and limited available space within the city. The World Bank has estimated that by 2100 the growing global urban population will be producing three times as much waste as it does today.
Waste is generated from many sources:
Residential waste
- This mainly consists of food waste, plastics, cardboard and paper. In the developed world this is becoming a bigger issue as the growth of a consumer society leads to the purchase and disposal of more goods. In the developing world this is also an issue, but less so as people often live less ‘disposable’ lifestyles. Often in slum or unofficial settlements without adequate sanitation or waste disposal units, this can become a large health issue for the residents as well an environmental issue
Industrial waste
- Industrial waste is defined as waste generated by manufacturing or industrial processes. Industrial waste can be hazardous e.g. chemicals and pesticides
Commercial
- Waste produced by businesses like restaurants or shops e.g. paper, plastics, food, packaging
Lifestyles and attitudes and their impact upon waste
- Waste is an issue in both developed and developing world urban areas. The type of waste is the main difference. In the developed world where many people are wealthy, people produce large volumes of consumer waste. This waste is often transported to disposal sites, such as landfills or incineration plants, which are typically located outside urban areas to avoid the environmental and health impacts within the city. Additionally, some developed countries export their waste to other nations, particularly developing countries, where the waste can be processed for economic gain. While this can create economic opportunities in the receiving countries, it often leads to environmental and health issues, as the waste management infrastructure in these countries may not be adequate to handle large volumes of imported waste safely. Thus, while developed countries generate large amounts of consumer waste, they often externalize the problem by moving waste to areas outside the city or even to other countries.
- In developing world cities, waste is not regarded as an environmental problem but as a potential resource. In squatter settlements, where waste is left on the street and people live their lives surrounded by this waste, the economic potential of waste is greater than concern for the environmental and health implications that it holds. For example, people can become waste pickers - collect and sort through the waste, looking for materials that can be sold or recycled. This helps them earn a living.
Approaches to waste management
Unregulated disposal
- Unregulated waste disposal is an issue in many cities across the world - waste is dumped in places that aren’t official disposal sites
- In developing world cites where environmental laws are less structured, many large organisations will release liquid and solid waste into local water courses. As well as damaging ecosystems, it also contaminates water —> can lead to ill-health for local people —> impact life expectancy
- In the developed world, illegal dumping from industrial sources in cities is still an issue but not to the same extent as in the developing world due to the better regulated environmental laws. Most companies dispose of their waste in the appropriate way, not only to avoid heavy fines but to maintain a high perception of environmental stewardship with their customers
Recycling - converting waste into new products
- In the developed world cities there has been an increase in the amount and range of materials that are being recycled rather than being sent to landfill. Materials such as paper and cardboard are regularly recycled. This has a positive environmental effect due to the reduced landfill space required and also reduces the need to exploit additional natural resources
- In the developing world, unregulated recycling takes place e.g. waste pickers - collect and sort through the waste, looking for materials that can be sold or recycled. This helps them earn a living.
Negatives?
- Recycling requires waste to be separated and categorised —> some people cannot be bothered
- Requires construction of new facilities to process waste —> construction leads to be more air pollution and more GHG/ construction can be expensive
Recovery
In developed world cities in particular, recovery takes place. This is where instead of disposing of waste, the original material is reused for another purpose (focuses on new uses of materials) —> reduces the amount of waste going to landfill
Incineration
- Incineration is a waste treatment process that involves burning waste. Incineration of waste materials converts the waste into ash, gas, and heat. Burning waste can emit greenhouse gases/ release toxic chemicals into the air —> environmental and health impacts. In some cases, the heat generated by incineration can be used to generate electric power and this can be a positive impact as it reduces the need for fossil fuel powered stations.
Burial (landfill)
- Leads to environmental issues —> As waste decomposes, it can produce methane gas, which contributes to global warming. Landfills can also contaminate surrounding land with chemicals and toxins and attract vermin, posing health risks. However, many landfill sites in the developed world now recognise that the decomposition of organic waste leads to the release of methane gas, which is now more likely to be collected and used as an energy source.
Submergence - dumping waste under water
- Submerged waste can damage ecosystems e.g. animals can be harmed if they swallow or get tangled in plastic waste
Trade
- Waste can be bought and sold by countries e.g. developed countries may pay developing countries to take their hazardous waste —> developing countries may not dispose of hazardous waste safely —> damage local environments e.g. air pollution —> damages human health
Facts about waste:
- The average person in the UK produces 517kg of household waste each year
- Waste is estimated to account for 5% of global greenhouse gas emission
- Globally, waste increases by about 7% each year
Impacts of increasing waste generation?
- Cost —> The cost of collecting and treating waste are high
- Collection —> Many city authorities are struggling to collect increasing quantities of urban waste. In 2012 the World Bank found that 30-60% of urban solid waste in LICs is uncollected
- Pollution —> Impacts air/water quality —> impacts health —> diarrhoea and cholera
- Space —> Cities are running out of landfill space so rubbish is left in public places e.g. rivers —> contaminates water —> water pollution
London and Mumbai managing waste?
London:
- London produces enough waste every year to fill 1500 olympic sized pools
Managing waste?
- Reduce single use plastic water —> partnered with thames water to install a network of more than 100 drinking water fountains across london
- Helping businesses reduce food waste —> FoodSave have supported over 200 food organisations in London to prevent food waste
Mumbai:
- Increasing population in Mumbai produces more waste —> e.g. in the neighbourhood of Chembur, waste in open rubbish dumps are burnt —> air pollution —> impacts health —> 25% of deaths in Chembur between 2008 and 2010 were caused by respiratory problems
Managing waste?
- Clean up Mumbai campaign —> cleaning up streets and educating people about how to recycle + dispose waste to limit environmental damage
- Waste pickers —> sort though piles of waste and separate the different materials —> less rubbish ends up in landfills and more is recycled
Sustainable cities
Ecological footprint:
- An individual’s ecological footprint is the amount of land that is needed to produce everything they consume, and to absorb their waste
The ecological footprint of a city depends on:
- Wealth - e.g. consumption and waste production is higher in cities in richer countries
- Size of city - e.g. compact cities are easier to travel around on foot or by bike, so they produce less pollution
- Quality of public transport — efficient public transport systems decrease car use, and therefore reduce pollution
Dimensions to sustainability:
- To be sustainable, a city must meet the needs of people today without preventing future generations from meeting their needs
Natural:
- Natural sustainability is about how the environment, resources and waste are managed
- Cities with a high level of natural sustainability rely on renewable energy sources (e.g. wind). They produce relatively little waste, and reuse or recycle the waste they produce
- Cities where people walk, cycle and use public transport a lot produce less pollution, so they are more sustainable
Physical:
- Physical sustainability is about how well a city is able to support the people living there
- To be sustainable, a city must provide enough resources to support the population e.g. jobs
- Features of physically sustainable cities include plentiful high quality housing and secure supplies of nutritious food, safe water and energy for all residents
Social:
- Social sustainability is about how people live together, their quality of life, and the availability of basic services e.g. healthcare
- Cities offer good living conditions for all residents, with access to basic services e.g. hospitals, schools etc. are within easy reach
- Socially sustainable cities are peaceful, tolerant, respect human rights and are politically stable
Economic:
- Economic sustainability is about maintaining economic growth without causing long-term negative effects e.g. environmental damage, social inequality
- Cities with high levels of economic sustainability are wealthy, have low levels of inequality and little debt. They are home to profitable, ethical businesses that offer plenty of well-paid jobs
Liveability:
- Sustainability can affect the liveability of a city - this is a measure of how good living conditions in an area are
- Liveability depends on many factors, including job opportunities, crime rates, open space and access to education
- Different factors matter more to different people, so everyone’s view of what makes a city liveable will be different
What makes sustainable development of urban areas easier than rural areas (opportunities to make cities more sustainable):
- People are more densely concentrated in cities than in rural areas, so the provision of services such as public transport is easier and cheaper
- Governments may invest more in urban sustainability than rural sustainability because it benefits more people
Challenges:
- LICs don’t have enough money to invest in expensive sustainable ways of living e.g. changing transport to be renewable etc
- Fast urbanisation rates makes it difficult to meet the needs of an ever-growing population
- Many people living in HICs aren’t willing to change their lifestyle habits e.g. using less water or driving less
- Some cities don’t have appropriate infrastructure e.g. roads may be too narrow to build cycle lanes
Strategies to develop sustainable cities:
- Reducing number of cars on roads - Constructing new cycle lanes, introducing park and ride schemes and improving public transport —> decreases CO2 emissions
- Green space - Green spaces e.g. parks can reduce pollution or flooding, as well as making the area more attractive and pleasant for its residents
- Reducing water use - authorities can insist that new buildings are fitted with water metres and water-efficient fittings to ensure that people use less water e.g. in Cape Town, South Africa, water pressure was reduced so that showers, hosepipes etc would use less water
- Making buildings energy efficient - Houses have to be built to be energy efficient e.g. installing solar panels and energy efficient lightbulbs
Sustainable city case study
Curitiba case study- sustainable city
Curitiba location?
- South East of Brazil around 1000km from Rio de Janeiro
Issues with urban growth?
- Lots of cars on roads —> increases fossil fuel consumption —> increases pollution —> trigger different microclimate responses/impacts health
- Unemployment—> high proportion of people who move to cities are young —> lots of pressure on jobs —> some people unable to find one due to high proportion of people wanting a job
- Lack of urban services —> when more people move to cities, the demand for services increases —> lack of urban services due to high demand —> ill —> can’t go to work —> can’t pay tax
- Shortage of housing —> leads to informal settlements
What has been done to make the city sustainable?
Transport
- Central bus lane —> speeds up journey
- Bendy buses —> boosted number of passengers per bus to 4000 per day
- Bus doors are wider and open directly into the tube —> maximises use for all types of users// faster loading and unloading on bus —> cuts travel times —> more attractive option
(lots of cars on roads)
Parks and open space
- Curitiba has 4x the green space recommended —> trees take in CO2 —> better air quality
- Curitiba has 4x the green space recommended —> interception increases —> less flooding —> reduces damage to infrastructure —> helps save money and resources —> more sustainable
Housing and social projects
- Site and service schemes —> residents are trained to build the houses —> adequate conditions —> electricity, sewage and running water —> not ill so able to go to work (shortage of housing)
Waste
- Green exchange —> Curitiba reuses 2/3 of its waste —> people in slums collect rubbish + the council pay for the weight using fruit and veg —> council gains as people collect rubbish in narrower roads where the councils collection trucks can’t get to —> saves on expensive road widening// generates jobs and reduces landfill (unemployment)
Suburbanisation and counter-urbanisation
Suburbanisation - refers to the outward growth of urban areas as people move from city centres to the suburbs
Counter urbanisation - movement of people from urban areas to rural areas —> happens due to push and pull factors
Causes of suburbanisation/counter-urbanisation:
- Push factors from urban areas: congestion, pollution, poor quality housing
- Pull factors to suburbs/rural areas: more space, better quality of life, larger houses, green spaces, better schools, lower crime rates
What has allowed suburbanisation/counter urbanisation to take place:
- Improvements in transport links —> people can commute to work
- Better communications —> people can work from home
Impacts:
- More car dependant lifestyle leads to an increase in fossil fuel consumption —> increases pollution —> impacts health/trigger different microclimate responses
- Segregation —> wealthier middle-class people may move to the suburbs and those that are left behind are poorer and may include foreign immigrants
- Environmental impact —> deforestation to make space for housing
Urban climate
Winds:
1. Average wind speed is usually lower in cities than in rural areas. This is because tall buildings create friction that slows down the moving air
2. You get turbulence around buildings. This happens when wind hits the face of a building — some of it’s deflected down, some around the sides and some over the top. When these winds hit other buildings or the ground they causes vortices (bodies of swirling air)
3. You get powerful gusts of wind when wind is channelled down streets this is known as the canyon effect. The canyon effect has implications for building design and town planning e.g. positioning of buildings, and the location of doorways on buildings
There’s more rain, fog and thunderstorms:
Rain:
1. It rains more often in urban areas than in the surrounding countryside (Precipitation is 5-15% greater in urban areas than in rural areas)
2. The rain is also more intense and there are more thunderstorms
There are two main reasons for these things:
- The UHI effect means the air in urban areas is warm, and warm air can hold more water. The warm, moist air rises. As it rises it cools, the water vapour condenses and it rains. This type of rain is called convectional rainfall
- Urban areas generate huge amounts of dust and pollution. Particles of dust and pollution floating about in the air act as condensation nuclei (they trigger water to condense around them). This encourages clouds to form and therefore leads to rainfall
Fog:
- The higher concentration of condensation nuclei in urban areas also increases the frequency of fog
- Wind speeds are lower in urban areas so fogs are not so easily dispersed
- Presence of pollution prevents sun’s rays penetrating to the ground. The suns rays warm up the fog instead - fog is not dispersed
Snow:
- It doesn’t snow as often in urban areas, and when it does, the snow melts faster. This is because it’s warmer due to the UHI effect
Pollution
Pollution:
- Urban areas experience twice as much CO2 in their local atmosphere —> impacts health
- Particulates are tiny pieces of solids and tiny droplets of liquids floating in the air
- More particulates are found in urban areas than in rural areas
Sources of particulates:
- Vehicle exhausts - they produce very fine particulates (0.01 micrometers - 1.0 micrometers). About 80% of fine particulates in urban areas are from vehicle exhausts
- Burning of refuse, cigarettes and fuel
- Construction, mining and quarrying - these activities produce coarse particulates (10 micrometers - 100 micrometers) e.g. tiny fragments of rock, brick and cement dust
- Particulates can cause health problems. Coarser particulates are usually filtered out by the nose and throat, but finer particulates less than 10 micrometers in diameter (often called PM10) can enter the lungs. PM10 could cause or make worse problems like asthma, bronchitis, lung cancer and heart disease
Photochemical smog:
- Photochemical smog - smog that is created when sunlight and pollutants react to produce low level ozone which is very dangerous to health
- Photochemical smog is a problem in many cities e.g. Los Angeles (USA), Beijing (China), Mexico City (Mexico) and Barcelona (Spain). It’s more common in places with hot and sunny climates because there’s more sunlight
- These locations often have a temperature inversion, which keeps the pollutants at ground level
- Photochemical smog is linked to health problems such as coughing, shortness of breath, asthma and headaches
Ways to reduce air pollution
Congestion charging:
- People are charged if they use their vehicles in certain places at certain times
- In Central London congestion charging reduced traffic and emissions in the congestion zone by around 15% in its first year of operation ✅
- However, some people travel around the edge of zones to avoid being charged —> traffic increases in these areas —> so it just moves the problem to other areas ❌
Pedestrianisation:
- Vehicles are restricted from entering certain places. Many cities have pedestrianised zones e.g. London
Public transport improvements:
- Encouraging people to use public transport instead of their cars reduces pollution
- Improved bus services - make bus journeys cheaper, faster and more efficient e.g. many cities have introduced bus lanes so buses don’t get caught in traffic
- Trams and light railway services - don’t get caught in road congestion e.g. The Metrolink in Manchester links the city centre to the suburbs —> has taken around 2.6 million cars off the roads
- Public transport improvements are often expensive e.g. construction of the Metrolink cost over £1 billion ❌
Other schemes reducing traffic:
- In Mexico City drivers are banned from using their cars one weekday per week, based on the last digit of their number plate e.g. number plates ending in 5 or 6 can’t be used on Mondays ✅ However, some richer households get around the system by buying two cars ❌
- Car sharing schemes encourage people making the same journey to share a car ✅ However, some people find car sharing inconvenient, or worry about sharing a car with a stranger ❌
Larger scale ways to tackle air pollution:
Legislation/laws:
- Introducing tall chimneys —> pollutants are dispersed higher in the atmosphere so they’re less harmful to people in the city
- The Road Vehicles Regulations reduce exhaust emissions by ensuring cars pass an emissions test in their MOT
- Throughout the UK, local authorities can issue fines to people who leave their engines running unnecessarily
Alternative fuels:
- Petrol and diesel are replaced with cleaner fuels that pollute less e.g. biofuels are produced from plants ✅ However, increased deforestation to grow plants ❌
- Electric vehicles have lower emissions because they run off batteries, rather than conventional fuel ✅ Electric vehicles are more expensive ❌
Waste in urban areas
Sources of waste:
Personal waste:
- Any waste leached by private homes e.g. food packaging, food waste, plastic bottles etc
Industrial waste:
- Waste generated by manufacturing or industrial processes. Industrial waste can be hazardous e.g. chemicals and scrap meats etc
Commercial:
- Waste produced by businesses like restaurants or shops e.g. paper, plastics, food, packaging
- A waste stream is the flow of waste from its origin through to its eventual disposal
Ways to manage urban waste:
- Unregulated - Waste is dumped in places that aren’t official disposal sites e.g. solid waste left on streets or untreated liquid waste entering water courses. This can damage ecosystems e.g. animals can be harmed if they swallow or get tangled in plastic waste
- Recycling - Converting waste into new products
- Recycling reduces demand for raw materials —> resource extraction decreases —> environmental impact decreases ✅
- Producing products from recycled products generally uses less energy than making them from scratch —> less greenhouse gases are emitted ✅
- Recycling requires waste to be separated and categorised —> some people cannot be bothered ❌
- Requires construction of new facilities to process waste —> construction leads to be more air pollution and more GHG/ construction can be expensive ❌
Recovery - Using waste for energy or direct reuse
- Reduces the amount of waste going to landfill ✅
- Waste that is burnt can be used to generate electricity (energy recovery) —> reduces use of fossil fuels ✅
- Burning waste can emit greenhouse gases/ release toxic chemicals into the air or water ❌
Incineration - Involves using waste instead of new products e.g. waste concrete can be crushed and used as a base for new roads and buildings
- Reduces the amount of waste going to landfill ✅
- Reduces demand for raw materials —> resource extraction decreases —> environmental impact decreases ✅
Burial - Waste goes to landfill
- Convenient and cheap ✅
- Contamination of water supplies —> rainwater passes through waste and picks up harmful chemicals/pollutants ❌
- Methane is released —> GHG ❌
- Running out of space ❌
Waste submergence - Dumping waste under water
- Submerged waste can damage ecosystems e.g. animals can be harmed if they swallow or get tangled in plastic waste ❌
Trade in waste - Waste can be bought and sold by countries e.g. developed countries may pay developing countries to take their hazardous waste —> developing countries may not dispose of hazardous waste safely —> damage local environments e.g. water pollution
Facts about waste:
- The average person in the UK produces 517kg of household waste each year
- Waste is estimated to account for 5% of global greenhouse gas emission
- Globally, waste increases by about 7% each year
Impacts of increasing waste generation:
- Cost —> The cost of collecting and treating waste are high
- Collection —> Many city authorities are struggling to collect increasing quantities of urban waste
- Pollution —> Impacts air/water quality —> impacts health —> diarrhoea and cholera
- Space —> Cities are running out of landfill space so rubbish is left in public places e.g. rivers —> contaminates water —> water pollution
London and Mumbai managing waste:
London:
- London produces enough waste every year to fill 1500 olympic sized pools
Managing waste?
- Reduce single use plastic water —> partnered with thames water to install a network of more than 100 drinking water fountains across london
- Helping businesses reduce food waste —> FoodSave have supported over 200 food organisations in London to prevent food waste
Mumbai:
- Increasing population in Mumbai produces more waste —> e.g. in the neighbourhood of Chembur, waste in open rubbish dumps are burnt —> air pollution —> impacts health —> 25% of deaths in Chembur between 2008 and 2010 were caused by respiratory problems
Managing waste?
- Clean up Mumbai campaign —> cleaning up streets and educating people about how to recycle + dispose waste to limit environmental damage
- Waste pickers —> sort though piles of waste and separate the different materials —> less rubbish ends up in landfills and more is recycled
Environmental issues in urban areas
Environmental problems in urban areas
Atmospheric pollution:
1. Atmospheric pollution is often a problem in urban areas
2. In many developed countries, reliance on fossils fuels is decreasing, and use of less-polluting energy sources (e.g. natural gas) is increasing. As a result, air quality in many cities has improved since 1950. However, car ownership is increasing and congestion can cause significant atmospheric pollution
3. Many developing countries and emerging economies still rely heavily on fossil fuels. Increases in industrial activity and car ownership, combined with a lack of regulation of emissions, mean that atmospheric pollution is often severe. In many developed countries, there are strategies to limit air pollution, such as promoting green’ modes of transport e.g. cycling, and expanding green spaces
Water pollution:
- Cities have a high population density, so they produce a lot of waste. Waste can enter and pollute watercourses
- Many cities have a high concentration of factories. Industrial waste and pollute can enter watercourses
- Water pollution can cause damage to ecosystems, and contaminated drinking water can cause health problems e.g. cholera. Strategies such as catchment management and SUDS can also help
- In developed countries, there are strict regulations about untreated water, and water quality is monitored. However, litter dropped in or around water can still cause pollution
- In many developing countries and emerging economies, there are few regulations and inadequate provision of treatment facilities. This means that untreated industrial waste and sewage often enter watercourses and water pollution is common
Urban dereliction:
- Urban dereliction happens when economic activity in urban areas declines and buildings become run down
- The movement of manufacturing overseas and the decentralisation of industry leads to industrial decline.
Many unemployed people leave urban areas in search of work
- If lots of people leave the area, shops may be forced to close and services go into decline. As industry, people and services move out, they leave empty buildings
- Empty buildings and derelict areas often have problems with vandalism, graffiti and crime
- Strategies to manage urban dereliction include the redevelopment of former factories into commercial and residential properties, the construction of new housing in derelict areas and the creation of green spaces
Global scale:
- At a global scale, cities increase demand for resources such as food, water and energy. Cities are home to around half the world’s population, but account for about three-quarters of resource use. This is putting pressure on finite resources
- Cities are also responsible for about 60% of greenhouse gas emissions, which contribute to climate change
