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Contemporary Urban Environments - Coggle Diagram
Contemporary Urban Environments
Urban drainage
Sustainable urban drainage Systems (SUDS)
Systems designed to manage the flow of urban water sustainably, rather than using construction and environmentally unsustainable techniques, SUDS are techniques that recreate natural drainage systems > Meaning water flows gradually through the system rather than being removed as quick as possible (increasing risk of flooding)
Permeable surfaces such as grass verges, permeable roads and pavements ~ increases infiltration
Green Roofs increase transpiration
Rainwater harvetsing
Ponds
Swales ~ small depressions covered in grass that slowly transport water away.
Impermeable surfaces mean water cannot infiltrate and can only run-off. Drainage structures have been built in urban areas to direct water elsewhere.
During high rainfall, water is quickly transported to rivers in urban areas as the majority of water cannot be stored within the urban area drainage basin ~ Causing floods to have short lag time and high peak discharge.
Catchment management
Urban river catchments can be managed in order to reduce issues associated with the urban water cycle (Flooding, riverbank erosion, contamination of groundwater, water shortages etc).
Dredging ~ Sediments are removed from the river channel so more water can flow into it.
Dams and reservoirs ~ Dams manipulate water flows and stores to reduce flooding, and reservoirs can be used as a water supply. > Dams take up lots of space.
Flood defences and water channel management ~ Physically altering the waters course through straightening channels, constructing flood walls, and creating drainage pipe systems can be an effective way to force water out of urban areas. > Can worsen flooding downstream
Urbanistation
The increase of the proportion of
people moving to urban areas
Urban area:
Towns or cities
high pop density
Low agricultural employment
Rural area:
Small villages
Low population density
The two are mutually exclusive
Global patterns of urbanisation
Urbanisation rates began to grow rapidly in the mid-20th century. The amount of people moving to urban areas in increasing globally.
55% of people live in urban areas, a 25% increase from 1950.
Expected to be 68% in 2050
Since 1950, world's urban population increased from 750 million to 4.2 billion.
Global urbanisation continues to increase, suburban areas are becoming more urbanised and surrounding rural areas are becoming suburbanised
Suburbanisation
Where urban areas grow so that rural settlements such as villages become absorbed into the urban areas.
~ Usually occurs as wealthy people move away from the central city into suburbs ~ The demand in housing causes these suburban areas to grow.
Issues with suburbanisation:
Can lead to inner-city areas becoming deprived and suburb house prices increasing.
Urban Sprawl ~ however this is limited by strategies such as a green belt (area where building is restricted to preserve rural areas)
Counter urbanisation
Process of people moving out of cities into rural areas. Happens as people seek a better quality of life.
Rural areas have: clean air, more space, countryside and better value housing
Modern technological advancements have reduced the drawbacks of living in a rural area such as
Transport means people can easily commute
Counter Urbanisation is increasing but hasn't overtaken urbanisation rates
Urban resurgence
Process of people moving back into the city especially after deterioration of the area.
Usually occurs when schemes are put in place that aim to improve the quality of life and encourage economic growth and regeneration.
Urban resurgence can lead to socioeconomic issues as original population struggle to keep up with the higher price of housing and living ~ Outsider.
Megacities
Urban areas with a very high population ~
Over 10 million
Urbanisation means the number of megacities is rising quickly
~
Megacities contribute to national and regional economies ~ Large workforce allows for rapid economic growth ~ Business investments also usually concentrated within megacities increasing growth.
World cities
Cities that have significant political and economic influence on a global scale ~ Not defined by size or pop but importance to global affairs
These cities usually drive economies and businesses
Processes of urbanisation
:
Social
different cultures migrate into city making it more diverse.
Urbanised areas develop into cultural hubs with museums, theartes, shops, etc ~ Increasing quality of life.
Improves access to different jobs, education, healthcare ~ Larger investment in cities.
Access to a wide range of jobs increasing income
Economic
Leads to more jobs in tertiary sector - finance - higher wages - economic development
Economic decline in areas people migrated from
Development of a range of businesses and industries.
Unsustainable urbanisation can lead to economic inequality -- Brazilian favelas.
Technological
Urban areas become centres for tech advances ~ silicon valley
New technology is often introduced into cities first as there is a higher demand for it
Political
Urban areas are always the focus of political activities
Political movements are often more prevalent in cities
Demographic
Cities host lots of cultural diversity, making the demographic more diverse
Predominantly young adults, as many move for education, social life, and employment opportunities
Older people move away from cities for a better quality of life, also altering the demographic of urban areas.
Urban Change
Deindustrialisation
Deindustrialisation > Decline of industry within a country, usually measured by the reaction of industry employment. ~ Began in mid 20th century in developed countries but now process is apparent in developing countries
Happened on a mass scale in western society due to the struggle for industries to compete with cheaper labour and manufacturing costs in countries such as China, Singapore or Taiwan
Deindustrialised areas:
Low quality of life ~ unemployment and lack of support
Social deprivation ~ Leading to worse health, education and crime
Rise of the service economy
A service economy is one where the dominant source of economic growth is through providing services. (Tertiary)
Originally the service sector (tertiary) grew to support Primary and Secondary industries that needed the supporting commercial, financial and legal services to allow their business to grow successfully. Since then it is now the dominating sector in the world
Decentralisation
The process of urban developments away from the city centre, such as large shopping centres or retail parks ~ cheaper away from the city as land prices are usually cheaper than within CBD
Can cause issues as it drives customers away from the city which can lead to city centre degradation
Urban regeneration in Britain
Due to Socioeconomic and environmental effects of deindustrialisation and decentralisation, Urban regeneration has become a priority ~ Since 1979 Urban regeneration policies have been implemented nationwide to improve cities condition.
Urban development corporations
~ Created policies to: ensure effective use of land, develop industry, provide housing and social facilities and to overall enhance the quality of deteriorated areas.
London docklands built 24000 new homes and created 85000 jobs in derelict london docklands.
Enterprise zones
~ Specific areas of land with economic incentives such as tax breaks and government support that aim to entice business to invest into an area that would benefit from business.
Government grants
~ Used to entice private investors to develop and regenerate urban areas
~ City grant 1988 allowed development plans to bypass local authorities making them easier to go ahead.
English partnerships
~ National regeneration agency that aimed to develop derelict areas ~ Have certain powers such as compulsory purchase orders.
New initiatives
~ bottom up schemes where local communities are encouraged to be a part of the regeneration schemes
Urban forms
Refers to physical characteristics ~ its layout, size and land use
Majority of urban areas were in areas with favourable resources such as water, food, fertile land or security.
Urban forms change over time based on physical factors of the area and human influence.
Human
Wealth and development
Rich countries often have structurally safer buildings due to regulations with social and environmental factors considered. In developing countries urban growth can be rapid and urban sprawl can sometimes be unmanageable.
Planning
Planned developments are considerate of space, safety and well-being ~ unplanned developments can be unsafe and potentially overcrowded
Patterns of growth
Higher land value is often in the CBD and land decreases in value away from it. Wealth businesses occupy the CBD and so less wealthy businesses are further away.
Economic activities
Land use is affected by economic activities ~ Port built for trade.
Past developments
The original structure of a city may change how it develops, such as limiting construction to protect listed buildings or poor transport links as old roads aren't wide enough.
Physical
Natural Resources
Areas rich in natural resources encourage development in cities as resources support the population and economy ~ Building material, coal or oil
Water
Necessary for agriculture, sanitation and health ~ UAE have to adapt to optimise and conserve water supplies ~ coasts can be a barrier of urban sprawl
Topography
Flat ~ easier to build on ~ building can be more spaced out ~ Urban sprawl is difficult on slopes meaning all building can be very densely compacted into one area suitable for building.
Climate and Land-type
Unsuitable soils, permafrost or waterlogged ground can be difficult and expensive to build on
New urban landscapes
More prominently in developed countries planning and investment have allowed the emergence of new urban landscapes.
Fortress developments
~ Areas secured off from public with only people with permission allowed to enter ~ to provide a safe space for people
Cultural and heritage quarters
~ Large areas within urban areas of particular cultural importance
Mixed use developments
~ Different buildings with different uses are all in close proximity meaning people do not have to travel around a city for different needs.
Edge cities
~ Area of business, shops and entertainment services on the outskirts of a city, usually by major transport links. ~ develop due to cheaper land being outside CBD
Post modern western city
~ Contemporary cities changing their industries, architectural style and land use with socioeconomic changes in society
Unusual architecture
Tertiary and Quaternary main sectors
Fragmented urban form rather than things being concentrated in one area
Large amount of socioeconomic inequality.
Gentrification
Process of housing improvement on a piecemeal basis associated with low income groups being displaced and more affluent people moving in. Wealthier individuals buy and renovate properties in run down areas, often in the inner city.
~ occurs due to:
People renovating property for profit
Young people want to live in inner city and move into small residences which they do up
Desirable to live in the inner city
Inner-city areas have reputation of being new 'hipster' neighborhood
May be encouraged locally by the council who can see the benefits of improving the status, class and physical environment.
Benefits
:
Rise in level of prosperity and rise in business and services
Increased tax revenue
Improved physical environment
Costs
Low-income groups priced out
Threat to community
Tension between new and old residents
Losses to lower order local services
Process
Lower-middle class migrate into cheap outdated run down inner city area
Some renovate
Place gains fashionable status
Privste sector investors buy and renovate more of the housing
Local gov invests
Wealthy migrants and foreign investors move in
House prices increase far beyond average salary ~ locals are priced out.
Land use differences in contrasting urban areas:
LICs have high cost residential areas in the inner city such as luxury apartments or estates
In HICs high rise flats in the inner city due to land prices but quality of life is often poorer.
HICs inner city is also home to industrial sites and near to major transport links.
HICs often have sub-urban areas higher in value whereas in LICs edges of the city tend to have very poor housing quality that have been constructed with little to no regulations. ~ Slums
Economic equality
HICs
Wealthier, less deprived populations live in suburban areas for a better quality of life. Affluence is also concentrated in the centre as prices are so high.
There is a great deal of poverty within cities in developed countries ~ deprivation - homelessness
These deprived areas have high population density, strained public services, low access to green spaces, high crime and unemployment.
LICs
Economic equality is much more severe & follows different spatial patterns
E.g. Rio de Janeiro -> wealthiest live near the centre along coast & poorest live furthest away from city
No wealth or resources to support poorer pops
Leads to very severe poverty in cities ->
development of slums
social issues such as gangs emerge because of this
Accessibilty
Can be limited by poor transport links
e.g. if people can't travel to work -> limited income by smaller opportunities available
Cultural Diversity & Social Segregation
International migration = major driver in creating rich cultural diversity within cities
People migrate to cities for better work opportunities etc.
Allows people to celebrate different cultures
Brings tourism
Issues:
People may not tolerate different cultures, some experience prejudice behaviour or racism
Cultures may feel under-represented within their area, may not have access to important aspects of culture e.g. places of worship
Not many resources available to improve quality of life for those with different cultures -> information in multiple languages
Social segregation:
Groups live apart from one another due to wealth, ethnicity, religion or age
Occured in many urban areas -> ethnic groups to be segregated & live without social cohesion
'Gated communities' exists within urban areas -> wealthy live in secured, fenced-off community
Issues:
Areas can be under attack from prejudice & racism
People may feel isolated -> not within demographic of majority that live in area
Low paid migrant jobs -> migrants limited to housing options & live in cheaper more deprived areas -> high levels of crime, unemployment & social issues
Role of government policies
By investing in infrastructure ~ Rail / airport developments ~ Maintains growth and improves accessibility to regenerate regions
Gov policies control the rate and type of developments allowed through planning laws, creating house building targets, considering house affordability and gaining permission
Gov decisions about international migration and the deregulation of capital markets (e.g. allowing foreign investment in london real estate) significantly impact growth and direct/indirect investment
Strategies to Manage Urban Issues
City minimum wages - in some cities the minimum wage is higher than in the rest of the country due to cost of living. Higher minimum wages work to reduce economic inequality as people have more money for resources
Fair rent & housing policies - Legislation can be put in place in cities to ensure people have access to safe & affordable homes -> reduce economic equality existing within cities
laws in place to ensure people pay fair price for their rent
Recognising informal housing issues - Informal housing can exacerbate severe inequalities
Some countries, residents of squatter settlements are evicted & their homes demolished as a way to limit growth of informal residential areas -> limit inequality & social issues -> recognised by law as actual residential areas and therefore provide tools & resources to make them safe -> access to clean water, sanitation, transport
Encouraging multiculturalism - Festivals such as Notting Hill Carnival can encourage social cohesion & allow people to celebrate different cultures
European social fund
Aims to tackle poverty and social exclusion by increasing employment and helping people to access sustainable employment, as well as investing in skills and improving the diversity of the workforce and investing in young people with skills required for the quaternary sector
Urban Policies & Regeneration
Retraining ~ Population retrains from primary/ secondary sector skills to new service sector (tertiary) >> Essential for reducing negative impacts of deindustrialisation by boosting employment opportunities.
Economic policies ~ At a local level, governments can positively promote a place to carry out economic activitiy ~ Policies to change tax ~ Boosterism
~ At an international level, FDI can be used to revitalise a deindustrialised place, through stimulating tertiary growth and investment by foreign MNCs
Environmental policies ~ Gov can set environmental standards that closing industries have to follow ~ Not to leave unsightly derelict land strewn with toxic waste
Re-Urbanisation
Large scale government backed movement of people back into the city centre as part of regeneration.
Pop living in cities has doubled since 2001
city centres are the location of 72% of all highly skilled jobs
21% more productive than non-urban areas
Trends in re-urbanisation
Increase in construction of centrally located residential areas, composed more of flats and apartments which attracts demographic around the 'young professional'
Increase in studentification with expansion of city centre student accommodation and rise of centrally-located new university.
Growth of 24 hour culture and central centertainment districts has increased the attraction of the CBD
Effective public transport networks have made city centre living more viable.
Urban climate
Urban heat island effect
Phenomenon where the characteristics of urban areas and the activity within them cause the areas to produce and retain more heat that the surrounding areas.
Urban heat islands develop because:
Wasted heat from urban activities ~ Traffic, factories, homes, businesses.
Urban materials ~ Absorb and store more solar energy (lower albedo) than other surfaces such as grass ~ Tarmac, concrete and brick emit absorbed heat as long wave radiation, warming surroundings
Lack of evapotranspiration ~ heat energy is lost through evapotranspiration > urban areas tend to have less vegetation, meaning less heat energy is lost via transpiration ~ Urban drainage takes water away meaning less heat is lost through evapotranspiration.
Weather in urban areas
Rainfall
:
Rainfall increases over urban areas in comparison to surrounding rural areas as well as more frequent intense rainfall events.
Atmospheric instability caused by the urban heat island ~ Warm, moist air rises above urban areas , then cools and condenses as rain.
~
Altering wind patterns > airflow obstructed by tall buildings reduces ability for moist air to disperse.
~
Aerosols and particulates - Particles in the air can cause water vapour to condense and form clouds.
Wind
:
Wind patterns are greatly altered in urban areas due to the presence of many tall buildings which cause friction and act as a barrier to wind.
Turbulence can also occur around buildings due to frictional drag, forcing air to be deflected and swirl like a vortex
Air quality
Significantly poorer in urban areas due to urban activities creating particulates that stay suspended in the air. They come from:
Vehicle exhausts ~ Produce pollution such as Carbon dioxide and monoxide, nitrous oxides, volatile organic compounds and particulate matter.
Industrial activities ~ Coal burning factories produce particulates ~ Power plants contribute sulfur dioxide which makes acid rain
Construction work ~ Agitates coarse particulates such as fragments of cement or brick that can become suspended in the air.
Photochemical smog:
Type of air pollution cause when particles react with UV light. ~ Nitrous oxides and volatile organic carbons react to form harmful secondary pollutanats such as Ozone and PANs > More in sunnier countries
Stays at ground level due to temprature inversion - cool air is trapped beneath warm air
Causes respiratory disorders such as asthma as well as others.
Policies to reduce air pollution:
Legislations for cleaner air
Laws for cars - emissions testing/ cat converter requirements.
Bans of air polluting activities ~ burning rubbish
Laws to reduce emissions:
Uks ban on gas cars by 2035
Industrial laws for high chimneys to reduce city pollution
Tech advancements
Alternate fuels
catalytic converters
reducing congestion
Public transport
Congestion zones
Pedestrianised areas
Urban waste
There are three sources of urban waste:
Industrial
Commercial
Personal
Ways of managing waste:
Unregulated
:
Illegally dumped in places not designated for waste disposal > harmful to ecosystems > Fly tipping
Recycling
:
Reprocessing materials so that they can be used again > Reduces the need to produce more materials > Environmentally sustainable
Incineration
:
Burning waste rather than storing it > Reduces the amount that goes to landfill but releases greenhouse and toxic gasses
Recovery
:
Using waste products as a replacement for other products ~ Repurposing waste concrete into bricks for building > Reduces what goes to landfill.
Burial
:
Dumping waste into areas designated for waste ~ landfill sites > Unsustainable as disrupts the natural environment, takes a long time and produces methane as waste breaks down (GH gas)
Submergence
:
Dumping waste into ocean > Many harmful effects ~ Disrupts marine life, releases toxic chemical.
This is illegal however countries such as China still do it ~ Dumped 200.7 million cubic meters of waste into coastal waters in 2018
Trade
:
Selling waste to other countries so they can process it, effective if the waste is managed properly by receiving country. > Must be transported which also requires energy.
Waste in contrasting urban areas:
Type of waste is different ~ HICs produce less organic waste than middle-income and low-income countries.
Developed countries are increasingly developing into consumerist societies where there is a 'throw-away' culture. Often due to unnecessary packaging, making processing difficult and expensive.
Developed countries usually produce more waste but also have better systems in place to collect waste. World bank say 90% of waste in LICs is burnt or dumped.
Sustainable urban development
Urban areas have massive effects
Pollution causes health problems and global warming
Littering and waste harms the environment and marine life everywhere
Therefore it is important that urban areas are sustainable in their practises
Ecological footprint
:
A measure of how much we consume in comparison to how much the earth can regenerate. ~ Larger footprint means consumption is large compared to the Earth's ability to deal with the waste/ make new resources.
Urban areas have larger ecological footprints to rural areas, However this does differ depending on the urban area:
Transport ~ Large amount of cars > Great deal of fossil fuel consumption > More efficient public transport reduces ecological footprint
Building materials ~ Slow development lowers ecological footprint as it allows time for the earth to naturally produce more materials for development.
Needs of population ~ Larger populations consume more things > More waste > larger footprint
Dimensions of sustainability
:
Natural sustainability ~ How successfully the environment is managed - use of natural resources, waste, ecosystems
Physical sustainability ~ Ability for city's resources to support current and future populations
Social sustainability ~ Residents have a good quality of life with access to good public services, good living conditions and leisure
Economic Sustainability ~ Ability to grow economically and to grow economically for future generations without any negative effects.
Developing a sustainable city:
Opportunities
Importance of living sustainably is understood meaning there is more investment and research with more people wanting to live sustainably
Investment to cities are more common than rural areas
Services can be implemented easily to many people as there is a high pop density
Challenges
In LICs cities do not have enough money to invest in expensive sustainable ways of living
Fast urbanisation rates make it difficult to meet the needs of an ever-growing population.
Many people dont want to make the necessary lifestyle changes
Strategies to develop sustainable cities
:
Reduce waste ~ Unsustainable environmentally, physically and economically > Waste can be reduced through Recycling, Composting or less packaging
Transport ~ People in cities will always have to travel around so sustainable methods of travel should be put in place > Zurich unreliant on cars with tram stops every 300 m in city
Green space ~ Improves the environment while also reducing pollution and flooding > Improves physical, social and natural sustainability
Efficiency of buildings ~ Structures made more efficient to enhance sustainability > E.G. Buildings with south facing windows or with effective insulation require less heating, Rain water harvesting for toilets, renewable energy like solar panels.