Contemporary Urban Environments Flashcards
Shanty Towns
Unplanned and often illegal settlements made out of any material available.
Urbanisation
-This is the growth in the proportion of people living in urban areas
-It usually occurs because of migration and natural increase.
-In developing countries, urbanisation can result in shanty towns.
Suburbanisation
-This is the migration of people from city centres to the outskirts of cities.
-As urbanisation increases, city centres become overcrowded and people desire more space.
Counter-urbanisation
-This is the movement of people out of the city into surrounding villages and rural areas.
-It can lead to new housing estates being built in rural areas
Urban Resurgence
-This is the movement of people back to the city centre.
-Common in many post-industrial countries
Why do megacities develop?
Rural-urban migration and natural increase. Migrants tend to move to large cities, and to cities that are expanding rapid economic growth, so their population increases rapidly.
World City
A city that has political and financial influence over the whole world.
They usually dominate international trade and regional economies in their area.
Economic developments in cities:
-Cities attract people from rural areas because they offer more job opportunities, and jobs are often better paid.
-As the urban population increases, businesses such as factories and shops grow in size and become more profitable. This leads to more jobs and wage rises.
-As countries develop, commercial farming overtakes subsistence farming as the primary method of food production. The decline in agricultural jobs drives even more people into towns and cities.
Social developments in cities:
-Cities tend to have higher living standards than rural areas.
-As more people move to a city and the economy grows, it can become a centre for cultural expansion.
-The migration of people into urban areas increases the mix of people from different social backgrounds.
Technological developments in cities:
-With the emergence of factories in cities, urban areas become hotspots for technological advancement.
Political developments in cities:
-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.
Demographic developments in cities:
-As cities become larger and wealthier, they attract migrants from all over the world.
-Urban areas become more culturally and ethnically diverse and new areas emerge.
Decentralisation
as land prices in city centres increase, businesses such a as shops and offices may relocate to suburbs. This has led to the rise of out-of-town retail parks.
Urban Development Corporations - 1979-1990s
-Use private sector funding to restore derelict areas
-By 1993, twelve UDCs had been established, helping to redevelop some of the most rundown areas of the country. However, the UDCs were criticised for ignoring the needs of local residents.
Enterprise Zones -
1981-present
-Established in areas with high unemployment. Their aim was to attract start-up companies to the area to create jobs by reducing tax
-By 1990, the EZs housed over 5000 companies, employing more than 125,000 people.
-Tax reductions encouraged existing companies to move their premises and staff to the EZs, which limited the number of new jobs that were created.
City Challenge
1991-1997
-Local authorities competed for government funding to regenerate deprived urban areas. They worked with the local community and private companies to improve the physical, economic and social environment of the area.
-Funding was allocated to projects that benefited the local community.
-BY 1997, over 50000 jobs had been created and 40000 houses improved.
Partnership Schemes
2010-present
-Since 2010, the government has worked with private companies to provide financial support and expertise for urban regeneration.
-The schemes are designed to improve physical, economic and social conditions in deprived areas.
Four physical factors affecting urban form
- topography
- Water
- Natural Resources
- Land type
Three human factors affecting urban form
- planning
- infrastructure
- land value
Inner city land-use patterns
They have high land value, so housing is typically high density. Wages are often low, and many residents live in relative poverty. The proportion of people from ethnic minorities tends to be high.
Rural/Semi-rural area land-use patterns
Land value is lower 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.
Town Centre Mixed Developments
- Areas where land use is miced so residential, commercial and leisure uses are combined.
- Developments are planned by local councils, often with private investment. The aim is to attract people back to city centres by giving them opportunities to live, work and relax there.
Cultural and Heritage Quarters
- These areas focus on the history or character of a city
- Such 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, encouraging economic development and creating jobs.
Fortress Developments
- These are developments with lots of security. They are often located in suburban areas of large cities, and only those with permission can enter them.
- They are designed to give a safe environment for families, but they are very divisive - only rich people can afford to live in or use them
Gentrified Areas
Often have a large range of services and contain high-quality housing.
However, poorer residents may be displaced as the cost of living increases, leading to social and ethnic segregation.
Edge Cities
- New areas of offices, shops and leisure facilities that develop close to major transport links
- They often contain some housing, but most people travel to them for work or to use the services available.
- They have developed since the 1950s/60s as car ownership increased.
Urban Heat Island Effect
The phenomenon of urban areas being warmer than rural areas
Absorption of heat by urban surfaces
Concrete, brick and tarmac surfaces absorb and store heat from the sun during the day. They slowly release the heat as long wave radiation - this is most noticeable at night, when it warms the air.
heat from human activity
Cars, factories, offices, central heating, air conditioning units and people themselves all release heat.
Air pollution
From cars and factories increases cloud cover over the city. It also creates a ‘pollution dome’ - a layer of pollution over the city. Both these things trap outgoing heat radiation and reflect it back to the surface
Less Evapotranspiration
When it rains the water’s quickly removed by drainage systems, so there’s little surface water to evaporate. Also, there isn’t much vegetation, so there’s little transpiration. Evapotranspiration uses heat energy, so less Evapotranspiration means higher temperatures.
Congestion Charge to reduce air pollution
Reduces pollution by reducing road traffic.
However, some people travel around the edge of zones to avoid being charged, increasing traffic in these areas. It’s hard to enforce the charge because the volume of traffic is so large that it’s hard to process all the fines correctly.
Pedestrianisation to reduce air pollution
Vehicles are restricted from entering certain places at certain times. It reduces pollution by reducing road traffic.
It can lead to shop[s receiving fewer customers because people can only get to them on foot.
Public Transport Improvements to reduce air pollution
Improved bus services, park and ride schemes, trams and light railway services.
However, public Transport improvements are often expensive
Legislation to reduce air pollution
Laws aim to reduce pollution by limiting emissions and setting air quality standards.
the UK clean air act of 1956 and 1968
Reduces domestic pollution by introducing smoke control areas where only smokeless fuels could be burned, and reduced industrial pollution by introducing the use of tall chimneys
Alternative fuels in order to reduce air pollution
Petrol and diesel are replaced with cleaner fuels that pollute less. For example, biofuels, liquefied petroleum gas and electric vehicles
Biofuels
produced from plants.
They can directly replace petrol and diesel, and have lower particulate emissions. However, growing the crops needed to make biofuels can reduce biodiversity
Liquefied Petroleum Gas (LPG)
Is a gas produced from fossil fuels that has lower emissions than petrol or diesel. However, cars have to be converted to use LPG, and service stations have to be adapted to distribute it.
Electric Vehicles
have lower emissions because they run off batteries, rather than conventional fuel.
They need recharge points, and producing and disposing of the batteries can cause environmental problems.
Catchment Management
A way of managing rivers and improving drainage systems by looking at the whole river catchment, and the interactions between water and land.
Aims of catchment Management
It aims to minimize issues such as flooding, drought, water pollution and erosion in sensitive areas, and to improve river ecosystems.
Hard Engineering examples to manage river catchments
Dams, flood walls and reservoirs, which are often used to prevent flooding and ensure a constant water supply.
Soft engineering to manage river catchments
Planting trees to decrease flood risk and water pollution.
Preventing building on the flood plain.
River restoration and conservation.
Sustainable Urban Drainage Systems
Aim to imitate natural drainage systems, rather than channeling water through pipes and drains
Vegetated Trenches (Swales)
increases interception of rainfall, and retention basins store water. They help to increase infiltration and water storage - this decreases runoff and channel flow, which lowers flood risk. Increased infiltration also decreases the amount of pollutant entering water courses.
Vegetated Roofs
intercept rainfall and increase Evapotranspiration, which reduces flood risk.
Roof Containers
containers on the roofs of buildings catch and store rainwater for reuse. This helps to reduce drought risk.
Why are SUDS more sustainable than urban Drainage methods?
They work with the natural environment to improve drainage and water quality. Vegetated Trenches and roofs also provide new habitats and increase biodiversity.
The three Primary Sources of Waste in urban areas:
industrial
commercial
personal
Unregulated waste disposal
waste is dumped in places that aren’t official disposal sites. Waste that isn’t properly disposed of can damage ecosystems.
Recycling Waste
Waste is reprocessed into new products. It reduces demand for raw materials, which decreases the environmental impacts of resource extraction. Producing recycled products generally uses less energy than making them from scratch, so less greenhouse gases. However, recycling requires separate collections and the construction of new facilities to process waste.
Incineration to Manage Waste
Waste is burnt. This reduces the amount of waste going to landfill, but it emits greenhouse gases and causes air pollution. It can be used to generate electricity. This reduces use of fossil fuels, but burning some waste can release toxic chemicals into the air or water.
Waste recovery
this involves using waste instead of new products. This reduces the amount of waste being sent to landfill and means that fewer natural resources are exploited because goods are reused.
Burial/Landfill
Waste is placed in disused mines, quarries or landfill sites. Many sites are line to prevent leaching of chemicals into the environment however, unregulated chemicals can contaminate groundwater, while gases cause air pollution.
Submergence
disposing of waste by dumping it in oceans is illegal, but it is still common in some areas. It can release toxic or radioactive substances, damaging ocean ecosystems.
Trade to manage urban waste
waste can be bought and sold by countries. However, developing countries may not dispose of hazardous waste safely, meaning that it can damage local environments.
Urban dereliction
happens when economic activity in urban areas declines and buildings become run down
Ecological Footprint
The amount of land that is needed to produce everything they consumer.
Natural sustainability
How the environment, resources and waste are managed.
Cities rely on renewable energy sources. They produce relatively little waste and reuse/recycle they waste they do produce.
Physical Sustainability
How well a city is able to support the people living here.
To be sustainable, a city must provide enough resources to support the population.
Social Sustainability
How people live together, their quality of life, and the availability of basic services.
Cities offer good living conditions for all residents, with access to basic services.
Economic Sustainability
About maintaining economic growth without causing long-term negative effects.
These cities are wealthy, have low levels of inequality and little debt.
