Contemporary Urban Environments

The settlement Hierarchy

Isolated dwelling - Hamlet - Village - Small town - Large town - City - Conurbation

Megacity

A city or urban area with a population of over 10 million

Metacity

A city or urban area with a population of over 20 million

Urban growth

An increase in the number of urban dwellers

Urbanisation

An increase in the proportion of a country’s population that lives in urban areas (towns and cities)

Urban sprawl

The spread of an urban area into the surrounding countryside.

Suburbanisation

The movement of people from the inner parts of a city to the outer edges

Counter - urbanisation

The movement of people from large urban areas into smaller urban areas or into rural areas

Decentralisation

The movement of population and industry from the urban centre to other areas, such as suburbs or rural areas

Deindustrialisation

The decrease in secondary industries, such as manufacture

Gentrification

The improvement of housing in an area by wealthier people, making it unaffordable for those previously living there

Edge - cities

Self contained settlements that have grown from the edge of cities after decentralisation has happened

Consequences of urbanisation

Urban sprawl, lack of housing, lack of services, unemployment and underemployment, transport issues

Deindustrialisation

The move away from industry and manufacture to towards services

Service economy

An economy focussed on providing services, rather than products

Urban Development Corporations (UDC’s)

Aimed to regenerate vacant brownfield sites and attract more private sector investment - London Docklands Development Corporation

Enterprise Zones

Aims to attract high tech businesses to move to an area through reduced rates and exemption from taxes

City challenges

Provide certain local councils with money that they could spend on whatever they wanted

Local Enterprise Partnerships

Designed to improve physical economic and social conditions by bringing local councils and businesses together to work together

Metro Mayors

Give elected people power and funding to make decisions over a range of issues in their areas

Levelling up

Improving areas of the UK to allow all areas to have equal access to services and opportunities

Urban Form

The physical characteristics of built up areas including the shape, size, density and makeup / configuration of settlements

Physical factors which affect settlement location

Relief of the land, drainage of the land, rivers and lakes, natural resources, type of land and climate

Human factors which affect settlement location

Land value, transport links, communication infrastructure, education and healthcare opportunities and planning and policy

Population - Urban form change

Globalisation makes flows of people less predictable, may lead to a lack of infrastructure

Environment - Urban form change

Pollution may end up in the environment if physical infrastructure for waste does not grow

Economy - Urban form change

Hug population leads to industry settling there, and moves with it

Technology - Urban form change

Some industries need wired networks, so all locate near one another, while others may not, leading to them spreading out

Policies - Urban form change

Government policies affecting infrastructure, planning and the economy way encourage (reduced tax) or restrict (greenbelts) changes

Mega cities

Over 10 million, edge cities spawning and absorbed, aging infrastructure fails, car dominates, intense living areas, transit oriented development, increased distance between socio - economic classes, environmental problems and saving historic cores from destruction

World cities

City with a disproportionate power and influence on a global scale, due to the headquarters of multinational corporations that settle within and having some of the best services and infrastructure

London - world city - hub of production

HQ of Barclays, branches of Citibank UK (USA owned) and world renowned for theatre and literature

London - world city - hub of Political decision making

Member of G7 allowing UK to contribute to global policy, UK government located within

London - world city - hub of migration

42 universities attracting international and domestic universities

Town centre mixed development

The development of functions other than retailing to increase the attractions of the city centre - cinemas, theatres and developing nightlife

Exeter, Devon - 2007

Opening of a mixed use city centre redevelopment scheme to replace undesirable post war development with 60 retail units, 122 flats and a unique visitor attraction (medieval underground passage)

Cultural and heritage quarters

Spread people out across the city by dividing it based around its history and culture

Birmingham Jewellery Quarter

Historically manufactured jewellery, and still does to build up national importance

Fortress Landscapes

Areas designed around security, protection and surveillance and exclusion, creating people who are ‘insiders’ and ‘outsiders’

Fortress LA

Developed a reputation of fear and paranoia of gangs, homeless and minorities causing gated communities, armed response teams and staked metal fencing to form

Edge cities

Self contained settlements which have emerged beyond the original city boundary caused by urban sprawl, causing extreme social segregation as the wealthy move and leave the poor behind

Los Angeles (Edge cities)

Core city is 30km wide, with under 4 million people while the metropolitan area is over 100km wide and has nearly 18 million people - over 20 edge cities

Post Modern City

Changes in urban structure, architectural design and planning, leading to fragmented urban forms with eclectic and varied architecture but heightened economic and social inequalities and polarisation

Las Vegas (Post Modern City)

Large number of edge cities, large number of hotels for tourism many of which are extremely themed with a high rate of violent crime

Cultural Diversity

The existence of a variety of cultural or ethnic groups within society

Economic inequality

The difference between levels of living standards, income etc, across the whole economic distribution

Social segregation

When groups of people live apart from the larger population due to factors such as age, wealth, ethnicity, or religion

Town centre mixed development and cultural and heritage quarters contributions to economic inequality

Tourist and commercial investments keep property prices high, forcing those on a lower income out.

Gentrified areas contributions to economic inequality

Gentrification leads to the displacement of lower income residents, forcing them to move further out of the city.

Fortress landscapes contributions to economic inequality

Wealthy residents choose to live in safe, secure gated communities on the outskirts of cities, leading to them living separately from low income residents

Edge cities contributions to economic inequality

The wealthy are in the suburbs and edge cities while the low income people remain in the inner city. Transport costs means that the edge cities are inaccessible for the low income, inner city residents

Town centre mixed developments and cultural and heritage quarters contributions to social segregation

A greater focus on tourists and not meeting the local communities needs leads to hostility between communities

Gentrified areas contributions to social segregation

The new and old residents rarely mix, causing no community to form

Fortress landscapes contributions to social segregation

This further reinforces fear and distrust in lower income residents creating greater segregation

Edge cities contributions to social segregation

Inner cities tend to have high rates of migrants due to their lower initial income.

Spatial patterns

The arrangement and distribution of different elements within a landscape, such as the size, shape and location of the various features

Issues associated with cultural diversity - Gender

Women from ethnic groups are more likely to retain their traditions and cultural norms

Issues associated with cultural diversity - Housing

Multiple occupancy housing (resented) is common amongst new migrants as they are often poor, often in the inner city

Issues associated with cultural diversity - Health

Inner - city ethnic minority groups tend to have an average of poorer health - poor quality of built environment

Issues associated with cultural diversity - Education

Local schools may become dominated by one ethnic group, leading to changes to the curriculum needing to be made (extra English lessons) or specialist schools opening

Issues associated with cultural diversity - Language

If the host country language is not adopted quickly enough it will act as a barrier to integration and restrict employment and education opportunities

Issues associated with cultural diversity - Food, music and sport

75% of Europeans considered sport as a means of intergtration

Issues associated with cultural diversity - Religion

Migrants may wish to continue to follow their own religious calendar, leading to friction with employers and local community

Issues associated with cultural diversity - Economic

Migrants often fill in labour shortages in the service and manufacturing economy, potentially leading to the perception of “jobs for migrants” during economic recession

Urban microclimates

Small scale variations in temperature, precipitation, humidity, wind speed and evaporation that occur in a specific environment, such as an urban area

What impacts urban microclimates

Urban form, human activities, physical location, diurnal and nocturnal temperatures and seasonal changes

The urban microclimates can affect

Temperature, precipitation, fog, thunder, windspeed and direction, and air quality and visibility

Temperature inversion

An atmospheric condition in which temperature, unusually, increases in height

Albedo

The reflectivity of a surface (the ratio of light coming in compared to the reflected amount)

Urban heat island

The zone around and above an urban area, which gas higher temperatures then the surrounding rural areas

Thermal gradient

Temperatures are higher in the CBD and slowly decreases out towards the rural areas

Anticyclonic conditions

High pressure creates very stable conditions with clear skies so heat remains over the city

Condensation nuclei

Dust and pollution particles that rising water vapour attaches itself to speeding up the condensation process

Reasons for the urban heat island

Urban areas have a lower albedo, more glass and steel to reflect heat, lower humidity, poor insulation leaks heat, all parts of a city generate heat and more conventional thunderstorms

Fog

Urban air pollution results in more condensation nuclei, which encourages the formation of it overnight (cooler temperatures) - tends to be thicker and last longer during anticyclonic weather

Precipitation

Urban heat island warms up the city more than other areas - more evaporation - more condensation due to condensation nuclei - larger clouds form over cities - 5-15% more rain more frequently

Thunder

Urban heat island effect hottest in late afternoon and early evening - hot air rises up large buildings - condenses quickly - water droplets charge the could and discharge as lightning - 25% more likely in urban areas

Wind

Wind hits a building and is pushed downward in a spiral - wind is pushed over a building and begins to spiral in the wake / lee of it - wind is funnelled between the buildings leading to strong gusts (Venturi effect)

Smog

Fog and smoke particles - causes respiratory problems and is found in industrially developing cities

Photochemical smog

Chemical reaction between nitrogen oxides and hydrocarbons - causes damage to crops, headaches, coughs, eye irritation and chest pains - found is most cities

Causes of air pollution - Vehicles

Carbon monoxide - headaches, nausea and fatigue - nitrogen dioxide - inflame lungs and acid rain - particulate matter - settle in airway and lungs leading to health problems

Causes of air pollution - burning fossil fuels

Sulphur dioxide - coughing, tightening of the chest, haze and acid rain

Legislation to reduce air pollution

Clean air act 1956 - reinforced by later policies such as ULEZ and congestion charge

Vehicle restrictions and inscentives

ULEZ and upgrades to buses to make them hybrid or zero emission

Technical innovation

Filters to prevent harmful chemicals from being released - development of electric vehicles

London ULEZ

Introduced April 2019 - pay a charge for vehicles that do not meet the emission standards - NOx emissions 54% lower - can become expensive for residents that cannot afford to upgrade

Clean Air Act 1956

Clean up the air after the London Smog of 1952 - created no smoke zones - improved air quality but required other legislation to make councils change in 1968

Catchment management in urban areas - river flow

Increased flow leads to flooding and erosion during wet periods - decreased flow during dry weather harms fish and other aquatic wildlife

Catchment management in urban areas - Issues

Higher water temperatures can disturb ecosystems - high flows can overload the local water system resulting in raw sewage on the surface

Catchment management in urban areas - Pollution that can end up in rivers

Sediment from building sites, viruses from pet waste, oil, toxic chemicals and heavy metals from cars, pesticides and nutrients from parks and road salt can all damage the river

River straightening

Hard - remove meanders to increase gradient and speed of flow

Natural levee heightening

Hard - increase capacity in river

Embankments

Hard - raise the riverbanks to increase flow

Diversion spillways

Hard - reduce flood risk by providing alternative path

River channelisation

Hard - lining straightened channels with concrete to reduce friction

Afforestation

Soft - increase interception and reduce surface runoff

Riverbank conservation

Soft - planting bushes to prevent riverbank collapse

Floodplain zoning restrictions

Soft - limiting what can be built on floodplains to reduce potential flood damage

River restoration

Soft - the return of a channel to its natural course

Impact on drainage in an urban area - buildings

Hold water on roof and guttering - quicker surface runoff and movement of water