Urbanization, Centripetal and Centrifugal Movements

IB Geography II

PART 1: URBANIZATION

Bell Ringer: Make a list of 5 valid claims relating to patterns of urbanization you can see in the map

The Process of Urbanization

• Urbanization: the process by which an increasing percentage of a country’s population comes to live in towns and cities. It may involve both rural-urban migration and natural increase.

Causes of urbanization

1. Rural to urban migration2. Natural Increase

Rural – urban migration• Rural to urban migration – result of push and pull factors

Push and pull factors

Push factors Pull factors

Difficult/harsh climate – eg. droughts Chance of a better life

Struggle to provide food for family Better housing and amenities

Very low income Chance of good jobs – higher wages, more varied employment

High rates of population growth have put pressure on natural resources such as water/energy/land

Better medical/health care

Can’t afford to fertilizers to increase yields Children able to go to school

Mechanization of farming favors rich farmer and leads to unemployment or underemployment of poor farmer.

Natural increase

• The people that migrate into towns and cities tend to be young resulting in high levels of natural increase

• high % of young adults = high levels of births• Falling death rates due to improved medical care means more

babies are born than people dying, further increasing the urban population

% urban population

World Urban Population

Elbow Partner Discussions

• Using the last two data slides, discuss this question: – Why are there higher rates of urbanization in

developing nations compared to developed nations?

Graphing Global Urbanization Activity • Step 1: Take 5 minutes to read/annotate data set. Be

sure to read definition of agglomerations for notecards!

• Step 2: In elbow partners, answer the following questions: – How many urban agglomerations had a population greater

than 10 million in 1950? Where were these urban areas? – Describe the changes in the number and location of urban

agglomerations in 1975, 2000, and 2010. – What changes does the UN project for 2025?

• Step 3: Graph the Data. – Create a comparative bar graph showing bars for

each of the following continents (N. America, S. America, Europe, Asia, Africa) and different colors for each time period in the handout

– Y axis will be number of urban areas in each time period in each continent

Graphing Global Urbanization Activity

• Step 4: Analyze the data. In one paragraph, answer the following prompt using data from your graph as resources.

• Discuss changing patterns of urbanization from 1950-2025.

Graphing Global Urbanization Activity

PART 2: CENTRIPETAL MOVEMENTS

Centripetal Movements involve the migration of people into

towns and cities

Inward Movement (Centripetal)Rural to urban migration, gentrification, re-urbanization, urban renewal

Urban Processes can be seen as inward and outward movements

Outward Movement (Centrifugal)Suburbanization, urban sprawl, counter-urbanization

Rural Push Factors

• High rates of population growth have put pressure on natural resource such as water and energy and reduced the size of land holdings

• New farming technology favors the rich farmer, but for others it leads to unemployment or underemployment

• Migration for work is often the only option• (See complete list of rural push factors in

yesterday’s notes)

Urban Pull Factors

• Higher wages• More varied employment • Educational opportunities • (See complete list in earlier notes)

The Consequences of Urbanization

• Economic Growth: – Urban economies are

almost always more productive than rural ones

– Industrial productivity is higher in cities.

– Cities are usually responsible for a greater percentage of total GDP

The Consequences of Urbanization

• Gentrification – The Reinvestment of capital into inner-city areas. – Improvement in residential areas– It is a type of filtering that may lead to the social

displacement of poor people (as a place becomes gentrified, housing prices rise and the poor are unable to afford it– often times minorities)

The Consequences of Urbanization

– Re-urbanization: (urban renewal) the development of activities to increase residential population densities within the existing built-up area of a city.

– This may include the redevelopment of vacant land and the refurbishment of housing and the development of new businesses.

The Consequences of Urbanization

– Brownfield Sites: abandoned or underused industrial buildings and land, which may be contaminated but have potential for redevelopment

Centrifugal Movements

Centrifugal Movements

• Also known as Decentralization • The outward movements of a population from

the center of a city towards its edge or periphery, resulting in the expansion of a city.

Suburbanization

• Suburb: a residential area just outside the boundaries of a city.

• Suburbanization: the outward growth of towns and cities to engulf surrounding villages and rural areas. This may result from the out-migration of population from the inner urban areas to the suburbs.

Urban Sprawl

• The unplanned and uncontrolled physical expansion of an urban area into the surrounding countryside. It is closely linked with the process of suburbanization.

• Good examples of Urban Sprawl include Mexico City

• http://www.dailymail.co.uk/news/article-2401975/Amazing-aerial-photos-Mexico-City-natural-boundaries-stand-way.html

Counter-Urbanization

• A process involving the movement of populations away from inner urban areas to a new town, new estate, commuter town or village on the edge or just beyond the city limits or rural-urban fringe.

• Characteristic of wealthy cities in MEDCs • It is a response to increasing stress of

overcrowding, congestion, pollution and crime.

Reasons for counter-urbanization

• Increased car ownership• Increased wealth• De-industrialization• Relocation of industry/employment to rural urban

fringe• Desire for safe, pleasant environment, the rural

ideal/utopia• Perception of urban areas as dangerous, high

levels of crime, racial/ethnic problems – ‘white flight’

• Change in tenure from public/renting to private ownership. Sell property and move out.

The Consequences of Centrifugal Movements

• Centrifugal movements involve a shift of population and economic activity from the center of the urban area to its periphery and beyond, which is detrimental to the center.

• Construction of roads and buildings destroy open space and increases air pollution

Response to Consequences

• Urban Planners have focused on ways of reviving the urban center(urban renewal/gentrification) and restricting new construction in urban hinterlands

• Hinterlands: the zone surrounding a city

The Family Life Cycle

• Intra-urban population movement may involve shifts of population during the family life cycle.

• A person is likely to move around different zones of city depending on their age and their need for a house of a certain size.