RGPL 103 Quiz2€¦ · • In general, a primate city must be at least twice as populous as the...

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RGPL 103Quiz 2 Material

(Will also be on Exam 2!)

World Population,Demographic Transition Model,

Primate Cities,Case Study: Mexico City

http://navigator‐iup.passhe.edu/login?url=http://digital.films.com/

PortalPlaylists.aspx?aid=1972&xtid=34174

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http://www.radicalcartography.net/

http://www.radicalcartography.net/

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World Population Distribution Stats:• Uneven population distribution uneven population density

• World is increasingly urbanizing • 50% of the world’s population lives in cities

• Europe and South America are two of the most urbanized regions with close to 80% urbanized

• 90% of all people live north of the Equator

• 60% live between 20° and 60° North (Temperate Climate)

• 50% of the world’s population live on just 5% of its land area• Almost 90% of the population live on less than 20% of its land area

• People favor lowland areas over high altitude areas• 80% live below 500 meters above sea level

• Coastal areas have the densest settlement• 60% of the world’s population lives within 100 km of the ocean

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Global Populationhttp://www.bloomberg.com/news/2010‐09‐21/u‐s‐loses‐no‐1‐to‐brazil‐china‐india‐market‐in‐global‐poll‐

on‐investing.html

http://gecon.yale.edu/

http://gecon.yale.edu/large-pixeled-contour-globe

Global Population• Currently estimated to be 6,870,100,000

• The highest growth rate observed was during the 1950s, 60s and 70s, peaking in 1963 at 2.2%

• US Census Bureau Projections show a steady decline in population growth rate

• UN projections show a rise in growth rate

US Census Bureau Total Global Population United Nations Developing vs. Developed

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The World’s most Populated City Regions

Rank Metropolitan area Country Population

1 Tokyo Japan 32,450,000

2 Seoul South Korea 20,550,000

3 Mexico City Mexico 20,450,000

4 New York City United States 19,750,000

5 Mumbai India 19,200,000

6 Jakarta Indonesia 18,900,000

7 São Paulo Brazil 18,850,000

8 Delhi India 18,600,000

9 Osaka‐Kobe‐Kyoto Japan 17,375,000

10 Shanghai People's Republic of China 16,650,000

Trends in population growth in Developing World

• The world’s human population has increased nearly fourfold in the past 100 years

• Each day 200,000 more people are added to the world food demand

• It is projected to increase from 6.7 billion (2006) to 9.2 billion by 2050• It took only 12 years for the last billion to be added, a net increase of nearly 230,000 new people

each day, who will need housing, food and other natural resources

• The largest population increase is projected to occur in Asia, particularly in China, India and Southeast Asia, accounting for about 60% and more of the world’s population by 2050

• The rate of population growth, however, is still relatively high in Central America, and highest in Central and part of Western Africa.

• In relative numbers, Africa will experience the most rapid growth, over 70% faster than in Asia

• In sub‐Saharan Africa, the population is projected to increase from about 770 million to nearly 1.7 billion by 2050

UN population Division, 2007

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What is the cause of such population growth in Developing World?

• Intensified globalization• Resulting in rapid urban‐industrial capitalism

• Clustering of producers and consumers results in urban agglomeration economies

• This process leads to greater productivity and technological innovation

• Thus, resulting in a snowball effect that stimulates urban industrial expansion

• While there are many positives, the negatives spill over creating societal challenges and environmental consequences

Population Pyramids

• A population pyramid is a graphical illustration that shows the distribution of various age groups in a population

• also called age‐sex pyramid

• It typically represents a country or region of the world, and normally forms the shape of a pyramid

Males Females

Three general kinds of Population Pyramids

1. Stationary2. Expansive3. Constrictive

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Expansive Pyramid

• A steady upwards narrowing shows that more people die at each higher age band

• This type of pyramid indicates a population in which there is a:

• high birth rate

• high death rate

• short life expectancy

• This is the pattern of a economically developing country

Stationary Pyramid

• A population pyramid showing an unchanging pattern of fertility and mortality

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Constrictive Pyramid

• A population pyramid showing lower numbers or percentages of younger people

• The country will have a graying population which means that people are generally older

Changes in Population ‐ Japan

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“Normal” US City – Marion Co. IL

http://www.tripplannermag.com

College Town – Gainsville, FL


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Aging City – Sarasota, FL


Population Pyramid – USA (2000)

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Population Pyramid – USA (2012)

Demographic Transition Model (DTM)

• A general rule‐of‐thumb that identifies periods of development with population characteristics

• The DTM is based on variations in • Crude birthrates – the annual number of live births per 1000 population

• Crude death rates – the annual number of deaths per 1000 population

• Five Phases identified:• Phase 1 – High births, high deaths

• Phase 2 – High births, declining deaths

• Phase 3 – Declining births, Low deaths

• Phase 4 – Low births and low deaths

• Phase 5 – Deaths higher than births

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Characteristics of DTM Phases:

• Phase 1 –High births, high deaths

• Pre‐industrial economy

• Phase 2 –High Births – Declining Deaths

• Developing Country

• Improving food and water supply

• Improving Sanitation

• Improvements in farming technology

• Improvements in education

• Results in a large population increase

Many Latin American countriescurrently in this phase, including;

• Bolivia• Peru• Paraguay• Guatemala

No Latin American country is in this phase today – all have passed through this phase

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Characteristics of DTM Phases:• Phase 3 –

Declining Births – Low Deaths• Contraception• Wage increases• Urbanization• Reduction of subsistence agriculture• Increase in status and education of women

• Reduced child labor• Increase in parental investment in children

• Population growth begins to level off

Brazil and Mexico in this phase

• Phase 4 –Low births and low deaths• Stabilization of population• Idealized end point

Uruguay, Cuba in this phase,

Chile and Argentina approaching

• Phase 5 –Deaths higher than births• Shrinking population• Threat to Industrial Societies• Norm in post‐Industrial/deindustrialized societies

• Mitigated through immigration

No Latin American country in this phase

Phase 3 Line Graph

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Phase 4 Line Graph

Phase 1 – High births, high deaths

Phase 2 – High births, declining deaths

Phase 3 – Declining births, Low deaths

Phase 4 – Low births and low deaths

Phase 5 – Deaths higher than births

Mexico is emerging out of Phase 2 and into Phase 3

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Population Pyramids ‐Mexico

Notice top age is 80+ years

Population Pyramids

Notice top age is 75+ years Notice top age is 100+ years

All of Latin America Mexico

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Primate City (a result of rapid urbanization)

• A primate city is the major city of a country, serving as the financial, political, and population center and is not rivaled in by any other city in that country

• In general, a primate city must be at least twice as populous as the second largest city in the country

• The presence of a primate city in a country usually indicates an imbalance in development

• An expanding core

• A stagnant periphery

Some Primate Cities of Latin America include:

Central America:•Mexico City, Mexico•Guatemala City, Guatemala•Havana, Cuba•Managua, Nicaragua•Panama City, Panama•Port‐au‐Prince, Haiti•San José, Costa Rica•San Salvador, El Salvador•Santo Domingo, Dominican Republic

South America:•Buenos Aires, Argentina•Caracas, Venezuela•Lima, Peru•Montevideo, Uruguay•Santiago, Chile

Deriving information from Population Statistics

• Population pyramids and the DTM informs us about the basic structure of a place’s population, and about the basic trends of a place’s stage of development transition

• But we want to know more about the quality of life of the populations of places

• Things such as:• What are the levels of poverty?

• What is the wealth distribution of a population?

• What is the urban / rural distribution of a population?

• What are the living conditions like for urban populations? (or rural populations)

• What is the quality of the built‐environment ?

• What is the quality of the natural environment?

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Phase 1 – High births, high deaths

Phase 2 – High births, declining deaths

Phase 3 – Declining births, Low deaths

Phase 4 – Low births and low deaths

Phase 5 – Deaths higher than births

Mexico is emerging out of Phase 2 and into Phase 3

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GINI Coefficients• The GINI Coefficient is a useful metric for understanding the state of cities (or countries) with

regard to distribution of income or consumption

• It is the most widely used measure to determine the extent to which the distribution of

income (or consumption) among individuals (or households) deviates from a ‘perfectly equal

distribution’

• Equal Distribution (of income) meaning every individual has an equal amount of income

• Not going to happen, correct? But it does give us an indicator as to how the income in a place

is distributed throughout the population – and that is useful!

• The data used here is supplied by the United Nations and is collected from national surveys

and censuses (which will each have a different level of accuracy)

• Most GINI coefficients are usually compiled for a region or country

• GINI coefficients for cities are a relatively new way using data to look a the income

distribution of cities

GINI Coefficients

• The GINI coefficient is derived from a statistical formula and expresses the degree of evenness or unevenness of any set of numbers as a number between 0 and 1

• based on the Lorenz curve which plots the proportion of the total income of the population (y axis) that is cumulatively earned by the bottom x% of the population

• A Gini Coefficient of 0 would indicate equal income for all earners

• A Gini Coefficient of 1 would mean that one person had all the income and nobody else had any

• So… lower Gini Coefficients indicate more equitable distribution of wealth in a society, while higher Gini Coefficients mean that wealth is concentrated in the hands of fewer people

• Sometimes the Gini Coefficient is multiplied by 100 and expressed as a percentage between 0 and 100. This is called the "Gini Index"

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What do the ‘coefficients’ mean?

The table below provides a general guide that is used to identify possible causes and consequences associated

with different GINI coefficient values

UN‐Habitat, ‘State of the World’s Cities 2008/2009. 2010

GINI Index – Income Disparity since WWIINotice the USA has an increasing GINI index (meaning income disparity is growing), and that the USA’s

GINI coefficient is much closer to that of Mexico than that of Canadawww.wikipedia.com, using World Bank data

Alertline

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Urban and Rural GINI Coefficientsfor select developing countries

Urban and Rural GINI Coefficientsfor select developing countries

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UN‐Habitat, 2009

LATIN AMERICA

Income Inequality GINI coefficients for selected cities:

ASIA AFRICA

The red line represents 0.4 on the GINI coefficient scale

UN‐Habitat, 2009

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Urban Inequalities in Latin America & Caribbean

UN‐Habitat, 2009

Latin American Urban Populations• Brazil and Mexico together are home to ~54% of the region’s urban population

• In Brazil, 34 percent of households are classified as ‘slums’• Of these, 12% lack improved sanitation for wastewater

• The highest proportion of slums in Latin America can be found in Haiti, Guatemala, Nicaragua (C.A.), and Bolivia (S.A.)

• In most of Latin America, access to improved water and improvedsanitation for wastewater is more common than in other parts of the developing world

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UN‐Habitat, 2009

UN‐Habitat, 2009

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UN‐Habitat, 2009

Latin American Urban PopulationsLatin America and the Caribbean have almost completed its urban transition

Urbanization rates are stabilizing and slum growth rates are slowing

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Age‐sex pyramids for slum, non‐slum and rural populations in Brazil

UN‐Habitat, 2009

SLUMSand urban inequalities

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How is a ‘Slum’ defined?• Our text book uses indicators of deprivation based on five conditions:

1. Poor access to improved water

2. Poor access to sanitation

3. Non – durable housing

4. Insufficient living area, and

5. Insecure tenure (lack of ownership)

• It is important to remember that even if it is defined as a ‘slum’, it is a community for the people living there…

Origin of the word, ‘slum’• The word ‘slum’ appeared in London at the beginning of the 19thc, designating, initially, “a room of low repute”

• At the end of the 19thc, the word appears in the Oxford English Dictionary:

• The contemporary use of the word ‘slum’ is often inter‐changed with ‘shanties’, as in ‘shanty‐towns’

• Shanty‐towns are spontaneous settlements that develop in outskirts of towns

• While officially different, ‘shanties’ are now considered by some as a type of slum

“A street, alley, court, etc., situated in a crowded district of a town or

city and inhabited by poor people or a low class or by the very poor;

a number of these streets or courts forming a thickly populated

neighborhood or district where the housed and the conditions of life

are of a squalid and wretched character”

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How is a ‘Slum’ defined?• The term ‘slum’ has loosely been used in the West when referring to housing areas that were once affluent, but have deteriorated

• This is not the same as the definition of ‘slum’ in the non‐western world

• Non‐western urban slums are not simply parallel to ‘poor areas’

• Contemporary slums of the non‐western world are informal settlements where newcomers to the city can find:

• affordable shelter

• enclaves of local culture, and

• support from a social network

• The United Nations (author of our text book) and many at the World Bank argue that slums should be eradicated

• Is that a solution? Is it achievable? Who would this serve most?

How is a ‘Slum’ defined?• Despite the few positives a slum may provide for rural newcomers to the city, slums are characterized by many negatives, such as:

• Poverty

• Illiteracy

• Unemployment (official, taxable employment)

• Informal economies

• Crime

• Drug proliferation

• Disease

• ‘Waste’ collection

• Absence of disaster response and relief

• (fire, police, earth‐moving, etc.)

• Alternatively, it can be argued that these types of urban settlements represent the ultimate in the free‐movement of people, thus representing true democracy

• And that those cities that try to demolish them are totalitarian

What is the best course of action to address these types of settlements?

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• Sub‐Saharan Africa (62.2%) followed by South Asia (42.9) rank the highest in the proportion of urban populations living in slums

• Latin America (27%) is much lower and we can relate this to the region’s demographic transition (as seen in the DTM)

Rio de Janiero, Brazil

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Planning as a response to slums

• Understanding the function in concept, and geography of slums in context is necessary

• Urban Planning techniques include;• Monitoring and predicting of the expansion

• Improvement of existing facilities

• Disaster prevention

• Environmental resource management

• And, if absolutely necessary, relocation of residents to formal housing

• A crucial requirement for effective Urban Planning is to have access to accurate and updated spatial data

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Urban Environmental Risks

Urban Heat Islands

Urban “Heat Islands” (UHI)• An Urban Heat Island (UHI) is created around a metropolitan area, where the central urban area’s land cover (concrete, pavement, metal, etc.) absorb and retain more heat from the sun than those land covers of the surrounding countryside (grass, trees, dirt, etc.)

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Urban “Heat Islands” (UHI) ‐Measuring

• Urban heat islands may be identified by measuring surface or air temperatures

• Surface temperatures have an indirect but significant influence on air temperatures

• For example, parks and vegetated areas, which typically have cooler surface temperatures, contribute to cooler air temperatures

• Dense built‐up areas, on the other hand, typically lead to warmer air temperatures

• Because air mixes within the atmosphere, though, the relationship between surface and air temperatures is not constant

Urban “Heat Islands” (UHI) ‐Measuring• Surface and atmospheric temperatures vary over different land use areas

• Surface temperatures vary more than air temperatures during the day, but they both are fairly similar at night

• The dip and spike in surface temperatures over the pond show how water maintains a fairly constant temperature day and night, due to its high heat capacity

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Urban “Heat Islands” (UHI) ‐Measuring

• Remote Sensing techniques can be used to measure the amount of heat that is being generated by a conglomeration of land covers

• Remote Sensing is the acquisition of information about an object or phenomenon using equipment that does not make contact with the object.

• It takes measurements of various types of emitting energy / radiation from the object

•All surfaces give off thermal energy that is emitted in wavelengths. •Instruments on satellites and other forms of remote sensing can •identify and measure these wavelengths, providing an indication of temperature

Atlanta, GAUHI effect

Atlanta surface heat signatures

http://thinkgreendegrees.com

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Urban “Heat Islands” (UHI) ‐ Impacts

• On a hot, sunny summer day, roof and pavement surface temperatures can be 50–90°F (27–50°C) hotter than the air

• While shaded or moist surfaces—often in more rural surroundings—remain close to air temperatures

• These surface urban heat islands, particularly during the summer, have multiple impacts and contribute to atmospheric urban heat islands

• Air temperatures in cities, particularly after sunset, can be as much as 22°F (12°C) warmer than the air in neighboring, less built‐up rural regions

Energy

• Energy is defined as the ability to do work

• All ecosystems, including the atmospheric environment, require energy to function

• The atmosphere largely depends on heat energy

• Heat energy comes from the movement of atoms & molecules in matter

• The sun is the ultimate source of heat energy

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Mechanisms of heat energy transfer

• Heat energy moves from objects that are hotter to objects that are colder when the two objects are in contact

• (land and air; or sea and air; or hot air mass and cold air mass)

• There are three mechanisms of heat energy transfer • Conduction

• Convection

• Radiation

Mechanisms of heat transfer

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Conduction

• The transfer of heat energy through a substance when molecules in the substance collide with each other

Convection

• The transfer of heat energy when a substance itself moves from one place to another

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Radiation

• The transfer of heat energy from a substance into its environment by means of electromagnetic waves

• These waves vary by wavelength, which depends on the temperature of the substance

• Hotter substances generate more radiation energy and radiation of shorter wavelength


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http://www.sustainablecitiesnet.com

‘Normal’ distribution of solar radiation

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The electromagnetic spectrum

Solar radiation

• Ranges from long to short wave, but is largely shorter wave

• Includes visible light

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Solar and earth radiation

Solar radiation is (1) reflected

• By aerosols and gas molecules in the atmosphere back into space

• By water and solid earth on the ground back into either the atmosphere or into space

• Albedomeasures an object’s reflectivity, expressed as a percentage of the radiation received by the object that is reflected

• Surface albedos vary considerably

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Albedo (reflectivity)

Solar radiation is (2) scattered

• By atmospheric aerosols and gas molecules to elsewhere in the atmosphere

• A greater concentration of larger aerosols results in more scattering

• Short wave radiation tends to scatter more

• Blue sky and an orange‐red sky both result from scattering of visible light radiation

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Solar radiation is (3) absorbed

• By aerosols and gases in the atmosphere

• By water and solid objects on the ground

• Absorption results in the transfer of heat energy to the object with which the radiation comes into contact

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‘Normal’ distribution of solar radiation

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UHI ‐Mitigation• Remember: Mitigation means, ‘to lessen the severity’ of something

• By increasing vegetative cover and by using construction materials that have similar energy absorption properties as the ‘natural world’, we can reduce UHI

• There are four main strategies to UHI Mitigation:• Increasing tree and vegetative cover

• Installing ‘green’ roofs

• Installing cool – mainly reflective – roofs, and

• Using cool pavement material

RGPL 103 Quiz2€¦ · • In general, a primate city must be at least twice as populous as the...

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