Topic: Population Density and Population Distribution Aim: How is population distributed throughout the world and how can that be measured? Do Now: 1.How.

Topic: Population Density and Population Distribution

Aim: How is population distributed throughout the world and how can

that be measured?• Do Now: 1. How many brothers

and sisters do you have?

2. How many did your parents have?

3. How many did your grandparents have?

Demography

• The study of human populations, particularly the size, distribution, and characteristics of members of population groups.

Why do we study population?

• Summer Assignment, Part 7:

• What issues are associated with a world population of 7 billion?– Food supply– Access to other resources– Health and life expectancy– Status of women– Migration

What do we call the frequency of something within a given unit of area?

Population density

• Total population relative to land size

• 3 ways to report it:1. Arithmetic

2. Physiologic

3. Agricultural

1. Arithmetic Density• Total number of objects in an area• Computation: Divide the population by the land

area– US: 325,000,000 people ÷ 3,800,000 square miles = 86

people per square mile

– 9,150,000 square kilometers = 35.5 people per sq km

• Used to compare conditions in different countries• Doesn’t show uneven distribution of population

throughout a country

ARITHMETIC DENSITY Geographers rely on the arithmetic density to compare conditions in different countries because the two pieces of information–total population and total land area–are easy to obtain. The highest arithmetic The highest arithmetic densities are found in Asia, Europe, and Central America. densities are found in Asia, Europe, and Central America. The lowest are in North and South America and South Pacific.

2. Physiological Density• Number of people supported by a unit area of

arable land• Computation: Divide the population by the

arable land– US 325,000,000 ÷4,100,000 sq km = 79 people per

sq km

• Higher the physiological density = greater pressure on land to produce sufficient food

• Shows relationship between population size and availability of resources

PHYSIOLOGICAL DENSITY The relatively large physiological densities of Egypt and the Netherlands demonstrates that crops grown on a hectare of land in these two countries must feed far more people than in the United States or Canada, which have much lower physiological densities. The highest physiological densities are found in Asia, sub-Saharan Africa, and South America. The lowest are in North America, Europe, and South Pacific.

Population Density Activity• Take out your “Area and Demographic

Data…” chart (textbook Appendix B)

• Find the arithmetic and physiologic population density measures for your two assigned countries

• Which country shows the bigger difference in the two measures?

• What are the implications for that country?

3. Agricultural Density• Two countries can have similar physiological

densities but produce significantly different amounts of food– Why?– Different economic conditions

• Ratio of the number of farmers to the amount of arable land

• Netherlands vs. India:– Much higher physiological density– Much lower agricultural density

AGRICULTURAL DENSITY The highest agricultural densities are found in Asia and sub-Saharan Africa. The lowest are in North America, Europe, and South Pacific.

Population Distribution• Summer Assignment, Part 7

• How would you describe population growth since 1800?

• Why?

• Where?

• Virtually all global population growth is concentrated in less developed countries.

Population J-CurveThis graphs depicts the actual growth in human

population from the beginning of agriculture until 2000!

1. What kind of map?2. Why this kind of map?3. What does it tell you about population distribution?

Population Distribution• People are NOT distributed evenly across the

Earth• Population is clustered in the mid-latitude climates– Near water, oceans, seas, lakes or rivers, temperate, low lying areas with fertile soils

• Population is relatively sparse in areas that are too dry, wet, cold, or high to easily grow crops

• 3 major areas of high density– East Asia (China), South Asia (India), Europe.

• 7 billion now, projected to rise to 9.3 billion by 2050.– 6 countries will account for half the population

• India, Bangladesh, Pakistan, China, Indonesia and Nigeria

What factors influence population

distribution?• What type of natural resources are in the area?

• Does it have oil, or arable land or access to water?

• What is the climate like?• Does it have capital resources such as transportation and technology?

Egypt’s population distribution is closely linked to the proximity of water. In the north, the

population clusters along the Mediterranean and in the interior, along the banks of the Nile River.

(2004)

All 7 billion could fit in LA…

• Why is that surprising?

• Most people live in a relatively small Most people live in a relatively small area of eartharea of earth

The World and the Top 20The World and the Top 20• Do you think your country’s population is in

the top 10?• What do you think are the top 10 most

populous countries?

Countries are displayed by size of population rather than land area. Countries named have at least 50 million people.

• Approx. 80% of world’s population lives in less-developed countries (all of Africa, Asia [excluding Japan], Latin America, and the island nations of the Caribbean and Pacific.

• Two countries, India & China, each have over 1 billion people and account for 1/3 or the world’s current population.

ASIA AFRICA

The same number of people live in the red (Bangladesh) as the blue

Where is population growing the fastest?