Topic 1. Population

Introduce the subject with the following video clip:

http://www.youtube.com/watch?v=YMY_-xYmJvE&NR=1

1. Population development

Demography is the science dedicated to the study of the growth, distribution,

structure (how it is organized by age groups) and movements of the population.

The main tools to carry out this study are the government census, the municipal

register and, in certain countries, such as Spain, the parochial certificates of baptism.

The growth of world population throughout the years has known different

stages:

- Until the middle of the 18th century population growth was very slow

because of a high tax of mortality

- From mid-18th century population growth in Europe and America

accelerated because of improvements in health care and nutrition

- By the 20th century population grew very quickly due to a lowering in the

death rate of Asia, Africa and Latin America.

- Since the 1980s population growth has been curbed by a fall in the birth rate,

though in the developing countries it hasn’t been so intense.

2. Population distribution

The world has today more than seven billions inhabitants. In July 1987 it was

five billions, so that in some more than twenty years it has grown about 20%.

However,

as you can see in

the map, the

world population

is not evenly

distributed.

Around the

world, there are

huge areas with

little or no

people living there at all, whereas certain areas are densely populated. This means many

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people living in areas of limited extension. There is a mathematical formula to express

population density:

Population density =

Number of inhabitantsArea of land (Km2)

a. Look at the map and list some of the less and some of the most populated

areas of the world.

There are a number of reasons to explain this fact. They are usually classified as

physical and human factors.

b. Give some ideas about what specific reasons can determine population density

of one sort or another.

Physical Human

Climate. Population tend to dwell in humid

areas with mild temperatures. Therefore,

deserts, jungles and polar regions are

mostly unhabited.

History. Most populated areas have a long

history of human presence, continued

nowadays, as is the case of Eastern Asia or

Europe.

Altitude and distance to the coast. People

live more often near the coasts and flat,

low altitude areas. Mountains have a scarce

population.

Economic development. Job opportunities

and welfare policies are main reasons for

people to migrate. Thus urban areas in most

developed countries are the destination for

many people from underdeveloped regions.

Soil fertility. Because of natural reasons,

some soils are more fertile than others.

Fertility is linked to abundance of crops,

which allows a higher growth of

population.

Political and religious persecution. Political

enemies and religious or ethnic minorities

are sometimes harassed by the state

authorities, so that they must leave their

countries in search of asylum.

Government policies. Governments

occasionally promote settlements in low

populated areas because of military or

economic interest. Another reason is to

reallocate an excess of population in certain

areas, as in Eastern China.

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3. Why is the population increasing?

If we consider the population of the entire world, the answer to this question is

easy: there are more births than deaths. However, there are huge differences if we

compare some countries with others. This is because not all the countries have the same

access to food or to medical facilities, to contraceptive methods, etc.

In order to compare the different paces of population growth two indicators are

used: birth rate and death rate. Birth rate is the number of babies born alive per

thousand of people in a given country or region. Death rate is the number of deaths per

thousand of people of a given country or region, no matter the age at which death occurs

or the reason

Birth rate =

Number of birthsx 1000 Death rate =

Number of deathsx 1000

Total population Total population

Why are so

different these

rates? There are

socio-economic

factors, for

instance, in

western culture

the age at which

women have their

first son or daughter is well over 20 years old. In African cultures it can be as low as 14

or 16 years old. Also, in Europe and America women quite often work outside home,

while in Third World countries they work as housekeepers.

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Cultural factors. When the education of women improves, the age of having the

first child is delayed, and the total number of sons is lesser. Religious beliefs also

influence the number of births, since almost all religions condemn birth control

measures. Hence, societies where religious influence is powerful usually have higher

birth rates.

Political factors. Governments may adopt policies which restrict or, otherwise

promote birth.

c. Look for the proper data in the Internet address

http://www.census.gov/ipc/www/idb/informationGateway.php (for extension

look at www.wikipedia.org and search by the country name), fill the blank

spaces of the table and answer to the questions

CountryExtension

(Km2)Population in

2009

Population Density in

2009

Population in 1991

Growth rate in 2009

Relative Growth 1991-2009

Crude birth

rate in 2009

Crude death rate in 2009

Spain 504,030 40,525,000 80 39,461,000 0,1 2.6% 10 10

Mali 8,512,000 2,6 57.9% 46 15

India 853,724,000 1,4 35.5% 22 8

Canada 28,118,000 0,8 19.0% 10 8

Of these four countries, which is the most densely populated? And the most sparsely?

Classify them by growth rate, and calculate the relative growth (in percentage) of each

country between 1991 and 2009, classifying them by relative growth. Is the order the

same? What might be the reason?

d. What’s the difference between absolute population and population density?

From the previous explanations we can now introduce the concept of natural

population increase. This is merely the difference between the rate of births and the

rate of deaths. If this difference is positive (there are more births than deaths),

population grows; when the difference is negative (there are more deaths than births),

population decreases. So that:

Rate of natural increase (RNI) =Birth rate – Death

rateObviously, different countries have different RNI, often related to their degree of

development.

A special chart is often used to summarize the demographic evolution of human

societies. It’s the graphic expression the evolution from the ancient to the modern

demographic behaviour of societies. It is usually known as the demographic transition

model. It may be explained as follows:

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As you can see below, in the first stage of evolution both birth and death rates

are high and up to a point variable (red and blue lines). As a result, population remains

stable (black line).

At certain

moment, death rates

start to decrease while

birth rate remains

stable for even

decades. This is the

second stage, when

population rises

rapidly.

In the third

stage, the number of inhabitants has risen enough as to produce a restraint in the birth

rate: population now begins to stabilize (i.e. it doesn’t grow so fast).

In the final, fourth stage, birth and death rates reach a minimum, and then no

further population increase is registered: population now is stationary or may even

slightly decrease when births fall below the deaths (as in modern western societies).

4. What are migratory movements?

Population distribution around the world is not only affected by births and

deaths, but also by migratory movements.

Migratory movements imply that some people moves from where they have

been living to another place—town, city, region or country.

Taking this into

account, we talk about

emigration, for instance,

when somebody that has

lived here till now moves

permanently to another

place.

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On the contrary, when somebody comes to live here, also more or less

permanently, from another place, we talk about immigration.

In the former example, we take the point of view of the departure place; in the

latter, that of the arriving place.

a. Give some examples of emigration and immigration

Why do people migrate? Migrations have usually economic, political or

religious reasons.

If there are few jobs available in their place of residence or they are not paid

enough, people have to move to another place with better opportunities. These are

economic migrations.

In some other cases, people have to flee because of their political or religious

beliefs. These are migrations too, but in this case these people are named refugees.

Take into account that migrations can be definitive or just temporary. Also,

migrations may occur inside a country, from rural to urban areas, or international, from

one country to another.

b. What consequences have migratory movements on the places of origin and of

destination?

5. Population structure

To better understand societies, population is often classified in different ways:

- By sex. The ratio of men to women. Usually, more boys than girls are born,

but women live longer.

- By age. Population is usually divided into three groups of age

o Young people (0-14)

o Adults (15-64)

o Elderly (65 and older)

- By economic activity

o Active population: people who have a job or are trying to find one.

This includes employed and unemployed population

o Inactive population: people who don’t work nor intend to do so for

whatever reason (age, disability)

- By literacy rate (taking into account only people over 15 years)

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o High literacy rates in developed countries where schooling is

compulsory until 16

o Low literacy rates in less-developed countries where children start to

work at early ages

o In the latter case is also true that female population usually has lower

literacy rates.

6. The population of Europe

Considered as a

whole, Europe has one of

the highest population

densities in the world,

with more than 700

million inhabitants in

10.500.000 Km2.

However, this density of

66 In./ Km2 is very

variable.

In some countries

birth rate is below death

rate, so that the number of inhabitants is decreasing.

There is a long life expectancy, over 75 in most of the countries.

For this reason, population is ageing, most evidently in the Western half of the

continent.

7. Population of Spain

Population in Spain grew fast in the 1970s, due to high birth and low mortality

rates. At present, Spain has over 46 million inhabitants.

The population density is rather low for Western Europe, with 92 inh/ Km2.

Since the 1980s growth has fallen to 0.2%: birth and death rates are both very

low.

Spanish population is suffering from acute ageing. 17% of all Spaniards are over

65 years old.

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Also, population is

unevenly distributed in Spain.

Most people live in the

periphery, near the coasts, with

the exception of the province of

Madrid and surroundings.

Central Spain is very sparsely

populated, in more or less little

towns with islands that

concentrate secondary poles of

population. Most often these are province capital cities such as Valladolid, Saragossa,

Ciudad Real, Albacete or Cordoba.

8. Population graphs

Graphs are commonly used in

Geography, since they allow to

represent geographical facts in a clear

and understandable way. Those most

frequently used in population studies

include the following:

Linear graphs whether with a

single line or several lines or areas,

show the evolution of a given variable. In the x or horizontal axis it is represented the

lapse of time; in the y or vertical axis it is represented the value of the given variable.

Where both data coincides a point is

marked. After marking all points, they

are joined by a line.

Simple bar charts use bars or

rectangles of a size proportional to the

value of the variable, but with the same

base. Complex bar charts feature a

single bar, horizontal or vertical, to

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represent proportional or

absolute data of a

geographical fact.

Sector graphs

represent data as proportions

of a circumference, so that

the variable to represent is a

sector of the total

circumference.

Population pyramids represent the distribution by sex and age of a given

population, allowing to analyse its structure. Population is divided into groups from five

to five years, males at the left side and females at right (0-5, 6-10, 11-15 and so on). The

horizontal axis represents the absolute number or the percentage of the individuals, and

the vertical one their group of age, superposing the elder over the younger until all the

population is included. The final result usually looks like a pyramid, from which the

graph takes its name. Different shapes of the pyramids allow reaching relevant

conclusions about the structure, ageing and distribution of the population.

c. From data of the following link, draw a linear chart of the population of Spain

[Classwork].

http://lolaceituno.googlepages.com/unequalpopulationdistribution

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Young population. The basis of the

pyramid is wide, while it narrows towards the

top. This pyramid is typical of

underdeveloped countries, with great birth

and death rates, and of developed countries

before the demographic transition took place.

Average population age is low, because there

are many children while elderly people is

relatively scarce

Adult population. The basis of the

pyramid becomes narrower because of the

decrease in the birth rate, while death rate

keeps high. This is a transitory stage for

developing countries, when most people

belong to intermediate age ranges

Elderly population. This is the final

stage of the model of demographic

transition. Now the basis of the pyramid is

the narrowest because birth rates are at a

minimum. The upper-medium part of the

pyramid is the widest, because birth and

death rates are found in the lowest level.

This profile is characteristic of developed

countries with an ageing population. Over time, the widest part of the population will be

at the top ranks of the pyramid because of the high life expectancy.

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