Population introduction notes

Population geography is a division of human geography. It is the study of the ways in which
spatial variations in the distribution, composition, migration, and growth of populations are
related to the nature of places. Population geography involves demography in a geographical
perspective. It focuses on the characteristics of population distributions that change in a
spatial context. Examples can be shown through population density maps. A few types of
maps that show the spatial layout of population are choropleth, isoline, and dot maps.
Population geography studies:

• Demographic phenomena (natality, mortality, growth rates, etc) through both space
and time
• Increase or decrease in population numbers
• The movements and mobility of populations
• Occupational Structure
• Grouping of people in settlements
• The way from the geographical character of places e.g. settlement patterns
• The way in which places in turn react to population phenomena e.g. immigration
• The following are definitions of some basic terms used frequently within
population geography.
• Natural Increase - The rate, at which a population increases, basically birth
rate minus the death rate, and excluding immigration. This number is
usually expressed per 1000 of the population, and may be expressed as a
percentage.
• Birth Rate- The number of births annually within a country or realm.
Usually expressed by numbers of births per one thousand of the population,
and may be expressed as a percentage.
• Death Rates - The number of deaths annually within a country or region.
Usually expressed by numbers of death per one thousand of the population,
and may be expressed as a percentage.
• Infant Mortality Rates - The number of deaths within a country or region,
age 1 or below. Usually expressed by numbers of deaths per one thousand of
the population, and may be expressed as a percentage. If infant mortality
rates are considered in life expectancy rates and are high, it may impact the
numbers significantly.
• Life Expectancy Rates - The number of years a newborn can expect to live,
calculated annually. Usually expressed as a percentage.
• Population Density - The number of people per square mile or kilometer,
usually takes total population of a country or region and total area. Can vary
dramatically within a state, an example is density figures for Tokyo and all
of Japan.
• Double Time - The number of years it would take for a population to double
in size if it continues to grow at the current rate.
• Migration - permanent movement of the population. May be voluntary or
forced.
• Immigration- migration of the population from one sovereign state to
another.
• Out- Migration - movement of a population out of a sovereign state, usually
a result of a lagging economy or civil strife.
• Median Age - the middle or fiftieth percentile in regards to age within a
population.
• Average Age - the sum of all ages divided by the total number of the
population.

Sex ratio is the demographic concept that measures the proportion of males to females in a
given population. It is usually measured as the number of males per 100 females. The ratio is
expressed as in the form of 105:100, where in this example there would be 105 males for
every 100 females in a population.

Sex Ratio at Birth

The average natural sex ratio for humans from birth is approximately 105:100. Scientists are
not sure why there are 105 males born for every 100 females around the world. Some
suggestions for this discrepancy are given as:

It is possible that over time, nature has compensated for males lost in war and other
dangerous activities to better balance the sexes.

A more sexually active gender is more likely to produce offspring of their own gender. Thus,
in a polygynous society (polygamy where one man has multiple wives), he is likely to have a
greater proportion of offspring that are male.

It is possible that female infants are under-reported and not registered with the government as
often as male babies.

Scientists also say that a woman with a slightly over average amount of testosterone is more
likely to conceive a male.

Female infanticide or the abandonment, neglect, or malnutrition of female infants in cultures
where males are favored may occur.

Today, sex-selective abortions are unfortunately common in countries like India and China.
The introduction of ultrasound machines throughout China in the 1990s led to a sex ratio of
up to 120:100 at birth due to familial and cultural pressure to have one's only child as a male.
Shortly after these facts became known, it became illegal for expectant couples to know the
gender of their fetus. Now, the sex ratio at birth in China has been reduced to 111:100.

The world's current sex ratio is somewhat on the high side – 107:100.

Total Fertility Rate

Total Fertility Rate Impacts a Country's Population
The term total fertility rate is used to describe the total number of children the average women in a
population is likely to have based on current birth rates throughout her life. The number, which ranges
from more than 7 children per woman in developing countries in Africa to around 1 child per woman in
Eastern European and highly-developed Asian countries.

Associated with total fertility rate is the concept of replacement rate. The replacement rate is
the number of children each woman needs to have to maintain current population levels or
what is known as zero population growth for her and her partner.

In developed countries, the necessary replacement rate is about 2.1. Since replacement can
not occur if a child does not grow to maturity and have their own offspring, the need for the
extra .1 child (a 5% buffer) per woman is due to the potential for death and those who choose
or are unable to have children. In less developed countries, the replacement rate is around 2.3
due to higher childhood and adult death rates.

Nonetheless, with total fertility rates of 7.38 in Mali and 7.37 in Niger (as of mid-2007), the
resultant growth in these countries' populations is expected to be phenomenal over the next
few years, unless growth rates and total fertility rates drop. For example, Mali's 2007
population is approximately 12 million. With its high total fertility rate per woman, Mali is
expected to grow to more than 15 million (a 3 million or 25% increase) by 2015! Mali's 2007
growth rate of 2.7 means a doubling time of just 26 years. Other countries with high total
fertility rates include Afghanistan at 6.64, Yemen at 6.49, and Samoa at 4.21.

DEMOGRAPHIC TRANSITION MODEL

Summary of the theory

Population pyramids for 4 stages of the model

Demographic change in Sweden from 1735 to 2000. Red line: crude death rate (CDR), blue line:
(crude) birth rate (CBR)

The transition involves four stages, or possibly five.

• In stage one, pre-industrial society, death rates and birth rates are high and roughly in
balance.
• In stage two, that of a developing country, the death rates drop rapidly due to improvements
in food supply and sanitation, which increase life spans and reduce disease. These changes
usually come about due to improvements in farming techniques, access to technology, basic
healthcare, and education. Without a corresponding fall in birth rates this produces an
imbalance, and the countries in this stage experience a large increase in population.
• In stage three, birth rates fall due to access to contraception, increases in wages,
urbanization, a reduction in subsistence agriculture, an increase in the status and education
of women, a reduction in the value of children's work, an increase in parental investment in
the education of children and other social changes. Population growth begins to level off.
• During stage four there are both low birth rates and low death rates. Birth rates may drop to
well below replacement level as has happened in countries like Germany, Italy, and Japan,
leading to a shrinking population, a threat to many industries that rely on population growth.
As the large group born during stage two ages, it creates an economic burden on the
shrinking working population. Death rates may remain consistently low or increase slightly
due to increases in lifestyle diseases due to low exercise levels and high obesity and an aging
population in developed countries.

As with all models, this is an idealized picture of population change in these countries. The
model is a generalization that applies to these countries as a group and may not accurately
describe all individual cases. The extent to which it applies to less-developed societies today
remains to be seen. Many countries such as China, Brazil and Thailand have passed through
the DTM very quickly due to fast social and economic change. Some countries, particularly
African countries, appear to be stalled in the second stage due to stagnant development and
the effect of AIDS.

Stage One

In pre-industrial society, death rates and birth rates were both high and fluctuated rapidly
according to natural events, such as drought and disease, to produce a relatively constant and
young population. Children contributed to the economy of the household from an early age
by carrying water, firewood, and messages, caring for younger siblings, sweeping, washing
dishes, preparing food, and doing some work in the fields.[4]

Raising a child cost little more than feeding him: there were no education or entertainment
expenses, and in equatorial Africa, there were no clothing expenses either. Thus, the total cost
of raising children barely exceeded their contribution to the household. In addition, as they
became adults they became a major input into the family business, mainly farming, and were
the primary form of insurance in old age. In India an adult son was all that prevented a widow
from falling into destitution. While death rates remained high there was no question as to the
need for children, even if the means to prevent them had existed.[5]

Stage Two
World population 10,000 BC - 2000 AD

This stage leads to a fall in death rates and an increase in population.[6] The changes leading
to this stage in Europe were initiated in the Agricultural Revolution of the 18th century and
were initially quite slow. In the 20th century, the falls in death rates in developing countries
tended to be substantially faster. Countries in this stage include Yemen, Afghanistan,
Palestine, Bhutan and Laos and much of Sub-Saharan Africa (but do not include South
Africa, Zimbabwe, Botswana, Swaziland, Lesotho, Namibia, Kenya and Ghana, which have
begun to move into stage 3).

The decline in the death rate is due initially to two factors:

• First, improvements in the food supply brought about by higher yields in agricultural practices
and better transportation prevent death due to starvation. Agricultural improvements included
crop rotation, selective breeding, and seed drill technology.
• Second, significant improvements in public health reduce mortality, particularly in childhood.
These are not so much medical breakthroughs (Europe passed through stage two before the
advances of the mid-20th century, although there was significant medical progress in the 19th
century, such as the development of vaccination) as they are improvements in water supply,
sewerage, food handling, and general personal hygiene following from growing scientific
knowledge of the causes of disease and the improved education and social status of mothers.

A consequence of the decline in mortality in Stage Two is an increasingly rapid rise in
population growth (a "population explosion") as the gap between deaths and births grows
wider. Note that this growth is not due to an increase in fertility (or birth rates) but to a
decline in deaths. This change in population occurred in northwestern Europe during the 19th
century due to the Industrial Revolution. During the second half of the 20th century less-
developed countries entered Stage Two, creating the worldwide population explosion that has
demographers concerned today.

Angola 2005

Another characteristic of Stage Two of the demographic transition is a change in the age
structure of the population. In Stage One, the majority of deaths are concentrated in the first
5–10 years of life. Therefore, more than anything else, the decline in death rates in Stage Two
entails the increasing survival of children and a growing population. Hence, the age structure
of the population becomes increasingly youthful and more of these children enter the
reproductive cycle of their lives while maintaining the high fertility rates of their parents. The
bottom of the "age pyramid" widens first, accelerating population growth. The age structure
of such a population is illustrated by using an example from the Third World today.

Stage Three

Stage Three moves the population towards stability through a decline in the birth rate.

There are several factors contributing to this eventual decline, although some of them remain
speculative:

• In rural areas continued decline in childhood death means that at some point parents realize
they need not require so many children to be born to ensure a comfortable old age. As
childhood death continues to fall and incomes increase parents can become increasingly
confident that fewer children will suffice to help in family business and care for them in old
age.
• Increasing urbanization changes the traditional values placed upon fertility and the value of
children in rural society. Urban living also raises the cost of dependent children to a family.
• In both rural and urban areas, the cost of children to parents is exacerbated by the
introduction of compulsory education acts and the increased need to educate children so they
can take up a respected position in society. Children are increasingly prohibited under law
from working outside the household and make an increasingly limited contribution to the
household, as school children are increasingly exempted from the expectation of making a

significant contribution to domestic work. Even in equatorial Africa, children now need to be
clothed, and may even require school uniforms. Parents begin to consider it a duty to buy
children books and toys. Partly due to education and access to family planning, people begin
to reassess their need for children and their ability to raise them.

A major factor in reducing birth rates in stage 3 countries such as Malaysia is the availability of family
planning facilities, like this one in Kuala Terenganu, Terenganu, Malaysia.

• Increasing female literacy and employment lower the uncritical acceptance of childbearing
and motherhood as measures of the status of women. Working women have less time to
raise children; this is particularly an issue where fathers traditionally make little or no
contribution to child-raising, such as southern Europe or Japan. Valuation of women beyond
childbearing and motherhood becomes important.
• Improvements in contraceptive technology are now a major factor. Fertility decline is caused
as much by changes in values about children and sex as by the availability of contraceptives
and knowledge of how to use them.

The resulting changes in the age structure of the population include a reduction in the youth
dependency ratio and eventually population aging. The population structure becomes less
triangular and more like an elongated balloon. During the period between the decline in youth
dependency and rise in old age dependency there is a demographic window of opportunity
that can potentially produce economic growth through an increase in the ratio of working age
to dependent population; the demographic dividend.

However, unless factors such as those listed above are allowed to work, a society's birth rates
may not drop to a low level in due time, which means that the society cannot proceed to
Stage Four and is locked in what is called a demographic trap.

Stage Four

This occurs where birth and death rates are both low. Therefore the total population is high
and stable. Some theorists consider there are only 4 stages and that the population of a
country will remain at this level. The DTM is only a suggestion about the future population
levels of a country. It is not a prediction.

Countries that are at this stage (Total Fertility Rate of less than 2.5 in 1997) include: United
States, Canada, Argentina, Australia, New Zealand, most of Europe, Bahamas, Puerto Rico,
Trinidad and Tobago, Brazil, Sri Lanka, South Korea, Singapore, Iran, China, North Korea,
Thailand and Mauritius.[7]

Stage Five

United Nation's population projections by location.

The original Demographic Transition model has just four stages, however, some theorists
consider that a fifth stage is needed to represent countries that have undergone the economic
transition from manufacturing based industries into service and information based industries
called deindustrialization. Countries such as United Kingdom (the earliest nation universally
recognised as reaching Stage Five), Germany, Italy, Spain, Portugal, Greece, and most
notably Japan, whose populations are now reproducing well below their replacement levels,
are not producing enough children to replace their parents' generation. China, South Korea,
Hong Kong, Singapore, Thailand and Cuba are also below replacement levels, but this is not
producing a fall in population yet in these countries, because their populations are relatively
young due to strong growth in the recent past.

The population of southern Europe is already falling, and Japan and some of western Europe
will soon begin to fall without significant immigration. However, many countries that now
have sub-replacement fertility did not reach this stage gradually but rather suddenly as a
result of economic crisis brought on by the post-communist transition in the late 1980s and
the 1990s. Examples include Russia, Ukraine, and the Baltic States. The population of these
countries is falling due to fertility decline, emigration and, particularly in Russia, increased
male mortality. The death rate can also increase due to "diseases of wealth", such as obesity
or diabetes, leading to a gradual fall in population in addition to above aging.

Effects on Age Structure

The decline in death rate and birth rate that occurs during the demographic transition lead to a
radical transformation of the age structure. When death rate is declined during the second
stage of the transition the result is primarily an increase in the child population. The reason is
that when death rate is high (stage one) the infant mortality rate is very high, often above 200
deaths per 1000 children born. When death rate decline or improves, this, in general, results
in significantly lower infant mortality rate and, hence increased child survival. Over time, as
cohorts increased by higher survival rates get older, there will be an increase also in the
number of older children, teenagers, and young adults. This implies that there is an increase

in the fertile population which, with constant fertility rates, will lead to an increase in the
number of children born. This will further increase the growth of the child population. The
second stage of the demographic transition, therefore, implies and rise in child dependency.

GLOSSARY

ge-Sex Pyramid (Population Pyramid): a series of horizontal bars that illustrate the structure
of a population. The horizontal bars represent different age categories, which are placed on
either side of a central vertical axis. Males are to the left of the axis, females to the right.

Ageing Population: In the population structure of many MEDCs there is often a high
proportion of elderly people who have survived due to advances in nutrition and medical
care. This creates problems since these people do not work and have to be provided with
pensions, medical care, social support, sheltered housing etc. from the taxes paid by a
proportionally smaller number of workers. In addition, an increasing number of young people
are employed as careworkers for the elderly. This removes them from more productive jobs
within the economy and harms a country's competitiveness.

Ageing Population Structure: a population pyramid with a narrower shape, broad at the top,
found in MEDCs. This reflects their low birth rates and the greater proportion of elderly
people.

Birth Rate: The number of live births per 1000 people per year.

Bulge of Young Male Migrants: on a population pyramid; young males move to urban areas
due to push-pull factors.

Census: a counting of people by the government every ten years to gather data for planning of
schools, hospitals, etc. This is unreliable for a number of reasons.

Child Dependency ratio: the number of children in relation to the number of working
(economically active) population, usually expressed as a ratio.

Concentrated Population Distribution: where people are grouped densely in an urbanised area
(see Port, Bridging-Point, Route Centre, Wet Point Site, Market Town, Mining Town,
Resort).

Contraception: using birth control to stop pregnancy.

Counter-urbanisation movement of people in MEDCs away from urban areas to live in
smaller towns and villages (see de-urbanisation and urban-rural shift).

Death rate: the number of deaths per 1000 people per year.

Demographic transition: the change from high birth rates and death rates to low birth rates
and death rates.

Demographic Transition Model: diagram which shows the relationship between birth and
death rates and how changes in these affect the total population.

Dependency ratio: the ratio between those of working age and those of non-working age.
This is calculated as:

% pop aged 0 -14 + % pop aged 65+
x 100
% of population aged 15-65

Dependent Population: those who rely on the working population for support e.g. the young
and elderly.

Depopulation: the decline or reduction of population in an area.

De-urbanisation: the process in MEDCs by which an increasingly smaller percentage of a
country’s population lives in towns and cities, brought about by urban-rural migration. (See
Counter-Urbanisation and Urban-Rural Shift).

Dispersed Population Distribution: the opposite of a concentrated distribution; the population
may be spread evenly over a fertile farming area, rather than concentrated in an urban centre.
Dispersed population distributions tend to be of low density.

Distribution (of a population): where people are found and where they are not found.

Economic Migrant: person leaving her/his native country to seek better economic
opportunities (jobs) and so settle temporarily in another country.

Emigrant: someone who leaves an area to live elsewhere.

Ethnic Group: the group of people a person belongs to categorised by race, nationality,
language, religion or culture.

Family Planning: using contraception to control the size of your family.

Family Ties: the lack of family ties (no wife or children) encourages young males to migrate
from LEDCs to MEDCs or from rural to urban areas to seek a better life. The young (20-35)
are also best-suited physically to heavy unskilled/semi-skilled work. See Guest-Worker.

Fertile Age Group: the child-bearing years of women, normally 18-45 years of age.

Ghetto: an urban district containing a high proportion of one particular ethnic group. The
term ghetto comes from the district of Geto in medieval Venice which was reserved for Jews.

Gross National Product (GNP) per capita: the total value of goods produced and services
provided by a country in a year, divided by the total number of people living in that country.

Guest-Worker Migration: people leaving their country to work in another land but not to
settle: the term is associated with unskilled/semi -skilled labour.

Human Development Index: a social welfare index, adopted by the United Nations as a
measure of development, based upon life expectancy (health), adult literacy (education), and
real GNP per capita (economic).

Immigrant: someone who moves into an area from elsewhere.

Infant Mortality: the number of babies dying before their first birthday per 1000 live births.

Life Expectancy: the average number of years a person born in a particular country might be
expected to live.

Literacy Rate: the proportion of the total population able to read and write.

Malnutrition: ill-health caused by a diet deficiency, either in amount (quantity) or balance
(quality).

Migrant: someone who moves from one place to another to live.

Migration: movement of people.

Model: a theoretical representation of the real world in which detail and scale are simplified
in order to help explain reality.

Natural Increase or Decrease: the difference between the birth rate and the death rate.
Additional effects of migration are not included.

Natural Population Change: the difference in number between those who are born and those
who die in a year. Additional effects of migration are not included.

Net Migration: the difference between the number of emigrants and the number of
immigrants.

New Commonwealth: the more recent members of Britain’s Commonwealth (ex-colonies,
now independent), including countries such as India and Pakistan and the West Indian
islands.

Overpopulation: where there are too many people and not enough resources to support a
satisfactory quality of life.

Population Change: Births - Deaths + In-Migration - Out-Migration = Population Change.

Population Density: number of people per square kilometre.

Population Pyramid: a graph which shows the age and sex structure of a place.

Push-Pull Factors: push factors encourage or force people to leave a particular place; pull
factors are the economic and social attractions (real and imagined) offered by the location to
which people move (i.e. the things which attract someone to migrate to a place).

Quality of Life: things (e.g. housing) that affect your standard of living.

Quality of Life Index: a single number or score used to place different countries in rank order
based on their quality of life. Various indicators are included, e.g. GNP per person, calorie
intake, life expectancy, access to health care, number of doctors per 100,000 etc.

Racial Prejudice: thinking unpleasant things about people because of the colour of their skin
and/or their ethnic group without knowing them.

Racism: unfair, ridiculing or threatening behaviour towards someone because oi their
particular racial group.

Refugees: people forced to move from where they live to another area.

Repatriation: a government policy of returning immigrants to their country of origin.

Rural Depopulation: people leaving the countryside usually to live in towns (ie. rural-urban
migration).

Rural Population Structure: young males move to urban areas due to push-pull factors. This
creates a characteristic indentation in the 20-35 age group population structure.

Segregation: where immigrant groups such as Turks in Germany become increasingly
isolated in inner city areas, of poor housing (see ghetto).

Sparsely Populated: an area that has few people living in it.

Sterilisation: a method of contraception: in men an operation prevents sperm from being
released, and in women an operation stops the production of eggs.

Structure (of a population): the relative percentages of people of different age groups, usually
shown on a population pyramid.

Urban-Rural Shift: the movement of people out of towns in MEDCs to seek a better quality
of life living in the countryside. Some work from home using telecommunications
technology; most travel into the city each day as commuters, contributing to the rush hour.

Urbanisation: the growth of towns and cities leading to an increasing proportion of a
country’s population living there. It as a gradual process common in LEDCs where 1 million
people move from the countryside to the cities every three days.

Urban Population Structure: young males move to urban areas due to push-pull factors. This
creates a characteristic population pyramid bulge in the 20-35 age range.

Voluntary Migration: where people move to another area through choice.

Working Population: people in employment who have to support the dependent population.

Youthful Population: in the population structure of LEDCs, there is often a higher proportion
of young people due to high birth rates and a reduction in infant mortality due to better
nutrition, education and medical care. This may create problems since the children need
feeding, housing, education and eventually a job. Medical care and education has to be paid
for by taxing a proportionally small number of workers.

Youthful Population Structure: seen as a wide base on population pyramids that reflect high
birth rates in LEDCs.

Population introduction notes

More Related Content

What's hot (20)

Viewers also liked (11)

Similar to Population introduction notes (20)

More from Moses Lutta (20)

Recently uploaded (20)

Population introduction notes