POPULATION

Definition of terms
Population

• Refers to people living in an area.

Population growth

• This refers to increase of population due to both natural increase

(birth rate – death rate) and net migration ( number of immigrants –
number of emigrants).
Natural Increase/ natural population growth

• It is the positive difference between number of births and deaths

(when births are more than deaths). It is calculated as BR – DR
 Definition of terms

Negative Population Growth/Natural decrease

• is when DR is higher than BR
Replacement Level
• this is when there are sufficient children born to balance
the no. of people who die.
Population explosion
• this is a rapid increase in population which takes place
inside a short period of time.
• It is usually as a result of marked decrease in death rate,
but sometimes amplified by a concurrent increase in birth
rate.
Graphs illustrating population growth trends
Graphs illustrating population growth trends
Graphs illustrating population growth trends
Describe the changes in birth rate on the graph shown below
Compare the changes in population growth rates in China and
Iran between 1970 and 2009.
 World population growth rates

• Between 1000 and 1700 population growth was very slow and
the population remained below 1 billion. Birth rate was high
but death rate was also high. The high birth rate was due to :
• there was lack of contraceptives or family planning methods
so birth control was difficult.
• Children were needed to work in the fields so they were
viewed as economic asserts.
• Women had a low socio-economic status, they were not
educated and could not take up any form of employment and
had no say in fertility issues.
• It was prestigious to have a large family in traditional societies.
 Reasons for high death rate before 1700

• There was prevalence of diseases which killed people eg

black death influenza
• There was poor supply of preventive and curative medical
drugs so many people died because their ailments were not
treated.
• There were food shortages/ famines which led to
starvation.
• Personal hygiene and sanitation were poor leading to
outbreak of diseases such as cholera.
• Civil wars were rampant and these killed many people.
•
Reasons for decrease in death rate between
1700-1939
• Between 1700 and 1939 there was rapid population growth
which led to a population explosion Birth rate remained high
but death rate suddenly decreased. The sudden decrease in
death rate was due to:
• The agricultural revolution improved food supply due to
mechanisation, irrigation and use of fertilisers.
• The industrial revolution created many jobs for people and
people earned incomes that improved their standards of living.
• There was improvement in clean water supply and sanitation
reducing outbreak of water borne diseases.
• There was improved supply of medicines that cured many
diseases.
 Reasons for low birth rate in MEDCs from
1940
• From 1940 onwards population growth slowed down in MEDCs but remained high in LEDCs.
Population growth was slow in MEDCs due to a significant reduction in birth rate caused by:
• Emancipation of women, they spent more in education thereby delaying marriages, they
took up jobs and were forced to limit child bearing, they had a say in fertility issues.
• Family planning programmes were put in place and contraceptives were readily available.
• There was preference for materialistic life styles and this meant reducing family size.
• Children were now viewed as economic liabilities and were very expensive to raise.
• Population growth remained high in LEDCs because birth rates remained high but death
rates fell sharply. Death rates fell sharply because:
• There were improvements in medical facilities which means many people had access to
health services.
• There were improvements in water supply and sanitation which reduced water borne
diseases.
• There were improved working conditions such as shorter working hours and provision of
safety clothing at work places.
• Diet improved in terms of quantity and quality which reduced malnutrition diseases such as
kwashiorkor.
 Components of population change

• Population change in a country is affected by:

• 1. The difference between births/fertility and mortality/deaths. Population increases if births are
more than deaths but decreases if deaths are more than births.
• 2. The difference between immigration and emigration (net migration). Population in a country
increases if there are more immigrants than emigrants (positive net migration) but decreases if
there are more emigrants than immigrants (negative net migration).
• Fertility
• it is a broad term that includes the reproductive performance of a woman in the child bearing
age group (15-49yrs) without fertility control or regulation
• fertility is measured by fertility ratio and birth rate
• Fertility ratio
• refers to the number of young children in the population related to the number of women in
child bearing age.
• Crude Birth Rate
• is the average number of live births in a year per thousand of total population.
• it is crude because it includes people who do not bear children e.g. men, children, the elderly.
• crude birth rate is high in most LEDCs and lower in MEDCs.
 Causes of high BR in LEDCs

• some religious sects like the Apostolic Churches and Catholics shun the use of birth control measures e.g.
contraceptives, leading to high birth rates
• Apostolic Churches and some cultures allow polygamy where women compete in child bearing thereby
raising the birth rate
• They also allow marriage at early ages (12 – 15 yrs) again leading to high birth rate
• The search for the male heir to sustain the family name raises the birth rate
• Large families are prestigious in traditional societies and this raises the BR
• low levels of education lead to high CBR by causing early marriages and disturbing proper use of
contraceptives
• Children are economic assets in agrarian societies as they are sources of agricultural labour
• high infant mortality rate and child mortality has led to high CBR in LEDCs so people opt to have many
children to ensure survival of others.
• There is lack of Social Security at old age eg lack of pensions , old people’s homes and funds to help the
elderly has led to high BR in LEDCs so people tend to bear many children to ensure social security at old age
• contraceptives may not be available and or accessible to traditional , remote rural societies leading to high
CBR.
• There is lack of women emancipation or low economic status of women in LEDCs e.g. being unemployed
and being regarded only as child bearers means that they cannot decide on the number of children that
they want to have.
 Attempts to reduce BR in LEDCs

• There should be provision of contraceptives free of charge so

that even the poor can access them
• The distribution points for contraceptives should be increased
so that they are readily available
• Educational campaigns should be conducted to raise awareness
on birth control measures
• Agriculture should be mechanised to reduce the need for child
labour in the fields
• Women should be emancipated – this empowers them to have
a say on fertility issues
• Governments should craft anti-natalist policies ( e.g. China’s
One Child Policy) to reduce birth rate.
 Causes of low birth rate in MEDCs

• more time is spent in school thereby delaying the age of marriage

• education raised the literacy levels which enabled the proper use of birth control measures
and loosened resistance to new ideas on birth control
• both males and females got formal employment hence rationalising between child bearing
and going for work
• Socio-economic status for women was raised and they could decide on fertility issues (i.e.
when to have children and how many) , the advent of employment meant limited maternity
leave
• Children are seen as liabilities, they are hindrances to work, studies, careers and are also
costly to raise
• various family planning methods or contraceptives are available and accessible so this
reduces birth rate.
• Agriculture got mechanised (tractor drawn disc ploughs, planters, cultivators , boom
sprayers , combine harvesters ...) thereby replacing children as a source of labour
• Social security at old age was put in place: pension schemes, old people ‘s funds, old
people’s homes so there is no need to have many children.
• Infant mortality rates are very low reducing the need for more children
 Attempts to increase BR

• Governments should introduce pro-natalist

policies that are incentivised e.g. free health
education for additional children , priority
accommodation , fully paid maternity
leave...etc.
 MORTALITY

• Refers to the occurrence of deaths in a population.

• it is measured by Crude Death Rate, Infant Mortality Rate , Maternal Mortality, Life Expectancy.
• Crude Death Rate
• refers to the number of deaths in a year per thousand of total population.
• it can further be expressed as a %
• it is higher in LEDCs and lower in MEDCs
•
•
• Infant Mortality Rate
• is the number of deaths of children under one year of age per thousand live births per year
• Maternal Mortality
• deaths amongst women whilst pregnant or during delivery due to pregnancy related problems.
• Life Expectancy
• it is the average life span of a person, the average age at which people die
• it is higher in MEDCs around 65yrs and lower in LEDCs approximately 40yrs
•
 Causes of high death rates in LEDCs

• there are poor medical facilities /poor quality health care /lack of medical drugs
• there is lack of education - people are still indulged in traditional medical
practices
• there is lack of immunization of infants die due to the seven killer
diseases(diphtheria, measles, whooping cough, tetanus, hepatitis B, polio )
• there is lack of food which leads to starvation
• there is poor sanitation i.e. lack of clean water ,toilets leading to water borne
diseases.
• health facilities are inaccessible due to poor road networks and distant
locations.
• There is high doctor to patient ratio which means many people will able access
the services of a doctor frequently.
• there is poor prediction of natural disasters e.g. floods and droughts which may
lead to humans losing their lives.
 Causes of low death rates in MEDCs

• health education is provided among citizens so that they know causes

and ways of preventing diseases
• children are immunised against the killer diseases and this reduces
infant mortality.
• there is good sanitation and hygiene i.e. clean water and toilets so no
outbreak of water borne diseases.
• There is adequate food supply and nutritious diets so people will not
suffer from malnutrition or starvation.
• drugs are available in hospitals as well as related medical technology so
various ailments can be treated.
• people can afford hospital fees they go for frequent medical check ups.
• the modern societies can predict natural hazards like floods and
droughts thereby saving people’s lives.
 Causes of high infant/ child mortality rates in LEDCs

• there is low quality health care

• there is lack of immunisation leading to deaths by the
six killer diseases
• there is poor nutrition leading to problems like
kwashiorkor
• there is poverty at family level leading to lack of food
on the table, warm clothing in winter.
• There is poor sanitation and lack clean water supply
leading to outbreak of diseases
•
 Countries with high infant mortality rates
also have high birth rates.
• This is because:
• People are likely to have many children/large families/want lots of
children;
• They think that many will not live long/hope some survive/to
replace children who die/lots of babies die.
• They want children to help on the land/farming.
• They want children to help in the home/look after siblings.
• They want children to fetch water/collect wood.
• They want children to go out and earn money/to work/for labour.
• They want children to look after them/take care of them in old
age as there are no pensions/state benefits for elderly.
 Attempts to reduce mortality

• There should be training medical staff and paying

them good salaries for them to stay in the country
• Governments have to construct protected wells
and drill boreholes to provide clean water .
• There should be adequate supply of medicines,
help can be sought from
WHO,UNICEF ,REDCROSS,USAID
• Diets should be improved in terms of quality and
quantity to avoid malnutrition.
 Population growth problems

• Problems caused by rapid population growth in LEDCs

• Large numbers of people lead to food shortages.
• Unemployment increases since the labour force will be more than the available
jobs.
• There is shortage of accommodation and this leads to overcrowding.
• Overcrowding cause fast spread of diseases.
• There is pressure on health and education services as the facilities fail to contain
the large numbers.
• Rapid population growth increases rural to urban migration and this may lead to
increased crime rates.
• It also causes shortage of land for farming and settlement
• The need for land leads to deforestation leading to soil erosion and loss of animal
habitats.
• Large numbers of people also lead to increased pollution.
•
 Measures to Control Population Growth

• A population policy can be introduced e.g.

China’s one child policy.
• There should be educational campaigns on
birth control measures and advantages of
small families e.g. by ZNFPC (Zimbabwe
National Family Planning Council)
 Causes of declining population in MEDCs

• some MEDCs have a higher death rate than

birth rate and this has led to declining
population.
• Higher death rate will be due to degenerative
diseases associated with old age eg cancer
and due to diseases related to obesity eg
heart diseases.
Question – Explain the reasons for lower birth
rates in MEDCs.
 Problems caused by low growth/ declining population in MEDCs

• MEDCs have an ageing population. This means they have a large proportion of
elderly people above the age of 65. Ageing population is caused by low birth
rate and high life expectancy. It causes the following problems:
• There is shortage of labour force so industries will not have workers.
• there is under enrolment in schools and this may lead to ghost schools.
• There is low industrial output due to shortage of workers
• Many migrants will come to such countries and this leads to conflicts between
locals and migrant workers.
• There is increased government spending on old people’s homes and pensions
for the elderly.
• There is high taxation on the economically active to meet the needs of the
elderly.
• some industries producing children’s items close since there are fewer children.
• the country becomes defenceless since there are many old people and fewer
youths to join the army.
 Attempts to reduce problems of population ageing in MEDCs

• Pro-natalist policies that are incentivized should be crafted e.g.

free education, health, and housing.
• There should be educational campaigns on the need for more
children.
• Governments should hire expatriate labour so that industries
have adequate number of workers.
• Taxes for couples with fewer children should be raised to try and
compel them to have more children.
• Elderly people can be engaged for part time employment eg as
consultants.
• Government can raise pensionable age to reduce the number of
people getting pensions
 POPULATION AND RESOURCES

Resources – these are the natural endowments of an

area/country –minerals, water , forests, climate, soils etc
Optimum Population
• this is when there is a balance between population,
resources and technology available in the country.
• it is a theoretical concept / an ideal situation leading
to high output per capita.
• there is no strain on resources, the population and
available technology leading to greater economic
welfare.
 Indicators of Optimum Population include:

• the highest standard of living

• high output per capita
• adequate provisions of food and other
services
• low BR and DR hence a small NI
• efficient transport networks
 Overpopulation

• occurs when there are too many people for

the available resources /number of people
exceeds the carrying capacity or the resources
are not enough to sustain all people.
• Examples of overpopulated countries are
Bangladeh, China, Indonesia, Nigeria,Niger,
Kuwait, Pakistan, Singapore, Israel
 Causes of Overpopulation

• high birth rate, low death rate leading to a high rate

of natural increase.
• complete lack of resources to support the
population as is the case with some deserts
• lack of technology with which to exploit the
available resources for use by the people
• wars and political instability impeding exploitation
and development of resources
• natural disasters / catastrophes that destroy existing
resources and technology infrastructure
 Problems associated with Overpopulation

• There is pressure on schools since many children want to

go to school.
• There is pressure on medical facilities since many people
need a lot of health care services.
• There is pressure on job opportunities since many people
need to find jobs.
• There is overcrowding due to shortage of accommodation
• There is shortage of land for farming and settlement.
• There is deforestation as land is cleared for farming and
settlement.
Problems associated with Overpopulation

• There is shortage of food since a large number

of people has to be fed.
• There is increase in anti-social behaviour such
as theft, drug abuse and prostitution because
many people are not employed.
• There will be water shortages resulting in
diseases such as cholera, diarrhea
• Traffic congestion increases.
• Land, air and water pollution will be prevalent.
Attempts made to address these problems

• Countries should invest in agriculture to

improve food production
• birth control measures implemented and
made available
• There should be educational campaigns to
reduce BR
 Overpopulation in Bangladesh

Why is the population growth rate high?

1. There is lack of availability and knowledge regarding
contraceptives.
2. Condoms are also unpopular in Bangladesh.
3. People have lots of children to help them work on the farms.
4. People also have lots of children with the hope that their
children will take care of them when they are too old to work .
5. IMR (Infant Mortality Rate) is therefore high and so people
have lots of children to replace those that die at a young age.
6. Females are not fully emancipated
What are the problems of Overpopulation in
rural areas of Bangladesh?
• 1. Many people live on the fertile floodplains of the
Ganges and the Brahmaputra River.
2. The land is heavily farmed, leading to over cultivation .
3. The farmers are poor and therefore cannot afford to
replace the nutrients in the soil, which leads to a
lowering of crop yields.
4. Bangladesh suffers from annual floods during Tropical
Cyclones at the Bay of Bengal where dense populations
live on the Ganges Delta. And having insufficient
resources to protect themselves from these Climatic
Hazards, this often results in a high death rate.
What are the problems of Overpopulation
in Bangladesh’s cities?
• 1. There is high population density in Dhaka and this puts
pressure on resources such as housing, health care, water and
sanitation, education etc.
2. Many people live in Bustees (shanty towns) located on the
edge of the Dhaka. These residences are overcrowded and lack
amenities such as electricity, sewage disposal, and clean water
supplies, which contribute towards the spread of diseases.
3. More people mean more traffic, which causes congestion
problems and the release of Nitrous Oxide from exhaust fumes
causes air pollution.
4. Many people are not be able to find a job which leads to high
unemployment rates, or people working in low paid informal
sector employment.
 Underpopulation

• this is when the population is too small to

make full use of resources/ there are surplus
resources.
• this occurs in frontier regions awaiting
development e.g. remote areas of Canada ,
Australia , Siberia, Russia, Bolivia, Argentina,
Lybia.
 Causes of underpopulation

• Some countries have many resources such minerals, water

• Other countries have small population sizes due to low
birth rate.
• Some countries experience a lot of emigration.
• Countries may be also very large in terms of land size.
• Some countries may have extreme climates eg very cold
temperatures in in Canada, Siberia and very hot
temperatures in parts of Australia.
• Other countries are landlocked thereby limiting trade links.
 Problems associated with underpopulation

• resources are not fully exploited

• there are labour shortages to fully exploit
resources.
• the country becomes defenceless because of
smaller number of economic active people
• there is problem of population ageing so
government spending on elderly increases to
support old people by providing old people’s
homes, pension, health care
 Case study : Australia

• With a population of 21.7 million and a labour force of only 11.6 million
Australia is underpopulated.
Causes of under-population in Australia
• Under-population is caused low birth and death rates which give a natural
population increase of 1.15%.
• Many people are educated (99% ) and this has reduced birth rate due to
emancipation of women and high use of contraceptives.
• Health care is also good, e.g the infant mortality rate is only 0.46%.
• Australia has a large land mass such that its population density is only 2.6
people per square km.
• Australia is very rich in resources such as iron ore, coal, gold, copper, natural
gas, uranium.
• Some parts of Australia experience extremely high temperatures and this
has caused underpopulation.
The problems created by under population in Australia?

• Shortage of workers which has led to lower optimum productivity.

• Conflicts caused in major cities such as Sydney by need to attract
foreign workers.
• Not possible to exploit all resources and large areas areunder
utilised.
• Less people paying tax. Taxes have been raised to fund retirement.
• Schools and hospitals close because there are not enough people
to support them.
• Public transport links close because of less customers. It is unlikely
that new transport systems will develop as there is not enough
people to support them.
• Hard to defend country.
 Population Density

• It refers to the number of people per unit area

• population density is obtained by dividing the
number of people by area in sq kms.
• density can be high, medium or low
(variations in density are a result of both
physical and economic factors)
• on a map population density is represented by
a choropleth /density map.
 Population Distribution

• It refers to the spread of people over

space/area
• on maps it is represented by dot maps (where
each dot represents a certain number of
people)
• variations in population distribution are a
result of physical, economic and sociopolitical
factors
 World Population Density

• The world is populated in a very uneven.

• densely populated areas as found in Eastern
Asia , Europe and USA especially in coastal
areas.
• areas with medium population densities as
found in the interior of Africa and USA.
• areas with low population density as found in
deserts, mountainous areas, polar regions and
the tropical rain forest.
Question : Explain why many coastal areas are
densely populated. [4]
Explain why places Y and X area sparsely populated.
Describe the population distribution in New Zealand
 Population distribution in New Zealand
• The distribution is uneven.
• More people live on North Island while there
is less on South island
• Large clusters on some areas Wellington.
• Many parts have scattered population.
• Many people live close to coasts while live few
in centre.
 Factors affecting population density and distribution

Physical Factors
1. Rainfall
2. Temperature
3.Nature of Soil
4.Altitude / height above sea level
5.Water Supply
Question : Explain how the given factors
influence population density and distribution.
 Human / Economic factors

1.Transport networks
2. Mining
3.Manufacturing activities
4.Government policy
Question : Explain how the given factors
influence population density and distribution.
 Case study -Population distribution in Zimbabwe

• Population distribution in Zimbabwe is

uneven.
Low population density
• Low population density areas (less than 20
pple/sq km) include the northern lowveld
region along the Zambezi valley, the south
east lowveld.
• These areas have low agricultural potential
mainly because of low rainfall which is usually
below 500 mm per year.
 Low population density

• Temperatures are very high so people suffer

from dehydration.
• The areas are mosquito and tsetse infested
causing malaria and sleeping sickness
respectively.
• The areas have lack of industries and minerals
so there are no job opportunities.
Question : Explain why population density is low
in the low veld areas.
 Medium population density
• Medium population density areas (20-40
pple/sq km) are found in most rural areas
which are formerly TribalTrust Lands.
• These areas include parts of Masvingo such as
Bikita, Zaka and Gutu.
• People are concentrated along rivers for water
supply and along roads for easy access to
transport.
 High population density
• High population density areas (densities in
excess of 40 pple/sq km) include major cities
such as Harare & Bulawayo, large populations
are attracted by industrial and commercial
activities.
• Zimbabwe’s capital, Harare, has received many
migrants from rural areas because it has the
most employment opportunities.
 High population density
• People have also migrated to Harare for better
educational facilities and higher institutions of
learning such as the University of Zimbabwe.
• Health facilities are better in Harare since
there are many health institutions and referral
hospitals such as Parirenyatwa, with many
doctors.
Questions : Explain why urban areas in
Zimbabwe have high population densities.