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1.1 Population and Change Explain population trends and patterns in birth rates, natural increase, death rates,

infant mortality rates, fertility rates and life expectancy in contrasting regions of the world.

Analyse population pyramids. Understand the concept of population projection and momentum.

Key TermsTerm Definition

Crude Birth Rate The number of births per 1000 population in a given year.

Crude Death Rate The number of deaths per 1000 population in a given year.

Rate of Natural Increase/ Dec

The Crude Birth Rate minus the Crude Death Rate.

Total Fertility Rate The average number of children that would be born alive to a woman during her lifetime.

Life Expectancy The average number of years a person may expect to live when born, assuming past trends continue.

Infant Mortality Rate

The number of deaths of infants under 1 year of age per 1000 live births in a given year.

Child Mortality Rate

The number of deaths of children under 5 years of age per 1000 live births in a given year

Population momentum

The tendency for population growth to continue beyond the time that replacement level fertility has achieved because of an already high number of people of child bearing age.

Key TermsTerm Definition

Population Projection

The prediction of future populations based on the present age-gender structure, and with present rates of fertility, mortality and migrations.

Sex/ Gender Ratio

The number of males per 100 females in a population.

Population Structure

The composition of a population, the most important elements of which are age and sex.

Population Pyramid

A bar chart, arranged vertically, that shows the distribution of a population by age and gender.

When Describing trends and patterns, remember:

“It only takes a SEC to write a good description.”

S = Statement (Make a statement about the pattern or trend)E = Evidence (support your statement with evidence)C = Comparison (make a comparison to highlight the evidence more clearly)

Describing Trends and Patterns

Exam practice describing trends

“Describe the trend of crude births for Africa” (3 marks)

Statement – Africa’s crude birth rate is decreasing.Evidence– In 1950 it was 48 per 1000 Comparison - whereas in 2010 it had dropped to 38 per 1000, a decrease of 10.

Exam practice

“Describe the global pattern of infant mortality in 2008” (3 marks)

Statement – Infant mortality rates are the highest in central Africa.Evidence– In some central African countries rates are as high as 175 infants per 1000 of the population.Comparison – This compares to Europe and the USA where rates fall below 10.

Figure 1: Infant Mortality Rates 2008

Factors affecting crude births and deathsLEDC’s tend to have higher crude birth rates because…

• Religion/ Culture• Pride/ tradition?• Access to and affordability of

contraception• Lack of education• To ensure survival and combat the IMR• Early marriage• Workers for agriculture

LEDC’s tend to have higher crude death rates because…

• Inadequate healthcare (poor facilities, resources, medical training and number of doctors per person)

• Poor sanitation• Lack of access to safe drinking water• Poor diet• Lack of education on health practices• Famine/ War/ Disease prevalence

MEDC’s tend to have lower crude birth rates because…

• Changing status of women • Decisions affected by expense of

children• Access to contraception and family

planning• Later marriages

MEDC’s tend to have lower crude death rates because…

• Vaccinations• Improved healthcare• Regular access to sanitation and clean

water• Improved education on healthy practice• Health and safety regulations in workplace• Environmental regulations

Population pyramids are used to show information about the age and gender of people in a specific country.

Male Female

Population in millions

In this country

there is a high Birth

Rate shown by a wide

base

There is also a high Death

Rate shown by a concave sloping.

This population pyramid is typical of countries in poorer parts of the world (LEDCs.)

Population Pyramids

In some LEDCs the government is encouraging

couples to have smaller families. This means the

birth rate has fallen, shown by a narrowing base.

Male Female

Population in millions

In this country the number of people in each

age group is about the same.

The largest category of

people were born about 40

years ago.

In this country there is a low Birth Rate and a low Death Rate.

This population pyramid is typical of countries in the richer parts of the world (MEDCs.)

Population in millions

Male Female

In this country the birth rate is decreasing.

In the future the elderly people will make up the

largest section of the population in this country.

This is happening more and more in many of

the world’s richer countries.

Male Female

Population in thousands

This country has a large number of temporary workers. These are

people who migrate here especially to find a job.

OMAN

Population Momentum

The continued growth of a population after fertility rate is equal or actually below the replacement rate. This is happens if there is a large concentration of people in the reproductive age range.

Population Projection

A prediction of future population changes based on current trends of mortality, fertility and migration. Some questions to consider include: Why are population projections so important to governments and why are populations so difficult to make in some places?

Population momentum and projections

Sample exam question

Distinguish between population projection and momentum. (4 marks)