Grade 9 Geography – Unit 2 Lesson 13
Population Pyramids
A Population Pyramid is a graphical illustration that shows the distribution of
various age groups in a population.
Most often, a population pyramid consists of two back-to-back bar graphs.
Population is plotted on the X-axis and age on the Y-axis. One bar graph shows
the males, while the other graph shows females in a particular population. The
ages are made up of five-year age groups (also called cohorts). Males are shown
on the left and females on the right. The number of males and females may be
shown as absolute numbers or as a percentage of the total population.
Types of Pyramids
Pyramid shapes differ from country to country, or within a country, region to
region. However, four general pyramid shapes, as determined by fertility rates
and mortality rates, have been noted.
?
Expansive — A broad base, indicating a high
proportion of children, a rapid rate of
population growth and a low proportion of
older people. The pyramid points upward.
Fertility is high so the many children are born
replacing the parents. In Canada, Nunavut is
an example of an expansive type population
pyramid.
?
Stable growth — A structure with indentations that even out and reflect slow
growth over a period. The Northwest Territories is an example of a stable type
population pyramid.
?
Stationary — A narrow base and roughly equal numbers in each age group,
tapering off at the older ages. The base and the centre of the pyramid make a
box shape. In this case, fertility equals mortality. Manitoba is an example of a
stationary type population pyramid.
?
Declining — This pyramid has a small base suggesting a low proportion of
children to many older people. The pyramid points downward. Fertility is so
low that the number of children born does NOT replace the parents. In
summary, a high proportion of aged persons and declining numbers.
Newfoundland and Labrador is an example of a declining type population
pyramid.
Total Fertility Rate
Another element of Population Pyramids is Total Fertility Rates (TFR). It is the
single most important factor in determining future population.
TFR is the average number of babies born to women during their reproductive
years OR the sum of the age-specific birth rates of women in five-year age
groups. Note - Fertility rate is the number of children born alive per thousand
fertile women per year.
? A TFR of 2.1 is considered the replacement rate. Once TFR reaches 2.1, the
population will remain stable assuming no immigration or emigration takes
place.
? When TFR is greater than 2.1, a population will increase.
? When it is less than 2.1, a population will decrease, although due to the age
structure of a population it will take years before a low TFR is translated into
lower population.
Although still high in many parts of the world, TFR has been declining
dramatically over the past decade. As shown in Table 1, the TFRs in the
developed countries (e.g., Canada are below the replacement rate, although in
many of these countries population continues to grow due to the age structure of
the population as well as immigration. Currently 61 countries have a TFR of 2.1
or less (Canada’s 1998 TFR was 1.7).
The TFR for less developed countries is twice as high as the developed
countries. However, it is falling -- TFRs in less developed countries dropped
almost 40 percent from 4.7 in 1990 to 3.1 in 2000. Although the cause is
debated, there is no doubt that women all over the world are having fewer
children.
Table 1. World Total Fertility Rates (Observed and Predicted).
Region
1990 TFR
2000 TFR
2010 TFR
2020 TFR
World
3.4
2.8
2.5
2.3
Less
4.7
3.1
2.7
2.4
Developed
Countries
Developed
1.9
1.6
1.7
1.7
Countries
Source: www.overpopulation.com/faq/basic_information/total_fertility_rate
In 2005, Niger has the world’s highest TFR at 8.0 children.
How do you calculate TFR?
This is the data for Canada.
? Divide Number of Live Births / Female Population in the Age Group to
determine the Age Specific Birth Rate
? Sum the Age Specific Birth Rates
? Multiply by 5 to calculate the TFR.
Table 2.
Age of
Mother
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-49
Number of
Live Births
367
15 267
30 613
42 245
39 105
17 378
2 808
94
Female Population
in the Age Group
387 341
408 422
403 191
397 398
446 488
469 810
458 439
413 377
SUM
Age Specific
Birth Rate
0.0009
The TFR is the sum of the age-specific birth rates multiplied by five. What is
Canada’s TFR?
From the above information, is Canada’s childbearing population is replacing
itself? Provide an explanation with your answer.
Grade 9 Geography – Unit 2 Lesson 9
Population Pyramid – India
All information is from the 2007 CIA World Factbook.
India is the second most populous country in the world with a 2006 population of
just less than 1.1 billion people.
Population Density is 368.4 persons / km2
Population Growth Rate is 1.38%.
Fertility Rate is 2.73 children / woman (2006 estimate).
Life Expectancy is 64.7 years.
Infant Mortality Rate is 54.6 deaths / 1 000 live births.
Median Age is 24.9 years
Slightly over 30% of the population is under the age of 15.
Literacy Rate (15 years and older who can read) is 59.5%
Annual GDP per capita (Purchasing Power Parity (PPP)) is $3 700.
Unemployment Rate is 7.8%
Over 25% of the population lives below the poverty line.
About 80% of the population is Hindu.
India has 14 official languages.
India’s debt is about $132 billion, and India receives $2.9 billion in aid annually.
A population pyramid can reveal much information about a country’s population,
age structure, future service needs and priorities, potential, etc. Construct a
Population Pyramid of the following datasets.
Table 1 . Percentage of Males and Females in Various Age Groups for the 2000
India Population
Age
% Female
% Male
0-4
11.9
12.2
5-9
11.1
11.4
10-14
10.4
10.6
15-19
9.9
10.0
20-24
9.3
9.3
25-29
8.7
8.6
30-34
7.6
7.6
35-39
6.5
6.5
40-44
5.5
5.5
45-49
4.6
4.6
50-54
3.8
3.8
55-59
3.2
3.1
60-64
2.6
2.5
65-69
2.0
1.8
70-74
1.4
1.2
75-79
0.8
0.7
80+
0.6
0.4
Note: Total India population in 2000 was just over 1 billion people.
Table 2. Projected Percentage of Males and Females in Various Age Groups for
the 2050 India Population
Age
% Female
% Male
0-4
6.4
6.6
5-9
6.4
6.6
10-14
6.5
6.7
15-19
6.5
6.8
20-24
6.5
6.9
25-29
6.5
6.9
30-34
6.4
6.9
35-39
6.4
6.9
40-44
6.4
6.8
45-49
6.4
6.7
50-54
6.2
6.4
55-59
5.7
5.8
60-64
5.2
5.2
65-69
4.8
4.6
70-74
4.2
3.8
75-79
3.5
2.9
80+
5.8
3.6
Note: Total ESTIMATED population for India by 2050 is 1.8 billion people.
Answer the questions…
1. Describe the general shape of the two population pyramids?
2. What were the major similarities and differences between the two years
targeted for review?
3. What are the implications for India if the projection occurs?
4. Offer some possible solutions (e.g., reduced birth rate)