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Text Exercises with Answers
1. Read and study the text and the definition
of population growth rate
and answer the following questions.
- What does population
growth rate measure? [Population growth rate (PGR) is the increase
in a countrys population during a period of time, usually one
year, expressed as a percentage of the population at the start of
that period. It reflects the number of births and deaths during a
period and the number of people migrating to and from a country.]
- If you wanted
to get an accurate picture of population growth trends in a country,
would you look at the average annual growth rate for a single year,
or for a period of years? [a period of years] Explain why.
[Looking at growth rates over a period of years helps to counteract
any uncommon short term events that might give an inaccurate picture
of population trends. For example an epidemic, famine, or war could
cause a significant drop in PGR one year, but the change would not
be due to any long term shift in peoples behavior, and therefore
would not be as pronounced if looked at over a 10 or 15 year period.]
2. Answer each of
the following questions briefly, referring back to the text
if necessary.
- Why have death
rates and birth rates declined? [Death rates have declined largely
because people have more access to better health care and better nutrition.
Birth rates have declined because parents are more confident that
their children will live to adulthood; more people have access to
family planning; and more girls are receiving basic educations, and
are choosing to start their families later in life and to have fewer,
healthier children.]
- What causes population
momentum? What are its consequences? [Population momentum occurs
when a population consists of a large number of young people who are
at childbearing ages. Because of their sheer numbers, and because
they are having children, population in these countries continues
to rise, even if they are reproducing at replacement fertility levels.
As a consequence, population momentum does not allow the full effect
of a lower PGR to be felt for several decades. The resulting larger
population imposes additional demands on a countrys social services,
economy, and environment.]
- How might increasing
urbanization affect environmental conditions in a country? [Increased
urbanization can result in increased consumption of natural resources
such as trees for lumber and fresh drinking water; more pollution
which can affect air and water quality and can have a negative effect
on health conditions, wildlife, and vegetation; more "crowding";
and fewer "green spaces".]
- To what extent
does migration between your country and others, or from rural to urban
areas within your country affect your countrys economic, environmental,
or social situation? [Answers will vary.]
- What sorts of
services and support can a government provide to its citizens that
will help slow the population growth rate? Explain why you think these
strategies may help. [Governments can increase education, especially
for girls; offer better family planning services to more people; provide
medical insurance, pension plans, and social security; improve health
care and decrease infant mortality; and increase people's awareness
of problems of rapidly growing populations.]
- What might be
some reasons why women with a basic education tend to have fewer children?
[They may be more aware of family planning options; they have have
probably learned about health, hygiene, and good nutrition, so more
of their children survive; and they are better qualified to work outside
the home and earn money, so they have more options in life and may
choose to start families later and have fewer children.]
3. Calculate the
annual population growth rate for countries A, B, and C using data provided
in the table below and this formula:
|
Population
increase in a year
____________________________
Population at the start of the year
|
X
|
100
|
=
|
Annual population growth rate %
|
|
Note:
Average annual population growth rates for a period of years provide
a better picture than annual rates. For this reason, they are used in
the Data Table. Calculating any growth rate for a period longer
than a year requires more complicated mathematical formulas than the
one used to calculate an annual rate.
|
Country
|
Population
at the start
of the year
|
Population
at the end
of the year
|
Population
increase
during the
year
|
Annual
population
growth
rate (%)
|
| Country
A |
22,000,000
|
22,400,000
|
[400,000]
|
[1.8%]
|
| Country
B |
8,500,000
|
8,800,000
|
[300,000]
|
[3.5%]
|
| Country
C |
400,000,000
|
410,000,000
|
[10,000,000]
|
[2.5%]
|
4. Population growth
rates are small numbers, but they have large effects on population.
To see what this means, complete the following exercises.
- Assume the world
population at the beginning of 1999 was about 6 billion. If the projected
2000 average annual population growth rate for the world was 1.1%,
how many more people would be added to the world by 2001. [66 million]
- If the 2000 world
population grew at .2%, the same projected rate as the United Kingdom,
how many more people would be added to the world by 2001. [12 million]
- If the 2000 world
population grew at 1.7%, the same projected rate as Kenya, how many
more people would be added to the world by 2001. [102 million]
- Use your answers
to questions 3a,b, and c to make a general statement about the relationship
between population growth rates and the change in the size of a population.
[Even small changes in population growth rates have a significant
impact upon the size of the worlds population.]
5. Use the calculations
and data in the table below to calculate the birth rates, death rates,
and population growth rates for three countries and fill in the missing
information.
|
Number
of births (%)
__________________
Population
|
X
|
100
|
=
|
Birth rate
|
|
|
Number
of deaths (%)
__________________
Population
|
X
|
100
|
=
|
Death rate
|
|
|
Birth
rate (%)
|
-
|
Death
rate (%)
|
=
|
Population growth rate (%)
|
|
|
Country
|
Births
|
Deaths
|
Population
|
Birth
rate
|
Death
rate
|
Population
growth rate
|
|
Country
A
|
662,000
|
297,000
|
33,100,000
|
[2%]
|
[0.9%]
|
[1.1%]
|
|
Country
B
|
411,000
|
191,800
|
27,400,000
|
[1.5%]
|
[0.7%]
|
[0.8%]
|
|
Country
C
|
211,200
|
96,800
|
4,400,000
|
[4.8%]
|
[2.2%]
|
[2.6%]
|
6. If a population
growth rate is low, population is growing slowly. If it is high, population
is growing rapidly. To understand what "slow" and "rapid"
mean, it helps to look at how long it will take different countries
growing at different rates to double their population.
- The number of
years it takes a population to double can be estimated by dividing
the number 70 by that population's growth rate. Calculate the doubling
time of populations growing at the rates shown in the key to the map.
[Less than 1%, 70 years or more; 1% to 1.9%, between 70 and 36
years; 2% to 3%, between 35 and 23 years; more than 3%, less than
23 years.]
- Is three percent
a rapid growth rate? Explain. Is two percent a rapid growth rate?
Explain. Is one percent a rapid growth rate? Explain. [Answers
will vary.]
- Use the projected
population data in column 2 of the Social Data
Tables for 19982015 to calculate the population doubling
time for these countries: your country, Canada, Chile, Finland, India,
Zambia. [Canada (70/.6 = 116 years); Chile (70/1.1 = 64); Finland
(70/.1 = 700) India (70/1.3 = 54); Zambia = (70/1.7 = 41)]
- Assume that your
country has an average annual population growth rate of 1.8%. It will
take 39 years for your countrys population to double. What changes
will your country need to make to deal with this growth in population?
Consider such issues as housing, health care, food supplies, transportation,
employment, education, and the environment. Do you think your country
presently has the resources to handle this rate of population growth?
Why or why not?
7. What consequences
might a declining population growth rate have on a countrys economy
and environment? [This depends on a number of variables including
the use of technology and the level of demand for goods and services.
Smaller populations may require fewer natural resources, but if demand
remains high, or if the country is able to export its surplus production,
there may be no significant decrease in overall environmental impact.
Slower population growth might allow a country to implement environmental
policies and develop the institutions which can help protect the environment.
A smaller population may mean that there will be fewer workers, and
thus fewer goods and services (unless technology helps to increase production).]
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