1.1 Population Change
-
Upload
jodiecmills -
Category
Environment
-
view
110 -
download
0
Transcript of 1.1 Population Change
7 Billion, National Geographic Magazine – YouTubeAre you average
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)