1. What do you think these cartoons are saying?
Hanel, Germany
J. Gathorpe-Hardy

2. DTM
and
Population
Pyramids
Revision

3. Demographic
Transition
Model

4. Natural increase is the balance between birth rates and death rates
Population Change
Outputs
Inputs
Deaths
Births
Natural Increase
Total
Population
Emigrants
Immigrants
Migration
The total population of an area is the balance between 2 forces of change: natural increase and migration
Natural increase is the balance between birth rates and death rates

5. World Population Changes

6. Global Natural Increase

7. Doubling Time
This map shows how long it will take for countries to double their population if it continued to grow at the present rate

8. Demographic Transition Model
Stage 1
Stage 2
Stage 3
Stage 4
Total
Population
Natural
Increase
In Population
Natural
Decrease
In Population
Birth Rate
Birth Rate
Death Rate

9. Stage 1 High Fluctuating
Low population
Increasing very slowly
High birth rate
High death rate
Ethiopia/Niger
UK: pre-1780
Birth Rate
Death Rate
Total
Population

10. Reasons for Stage 1 High Fluctuating
Little access to birth control
Many children die in infancy so parents have more to compensate
Children are needed to work on the land
Some religions encourage large families
Death rates are high due to disease, famine, poor diet, poor hygiene, little medical science
Birth Rate
Death Rate
Total
Population

11. Stage 2 Early Expanding Population growing at faster rate
High but decreasing birth rate
Decreasing death rate
Sri Lanka/Bolivia
UK:
Birth Rate
Death Rate
Total
Population

12. Reasons for Stage 2 Early Expanding
Improvements in medical care
Improvements in sanitation and water supply
Quality and quantity of food produced improves
Transport and communications improve movements of food and medical supplies
Decrease in infant mortality
Birth Rate
Death Rate
Total
Population

13. Stage 3 Late Expanding
Stage 3
Population, still increasing, but rate of increase slowing down
Decreasing birth rate
Low death rate
Uruguay/China
UK:
Total
Population
Birth Rate
Death Rate

14. Reasons for Stage 3 Late Expanding
Increased access to contraception
Lower infant mortality rates so less need for bigger families
Industrialisation and mechanisation means fewer labourers required
As wealth increases, desire for material possessions takes over the desire for large families
Equality of women means they can follow a career rather than just staying at home
Stage 3
Total
Population
Birth Rate
Death Rate

15. Stage 4 Low Fluctuating High population, almost stable Low birth rate
Low death rate
Canada/USA
UK: post-1940
Total
Population
Birth Rate
Death Rate

16. Reasons for Stage 4 Low Fluctuating
Rates fluctuate with ‘baby booms’ and epidemics of illnesses and diseases
Reasons for Stage 4 have improved and it stabilises
Total
Population
Birth Rate
Death Rate

17. Demographic Transition Model
Stage 1
Stage 2
Stage 3
Stage 4
Total
Population
Natural
Increase
In Population
Natural
Decrease
In Population
Birth Rate
Death Rate
Ethiopia/
Niger
UK:
pre-1780
Sri Lanka/
Bolivia
UK:
Uruguay/
China
UK:
Canada/
USA
UK:
Post-1940

18. Stage 5: Depleting Population
Is there a Stage 5? ? ? ?
Stage 5: Depleting Population

19. Problems What problems do you think there could be with the model?
It does not include the influences of migration
It assumes that all countries will go through the same pattern
There is no time scale
Reasons for birth rates and death rates are very different in different countries
And finally, is there a stage 5?

20. The End?

21. Population Pyramids

23. Population Pyramids
The population structure of a country is how it is made up of males and females of different ages.
The common method to show the structure is by a population pyramid.
This diagram is made up by putting two bar graphs (one for male, one for female) side by side.
From this you can read off what percentage of a population is of a certain gender and age range.

24. Developing Countries
This population pyramid is wide at the base, which means there is a large proportion of young people in the country.
It tapers very quickly as you go up into the older age groups, and is narrow at the top.
This shows that a very small proportion of people are elderly.

25. Developed Countries This shape is typical of a developed country.
It is narrow at the base, wider in the middle, and stays quite wide until the very top, as there is a sizable percentage of older people.
Note that there are more old women than men.

26. Ever-Changing Populations
UK Population –

27. Different Population Pyramids
Stage 2
Stage 3
Stage 4
Stage 5

28. Population Sketches
Stage 2
Stage 3
Stage 4
Stage 5

31. Urban v. Rural Structures

36. Differences between Models
Demographic Transition Model
Population Pyramid Model
Drawn as a line graph
Doesn't show male and female populations
Shows total population as a separate line
Gives details of countries in stages
Shows the relationship between birth and death rates and how these affect total population
Only one diagram necessary to show all stages
Drawn as a bar graph
Shows male and female population proportions
Total population is shown as the total area of the graph
Shows greater detail about the populations at each stage
4/5 diagrams necessary to show all stages

37. Population Pyramid for …?…