Demographic Transition ModelDemographic Transition Model

                                                                

What is the Demographic Transition Model (DTM)?

• The demographic transition model explains the transformation of countries from having high birth and death rates to low birth and death rates.

• In developed countries this transition began in the 18th century and continues today.

• Less developed countries began the transition later and many are still in earlier stages of the model.

Stage One

Birth Rate is high because of:

• Lack of family planning • High Infant Mortality Rate: putting

babies in the 'bank' • Need for workers in agriculture• Religious beliefs• Children as economic assets

Death Rate is high because of:

• High levels of disease • Famine • Lack of clean water and

sanitation • Lack of health care • War • Competition for food from

predators such as rats • Lack of education

Typical of Britain in the 18th century and the Least Economically Developed Countries (LEDC's) today.

Birth Rate and Death rate are both high. Population growth is slow and fluctuating.

Model 1: The DTM (Demographic Transition Model)

Stage A / 1

Both high birth rates and death rates fluctuate in the first stage of the population model giving a small population growth (shown by the small total population graph).

Stage Two

Death Rate is falling as a result of:

• Improved health care (e.g. Smallpox Vaccine) • Improved Hygiene (Water for drinking boiled) • Improved sanitation • Improved food production and storage • Improved transport for food • Decreased Infant Mortality Rates

Typical of Britain in 19th century; Bangladesh; Nigeria

Birth Rate remains high. Death Rate is falling. Population begins to rise steadily.

Model 1: The DTM (Demographic Transition Model)

Stage B / 2

Birth rates remain high, but death rates fall rapidly causing a high population growth (as shown by the total population graph).

Stage 2 Kenya

Stage ThreeStage Three

Reasons behind birth and death rate falling:

• Family planning available • Lower Infant Mortality Rate • Increased mechanization reduces need for workers • Increased standard of living • Changing status of women

Typical of Britain in late 19th and early 20th century; China; Brazil

Birth Rate starts to fall. Death Rate continues to fall. Population rising.

Stage 3 Brazil

Model 1: The DTM (Demographic Transition Model)

Stage C / 3

Birth rates now fall rapidly while death rates continue to fall. The total population begins to peak and the population increase slows to a constant.

Stage Four

• Birth Rate is low.• Death Rate is low. • Population steady.

Typical of USA; Sweden; Japan; Britain

Stage 4 UK

Model 1: The DTM (Demographic Transition Model)

Stage D / 4

Both birth rates and death rates remain low, fluctuating with 'baby booms' and epidemics of illnesses and disease. This results in a steady population.

Stage Five• Birth Rate slight

fall.• Death Rate stable. • Natural increase:

gentle decrease

Typical of Germany

Reasons for changes in birth rate:• Family planning• Better health• Later marriages• Improved status of women

Reasons for changes in death rate:

• Good health care• Reliable food supply• People are generally

living longer

Stage 5 Germany

Model 1: The DTM (Demographic Transition Model)

Stage E / 5?

A stage 5 was not originally thought of as part of the DTM, but some western countries are now reaching the stage where total population is declining where birth rates have dropped below death rates.

Model 2: The PPM (Population Pyramid Model)

The PPM - 'Population Pyramid Model' shows how dynamic (subject to change) population is. The model is structured to show 'snapshots' of a population at four points during its development, which are shown as Stages 1 - 4 (A - D). A country will progress through the stages.

What limitations 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

What are the limitations?

Homework

• Complete the worksheet.

• Most questions can be completed on the worksheet – others need to be written on lined paper.