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Demographic Transition Model. Population Changes. The total population of an area depends upon changes in the natural increase and migration. The natural increase (or decrease) is the difference between the birth rate and the death rate. - PowerPoint PPT Presentation
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Demographic Transition Demographic Transition ModelModel
Population ChangesPopulation Changes The total population of an area depends upon changes The total population of an area depends upon changes
in the in the natural increasenatural increase and and migration.migration. The natural increase (or decrease) is the difference The natural increase (or decrease) is the difference
between the birth rate and the death rate.between the birth rate and the death rate. The birth rate is the number of live births in a year for The birth rate is the number of live births in a year for
every 1000 people in the total population.every 1000 people in the total population. The death rate is the number of people in every 1000 The death rate is the number of people in every 1000
who die in a year.who die in a year. If the birth rate is higher then the total population will If the birth rate is higher then the total population will
increase. If the death rate is higher then the total increase. If the death rate is higher then the total population will decrease.population will decrease.
InteractiveInteractive http://www.ngfl-cymru.org.uk/vtc/demographic_trhttp://www.ngfl-cymru.org.uk/vtc/demographic_tr
ans/eng/Introduction/Main1.htmans/eng/Introduction/Main1.htm part 1 part 1
http://www.ngfl-cymru.org.uk/vtc/demographic_trhttp://www.ngfl-cymru.org.uk/vtc/demographic_trans/eng/Introduction/Plenary.htmans/eng/Introduction/Plenary.htm Part 2Part 2
http://www.geographyalltheway.com/ib_geographttp://www.geographyalltheway.com/ib_geography/ib_population/ib_demographic_transition_mohy/ib_population/ib_demographic_transition_model.htmdel.htm GATW site GATW site
*The DTM describes a sequence of *The DTM describes a sequence of changes in the relationships between changes in the relationships between birth and death rates.birth and death rates.
*The model was produced using *The model was produced using changes in the natural increase in changes in the natural increase in several countries in Western Europe several countries in Western Europe and North Americaand North America..
It suggests that the It suggests that the population growth rates for population growth rates for all countries can be divided all countries can be divided into 4 stages.into 4 stages.
Stage 1Stage 1
Birth RateBirth Rate - Very High - Very HighDeath RateDeath Rate - Very High - Very HighNatural IncreaseNatural Increase - -
Population SteadyPopulation Steady
Reasons for Reasons for changes in birth changes in birth rate:rate:
Children needed for farmingChildren needed for farming They die at an early age due to They die at an early age due to
illnessesillnesses No family planningNo family planning And religious and social And religious and social
encouragement.encouragement.
Reasons for Reasons for changes in death changes in death rate:rate:
DiseaseDisease Famine Famine Poor medical knowledge and so Poor medical knowledge and so
many people die.many people die.
little access to birth control many children die in infancy (high infant mortality) so parents tend to have more children to compensate in the hopes that more will live children are needed to work on the land to grow food for the family children are regarded as a sign of virility in some cultures religious beliefs (e.g. Roman Catholics and Hindus) encourage large families high death rates, especially among children because of disease, famine, poor diet, poor hygiene, little medical science.
Stage 1 high stationary
Stage 2Stage 2
Birth RateBirth Rate - Very High - Very HighDeath RateDeath Rate - Falling Rapidly - Falling RapidlyNatural IncreaseNatural Increase - Very - Very
Rapid IncreaseRapid Increase
Reasons for Reasons for changes in birth changes in birth rate:rate:
Children needed for farmingChildren needed for farming They die at an early age due to They die at an early age due to
illnessesillnesses No family planning and religious and No family planning and religious and
social encouragement. (same as social encouragement. (same as stage 1)stage 1)
Reasons for Reasons for change in death change in death rate:rate:
Improvements in medical careImprovements in medical care Water Water Supply and sanitationSupply and sanitation Fewer children die.Fewer children die.
improvements in medical care - hospitals, medicines, etc. improvements in sanitation and water supply quality and quantity of food produced rises transport and communications improve the movements of food and medical supplies decrease in infant mortality.
Stage 2 early expanding
Stage 3Stage 3
Birth Rate:Birth Rate: Falling rapidly Falling rapidlyDeath Rate:Death Rate: Falling more Falling more
slowlyslowlyNatural Increase:Natural Increase: Rapid Rapid
increaseincrease
Reasons for Reasons for changes in birth changes in birth rate:rate:
Improved medical care and dietImproved medical care and diet Fewer children are neededFewer children are needed
Reasons for Reasons for changes in death changes in death rate:rate:
Improvements in medical care Improvements in medical care WaterWater Supply and sanitation Supply and sanitation Fewer children dieFewer children die
•increased access to contraception lower infant mortality rate means there is less need to have a bigger family •industrialisation and mechanisation means fewer labourers are required •the desire for material possessions takes over the desire for large families as wealth increases •equality for women means that they are able to follow a career path rather than feeling obligated to have a family
Stage 3 late expanding
Stage 4Stage 4
Birth Rate:Birth Rate: Falling more slowly Falling more slowly Death rate:Death rate: Slight fall Slight fall Natural Increase:Natural Increase: Very slow Very slow
increaseincrease
Reasons for Reasons for changes in birth changes in birth rate:rate:
Family planningFamily planning Good health Good health Later marriages Later marriages Improving status of womenImproving status of women
Reasons for Reasons for changes in death changes in death rate:rate:
Good health careGood health care Reliable food supplyReliable food supply People are living much longerPeople are living much longer
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 4 low stationary
Stage 5Stage 5
Birth Rate:Birth Rate: Slight fall Slight fall Death Rate:Death Rate: Stable Stable Natural Increase:Natural Increase: Gentle decrease Gentle decrease
Reasons for Reasons for changes in birth changes in birth rate:rate:
Family planningFamily planning Good healthGood health Later marriagesLater marriages Improving status of womenImproving status of women
Reasons for Reasons for changes in death changes in death rate:rate:
Good health careGood health care Reliable food supplyReliable food supply People are living much longerPeople are living much longer
A stage 5 was not originally thought of as part of the DTM, but some northern countries are now reaching the stage where total population is declining where birth rates have dropped below death rates. One such country is Germany, which has taken in foreign workers to fill jobs. The UK's population is expected to start declining by 2021.
Stage 5??? declining
ExamplesExamples
Stage 1
Ethiopia / Bangladesh
UK: pre-1780Stage 2
Sri Lanka / Brazil
UK: 1780 - 1880Stage 3
Uruguay / China
UK: 1880 - 1940
Stage 4
Canada / Japan
UK: post-1940
Problems with the Demographic Transition
Model
• based on European experience, assumes all countries will progress to complete industrialization• many countries “stuck” in stage 2 or stage 3• reflects logic of continuous growth, an impossibility•Does not take into account immigration
Interactive testInteractive test http://www.geographyalltheway.com/igcsehttp://www.geographyalltheway.com/igcse
_geography/population_settlement/populat_geography/population_settlement/population/popups/popup20.htmion/popups/popup20.htm