Unit 3 People and Unit 3 People and PlacesPlaces

A – MigrationIntroduction

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What is the unit about?What is the unit about?•How does migration affect the rate of

population change?•This where we will start today – to do

this we need to be able to understand terms like birth rate, death rate, natural change and how these change over time and as countries develop.

•We then go onto consider how migration – both in-migration and out-migration affect what is happening to a country

•Then ….

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……..we will look at …..we will look at …• Where do people leave from and where do

they go to? • As an example we use the UK – where did

those who left go? Where did those who arrived come from? What about those who moved from one place to another inside the country? [remember the start of the Welsh coal fields, and then later on. What happened?]

• After that, what are the reason for people to migrate? Is it more likely to leave a bad environment or go to a good one? We look examples of both occurring.

• When people migrate within countries, what the effects on the places they leave and the places they go to?

Unit 3 People and Unit 3 People and PlacesPlaces

A – Migration1 – What makes population

change?Textbook p118 - p119

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Defining terms and raising issuesDefining terms and raising issues• Crude birth rate The number of births in a year per

1000 of the total population.• For example, if a country has a population of one

million and 15,000 babies were born last year, we divide both the 1,500 and 100,000 by 100 to obtain the rate per 1000. Thus the Crude Birth Rate is 15 per 1000.

• The Crude Birth Rate is called "crude" because it does not take into account age or sex differences among the population. In our hypothetical country, for every 1000 people it is likely is that around 500 are men and about 500 are women. Only a certain percentage of the women are capable of giving birth in that year. Thus we don’t know whether in truth a few women are having a lot of babies or if the country has a young profile, then in fact fertile women may be having only one or 2 children each.

• That is why it crude – but from now own we will refer to it as the Birth Rate.

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Defining terms and raising issuesDefining terms and raising issues

•Similarly crude death rate is the number of deaths in a year per 1000 of the total population. It again takes no account of who is dying or why, hence the crude, but from now on we will refer to just the Death Rate

•Natural increase is the growth in population produced when the crude birth rate exceeds the crude death rate.

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What makes a population What makes a population change?change?• Population change can be population increase or

population decrease and depends on 3 things• 1.Birth rate1.Birth rate, 2.Death rate2.Death rate and 3.Migration rate3.Migration rate• 1. Birth rate is number of live births per 1000 of the

population per year

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Birth rateBirth rate•A high birth rate can contribute to

higher population growth - the lilac ones at the back –

UN World Population statistics

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What contributes to a high birth What contributes to a high birth rate?rate?

High in LEDCLittle birth control. Large families the

norm

High in LEDCChildren wanted for

work To look after the old

High in LEDC Family planning against

religion, not supported by government

Low in MEDCGovernment financed birth

control

Low in MEDCChildren cost

lots - pensions

Low in MEDCMany family

planning methods; 2-3

children the norm

Political reasons

Economic reasons

Social reasons

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2 Death rates2 Death rates• Low death rates also contribute to population growth• Lowering death rates are due to improved health

care. • Primary health carePrimary health care in particular protects against

people becoming ill in the first place. • Primary health care includes immunisation, clean

water and adequate sanitationSecondary health Secondary health carecare is provided by hospitals and the application of medicines and procedures once things have gone wrong.

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What is population change?What is population change?•2. Death rate is the number of deaths

per 1000 of the population per year

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What is population change?What is population change?• The Birth rate – death rate = natural change ratenatural change rate• As you can see a number of places have a natural

decrease, not a natural increase

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One useful measurementOne useful measurement•The rate of natural changerate of natural change is

•Birth rate ÷ death rate

•But before we see what this means – I want to make under standing it a bit easier

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Cars in and out of a car park Cars in and out of a car park • Between 9 and 10 in the

morning, 10 arrive but 5 leave so the rate of change is

• Arrivals ÷ departures • 10/5 = 2 is the rate of change• So what does the 2 tell you?

And over time to number of cars in the car park, what?

• Between 4 and 5 in the afternoon, only 5 cars arrive but 10 leave – what is the rate of change? What does this tell you? What happens to the number of cars in the car park

• The rate of natural change is just the same

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One useful One useful measurementmeasurement• The rate of natural changerate of natural change is

• Birth rate ÷ death rate• So what does the 2.88 for Africa tell you? • So what is happening to the population?• In Europe it is 0.92 – what does this number tell

you – so what is happening to the population?

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What is a Model?What is a Model?

•Models are representations of things that are (usually) complex.

• (If they are very simple, we would not need the model to understand them.)

•We use models to help us make sense of the complex reality, or attend only to those features of it that are of interest to our present enquiry.

•Or as in the case we are going to look at to see if there is a pattern to population growth

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Where do we find models in Where do we find models in geography?geography?• One area is climate

• We break the world’s climate down into about 8 different types – each is a model – it does not tell you exactly what to expect in terms of daily weather in particular place, but it gives you’re a general of picture of the climate.

• The model we will look at is the Demographic Transition Model Demographic Transition Model which shows how the death rate and the birth rate change over time and so influence the population growth.

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This is the original demographic This is the original demographic transition model using UK figurestransition model using UK figures

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This is what the demographic transition model says This is what the demographic transition model says about the worldabout the world

This next bit is just for This next bit is just for the curiousthe curious

If you don’t get it, it really doesn’t matter

As I said it has not even found its way into the

textbooks yet

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If it bothers you as to why there is a rising If it bothers you as to why there is a rising death rate death rate

• But once the number of births drop, the average age of the population goes up, so more older people, greater proportion to die of old age so the death rate begins to climb again

The worst current DR is 30

• For a start the model has its DR off line

• As the life expectancy goes up in 3 while there is still quite a high birth rate, then it is a young population as there are fewer older people, there will be fewer deaths.

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What is population change?What is population change?• 3. Migration is the difference between in-migration

(immigration) and out-migration (emigration). This difference is called the migration balancemigration balance, + for more immigrants and – for more emigrants

• Net migrate rateNet migrate rate is the number of migrants per 1000 of the population per year

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What is population change?What is population change?

•So we can imagine it like this

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So what did we find out?So what did we find out?

• In LEDCs, the birth rate was …. (higher/lower) and the death rates was …. But this gave rise to a natural ….., which means the population was …..

• In MEDCs the birth rate was …. and the death rates was …. But this gave rise to a natural change, which means the population was either … or …..

•The net migration rate was positive in (areas) … which means that ….. It was negative in (areas)… which means that …