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AQA REVISION POWERPOINT POPULATION. Make sure you are familiar with the content of these slides. Population Density. Is the number of people living in a given area (usually expressed per square km). It is calculated by dividing the total population by the total area.

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AQA REVISION POWERPOINT

POPULATION

Make sure you are familiar with the content of these slides.

### Population Density

• Is the number of people living in a given area (usually expressed per square km).

• It is calculated by dividing the total population by the total area.

• Some areas are densely populated = a high number of people per km2.

• Other areas are sparsely populated = few people per km2.

• There are usually clear human and physicalfactors to explain this pattern.

World population distribution.

The most densely populated areas are shown in red and pink (more than 100 people per km2)

But why?

The most sparsely populated areas are shown in white. (fewer than 2 people per km2)

### Population growth and change

The world's population is growing very rapidly. In 1820 the world's population reached 1 billion. In 1990 it reached 6 billion people.

This rapid growth in population has been called a population explosion.

### Why has there been a population explosion?

• The major reason for population changes, whether in an individual country or for the whole world, is the change in birth and death rates. The birth rate is the number of live babies born in a year for every 1000 people in the total population. Death rates are number of people dying per 1000 people. When birth rates are higher than death rates the population of an area will increase. (natural increase).

• Over the past 150 years improvements in health care and sanitation around the world have led to a drop in the death rate. While birth rates have dropped in MEDCs, birth rates are still high in LEDCs. Therefore the number of people in the world has grown rapidly.

### Demographic Transition Model

• The demographic transition model shows four/five stages of population change over time.

• Population growth/change varies for each individual country- but the model shows there is a distinct pattern to growth.

• Countries develop through four or five stages as the population grows and the economy develops.

Demographic Transition Model

Stage 1Birth rate and death rate are high - low natural increase - low total population

Stage 3Falling birth rate - low death rate - high natural increase (population growth)

Stage 2 Birth rate is high - death rate is falling - high natural increase (population growth)

Stage 4Birth rate and death rate is low - low natural increase - high total population

The Demographic Transition Model does not take into account migration.

### Life Expectancy

• Life expectancy is the average age a person can expect to live to in a particular area. Life expectancy can be used as an indicator of the overall 'health' of a country. From this figure you can determine many features of a country e.g. standard of living. As a general rule the higher the life expectancy the more healthy (or developed) a country is.

Why high birth rates?

In many countries where people are subsistence farmers, children are needed to work on the farms.

Some religions eg. Roman Catholicism and Islam forbid the use of contraception

In places where death rates and infant mortality rates are high, families have large numbers of children to ensure some survive into adulthood.

In many countries where there is no state pension, people have many children so they can provide for them in their old age.

Why low birth rates?

Contraception is widely available in MEDC’s- giving people choice about family size.

Many women put their careers first, marry later and therefore have less children.

Because of low death rates people in MEDCs need fewer children. They are not needed to work or farms or support the elderly.

Children are expensive to provide for, many young people have only one child, or none at all.

Why high death rates?

Limited access to health care means even simple illnesses eg. Diarrhoea can be fatal.

A poor and unvaried diet does not provide essential nutrients.

Poor sanitation systems again cause disease and illness resulting in a high death rate.

No access to a clean water supply means that diseases like cholera and typhoid take many lives.

Why low death rates?

Health care facilities in MEDCs are modern and hi-tech meaning many diseases can now be cured.

A well varied diet means people get all the nutrients they need to be healthy

Modern sanitation systems mean that the threat of disease is minimal therefore the death rate is reduced.

Access to a clean water supply means that diseases like cholera and typhoid have died out.

### Population structure

• The population structure for an area shows the number of males and females within different age groups in the population.

• This information is displayed as an age-sex or population pyramid.

• Population pyramids of LEDCs (Less Economically Developed Countries) typically have a wide base and a narrow top. This represents a high birth rate and high death rate.

• Population pyramids of MEDCs (More Economically Developed Countries) typically have a roughly equal distribution of population throughout the age groups. The top obviously gets narrower as a result of deaths

Three Patterns of Population Change, 2000

Source: United Nations, World Population Prospects, The 1998 Revision.

A wide base = high birth rate.

A narrow top= low life expectancy

A ‘step’ between each age group = high death rate.

Typical LEDC stage 2 of the DTM.

A narrow base = low birth rate.

A tall pyramid with a wide top= high life expectancy

An MEDC stage 4

A very narrow base = low birth rate.

A tall pyramid with a wide top= high life expectancy

Fewer births than deaths.

MEDC stage 5

Age-Sex Structures in Transition

• The pyramid above has

• A wide base showing that children form the largest population group.

• A triangle shape with each successive age group making up a smaller proportion of the population.

• A high number of young, but few elderly dependents.

• Life expectancy is lower than in MEDCs

• The pyramid above has

• No real pyramid shape

• The shape reflects a low death rate/low infant mortality rate/high life expectancy.

• The widest group is 35-40yrs.

• There are more elderly females.

• There are a large number of elderly dependents (over 60s).

Both graphs give useful information about each country- especially highlighting the numbers of economically active (those who are capable of working, earning and paying taxes) and those who are dependent on the economically active eg. The young and the elderly dependents.

### Problems with an ageing population (UK)

• A growing number of the UK’s population is over 65 years old, so it has a high Dependency Ratio. This is because people are living longer (average life expectancy is 77 years) and because the UK’s Birth Rate is low.

• The UK’s Dependency Ratio is 32, so every 100 economically active Britons supports 32 dependants.

• This causes problems for the UK government:

• Some local councils have high numbers of elderly people, because many people move to England’s warm southerly coasts when they retire (e.g. Christchurch in Dorset)

• The high cost of providing long term, expensive healthcare for some elderly people .

• The elderly are retired and unlikely to work again, so they will be a permanent and increasing financial strain on the economically active.

• There is an increasing demand for certain facilities such as public transport, geriatric health care and sheltered housing.

The UK’s population could stop growing or decline which makes the problem worse because there will be fewer and fewer economically active people.

• The burden of these extra costs will fall on the economically active population who will pay higher taxes and higher pension contributions. The retirement age is having to increase to cope with the problem.

### Problems with a youthful population (India)

• Much of India’s population is under 16 years old, so it has a high Dependency Ratio.

• This is because life expectancy is short (63 years) and India’s Birth Rate is high.

• India’s Dependency Ratio is 63, so every 100 economically active people support 63 dependants.

• This causes problems for the Indian government:

• The high cost of providing basic healthcare and education for so many young people.

• A population explosion will happen when this youthful population matures and have their own families .

• There is an increasing demand for basics such as housing, food, energy. etc..

• The burden of these extra costs will fall on the economically active population.

• Managing population growth

• Population growth brings with it many pressures. The environmental impacts are discussed below, however, there are many other effects of this rapid growth.

• The main areas of rapid population growth are:

• - Asia, Africa and Latin America. These developing areas are moving through the demographic transition model from stage 2 to stage 3. In other words, during the second half of the 20th century their death rates fell, whilst the birth rates continued to be high. This was due to improving health care and sanitary conditions. As a result of the BR being so much higher than the DR, the population of these areas has exploded.

• This population growth in the LEDC’s could lead to a range of problems, which are listed below:

• - Urban areas will become increasingly overcrowded. Shanty towns will continue to grow, and people living there will do so in very poor sanitary conditions, which may well cause outbreaks of devastating diseases.

• - The increasing numbers of people in the cities will also cause more pollution and traffic congestion, leading to environmental problems and possibly diseases, or the increase of respiratory problems, such as asthma.

• - More people will be in need of jobs, and so the problem of massive unemployment will occur. This could lead to more people being forced to live in poverty or turn to a life of crime.

• - Governments may come under increasing pressure to provide adequate food and services to the increasing population. This may be beyond the current capability of many LEDC’s, and may result in them borrowing more money from the MEDC’s, thus increasing their debt problems.

### Types of migration

• Immigration Moving into another country

• Emigration Moving out of a country

• International Moving from one country to another

• Voluntary Moving by choice

• Forced Having to move - reasons could include: war, famine, natural disaster, political asylum

• Temporary/seasonal Moving for a short period of time

• Rural to urban Moving from the countryside to the city

• Urban to rural Moving from the city to the countryside

### Migration

• Migration is defined as a permanent or semi-permanent change in where someone lives. For instance, if you and your family move to Australia due to your dad getting a job out there, you have all migrated. If you all go Australia for a three week holiday, then you have not migrated.

• Some people migrate only for a short period. Turkish immigrant workers to Germany may only go there for a period of months. They have made a semi-permanent move so can be classified as migrants. People working as chalet-maids in a ski resort for the winter also could be classified as having made a semi-permanent migration.

• Migrations fall into two groups, they can bevoluntary (where the migrant decides to move) or forced(where the migrant has little choice but to move).

• Migration is because of push and pull factors.

People may migrate because of poor conditions where they live- these negative factors are called push factors

Lack of jobs or job opportunities

Poor quality of life

Poor levels of pay and conditions

Civil war/persecution.

Poor health and education services.

Climatic hazard eg drought leading to crop failure.

Isolated – few transport links, few leisure facilities

People may migrate because they are attracted to conditions elsewhere- these positive reasons are called pull factors

Job opportunities

Better quality of life

Perception of better quality of life.

Chance to earn more money

Range of health and education services.

Less likelihood of natural hazards.

Entertainment and facilities.

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• The following list includes some of the most famous forced migrations and the basic reasons for them:

• - Jews forced to move from Germany, Poland and other European countries by Hitler’s Nazi’s before and during World War 2. (Genocide).

• - Asians forced to move out of Uganda by Idi Amin in the 1970’s. (Threats of genocide).

• - Africans forced to travel in cramped conditions on boats across the Atlantic to the United States in the 18th and early 19th century. (The slave trade).

• - Nearly 2 million Vietnamese have migrated to Hong Kong since the end if the Vietnam War in 1975. (Fear of persecution by Communist rebels).

• - The population of Montserrat have been forced to move to the North of the island or migrate due to volcanic eruptions, which have now gone on for a number of years.

• - Mass migrations by people in Ethiopia during the mid-1980’s to look for water and food. (Drought meant that they had neither food or water).

• - The original population of Australia were prisoners from the United Kingdom, who were forced to go there, and usually stayed.

### The one child policy- China

• In the late 1970s, in an attempt to slow down the rate of population growth, the Chinese government introduced a number of measures to try to reduce the country's birth rate. The most important of the new measures was a one-child policy, which decreed that a couple in China could only have one child.

• The thinking behind the new policy was that China's population growth-rate was unsustainable.

• In 1950 the rate of population change in China was 1.9% each year. If this doesn't sound high, consider that a growth rate of 3% will cause the population of a country to double in just 33 years!

• Previous Chinese governments had actually encouraged people to have a lot of children, in order to increase the country's workforce. But by the 1970s the government came to realise that current rates of population growth would soon become unsustainable.

Images used to promote the one child policy

in China.

### The one-child policy

Many people claim that some women, who became pregnant after they had already had a child, were forced to have an abortion and many women were forcibly sterilised. There appears to be a lot of evidence to back up these claims.

The one-child policy, established in 1979, meant that each couple was allowed just one child.

Fines were placed on families that had more than one child.

The one-child policy was keenly resisted in rural areas, where it was traditional to have large families The one-child policy has been enforced strictly in urban areas, but remote rural areas have been harder to control.

Benefits, including access to education, childcare and health care, were offered to families that followed this rule, and withdrawn from those that had further children

### Impact of the policy

• The birth rate in China has fallen considerably in the last 25 years, and the rate of population growth is now just 0.7%. However there have been negative impacts too...

• Due to a traditional preference for boys, large numbers of female babies have ended up homeless or in orphanages, and in some cases killed. In 2000, it was reported that 90% of foetuses aborted in China were female.

• As a result, the gender balance of the Chinese population has become distorted. Today it is thought that men outnumber women by more than 60 million.

### Long term implications

• China's one-child policy has been somewhat relaxed in recent years. Couples can now apply to have a second child if their first child is a girl, or if both parents are themselves only-children.

• While China's population is now rising more slowly, it still has a very large total population (1.2 billion in 2002) and China now faces new problems:

• The falling birth rate is leading to the population structure becoming unbalanced between young and old, as the relative number of elderly people rises.

• At the same time there are fewer people of working age to support the growing number of elderly dependents. In the future China could have an ageing population.

## Test Time.

• Which parts of the world are sparsely populated?

• Central Australia, Northern Canada, Siberia, Sahara Desert, Amazon Rainforest.

• Which parts of the world are densely populated?

• Western Europe, Bangladesh, Eastern Seaboard, Japan.

• Choose one sparsely and one densely populated place and explain why.

Western Europe is densely populated. With it’s temperate climate (no extremes of hot and cold) and fertile land it is ideal for growing crops and rearing animals. There are good communications and many large cities with many job opportunities eg. London-which also has entertainment, good health care and education. In addition the countries of Western Europe have political and religious freedom and non-oppressive regimes- making it an attractive place for people to live.

The Sahara desert is sparsely populated. With constantly hot temperatures (+40C) during the day, and very little rainfall (1mm a year at Aswan in Egypt) the Sahara’s climate is difficult for people to live with. There is no soil- therefore agriculture cannot take place and with a limited water supply it is difficult for human life to survive. The sand drifts in sand storms. It is also very isolated, with poor communications, limited accommodation, few job opportunities- all of which fail to encourage people to live in a particular place.

• Define population density. How is it different from distribution?

• Population density is the number of people per unit area (usually expressed per km2) it is worked out by dividing the total population with the area.

• Distribution is where people are spread out- where people live.

• Define the terms Birth Rates, Death Rates and Natural Increase.

• Birth Rate is the number of live births per 1000 population per year.

• Death Rate is the number of deaths per 1000 population per year.

• Natural Increase is the difference between the birth rate and death rate. It is worked out by taking the death rate from the birth rate.

• What is the Demographic Transition model?

• A model to show changes in population over time, it has 4/5 stages and shows changes in the total population, birth rate, death rate over time. Every country fits into a stage on the model.

• Describe the birth and death rates for each stage of the DTM.

• Make a list of characteristics that can be identified on a population pyramid.

• The Proportion of males and females

• The population divided into 5 year age groups

• The birth rate (by looking at the base of the pyramid)

• The life expectancy (by looking at the height of the pyramid)

• The death rate (by looking at each of the age groups and the difference between them).

• There are two basic pyramid shapes. One for an LEDC and one for an MEDC- sketch them.

• Draw and label population pyramids for the following-

• An LEDC city with an influx of male migrants of working age.

• A country that has experienced civil war.

• An MEDC whose birth rate is so low that the population is declining.

• Define the term Infant mortality rate.

• The number of babies who die before their first birthday per 1000 live births.

• Do the following happen in an MEDC or LEDC?

• High life expectancy?

• MEDC

• High Infant mortality rate?

• LEDC

• High number of elderly dependents?

• MEDC

• High number of youthful dependents?

• LEDC

• Name three types of migration.

• Any from

• ImmigrationMoving into another country

• Emigration Moving out of a country

• International Moving from one country to another

• VoluntaryMoving by choice

• ForcedHaving to move - reasons could include: war, famine, natural disaster, political asylum

• Temporary/seasonal Moving for a short period of time

• Rural to urban Moving from the countryside to the city

• Urban to rural Moving from the city to the countryside

• Define these terms-

• Immigrant- a person who moved into a country

• Emigrant- a person who leaves a country to move elsewhere

• Refugee- a person who is displaced and forced to move

• Migrant- a person who has moved to live or work in another location

• Brain drain- highly skilled people moving to MEDCs to receive better pay and conditions (e.g. doctors moving to Australia)

• Name a case study where you have studied voluntary migration.

• Poles to the UK

case studies

in detail!

NOW GO AND HAVE

A REST!

THAT’S IT.

WELL DONE!