Changing Populations. Population density Population density is the amount of people living in a square kilometre. Densely populated – means lots of people.

Changing Populations

Population density

• Population density is the amount of people living in a square kilometre.

• Densely populated – means lots of people living in an area

• Sparsely populated – means very few people living in an area

What affects population density ?

Sparsely populated

Amazon rainforest• Too hot and wet

for people.• Dense forest

make communication

difficult.

Sahara desert• Too hot and dry

for people• Too dry and too

little soil for crops to grow

• Sand makes communication difficult

Greenland• Too cold for

people• Too cold and too

much snow/ice for crops to grow

• Snow and ice make communication difficult.

Densely populated

Western Europe• Low lying and

gently sloping• Pleasant climate • Good water supply

and soil for farming

• Easy communication

• Many resources for industry.

Bangladesh• Low lying and flat• Rich fertile soil.• Hot and wet. • Ideal farming

conditions

Population distribution

• Population distribution describe how people are spread out.

• E.g. Brazil

The distribution of the population in brazil is unevenly spread. The most densely populated regions are found in the South and South east (along the coast). The most sparsely populated regions are found in land towards the north

(the amazon rainforest).

Population Distribution

Click on the link to watch a BBC Bitesize video on ‘World population distribution.’

Population Change

There are three factors that influence population change these are : - 1. Death rates – number of people that die per 1000 of the

population

2. Birth rates - number of babies born alive per 1000 of the population

3. Migration

Click on the link to watch the BBC Bitesize video on ‘population change’

Population Change

The natural change of a population can be calculated - birth rate minus the death rate.

A natural increase – means the population is growing A natural decrease – means the population is declining.

13 – 8 = 5

(Birth rate) (Death rate ) (natural change)

World Population

• Global population increased slowly until 1800.

• Since then we have seen rapid population growth

• There are now 7 billion people on this planet.

Click on the link to watch a video on ‘World population growth’

Death rates

• Death rates tend to be low in MEDCs and falling in LEDCs : - – Better healthcare – People have less physically demanding jobs – Methods of preventing diseases are constantly being improved. – People are better educated about health and hygiene. – Water supplies are more reliable and cleaner. – There is more sanitary disposal of waste– Agricultural improvements provide better food supplies.– Higher incomes have resulted in improved living conditions.

• Death rates have increased in MEDCs due to an increasing number of elderly people in the population.

Birth rates High Birth rate = LEDC• Children provide labour • Children provide security in old

age• Large families are well looked

upon in the community• Some religions don’t approve

contraception• women have longer child bearing

years as they marry young• Women less likely to be educated

and have a career• Availability and knowledge of

contraception may be limited• High infant mortality.

Low Birth rate = MEDC• Child bearing years reduced as

women marry later• Women are often educated and

may prioritise a career over having children.

• Many women leave having children till later and many have fertility problems

• The high cost of living means children are expensive

• Couples prefer to spend money on material things e.g. cars and holidays

• Contraception is wide spread and easily available

Migration

• Migration is the movement of people from one place to another place.

• Migration can be international, regional or local

• Urbanisation = migrating from rural areas to urban areas

• Counter urbanisation = migrating from urban areas to rural areas

Migration

• Push factors – these are the things about the origin that make someone decide to move. They are usually negative e.g. lack of job or education opportunities

• Pull factors – These are things about the destination that attract people. They are usually positive things such as job opportunities or the perception of a better standard of living.

Urbanisation

• Incomplete slide • See case study in book on South

Africa

Counter-urbanisation

• Incomplete slide • See casestudy in booklet on

Shropshire

Population Structure

• The population structure is the ‘make up’ or composition of the population e.g. age and gender of the population

• Population structure is often shown using a population pyramid.

• Population pyramids change with development.

Population Pyramid

• Wide base = large number young dependants

• Narrowing shape = low life expectancy

• Few elderly dependants

• Narrow base = small number of young dependants

• Doesn’t narrow until the very top = large number of elderly dependants

• High life expectancy

• Narrowing base = decreasing birth rate

• Narrows less dramatically = improving life expectancy

Casestudy – China

Click on the link to watch the BBC Bitesize clip on ‘Managing Populations.’

• This is a population pyramid for the UK

• It is typical of many MEDCs

• There are many elderly dependants and few young dependants

• This is called an aging population

Casestudy - UK

Case

How can we tackle an aging population?• People are being encouraged to save for their

retirement• People will have too work for longer • Increased investment into facilities for the elderly

e.g. health care services and elderly homes.• Educated and skilled migrants will be attracted

into the country to fill labour shortages• Pro natalist policy – encouraging people to have

more children. E.g. government incentives and better child care.

Casestudy - UK

Casestudy – Nigeria

• The population pyramid for Nigeria is typical of many LEDCs.

• Nigeria is located in sub-Saharan Africa.

• There are many young dependants and high birth rate

• The pyramid narrows in every age group showing a low life expectancy.

• The high birth rate and large numbers of young dependants mean a large proportion of the population who need to be fed, housed, educated and have medical care.

• This puts a lot of pressures on Nigeria’s services. • To develop governments may try to decrease the

birth rate by offering incentives for having smaller families. They also may encourage the use of contraception and improve sex education programmes.

Casestudy – Nigeria