population distribution & density. population distribution patterns of population distribution...

PopulationPopulation

Distribution Distribution && Density Density

Population distributionPopulation distribution

Patterns of population distribution tend to be uneven. For example, in the UK there are more people living in the south-east of England and London than in Wales. It follows that populations are more or less sparse or dense in different locations, regions and countries.

The way in which people are spread across a given area is known as population distribution. Geographers study population distribution patterns at different scales: local, regional, national, and global.

Population densityPopulation density

• areas of high and low population density are unevenly spread across the world, but that

• the majority of places with high population densities are found in the northern hemisphere - that is, north of Equator.

Population density

Population density is the average number of people per square kilometre. It is a way of measuring population distribution. It shows whether an area is sparsely or densely populated. Like population distribution, population density can be calculated at a local, regional, national or global scale. The graphic shows patterns of population density on a global scale. Note that:

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Physical factorsPhysical factors

High density

Low density

Relief Relief (shape of the land)

Areas that are high and steep experience a colder, wetter climate, making it more difficult to grow crops. The steepness makes it hard to build on or grow crops because the soil is easily washed to the bottom of the slope. These areas are also remote. Eg the Himalayas.

Flat areas are easier to build homes, industry for jobs and communications on (roads and railways). The soil is usually deeper and more fertile so more food can be grown for the people living there. Eg Ganges valley, India.

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Physical factorsPhysical factors

High density

Low density

Relief Relief (shape of the land)

the Himalayas.

Ganges valley, India.

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Physical factorsPhysical factors ClimateClimate

High density

Low density

Some areas are too dry for soils to exist, so no food can be grown (deserts), or too wet so that a soil’s nutrients are washed out of it (rainforest). Extreme cold can also mean a permafrost layer limits what can be grown there, and also make transport and building difficult (tundra). Eg the Sahara or Alaska.

These areas have a climate which is not too wet or dry, not too cold or too hot. The climate is moderate enough to allow food to be grown and and pleasant to live in. Eg the UK.

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Physical factorsPhysical factors ClimateClimate

High density

Low density

Sahara or Alaska.

UK.

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Physical factorsPhysical factors Soil fertilitySoil fertility

High density

Low density

Areas with poorer soils – either because there is too much rain, or too little or it is too cold – will have problems growing food and so much fewer people will be able to live there. Eg Amazonia.

Areas that have soils with plenty of nutrients will be able to grow plenty of food and be able to support a high population. Eg the Netherlands.

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Physical factorsPhysical factors Soil fertilitySoil fertility

High density

Low density

Amazonia.

Netherlands.

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Physical factorsPhysical factors Water supplyWater supply

High density

Low density

Much drier areas will have problems since soils are more easily blown away, and are left useless. Similarly, areas that have too much rain also have poor soils because the nutrients are washed out of them (leaching). Eg Arabian peninsula.

Places with a moderate climate which receives good amounts of rainfall will have enough water for all the needs of humans – drinking, cleaning, cooking, transport. Eg East coast of China.

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Physical factorsPhysical factors Water supplyWater supply

High density

Low density

Arabian peninsula.

East coast of China.

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Human factorsHuman factors ResourcesResources

High density

Low density

Areas that don’t have resources will not attract so many people as there is less chance of making a living there, and consequently population density will remain low.

If an area has plenty of natural resources eg coal or iron ore, then this will attract people to go to that place for work in industry.

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Human factorsHuman factors ResourcesResources

High density

Low density

Sahara

Europe

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Human factorsHuman factors PoliticalPolitical

High density

Low density

Unstable countries tend to have lower population densities as people migrate, and this hinders further growth e.g. Afghanistan.

Countries with stable governments tend to have a high population density and this encourages further growth e.g. Singapore

Reasons for distributionReasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Human factorsHuman factors PoliticalPolitical

High density

Low density

Afghanistan

Singapore

End

Reasons for distribution

The reasons for the uneven distribution of population can be divided into two categories:- Physical and Human

Physical

Human

•Industry - Manufacturing/Tourism

•Political Policies - Encourage/Discourage growth

These factors can have a positive or a negative effect on population density.

People do not live evenly spread through the world. For example large parts of Australia are very sparsely populated (low population density), whereas areas in the south-east and around Perth are crowded (high population density). The spread of people around a country is known its population distribution The factors that tend to produce low population densities are

The factors that can produce a high population density are

•Fertile farming land - many, small farms able to support a large population

•Mineral resources - mines produce jobs, and provide raw materials for other industries

Wealthier areas - people will move to where the jobs and money are found

Factors affecting population densityThere are a number of different environmental and human factors which affect why people are not spread evenly across the world.The world is made up of a vast number of contrasting environments: Some areas have a temperate or mild climate, others are covered in ice. Some areas are fertile, others are desert. Some of these environments attract settlers,w hile other environments repel settlers - as shown in the diagram below.

Physical Factors High Density Low Density

Relief (shape and height of land)

Low land which is flat e.g. Ganges Valley in India High land that is mountainous e.g. Himalayas

Resources Areas rich in resources (e.g. coal, oil, wood, fishing etc.) tend to densely populated e.g. Western Europe

Areas with few resources tend to be sparsely populated e.g. The Sahel

Climate Areas with temperate climates tend to be densely populated as there is enough rain and heat to grow crops e.g. UK

Areas with extreme climates of hot and cold tend to be sparsely populated e.g. the Sahara Desert

Human Factors High Density Low Density

Political Countries with stable governments tend to have a high population density e.g. Singapore

Unstable countries tend to have lower population densities as people migrate e.g. Afghanistan.

Social Groups of people want to live close to each other for security e.g. USA

Other groups of people prefer to be isolated e.g. Scandinavians

Economic Good job opportunities encourage high population densities, particularly in large cities in MEDCs and LEDCs around the world.

Limited job opportunities cause some areas to be sparsely populated e.g. Amazon Rainforest

Population distributionPopulation distribution

Patterns of population

population distribution is

Population densityPopulation density

Population density is

Reasons for differences in densityReasons for differences in density

The reasons for the uneven distribution of population can be divided into two categories:-