Factors Influencing Population Distribution

Example of a densely populated flat plain

North China Plain, Bangladesh and the Netherlands.

What type of population density do low flatlands have and why

High population density. Flat land makes construction, farming and transport easier and cheaper; they are also often near rivers and have fertile alluvial soils.

What is alluvial soil

Fertile, transported soil formed by the deposition of sediments—such as sand, silt, and clay deposited by rivers and moving waterusually found on floodplains, river valleys, and deltas.

Why are steep mountainous areas sparsely populated?

Steep slopes make farming, construction and transport difficult; soils are often thin and erosion-prone, while high elevations have lower oxygen levels.

Example of a sparsely populated mountainous region

Andes Mountains or Tibetan Plateau.

Why are mountain soils often thin?

Rain, wind and gravity cause soil to erode and move downhill before thick soil can develop.

How does altitude reduce population density?

High elevations have thinner air and lower oxygen levels, making living and physical work more difficult and increasing the risk of altitude sickness.

What climates generally support high population densities?

Temperate climates with adequate, reliable rainfall and long growing seasons, and monsoonal climates.

Example of a densely populated temperate region

Western Europe.

Why does a long growing season increase population density?

It allows farmers to produce more food, increasing the amount of people the land can support.

Why do monsoonal climates support dense populations?

Heavy wet-season rainfall provides abundant water for staple crops such as rice.

Why are extremely dry climates sparsely populated?

Low rainfall limits water availability and agricultural productivity unless expensive irrigation is used.

Example of a sparsely populated dry region

Sahara Desert.

Why are cold climates sparsely populated?

Very low temperatures create short or nonexistent growing seasons and make living difficult and requires expensive infrastructure for survival

Example of a sparsely populated cold region

Northern Canada or Greenland.

Why can extremely wet climates have low population densities?

Heavy rainfall can leach nutrients from soils, reducing agricultural productivity.

Example of an extremely wet, sparsely populated region

Amazon Basin.

Why does irregular rainfall reduce population density?

Unpredictable rainfall makes it difficult for farmers to plan planting and harvesting and creates unreliable water supplies.

Why do fertile soils support high population densities?

They allow productive agriculture and provide a reliable food supply, increasing the carrying capacity of the land.

What is humus?

Decomposed plant and animal matter that adds nutrients and helps soil retain water.

How does humus increase population density?

It improves soil fertility and water retention, making agriculture more productive.

Example of a region with fertile humus-rich soils

Western Europe.

Why are river valleys often densely populated?

Rivers deposit nutrient-rich silt, creating fertile alluvial soils that support productive agriculture.

Examples of densely populated fertile river valleys

Yangtze in China, Ganges in India and Nile in Egypt.

Why are frozen soils sparsely populated?

Frozen ground makes agriculture extremely difficult or impossible.

Why are rainforest soils often infertile?

Heavy rainfall leaches nutrients from the soil, while many nutrients are stored in the vegetation rather than the soil.

Example of leached rainforest soils

Amazon Basin, Brazil.

Why are mountainous soils often unsuitable for dense populations?

They are usually thin, poorly developed and prone to erosion.

Why can soil degradation reduce population density?

Erosion and loss of nutrients reduce agricultural productivity and therefore the amount of food the land can support.

Example of degraded soils

Sahel region of Africa.

Why can grasslands support high population densities?

They are often flat, have nutrient-rich soils and are suitable for crop cultivation and livestock grazing.

Examples of densely populated grassland regions

East Africa and south-western Russia.

Why are dense rainforests sparsely populated?

Dense vegetation makes land clearance difficult and labour-intensive, while heavy rainfall often produces nutrient-poor soils.

Examples of sparsely populated rainforest regions

Amazon Basin and Congo Basin.

Why are coniferous forest regions sparsely populated?

Cold climates, poor soils and dense vegetation make agriculture and settlement more difficult.

Example of a sparsely populated coniferous forest region

Eastern Russia.

Why are areas with arid conditions often sparsely populated?

Arid conditions provide insufficient water and vegetation for agriculture and livestock.

Examples of sparsely vegetated regions

Arabian Peninsula, Central Asia and Mongolia.

Why is reliable water supply important for population density?

Water is essential for drinking, sanitation, agriculture and economic activities.

Why does evenly distributed rainfall encourage dense populations?

It provides a predictable water supply and allows farmers to plan planting and harvesting.

Example of a region with reliable rainfall and high population density

Western Europe or north-eastern USA.

Why are areas with low or erratic rainfall sparsely populated?

Water shortages limit agriculture, human settlement and economic activity.

Examples of areas with low or erratic rainfall

Sahara Desert and interior Australia.

Why do areas with low disease prevalence tend to have higher population densities?

Lower mortality and illness improve survival and labour productivity, making permanent settlement more attractive.

How can disease reduce population density?

It increases mortality, limits population growth and can reduce labour productivity.

Why can dangerous pests reduce population density?

They can spread disease, damage crops and make settlement less safe.

Example of a sparsely populated disease-affected region

Central Africa and lowlands of Papua New Guinea due to malaria.

How can natural resources increase population density?

Resource extraction creates jobs, attracts migrants and generates income that can fund infrastructure and services.

Why do mining areas often attract migrants?

Resource extraction requires workers, creating employment opportunities.

How can resource wealth increase population density indirectly?

Revenue can be invested in housing, transport, healthcare and education, making the area more attractive to settlers.

Can areas with few natural resources still have high population densities?

Yes. They can import resources from elsewhere and develop strong manufacturing and service economies.

Examples of resource-poor but densely populated regions

Netherlands, Japan and Taiwan.

Why don't abundant natural resources always produce high population density?

Resources may be difficult to extract, undeveloped, or extractive industries may require relatively few workers.

Why do productive agricultural areas have high population densities?

High food production creates large food surpluses and increases the carrying capacity of the land.

What is carrying capacity?

The maximum population that an environment can sustainably support with its available resources.

How does agricultural productivity encourage urbanisation?

High productivity allows fewer people to work in agriculture, freeing workers to work in manufacturing and services and encouraging town and city growth.

Examples of densely populated agricultural regions

China, northern India and Eastern Europe.

Why are areas with difficult farming conditions sparsely populated?

Low food production limits the number of people the land can sustainably support.

Examples of areas with difficult farming conditions

Sahara Desert, northern Canada and Tibetan Plateau.

Why do areas with established manufacturing industries have high population densities?

Factories create large numbers of jobs for workers, engineers, managers and other employees.

How does manufacturing attract migrants?

Industrial areas offer employment opportunities, encouraging people to migrate from rural areas.

Example of a densely populated industrial region

Ruhr Basin, Germany.

Example of a densely populated industrial region in Asia

Kanto Plain, Japan.

Why do areas with little manufacturing often have lower population densities?

They have fewer employment opportunities and often less investment in infrastructure.

How can manufacturing improve accessibility?

Industrial development encourages investment in roads, railways and other transport infrastructure.

Why do areas with good transport infrastructure have high population densities?

Good roads, railways, ports, canals and airports improve connectivity, trade and access to employment.

Examples of highly connected, densely populated places

Singapore, UK and Hong Kong.

How does connectivity increase population density?

It allows people and businesses to participate in the economy and attracts investment and employment.

Why are mountainous regions often poorly connected?

Steep terrain makes roads, railways and other infrastructure expensive and difficult to construct.

Examples of poorly connected mountainous regions

Altiplano in Bolivia and Tibetan Plateau in China.

Why can deserts and dense forests have poor transport networks?

Difficult terrain and environmental conditions make infrastructure expensive and difficult to construct.

Examples of areas with difficult transport infrastructure

Sahara Desert, Siberia and northern Canada.

How can government development policies increase population density?

Governments can deliberately develop new settlements, provide infrastructure and relocate people to less populated regions.

Example of a government-developed settlement

Mining settlements in the Russian Far East.

What is transmigration?

A government policy of relocating people from densely populated regions to less populated areas.

Example of transmigration

West Papua, Indonesia.

Why do areas with inadequate government investment often have low population densities?

Poor infrastructure and limited essential services make the area less attractive and less livable.

How can political conflict reduce population density?

Conflict destroys infrastructure and forces people to flee to safer areas.

Examples of conflict-affected countries

Syria, Afghanistan, Somalia, Sudan and South Sudan.

What is an IDP?

An internally displaced person: someone forced to leave their home because of conflict or another crisis but who remains within their own country.

What are the main physical factors affecting population distribution?

Landforms, climate, soils, vegetation, water, pests and diseases, and natural resources.

What are the main human factors affecting population distribution?

Agriculture, manufacturing, communications and transport, and political factors.

What is the general relationship between agricultural productivity and population density?

Higher agricultural productivity → greater food supply → higher carrying capacity → higher population density.

What is the general relationship between accessibility and population density?

Better accessibility → greater economic opportunities → more migration → higher population density.

What is the general relationship between extreme environments and population density?

More extreme physical conditions make agriculture, settlement and infrastructure more difficult → lower population density.