Places with a reliable climate and no temperature extremes are often densely populated as these areas provide good growing conditions for crops.

• Physical factor

• Human factor

Areas with low population densities tend to be steep, rugged mountains where soils are thin and air pressure is low (such as the Andes Mountains of South America) or high plateaux (such as Tibet).

• Physical factor

• Human factor

Areas where manufacturing industry has been established for many decades, or even centuries, usually have high population densities. Some examples of densely populated manufacturing regions include north-east China (also known as Manchuria), and the north-east of the United States.

• Physical factor

• Human factor

Areas where farming is difficult, perhaps because of climate, landforms or soils, have sparse populations, with some examples being the Sahara Desert

• Physical factor

• Human factor

Areas where it is physically easy and financially viable to construct communications infrastructure, such as ports, canals, roads, railways and airports, attract people and therefore tend to have high population densities. Examples of such areas include the United Kingdom, Singapore and Hong Kong.

• Physical factor

• Human factor

Government policies and decisions can cause areas to become either more densely population or less densely populated. Areas can become more densely settled when governments decide to develop new areas (such as mining settlements in the Russian Far East, or create new cities such as Shenzhen in China.

• Physical Factor

• Human factor

A reliable water supply is essential for human survival, and people are attracted to areas where the availability of water is sufficient without being excessive. Areas with high population include places with reliable, evenly distributed rainfall (such as western Europe and north-eastern United States).

• Physical Factor

• Human Factor

People avoid areas where there are dangerous pests and diseases. Therefore, places such as the lowlands of Papua New Guinea and parts of central Africa have sparse population densities because of malaria.

• Physical Factor

• Human Factor

People are attracted to areas with major concentrations of minerals or energy resources, such as the Pittsburgh region of the USA, South Wales in the UK, and the Ruhr basin of Germany.

• Physical factor

• Human Factor

Some places with abundant natural resources may have sparse population densities, either because the resources can be obtained with very few people (such as oil in Algeria, Iran or Saudi Arabia), or because the resources have not been developed (such as minerals in Eritrea or the Russian Far East).

• Physical factor

• Human factor