Population Statistics, Terminology and Factors that Affect Density

Population Density

If there are many people living in a place close together we call it densely populated. If there are a fewer people spread over a place we would describe the area as sparsely populated.

Birth Rate

The birth rate is the number of births per thousand of the population per year.

Death Rate

The death rate is the number of deaths per thousand of the population per year.

Natural Increase

The rate of natural increase in the difference between the birth and death rates (NI = birth rate - death rate).

Migration

Migration is the movement of people from one area or country to another to find work or a better standard of living.

Factors that Affect Population Density

Climate:

• Climates which are temperate are ideal for settling.

• Places which are extremely hot, cold or dry tend to have lower population densities, for example the Sahara Desert is very hot and dry and therefore very few people live there.

• Mountainous areas of the UK, which are wetter, windier and colder than the rest of the UK, have comparably lower population densities than the places with more favourable climates.

Relief of the land:

• Places which are flat or have gentle relief are best for settling because this usually provides a temperate climate and is easier for the construction of infrastructure. Therefore, the Himalayas has a low population density.

• Mountainous areas of the UK, such as the Grampians or Snowdonia, have lower population densities than flatter areas such as the southeast of England.

Fertility of soil:

• Areas where soil is fertile provide for productive agriculture. Therefore, population densities are greater in these areas.

• Fertile areas include land near rivers and at the base of volcanoes.

• Bangladesh, on the Ganges floodplain, has a high population density.

• Fig. 4.2 shows that East Anglia, with its fertile boulder clay soil, has a reasonably high population density.

Availability of natural resources: 

• Countries or areas which are rich in resources such as oil, coal and precious minerals are likely to have high population densities.

Perceived likelihood of natural disaster:

• Countries which are away from tectonic plate boundaries are less likely to experience other natural disasters such as hurricanes and floods are likely to be more densely populated. For example the UK is not likely to experience severe tectonic disasters or hurricanes and this is one reason why it has a high population density.  

Stability of government:

• Countries with unstable governments often experience high levels of emigration. For example, the Central African Republic has experienced many coups and has low population density. 

Job opportunities:

• Areas with many job opportunities are likely to have high population densities. For example, the southeast of the UK has a much higher population density that the rest of the UK, and this is partly due to the fact that London provides a multitude of jobs and high paid jobs. 

Population Pyramids

Population structure means the 'make up' or composition of a population. Looking at the population structure of a place shows how the population is divided up between males and females of different age groups.

Population structure is usually shown using a population pyramid. A population pyramid can be drawn up for any area, from a whole continent or country to an individual town, city or village.

The following graphs show the population pyramids of a High Income Country (HIC - the UK) and a Low Income Country (LIC - Mozambique), for 2000 and in 2025 using projected figures. The left side of each pyramid shows the number of men in each age group, the right side shows the number of women in each age group.

Key things to know about population pyramids (Analysing population pyramids)

• The shape of a population pyramid can tell us a lot about an area's population.

• It gives us information about birth and death rates as well as life expectancy.

• A population pyramid tells us how many dependants there are. There are two groups of dependants; young dependants (aged below 15) and elderly dependants (aged over 65).

• Dependants rely upon the economically active for economic support.

• Many LEDCs have a high number of young dependants, whilst many MEDCs have a growing number of elderly dependants.

How do pyramids change over time (Analysing population pyramids) ?

• A population pyramid that is very triangular (eg Mozambique in 2000) shows a population with a high number of young dependants and a low life expectancy.

• A population pyramid that has fairly straight sides (more like a barrel) shows a population with a falling birth rate and a rising life expectancy.

• Over time, as a country develops, the shape changes from triangular to barrel-like.

• Places with an ageing population and a very low birth rate would have a structure that looks like an upside-down pyramid.

UK Population Pyramid, 2000

Notice how in the UK 2000 pyramid there is a bulge in the area of the 30-34 and 35-39 age groups, with the numbers thereafter reducing fairly steadily as the ages increase.

Projected Population Pyramid for the UK, 2025

Compare this to the 2025 pyramid. Here the bulge extends much further, covering the age groups 30-64, with the numbers beginning to reduce significantly only after 64.

Mozambique Population Pyramid, 2000

Now compare the UK population pyramids with those for Mozambique. In this graph, notice that in 2000 the 0-4 age group contained the largest number of people, with the numbers thereafter declining steadily as the ages increase. 

Projected Population Pyramid for Mozambique, 2025

In this graph, notice that in 2000 the 0-4 age group contained the largest number of people, with the numbers thereafter declining steadily as the ages increase.