population structure

Population Structure

Learning Objectives

• Interpret the age-sex structure of a country from a population pyramid

• Describe how and explain why the UK’s population structure has changed

• Make links between the DTM and population structure

• Compare population pyramids from the LEDW and MEDW

Population Structure

• Population structure is the make up of the total population in a country or area where people are grouped by age and sex.

• The graphical technique used to summarise age structure is the population pyramid.

Interpreting Pop Pyramids

Start at the base – what has happened recently?

Next go to the top – how long do people live for?

Then look at the middle – are there any age groups that stand out? Long / short bars?

Dependent Population

Dependent Population

• The dependency ratio is directly linked to a country’s age structure.

• To calculate it, the population is split into economically active (15-64) and inactive (0-14 and 65+)

• Dependency ratio is calculated as a % using:

Number of economically active Number of non-economically active

X 100

How has the population structure of the UK changed over time?

How has the population structure of the UK changed over time?

How has the population structure of the UK changed over time?

Male Female

Population in millions

How has the population structure of the UK changed over time?

Population Structure of the UK

• Write a case study to describe how and why the population structure of the UK has changed from 1841-1981.

• Use annotated sketches of population pyramids to help you.

• P172-173

MEDW vs LEDW

• The shape of a population pyramid gives a clear indication of the development status of a country and can therefore be linked with countries in the MEDW or the LEDW.

LEDW

This country has a high BR – the pyramid has a

wide base

But it also has a high DR – shown

by the steeply sloping pyramid

Falling BR

In some LEDCs, the Government is

encouraging families to have fewer children so

the BR is falling – the base is becoming narrower.

MEDW

Male Female

Population in millions

Low DR – pyramid is wider at the top

The largest group of people was born

around 40 years ago – ‘baby boomers’.

There are roughly the same amount of people in each age

category – BR is stable.

Declining population

BR is falling – the number of people in each category is

getting smaller

In the future the elderly population will make up the largest section of the population – an

ageing population

MEDW vs LEDW

Male Female

Population in millions

Population Structure and the DTM

• The shape of a population pyramid gives a clear indication of the development status of a country and can therefore be linked with a particular stage of the DTM

• http://www.bbc.co.uk/scotland/education/geog/population/

Activity

• Using P174-175• Sketch population pyramid for each stage of

the DTM• Give reasons for the changes