Chapter 2 - Changing population and places
Population Change
- Global population is now about 7.4 billion
- Thomas Malthus said that earth could only support a finite population size
because food supplies are limited. He said that natural increase in the
human population increases in a geometric progression, food production
only increase in an arithmetic progression
- The growth in the world population has been caused by a combination of
death rates being lowered and life expectancies increasing
- Death rate: the proportion of the population that dies in a particular year
- Infant mortality: death rate of young children
- Average life expectancy: the number of years that a child born in a particular
country in a certain year can expect to live
- Just like population growth has been unevenly distributed in the [ast, growth is
likely to be unevenly distributed in the decades ahead.
- The structure of a population refers to the sex and age distirubtion of the
population. This is often shown as a graph with the number of proportions of
each age group shown as horizontal bars from a central vertical column that
represents age groups. These graphs are known as population pyramids, or
age-sex diagrams (See figure 2.5 on page 62)
- Children and adolescents (under 15 years old)
- The working-age population (15-64 years old)
- The elderly population (above 64 years old)
- A population pyramid with a wide base that narrows quickly upwards
represents a population with a high birth rate, a high proportion of
young people and a rapidly growing population.
- A population pyramid with steep vertical sides represents an aging
population with a low birth rate
- Developing countries tend to have a population structure with a wide
base, indicating that a large proportion of the population is below 15
years of age.
- Industrialized countries have population pyramids that have a
narrower base.
- Population pyramids with a narrower base are evidence of an ageing
population and a slower rate of population increase, or even a
declining population size
- Fertility rates: number of births per woman
- Fertility rates are very high in developing regions such as Africa and parts
of the Middle East, but low in most industrialised regions
- The rate of population increase in any area can be calculated by adding the
rate of natural increase and the rate of net migration
Population Change
- Global population is now about 7.4 billion
- Thomas Malthus said that earth could only support a finite population size
because food supplies are limited. He said that natural increase in the
human population increases in a geometric progression, food production
only increase in an arithmetic progression
- The growth in the world population has been caused by a combination of
death rates being lowered and life expectancies increasing
- Death rate: the proportion of the population that dies in a particular year
- Infant mortality: death rate of young children
- Average life expectancy: the number of years that a child born in a particular
country in a certain year can expect to live
- Just like population growth has been unevenly distributed in the [ast, growth is
likely to be unevenly distributed in the decades ahead.
- The structure of a population refers to the sex and age distirubtion of the
population. This is often shown as a graph with the number of proportions of
each age group shown as horizontal bars from a central vertical column that
represents age groups. These graphs are known as population pyramids, or
age-sex diagrams (See figure 2.5 on page 62)
- Children and adolescents (under 15 years old)
- The working-age population (15-64 years old)
- The elderly population (above 64 years old)
- A population pyramid with a wide base that narrows quickly upwards
represents a population with a high birth rate, a high proportion of
young people and a rapidly growing population.
- A population pyramid with steep vertical sides represents an aging
population with a low birth rate
- Developing countries tend to have a population structure with a wide
base, indicating that a large proportion of the population is below 15
years of age.
- Industrialized countries have population pyramids that have a
narrower base.
- Population pyramids with a narrower base are evidence of an ageing
population and a slower rate of population increase, or even a
declining population size
- Fertility rates: number of births per woman
- Fertility rates are very high in developing regions such as Africa and parts
of the Middle East, but low in most industrialised regions
- The rate of population increase in any area can be calculated by adding the
rate of natural increase and the rate of net migration
