Population Pyramids Population Pyramids A country is generally

Population Pyramids

Population Pyramids A country is generally defined as being a developed nation if it is amongst the world’s wealthiest countries, with a high per capita income,

Population Pyramids Developing nation refers to those countries that do not have a modern infrastructure or many industries. Countries such as those that comprise Southeast Asia, which are continually building up their industries and infrastructure, are known as newly industrialising countries.

Population Pyramids A population pyramid is a graph commonly used by geographers to show the age and sex structure of a given population.

Population Pyramids The pyramid is comprised of a series of bar graphs with the portions of the population along the horizontal x-axis and the five-year age groups (cohorts) along the vertical y-axis.

Population Pyramids Male population is shown to the left of the vertical axis and female to the right.

Population Pyramids Population pyramids typically take the form of one of four pyramid models, reflecting different stages of population development. Countries with high crude birth rates have an Expanding population (see page 326).

Population Pyramids A country with crude birth rates and crude death rates in balance will have a stable population

Population Pyramids A Contracting population will have a growth rate below replacement level (crude death rates exceed crude birth rates).

Population Pyramids Population pyramids that represent an expanding population are generally representative of developing countries

Population Pyramids Stable or Contracting populations are represented by pyramids of the developed nations.

Age Structure of Populations The age structure of a population is important because of the fact that people of different ages have different needs, abilities and responsibilities within a given society.

Age Structure of Populations Geographers divide populations into three different age groups: children under the age of sixteen working adults between the ages of sixteen and sixty-four adults sixty-five years and older.

Age Structure of Populations The Dependency Ratio is the ratio of the dependent part of the population (children under the age of sixteen and adults sixty-five and older), to the productive part (working adults between the ages of sixteen and sixtyfour).

Age Structure of Populations An ageing population, or a population with a high number of children under the age of sixteen, will have a higher dependency ratio than a population where there are more working adults aged sixteen to sixty-four. Page 328.

Age Structure of Populations Dependency ratio [(% under 15) + (% over 65)] / (% 15 to 64)

Demographic Transition Model Stage 1 of the Demographic Transition Model is characterized by extremely high birth and death rates, which means the population is barely increasing if increasing at all. There is little or no natural increase.

Demographic Transition Model Stage 2 is characterized by high birth rates, but declining death rates (usually because of advancements in medicine and hygiene). Therefore, in Stage 2, population growth is high. Kenya is in Stage 2 at the moment.

Demographic Transition Model Stage 3 is characterized by declining birth rates and continued declining death rates and the rate of natural increase begins to slow down. Malaysia is an example of a country in the Stage 3.

Demographic Transition Model Stage 4 occurs when there are low birth rates and low death rates producing no long -term natural increase or zero population growth. Canada is currently in Stage 4 of the model.

Demographic Transition Model Stage 5 represents those countries that have undergone deindustrialisation and have seen a natural decrease in population due to birth rates falling below death rates. Japan is the most notable country said to be in Stage 5.