Unit 3 Demography (Combined)

population pyramid

a bar graph representing the population of a country broken down by age and sex (male or female)

three shapes of population pyramid

expansive, constrictive, and stationary

expansive pyramid shape

triangle shape: wide base (bottom), narrow top

stationary pyramid shape

rectangular: roughly even bars from top to bottom

constrictive pyramid shape

diamond shape: narrow base (bottom), wide middle and top section

age cohort

age groups represented on the y-axis of a population pyramid (0-4, 5-9, 30-34, etc.)

expansive pyramid growth rate

rapid growth

expansive pyramid birth rate

high/very high birth rate

expansive pyramid level of development

underdeveloped

stationary pyramid growth rate

slow or stable growth

stationary pyramid birth rate

low or stable birth rate

stationary pyramid level of development

developed

constrictive pyramid growth rate

negative growth (population is shrinking)

constrictive pyramid birth rate

very low birth rate

constrictive pyramid level of development

highly developed

Population Density

The average number of people living in a given area (such as square miles)

Population Distribution

Describes how people are spread out across an area

Physical factors affecting population distribution

Climate, water, landforms

Human factors affecting population distribution

Economics, history, politics

2 Types of Factors Affecting Population Distribution

Human & Physical

Population Density Formula

Population Density = Total number of people ÷ Land area

Water: Effect on Population Distribution

People tend to live near bodies of water (coastlines, rivers, lakes)

Climate: Effect on Population Distribution

People tend to live in mild climates (not to hot, not to cold)

Landforms: Effect on Population Distribution

People tend to live far away from mountains and near fertile land such as plains

Economics: Effect on Population Distribution

People tend to live near economic opportunities (jobs and resources)

History: Effect on Population Distribution

People tend to live in areas that have historically been settled and populated

Politics: Impact on Population Distribution

People tend to live in areas with stable governments and favorable policies

population

Number of people who live in a place

birth rate

number of babies born in a place in a year

death rate

number of deaths in a place in a year

life expectancy

average number of years a person is expected to live

exponential growth

pattern of population growth where the rate of growth increases over time

developed countries

countries with strong economies, high average income, and high standard of living

developing countries

countries with less productive economies and a lower quality of life

underdeveloped countries

countries with unstable economies, low average income, and low standard of living

population grows if…

the birth rate is higher than the death rate

population shrinks if…

the death rate is higher than the birth rate

crude birth rate

the number of births per 1,000 people in a year

crude death rate

the number of deaths per 1,000 people in a year

national increase rate

the percentage growth rate of a population in one year

formula for crude birth rate

(births ÷ total population) x 1,000

formula for crude death rate

(deaths ÷ total population) x 1,000

formula for national increase rate

(crude birth rate - crude death rate) ÷ 10 *expressed as a percentage

reasons life expectancy has increased

medical advances, access to clean water, increased agricultural production