AP Human Geography: Population Concepts and Migration Patterns

Ecumene

The portion of Earth's surface permanently inhabited by humans

Population Density

A measurement of population per unit area, such as people per square kilometer

Arithmetic Density

Total population divided by total land area

Physiological Density

Total population divided by the amount of arable (farmable) land

Carrying Capacity

The maximum population size that an environment can sustainably support

Population Distribution

The pattern of where people live across a geographic area

Demography

The scientific study of population characteristics such as age, gender, and growth

Linear Growth

Population increases by a fixed amount over time

Exponential Growth

Population increases by a constant percentage, growing faster over time

Push Factor

A reason that causes people to leave their current location (e.g., war, famine)

Pull Factor

A reason that attracts people to a new location (e.g., jobs, safety)

Dependency Ratio

The ratio of people who are too young or too old to work compared to those of working age

Refugee

A person forced to leave their country due to war, persecution, or disaster

Asylum Seeker

A person who has left their country and is seeking protection in another but has not yet been legally recognized as a refugee

Migration

The movement of people from one location to another

Forced Migration

When people are made to move due to conflict, environmental disasters, or persecution

Voluntary Migration

When people move by choice, often for better opportunities

Step Migration

Migration that occurs in stages, typically moving from rural to urban areas gradually

Chain Migration

Migration in which people follow relatives or members of their community to a new place

Total Fertility Rate

The average number of children a woman is expected to have in her lifetime

Crude Birth Rate

The number of live births per 1,000 people in a given year

Crude Death Rate

The number of deaths per 1,000 people in a given year

Infant Mortality Rate

The number of deaths of infants under one year old per 1,000 live births

Maternal Mortality Rate

The number of women who die from pregnancy-related causes per 100,000 live births

Rate of Natural Increase

The rate at which a population grows, calculated by subtracting the crude death rate from the crude birth rate

Population Pyramid

A bar graph that displays the age and sex structure of a population

Overpopulation

When a population exceeds the environment's ability to support it sustainably

Transhumance

The seasonal migration of livestock and people between mountains and lowland pastures