Ap Human Unit 2

Population density

The number of people per unit of area

Arithmetic population density

Total population divided by total land area

Physiological population density

Number of people per unit of arable (farmable) land

Population distribution

The pattern of where people live across Earth

Megalopolis

A large region of cities merged together (e.g., Boston–DC corridor)

Census

Official count of a population

Total fertility rate (TFR)

Average number of children a woman has in her lifetime

Old-age dependency ratio

Ratio of elderly people (65+) to working-age population

Child dependency ratio

Ratio of people under 15 to working-age population

Doubling time

Number of years needed for a population to double

Population explosion

Rapid increase in population size

Zero population growth (ZPG)

When births equal deaths (no growth)

Crude birth rate (CBR)

Number of births per 1,000 people per year

Crude death rate (CDR)

Number of deaths per 1,000 people per year

Natural increase

Birth rate minus death rate

Demographic transition

Model showing population change over time (stages 1–5)

Stationary population levels

Stable population with little growth

Population composition

Structure of population by age and gender

Population pyramids

Structure of population by age and gender

Infant mortality rate (IMR)

Deaths of infants under 1 year per 1,000 births

Child mortality rate

Deaths of children under 5 per 1,000

Life expectancy

Average number of years a person is expected to live

Infectious disease

Disease spread person-to-person (e.g., flu)

Chronic/degenerative disease

Long-lasting disease (e.g., heart disease)

Genetic/inherited diseases

Diseases passed through genes

Expansive population policies

Government policies encouraging higher birth rates

Eugenic population policies

Policies aimed at improving genetic quality (often unethical)

Restrictive population policies

Policies aimed at reducing birth rates

Refugee camps

Temporary settlements for displaced people

Remittances

Money migrants send back home

Cyclic movement

Short-term, repetitive movement (e.g., commuting)

Periodic movement

Longer-term movement (e.g., seasonal work)

Migration

Permanent move to a new location

Activity spaces

Areas where people live, work, and interact

Nomadism

Moving constantly with no permanent home

Transhumance

Seasonal movement of livestock between pastures

International migration

Movement between countries

Emigration

Leaving a country

Immigration

Entering a country

Internal migration

Movement within a country

Forced migration

Migration where people have no choice

Voluntary migration

Migration by choice

Human trafficking

Illegal movement of people for exploitation

Laws of migration

Patterns of migration identified by Ravenstein

Gravity model

Predicts migration based on size and distance of places

Push factor

Negative condition that drives people away

Pull factor

Positive condition that attracts people

Step migration

Migration in a series of smaller steps

Intervening opportunity

Better opportunity interrupts migration

Deportation

Forced removal from a country

Kinship links

Family connections influencing migration

Chain migration

Migration following others from same place

Immigration wave

Large group migrating during a specific period

Colonization

Settlement of people from one place in another

Guest workers

Foreign workers allowed temporarily

Regional scale

Analysis at a region level

Migration islands of development

Areas that attract migrants due to economic growth

Refugees

People forced to leave due to danger

Internally displaced persons (IDPs)

People forced to move within their country

Repatriation

Return to one’s home country

Malthusian Theory

Idea that population grows faster than food supply