human geography un

Population Density

Measure of the average population per square mile or kilometer of an area. Measures

how crowded a place is.

Population distribution

The pattern of human settlement—the spread of people across the earth.

social stratification

The hierarchical division of people into groups based on factors such as economic

status, power, and/or ethnicity

Arithmetic density

The total number of people divided by total land

area.

Physiological density

The number of people per unit area of arable

land.

Agricultural density

The ratio of the number of farmers to the amount of arable land

Arable land

Land suitable for growing crops

Infrastructure

The facilities and structures that allow people to carry out their typical activities (sewer

systems, electrical grids, roads and bridges, etc

Overpopulation

Having more people than a region can support

Carrying capacity

The number of people a region can support without damaging the environment

Population pyramid

Based only on age and gender data. Provides

information on birth rates, death rates, how long people live on average, and economic development

Birth deficit

A negative birth rate, where there are more deaths than live births in a population

Baby boom

a period of increased birth rates, most notably the one in the United States from 1946-1964,

following WW2

Baby bust

A significant, widespread decline in birth rates and fertility

Potential workforce

People ages 15-64, the group expected to be the society’s labor force

Dependent population

People under 15 or over 64, considered too young or too old to work full-time and

therefore are assumed to rely on the economically active workforce to keep the society

Dependency ratio

Number of people who are too young or too old to work, compared to the number of

people in productive years.

Demographic equation

Describes the future population of a region of any scale

What is the demographic balancing equation?

Future

population= Currently population + (number of births- number of deaths) + (number of immigrants -

number of emigrants).

Immigrants

People who moved into the country

Immigration

Migration to a location

Emigrants

People who moved out of the country

Emigration

Migration from a location

Crude birth rate (CBR)

Total number of live births in a year for every 1,000 people alive in the society

Total fertility rate (TFR)

Estimate of the average number children a woman will have during her

childbearing years

Life expectancy

The average number of years people live

Infant mortality rate (IMR)

Annual number of deaths of infants under one year of age, compared with

total live births

Crude death rate (CDR)

Total number of deaths in a year for every 1,000 people alive in a society

Natural increase rate (NIR)

Percentage by which a population grows in a

year. Subtract CDR from CBR after converting the number to percentages

Population doubling time

The period it takes for a population to double in size at a constant growth rate

Demographic transition model

Shows five typical stages of population change that countries experience

as they modernize

DTM stage 1

(High Stationary):

High birth rate but fluctuating as needed for farm labor changes,

High death rate but fluctuating to reflect diseases and poor sanitation,

Natural increase in a year is 0-.5%

Population change is very low growth because births and deaths both high,

Population structure is very young,

Examples today are scattered isolated groups,

Economy and society based on subsistence agriculture and hunter gathering

DTM stage 2

(Early Expanding):

High birth rate but fluctuating to reflect desires for big families,

Rapidly declining crude death as nutrition, sanitation, and medicine improve,

Natural increase in a year is .5 to 4%,

Population change is rapid growth as death rates fall faster than birth rates,

Population structure is very young,

Examples today are Mali and South Sudan,

Economy and society based on rural agricultural society and less developed society

DTM stage 3

(Late Expanding):

Declining birth rates as urbanization decreases the need for child labor,

Declining death rate but not as fast as in previous stage,

Natural rate of increase yearly is 4 to .8%,

Population change is rapid but slowing growth as birth rates decline,

Population structure is young with rising life expectancy,

Examples today are Mexico, Turkey, Indonesia,

Economy and society has a large movement of people from farms to cities, emerging/industrializing

DTM stage 4

(Low Stationary):

Low birth rate but enough to keep the population stable,

Death rate is low and stable Natural yearly rate increase is .8 to 0%,

Very low growth in population change because births and deaths are both low,

Population structure is balanced with more aging,

Examples today are United States and China,

Economy and society is an urbanized service economy, highly developed, rising gender equality

DTM stage 5

Declining):

Birth rates are so low it falls below the death rate,

Death rate is low but sometimes increasing as the population ages,

Natural increase rate yearly is 0% to (-1%)

Population change is very low decline as births fall below deaths,

Population structure is very old,

Examples today are Japan and Germany

Economy and society have a urbanized service economy and are highly developed

Epidemiological Transition Model

An extension of the DTM and explains the changing death rates and

more common causes of death within societies: Stage 1- Disease and Famine, Stage 2- Receding

Pandemics, Stage 3- Degenerative and Human-Created Diseases, Stage 4- Delayed Degenerative Diseases

Malthusian theory

Theory by Thomas Malthus that population grows exponentially while food supply

grows arithmetically, leading to potential famine, disease, and conflict unless population growth is

controlled

Boserup theory

Theory that farmers will adopt new and modern methods to keep up with demand

caused by an increasing population

Neo-malthusians

Modern supporters of Malthus’ ideas who argue that rapid population growth, combined

with resource depletion and environmental degradation, threatens sustainability and could lead to global

crises

Migration

The long-term, permanent relocation of people from one place to another

Migration transition model (MTM)

A model that links a country’s stage of demographic transition with typical

patterns of migration (e.g., rural-to-urban migration in early stages, urban-to-urban or international

migration in later stages). shows that as a country becomes more developed, it shifts from

being a source of emigrants to being a destination for immigrants

Net migration

Difference between the number of immigrants and emigrants

Internally displaced person (IDP)

A person who is forcibly uprooted within their country but has not crossed

an international border

Pull factor

Convinces people to move into a new location.

Push factor

Convinces people to move out of a present location.

Intervening obstacle

Environmental or cultural feature that hinders migration

Intervening opportunities

Factors that cause a migrant to stop and settle before reaching their original

destination (e.g., finding a job or family support in a closer location

Distance decay

The principle that interaction between two places decreases as the distance between them

increases

Gravity model of migration

A model that predicts migration flows based on the size (population) of two

places and the distance between them — larger and closer places attract more migrants

Step migration

Migration that occurs in stages, moving from a small town → medium city → large city

rather than directly to the final destination

Rural to urban

The movement of people from countryside areas to cities, often driven by

industrialization, job opportunities, and better services.

Counter migration

When people move back to their place of origin after migrating somewhere else

Return migration

The voluntary movement of migrants back to their home country or region after some

time away

Refugees

People forced to leave their country due to war, persecution, or natural disaster, with a well-

founded fear of harm if they return.

Asylum

Legal protection granted by a country to someone who has fled their home country to escape

danger or persecution

Transnational migration

Migration in which people maintain connections to two or more countries —

socially, economically, or politically

Chain migration

Migration of people to a specific location because relatives or members of nationality

previously migrated there

Voluntary migration

Migrant has chosen to move for economic improvement

Forced migration

Involuntary movement of people caused by conflict, disaster, slavery, or government

policies (e.g., deportation).

Internal migration

Permanent movement within the same country

Guest worker

Migrant laborers allowed to temporarily work in another country, often to fill labor

shortages.

Transhumance

The seasonal migration of livestock between mountains and lowland pastures

Homestead act U.S. law (1862)

that encouraged westward settlement by granting free land to those

willing to farm and improve it.

Family reunification

Immigration policies that prioritize visas for close relatives of citizens or

legal residents, allowing families to live together

Xenophobia

Fear, dislike, or hostility toward people from other countries or cultures

Remittances

Money sent by migrants back to their home country to support family or community

members

Brain drain

The emigration of highly skilled or educated people from one country, often weakening the

sending country’s economy

Ethic enclaves

Neighborhoods or areas where a high concentration of one ethnic group lives,

maintaining cultural traditions and businesses

Least developed countries (LDC)

Countries with low levels of income, education, healthcare, and

industrialization; often experiencing high population growth rates

More developed countries (MDC)

Countries with higher levels of income, education, healthcare, and

industrialization; usually with slower population growth

Ravensteins law of migration

A set of 19th-century “laws” describing migration patterns — most

migrants move short distances, long-distance migrants head to major cities, and migration occurs in

counterflow (every migration flow, there is a return or counter flow

Pro-Natalist

Government policies designed to encourage population growth (e.g., financial incentives for

having children)

Anti-natalist

Government policies designed to slow population growth (e.g., restricting family size or

promoting contraception)

The difference between DTM and ETM

The DTM describes shifts in birth and death rate, while the ETM details the changing causes of death

ETM stage 1

Death caused by famine and pestilence (ex: black plague)

ETM stage 2

Death caused by receding pandemics (ex: better hygiene)

ETM stage 3

Death caused by degenerative and human-created diseases (ex: heart attack)

DTM stage 4

Death caused by delayed degenerative diseases (ex: diabetes)

DTM stage 5

Death caused by Re-emergent infectious diseases (ex: antibiotic resistance )

Gravity model equation

S = (P1*P2)/D²

RNI

RNI = CBR - CDR

What’s the population growth rate equation? (PGR)

(CBR - CDR + net migration)/10

Doubling time equation

70 / growth rate

What pyramid is this?

Expansive pyramid

What does the expansive pyramid show

Indicates high birth rates and a large portion of young people (typical for developing countries with rapid population growth)

What pyramid is this?

Stationary pyramid

What does the stationary pyramid show?

Even age distribution, signifying slow or zero population growth, birth and death rates are balanced

What pyramid is this?

Constructive pyramid

What does the constrictive pyramid show?

Narrow base with more people in older age groups, indicating a declining population due to low birth rates and high life expectancy

What does the y-axis show in a population pyramid

Age distribution

What does the x-axis show in a population pyramid

Sex ratio

What are the pre-reproductive ages?

0-14

What are the reproductive age?

15-44 or 15-64

What are the post reproductive ages?

45+ or 65+