AP HUMAN GEOGRAPHY
UNIT 2 VOCABULARY
Population and Migration Patterns and Processes
26 essential terms, organized by topic and aligned to the official College Board framework.
Population Measurement & Structure
Term Definition
Population The pattern of where people live across a given area.
distribution
Arithmetic density Total population divided by total land area.
Physiological Total population divided by arable (farmable) land area — shows pressure on food-
density producing land.
Agricultural density The number of farmers divided by arable land area — shows farming efficiency.
Carrying capacity The maximum population a given environment can sustainably support.
Population pyramid A graph displaying a population's age and sex composition, used to visualize growth
trends.
Dependency ratio The ratio of the non-working-age population (under 15 and over 64) to the working-
age population.
Zero Population A state in which a population's birth rate roughly equals its death rate, resulting in
Growth (ZPG) little to no natural growth.
Growth, Decline & the DTM
Term Definition
Demographic A model showing how birth and death rates change as a country moves through five
Transition Model stages of economic development.
(DTM)
Crude Birth Rate The number of live births per 1,000 people per year.
(CBR)
Crude Death Rate The number of deaths per 1,000 people per year.
(CDR)
Rate of Natural Population growth based only on births and deaths, excluding migration; calculated
Increase (RNI/NIR) as (CBR − CDR) ÷ 10.
Total Fertility Rate The average number of children a woman would have in her lifetime at current birth
UNIT 2 VOCABULARY
Population and Migration Patterns and Processes
26 essential terms, organized by topic and aligned to the official College Board framework.
Population Measurement & Structure
Term Definition
Population The pattern of where people live across a given area.
distribution
Arithmetic density Total population divided by total land area.
Physiological Total population divided by arable (farmable) land area — shows pressure on food-
density producing land.
Agricultural density The number of farmers divided by arable land area — shows farming efficiency.
Carrying capacity The maximum population a given environment can sustainably support.
Population pyramid A graph displaying a population's age and sex composition, used to visualize growth
trends.
Dependency ratio The ratio of the non-working-age population (under 15 and over 64) to the working-
age population.
Zero Population A state in which a population's birth rate roughly equals its death rate, resulting in
Growth (ZPG) little to no natural growth.
Growth, Decline & the DTM
Term Definition
Demographic A model showing how birth and death rates change as a country moves through five
Transition Model stages of economic development.
(DTM)
Crude Birth Rate The number of live births per 1,000 people per year.
(CBR)
Crude Death Rate The number of deaths per 1,000 people per year.
(CDR)
Rate of Natural Population growth based only on births and deaths, excluding migration; calculated
Increase (RNI/NIR) as (CBR − CDR) ÷ 10.
Total Fertility Rate The average number of children a woman would have in her lifetime at current birth
