APHUG Unit 2

Population Pyramids

Visual graphs that show a population’s age and sex distribution, revealing growth patterns, birth/death rates, and economic development level.

DTM (Demographic Transition Model)

A model showing how populations transition over time through 5 stages based on changes in birth rates, death rates, and natural increase as countries industrialize.

Malthusian Theory

The idea proposed by Thomas Malthus that population grows exponentially while food supply grows linearly, leading to inevitable shortages and checks (like famine or disease).

Anti-Natalist Policies

Government actions designed to reduce birth rates and slow population growth (e.g., China’s One-Child Policy).

Pro-Natalist Policies

Government actions encouraging more births to increase population growth (e.g., tax breaks for families, parental leave).

Overpopulation

When a region’s population exceeds its carrying capacity, leading to resource strain and lower quality of life.

Population Density

The number of people living in a given area; can be measured as arithmetic (total), physiological (per arable land), or agricultural (farmers per farmland).

TFR (Total Fertility Rate)

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

Push and Pull Factors

Reasons why people leave a place (push: war, lack of jobs) or are attracted to a new place (pull: safety, opportunities).

Carrying Capacity

The maximum population size that an environment can sustainably support with its resources.

Fertility Rates

A measure of how many children are being born in a population, often expressed as TFR.

Diffusion Types

The ways ideas, diseases, or innovations spread; includes relocation (physical movement), contagious (rapid, widespread), hierarchical (through power/urban centers), and stimulus (idea spreads but changes).

Demographic Momentum

Population continues to grow even after fertility rates decline due to a large base of young people.

Neo-Malthusian Theory

Modern version of Malthus’s ideas that emphasizes population pressure on not just food but all resources, predicting potential crises in developing countries.

Chain Migration

When migrants follow family or community members to a new place, creating migration “chains.”

Periodic Migration

Temporary movement that occurs over longer periods, such as college attendance or military service.

Cyclic Migration

Regular, short-term movements (e.g., daily commuting, seasonal work) that repeat over time.

Transhumance

A type of seasonal migration of livestock and people between mountains and lowlands, often by pastoralists.

Forced Migration

Movement of people compelled by external forces (e.g., war, persecution, disasters) without a choice.

Internal Migration

Movement of people within the same country (e.g., rural to urban migration).

Distance Decay

The idea that interaction between two places decreases as the distance between them increases.

Guest Worker

A person who migrates temporarily to another country to work, often in labor-intensive jobs.

Gravity Model

Predicts interaction between two places based on their size and distance: larger and closer places have stronger connections.

Step Migration

Migration that occurs in stages, such as moving from a village to a town, then to a city.

Doubling Time

The number of years it takes for a population to double in size, calculated using the Rule of 70 (70 ÷ growth rate).

Epidemic

Disease outbreak in a specific region.

Pandemic

Disease outbreak that spreads worldwide.

Endemic

Disease regularly found in a specific area.

Intervening Opportunity

A nearby opportunity that reduces the attraction of a farther-away destination, altering migration patterns.

Ravenstein’s Migration Laws

A set of principles (1880s) describing migration patterns, such as most migration being short-distance, occurring in steps, and often from rural to urban areas.

Refugee

A person forced to flee their country due to persecution, war, or violence, seeking safety elsewhere.