IGCSE Geography: Population and Settlement — Revision Notes

Condensed for the final weeks. For the full explanation, use the Population and Settlement study guide.

Population change

natural increase = birth rate - death rate
population change = natural increase + net migration

Rates are per 1,000 people per year. Forgetting migration is the commonest error in a population-change calculation.

The Demographic Transition Model

Stage	Birth rate	Death rate	Natural increase	Example
1 High fluctuating	High	High	Low	Remote tribal groups
2 Early expanding	High	Falling rapidly	Very high	Afghanistan, Niger
3 Late expanding	Falling	Low	Slowing	Brazil, India
4 Low fluctuating	Low	Low	Low / zero	UK, USA
5 Decline	Below death rate	Low	Negative	Japan, Germany

Stage 2 is where the population explosion happens, and the reason is a timing gap: the death rate falls first — better medicine, sanitation, clean water and food supply — while the birth rate stays high because attitudes, religion and the economic value of children change far more slowly. That lag is the whole model in one sentence.

The birth rate later falls in stage 3 due to contraception, female education and employment, lower infant mortality (so fewer births are needed), urbanisation, and the rising cost of raising children.

Limitations of the DTM: based on European experience, it ignores migration, assumes all countries follow the same path, and gives no timescale.

Population pyramids

• Wide base, rapidly narrowing → high birth rate and high death rate, stage 2. Young population, high dependency.
• Straight sides, narrow base → low birth and death rates, stage 4 or 5. Ageing population.

dependency ratio = (under 15 + over 64) / (15-64) x 100

Ageing population: rising pension and healthcare costs, a shrinking workforce, higher taxes on those working. Responses: raising the retirement age, encouraging immigration, and pro-natalist policies.

Government population policies, named: anti-natalist policies reduce the birth rate, e.g. China’s former one-child policy — but this caused a skewed sex ratio from sex-selective abortion, and left an ageing population with a shrinking workforce, which is why it was abandoned. Pro-natalist policies raise the birth rate, e.g. France’s and Singapore’s financial incentives, tax allowances and subsidised childcare — but these are expensive and have limited effect, since the decision to have children depends more on housing costs and career considerations than on a payment. Immigration policy fills labour shortages directly, e.g. Germany’s recruitment of foreign workers — but risks pressure on housing and services, and social tension if integration is not managed.

Youthful population: pressure on schools and healthcare, high future unemployment as the cohort reaches working age, and food and housing pressure — but a large future workforce.

Migration

• Push factors — unemployment, poverty, conflict, natural disaster, persecution, poor services.
• Pull factors — jobs, higher wages, better services, safety, family already present.

	Benefits	Problems
Receiving country	Fills labour shortages, often young workers who pay tax, cultural diversity	Pressure on housing and services, possible social tension
Source country	Remittances sent home, reduced unemployment, returning migrants bring skills	Brain drain, loss of working-age people, families separated

Always evaluate migration from both countries’ perspectives — that structure is what the mark scheme expects.

Settlement

Site — the actual land a settlement is built on. Situation — its position relative to surrounding features and other settlements.

Site factors: water supply, dry point, defence, relief, aspect, building materials, fuel, and fertile land.

Settlement hierarchy — as settlement size increases, the number of settlements decreases while the range and number of services increase. A hamlet may have nothing; a city has specialised services with a large sphere of influence.

• Range — how far people will travel for a service.
• Threshold population — the minimum number of people needed to support it.

A department store has a high threshold and a large range, so there are few of them; a newsagent has a low threshold and small range, so there are many.

Urban land-use model: CBD (accessible, high land values, tall buildings), inner city (old industry, terraced housing), suburbs (newer, lower density), rural–urban fringe.

Urbanisation in LICs is driven by rural–urban migration plus high natural increase among the young migrant population. Consequences: informal settlements, traffic congestion, pollution, and pressure on services. Responses include site-and-service schemes, self-help schemes, and improving rural areas to reduce the push.

Exam traps

• Omitting migration from population change.
• Saying birth rates fall in stage 2 — they fall in stage 3.
• Describing rather than explaining the DTM.
• Evaluating migration from only one country’s viewpoint.
• Confusing site with situation.
• Giving generic answers without named examples, figures or dates.

Self-test

1. Give the formula for population change in full.
2. Why does population grow fastest in stage 2 of the DTM?
3. Give the dependency ratio formula and what a high value means.
4. Give two benefits and two problems of emigration for the source country.
5. Distinguish range from threshold population.

Answers: 1. Natural increase (birth rate minus death rate) plus net migration. 2. The death rate falls rapidly due to improved medicine, sanitation and food supply, while the birth rate remains high because social attitudes change far more slowly — so the gap between them is at its widest. 3. (Under 15 + over 64) ÷ (15–64) × 100; a high value means a large non-working population supported by a small working population. 4. Benefits: remittances and reduced unemployment; problems: brain drain and separated families. 5. Range is how far people will travel to use a service; threshold population is the minimum number of people needed to make it viable.