World population distribution and migration for QCE Geography Unit 4
“Explain changes in world population distribution, including internal and international migration since the 1700s and projected 21st century change”
World population distribution has shifted since the 1700s through the demographic transition (falling death then birth rates), industrialisation and large-scale migration. Internal migration (rural to urban) concentrated people in cities; international migration redistributed people between continents, including colonial settlement, post-war movements and modern labour and refugee flows. Population is now concentrated in Asia, with growth shifting to Africa. Twenty-first century projections show ageing in the global north and continued growth in sub-Saharan Africa. Strong answers use the demographic transition model and named flows.
What this dot point is asking
QCAA wants you to explain how the distribution of the world's population has changed since the 1700s and why, including the role of migration. Distribution is where people live; density is how many per unit area. "Explain" means showing the processes (demographic transition, industrialisation, migration) that shifted the pattern. You should cover both internal migration (within a country) and international migration (between countries), and finish with projected change in the twenty-first century. Strong answers use the demographic transition model, named migration flows, and real data.
The answer
Distribution then and now
In the 1700s the global population was about 700 million to 1 billion, concentrated in agrarian river valleys and fertile regions of Asia and Europe. By the 2020s it exceeded 8 billion, heavily concentrated in Asia (China and India together around a third of humanity), with the fastest growth now in sub-Saharan Africa. The pattern is uneven: dense in fertile lowlands, river basins and coasts; sparse in deserts, high mountains, dense rainforest and polar regions. Physical factors (climate, water, soil, relief) set the broad pattern; human factors (economy, history, policy, migration) shape the detail.
The demographic transition
The demographic transition model explains how populations move from high birth and death rates to low ones through stages:
- Stage 1: high birth and death rates, slow growth (pre-industrial).
- Stage 2: death rates fall (sanitation, medicine, food) while birth rates stay high, causing rapid growth. Much of the global south has passed through or sits in this stage.
- Stage 3: birth rates fall as societies urbanise and women's education rises.
- Stage 4: low birth and death rates, stable population (most high-income countries).
- Stage 5 (debated): birth rates below replacement, leading to decline and ageing (Japan, parts of Europe).
This transition, beginning with industrialisation in Europe, drove first European growth and then the much larger growth of Asia and Africa, reshaping global distribution.
Internal migration
Internal migration redistributes people within a country, dominated historically by rural-to-urban movement as industrial and service jobs concentrated in cities. China's reform-era movement of hundreds of millions from rural interior to coastal industrial cities is the largest internal migration in history. In Australia, internal migration includes the long drift from rural and inland areas to coastal cities, plus more recent "sea change" and "tree change" movements to regional coasts and towns, accelerated by remote work.
International migration
International migration redistributes people between countries, driven by push factors (poverty, conflict, persecution, disaster) and pull factors (jobs, safety, family, opportunity). Major historical and modern flows include:
- Colonial-era European settlement of the Americas and Australasia from the 1700s and 1800s.
- The post-Second World War movement to Australia, including European migration that built the modern multicultural nation.
- Modern labour migration to the Gulf states and to Europe and North America.
- Refugee flows from conflict zones such as Syria, Afghanistan and Ukraine.
Migration is selective: it often draws working-age adults, ageing the source country and youthening the destination.
Twenty-first century projections
Projections suggest world population peaking and then plateauing or declining later this century as fertility falls almost everywhere. The growth that remains is concentrated in sub-Saharan Africa, while East Asia and Europe age and shrink. Australia's population is projected to keep growing, but mainly through migration rather than natural increase, because the national fertility rate is below replacement.
By the 2020s, more than half the world's people lived in urban areas, a threshold crossed around 2008. The shift from a rural to a predominantly urban species is the single largest distributional change of the modern era and is driven mainly by internal rural-to-urban migration plus urban natural increase.
- Confusing distribution with density
- Distribution is the pattern of where people live; density is the count per unit area. Use the right term.
- Treating migration as one type
- Internal (within a country) and international (between countries) migration are distinct and both are required.
- Forgetting the projection
- The dot point explicitly asks for projected twenty-first century change. End with peaking population, ageing north and African growth.
- Listing push/pull factors with no flow
- Name a real flow (post-war migration to Australia, China's rural-urban movement) and attach the factors to it.
Examples in context
Example 1. China's rural-to-urban migration. Reform-era industrialisation pulled hundreds of millions from the rural interior to coastal cities, the largest internal migration in history and a major redistribution.
Example 2. Post-war migration to Australia. European and later Asian and global migration reshaped Australia's distribution and built a multicultural urban society concentrated in coastal capitals.
Example 3. Sub-Saharan African growth. Still early in the demographic transition, the region holds almost all projected twenty-first century population growth, shifting the global centre of population southward.
Exam-style questions
Questions in the style of QCAA exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
Practice5 marksDescribe the population distribution shown in the map [in the exam, a map of population by latitude: most people live between about 20 and 40 degrees N, numbers thin toward the poles and across the equatorial belt, and the Northern Hemisphere holds far more people than the Southern] and suggest two reasons for the pattern - one for a zone of high population density and one for a zone of low population density.Show worked answer →
A full 5-mark response describes the distribution from the latitude map and then justifies it with two contrasting reasons.
Describe the pattern (use evidence). The map shows population is most dense in the mid-northern latitudes, roughly 20 to 40 degrees N, and thins markedly toward the poles and across the equatorial belt. The Northern Hemisphere holds far more people than the Southern Hemisphere, where the densest band sits around 20 to 40 degrees S but covers much less land.
Reason for a high-density zone. The mid-northern latitudes contain large fertile river basins and temperate to subtropical climates (East and South Asia, Europe, eastern North America) that support intensive agriculture and large cities.
Reason for a low-density zone. Sparse zones reflect physical limits: the equatorial tropics include dense rainforest and poor leached soils, while high latitudes are cold with short growing seasons, so both deter dense settlement.
Markers reward an accurate described pattern, two clearly located reasons (one high, one low), and map evidence.
Practice8 marksAnalyse the graph to describe trends in international migration over time. For two different regions, suggest an explanation for the trend and make an inference about an impact for each of these regions.Show worked answer →
This 8-mark question splits into a 6-mark analysis band and a 2-mark impact band.
Describe the trends with data (up to 6 marks). Net international migration varied by region across the four decades. Europe and Northern America recorded continual net gains every decade (about 15, 25, 35 then 30 million). Sub-Saharan Africa and Central and Southern Asia recorded growing net losses (rising toward about 15 million). Northern Africa and Western Asia shifted from a net loss in 1991 to 2000 to net gains in the next two decades.
Explain two trends. The sustained gain in Europe and Northern America reflects economic migration drawn by jobs and higher wages. The shift to gains in Northern Africa and Western Asia reflects refugee and labour flows into oil-rich Gulf states.
Infer an impact for each region (2 marks). A receiving region gains a larger, often younger workforce that supports economic growth; a sending region of net loss can suffer a brain drain and labour shortages.
Use precise figures from the graph for the top band.
Practice4 marksUse evidence from the table to identify the type of migration to Argentina, providing examples to support your response. [Table extract: migrants in Argentina by country of origin, with GDP per capita (USD): Paraguay 679 044 (about 5406), Peru 470 713 (about 6227), Bolivia 419 048 (about 3035); Argentina's GDP per capita is about 12 790.] What is an implication of this type of migration?Show worked answer →
This 4-mark part rewards identifying the migration type, supporting it with table evidence, and stating an implication.
Identify the type. Migration to Argentina is dominantly voluntary international economic migration from neighbouring countries (regional South to South migration).
Support with examples from the table. The largest flows come from lower-income neighbours: Paraguay (679 044, GDP per capita about 5406 USD), Bolivia (419 048, about 3035 USD) and Peru (470 713, about 6227 USD), all moving to higher-income Argentina (about 12 790 USD). Migrants move from lower to higher GDP per capita, confirming an economic pull.
State an implication. This inflow enlarges Argentina's labour force and can fill low-wage jobs, but it may also strain housing and services in destination cities and create dependence on remittances in the origin countries.
Markers reward the correct type, at least two supporting figures, and a plausible implication.