The World Population: Distribution, Density and Growth
Class 12 · Geography
4 ideas in Class 12 Geography, explained in plain words, with games and quizzes to practise.
Patterns of Distribution and Density
Part of: Where People Live and Why
Distribution is the way people are spaced over the earth, while density is the number of people on each unit of land. The spread is lopsided: about 90 per cent of people live on about 10 per cent of the land. A valley with 240,000 people on 800 sq km, for instance, holds 300 persons on each sq km on average.
Why it matters. Crowded and empty lands need very different plans for schools, roads, water and care. Density flags pressure on land, so you can judge which places strain their means and which still have room.
Formulas
- Density = population / area
- Density is read as persons per sq km
Key words
- population distribution
- : The way people are spaced over the surface of the earth.
- population density
- : The number of people living on each unit of land area.
- dense
- : Holding many people on little land, like river plains.
- sparse
- : Holding few people on wide land, like icy deserts.
Try it in two minutes
- Shade two boxes on paper: pack one with dots and leave the other nearly blank.
- Ask which box would need more taps, buses and classrooms.
- Share the dots by the boxes and work out dots per box for each.
Try at home. Find the people and area of your district with a parent and work out its density together.
Why People Cluster in Some Places
Part of: Where People Live and Why
People gather where life is easy and work pays. Fresh water draws crowds to river valleys; flat plains suit crops, roads and mills while steep heights block them; mild climates and rich soils feed more mouths. Mines pull workers, cities pull seekers with jobs, schools and care, and factories pull whole crowds of helpers. Holy towns draw pilgrims, unrest drives people off, and state grants can pull settlers into thin lands.
Why it matters. These pulls explain the map you see: crowded plains, busy ports and empty wastes. Once you can name the pull behind a crowd, you can also guess where the next roads, schools and clinics will be needed.
Key words
- river valley pull
- : Crowding near rivers that give water, crops and boat routes.
- urbanisation pull
- : Drift to cities for jobs, schools, care and city life.
- industrial belt
- : Cluster of mills that draws workers and service providers.
- social unrest push
- : Turmoil that drives people away from a troubled place.
- settlement incentive
- : State grant that lures settlers into thin or empty lands.
Try it in two minutes
- Name the nearest crowded spot and the nearest lonely spot you both know.
- Ask what water, work or road the crowded spot has that the lonely one lacks.
- Ask what single new pull, like a mill or a rail halt, could wake the lonely spot.
Try at home. List three crowded places in your state and write the main pull behind each one.
Growth, Births and Deaths
Part of: How Numbers Rise and Shift
Growth is the change in headcount between two dates, and the growth rate is that change in per cent. Births minus deaths gives natural growth; adding newcomers and subtracting leavers gives actual growth. The birth rate counts live births per thousand people in a year, and the death rate counts deaths per thousand. When births top deaths, or arrivals top departures, numbers rise.
Why it matters. Leaders read these rates to plan schools, jobs and clinics. If you can work out a rate and say why it moved, you can judge whether a place truly booms or merely counts better.
Formulas
- Natural growth = births - deaths
- Actual growth = births - deaths + in-migration - out-migration
- CBR = (births x 1000) / mid-year population
- CDR = (deaths x 1000) / mid-year population
Key words
- growth of population
- : Change in headcount of a place between two points of time.
- natural growth
- : Births minus deaths, leaving out all migration.
- actual growth
- : Natural growth plus arrivals minus departures.
- crude birth rate
- : Live births in a year per thousand people.
- crude death rate
- : Deaths in a year per thousand people.
Try it in two minutes
- Take your class strength this year and last year and find the change.
- Split the change into new joiners, leavers, and the rest.
- Ask which part raised numbers most and what the school should plan next.
Try at home. Ask a parent for your town's births last year and its people, then work out its birth rate per thousand.
Migration and Demographic Transition
Part of: How Numbers Rise and Shift
Migration shifts people from a place of origin to a place of destination; the same mover is an emigrant for the old home and an immigrant for the new one. Joblessness, unrest, calamity and harsh weather push people out, while wages, peace, schools and safety pull them in. The transition model then reads whole societies: stage one pairs high births with high deaths for slow rise; stage two keeps births high while deaths fall for a fast rise; stage three pairs low births with low deaths for stable numbers, city life and small families.
Why it matters. Moves and stages explain booms, slums and ageing lands. If you can spot the push, the pull and the stage, you can read why some regions strain and others grey, and what family planning can and cannot fix.
Key words
- place of origin
- : The home a mover leaves, which loses people.
- place of destination
- : The new home a mover reaches, which gains people.
- push factors
- : Troubles like joblessness and unrest that drive movers out.
- pull factors
- : Hopes like wages and peace that draw movers in.
- demographic transition
- : Shift of a society from high births and deaths to low ones.
Try it in two minutes
- Ask if anyone in the family moved home, and name the old and new places.
- Sort their reasons into pushes from the old place and pulls of the new one.
- Ask which transition stage your country sits in and what signs prove it.
Try at home. Interview a neighbour who moved, and list two pushes and two pulls behind the move.
What your child will practise
- Growth, Births and Deaths: Space Quick Fire (Quick Fire)
- Migration and Demographic Transition: Candy Puzzle (Clue Puzzle)
- Migration and Demographic Transition: Ocean Quick Fire (Quick Fire)
- Patterns of Distribution and Density: Jungle Quick Fire (Quick Fire)
- Why People Cluster in Some Places: Space Puzzle (Clue Puzzle)
- Quiz: Growth, Births and Deaths (8 questions)
- Quiz: Migration and Demographic Transition (8 questions)
- Quiz: Patterns of Distribution and Density (8 questions)
- Quiz: Why People Cluster in Some Places (8 questions)