Population: Distribution, Density, Growth and Composition
Population geography studies where people live, how dense they are, how fast numbers change, and what composition results. The exam tests definitions, measures, and interpretation of India and world patterns.
Distribution and density
- Distribution is uneven: plains, coasts and fertile valleys are crowded; deserts, high mountains and dense forests are sparse.
- Arithmetic density = total population / total area.
- Physiological density = population / arable land.
- Agricultural density = agricultural population / arable land.
Growth and composition
- Natural increase = births minus deaths; migration can add or subtract people.
- Demographic transition links falling death rates and later falling birth rates to phases of growth.
- Age–sex pyramid, dependency ratio, sex ratio, literacy and rural–urban composition describe structure.
Worked example
A district has 1,200,000 people and 4,000 km²: arithmetic density = 300 persons/km². If only 2,000 km² is arable, physiological density = 600 persons/km². The second figure reveals pressure on farmland that the first hides.
Traps
Arithmetic density says nothing about land quality; high density can occur in rich city-states. Distinguish growth rate from absolute increase. In India, sex ratio is females per 1,000 males, not the reverse. Do not treat a youthful pyramid as automatically a demographic dividend.