Population Geography: Measuring Distribution, Growth and Composition
Population Geography examines how people are distributed, how populations change, and how composition differs by age, sex, literacy, occupation and migration. The HSC paper tests definitions, measurement, interpretation of Indian and Maharashtra data, and policy reasoning rather than memorised lists alone.
Core measures
- Density = total population ÷ area, in persons per km². Physiological density uses cultivated area; agricultural density uses agricultural population per cultivated area.
- In the Indian census, sex ratio = females per 1,000 males, not males per female.
- Natural increase = births − deaths. Net migration = in-migration − out-migration. Actual growth includes both.
- Decadal growth rate = (P2 − P1) ÷ P1 × 100.
- Literacy rate is calculated for the population aged 7 and above.
Growth and migration
Demographic transition moves from high birth and death rates to low birth and death rates through a phase of rapid growth. Maharashtra's Census 2011 figures are useful anchors: population about 11.24 crore, density 365 persons/km², sex ratio 929, literacy 82.3% and urban share 45.2%. Pull factors draw migrants to Mumbai and Pune; push factors include drought risk in parts of Marathwada and Vidarbha.
Worked example
A district has 1,800,000 people and an area of 6,000 km². Density = 1,800,000 ÷ 6,000 = 300 persons/km². Births are 36,000 and deaths 12,000, so natural increase = 24,000. Net migration is +3,000, so total increase = 27,000. Growth rate = 27,000 ÷ 1,800,000 × 100 = 1.5%. Crude birth rate = 36,000 ÷ 1,800,000 × 1,000 = 20 per 1,000; crude death rate = 6.7; rate of natural increase = 13.3 per 1,000. The reasoning is that migration lifts growth above natural increase, and rates are expressed per 1,000 population.
Traps
Do not confuse density with physiological density; do not invert the sex ratio; do not treat natural increase as total growth; do not use total population as the literacy denominator.