Population and Urbanization
Overview
Population and Urbanization is a consistently tested topic in TNPSC Group II/IIA, appearing in both General Studies and Tamil Nadu-specific sections. Questions typically focus on Census 2011 data, state-wise rankings, density calculations, and urban growth patterns. Since Census 2021 was postponed, Census 2011 remains the authoritative source for all official statistics.
This topic connects geography with economics and current affairs. Understanding population dynamics helps explain India's demographic dividend, migration patterns driving urban growth, and the challenges of providing services to both rural and urban populations. For TNPSC, special attention to Tamil Nadu's demographic indicators is essential—the state often features as a comparison point or direct question subject.
Mastery requires memorizing key numbers (total population, density, sex ratio, literacy) for India and Tamil Nadu, understanding concepts like decadal growth and urbanization rate, and recognizing patterns in migration and settlement distribution.
Key Concepts
- Census of India: Conducted every 10 years since 1872; Census 2011 was the 15th census; first complete census was 1881; Registrar General and Census Commissioner of India conducts it under the Ministry of Home Affairs.
- Population Density: Number of persons per square kilometre; calculated as Total Population ÷ Total Area; reflects pressure on land and resource distribution.
- Sex Ratio: Number of females per 1000 males; India's overall sex ratio (2011) is 943; child sex ratio (0-6 years) is a critical indicator of gender discrimination.
- Decadal Growth Rate: Percentage increase in population over a 10-year period; India's rate declined from 21.5% (1991-2001) to 17.7% (2001-2011), indicating demographic transition.
- Urbanization: Process of population shift from rural to urban areas; measured as percentage of total population living in urban areas; driven by push factors (rural poverty) and pull factors (urban employment).
- Migration: Movement of people from one place to another; classified as internal (within country) or international; and as rural-rural, rural-urban, urban-rural, or urban-urban streams.
- Demographic Dividend: Economic benefit from a large working-age population relative to dependents; India's window estimated at 2005-2055.
Formulas / Key Facts
Census 2011 — India Key Data:
| Indicator | Value |
|---|---|
| Total Population | 121.09 crore (1.21 billion) |
| Males | 62.32 crore |
| Females | 58.77 crore |
| Decadal Growth (2001-11) | 17.7% |
| Population Density | 382 persons/sq km |
| Sex Ratio | 943 females per 1000 males |
| Child Sex Ratio (0-6) | 919 |
| Literacy Rate | 74.04% (Male: 82.14%, Female: 65.46%) |
| Urban Population | 31.16% |
| Rural Population | 68.84% |
Census 2011 — Tamil Nadu Key Data:
| Indicator | Value |
|---|---|
| Total Population | 7.21 crore (6th most populous state) |
| Population Density | 555 persons/sq km |
| Sex Ratio | 996 (3rd highest among major states) |
| Literacy Rate | 80.33% (higher than national average) |
| Urban Population | 48.4% (one of the most urbanized states) |
| Decadal Growth | 15.6% (lower than national average) |
State Rankings (Census 2011):
- Most populous: Uttar Pradesh (19.98 crore)
- Least populous (state): Sikkim (6.1 lakh)
- Highest density: Bihar (1106/sq km)
- Lowest density: Arunachal Pradesh (17/sq km)
- Highest sex ratio: Kerala (1084)
- Highest literacy: Kerala (93.91%)
Formulas:
- Population Density = Total Population ÷ Area (in sq km)
- Sex Ratio = (Female Population ÷ Male Population) × 1000
- Decadal Growth Rate = [(Population in current census − Population in previous census) ÷ Population in previous census] × 100
- Urbanization Rate = (Urban Population ÷ Total Population) × 100
Worked Examples
Example 1: Calculating Population Density A state has a population of 3.5 crore and an area of 50,000 sq km. Find its population density.
Step 1: Convert population = 3.5 crore = 3,50,00,000 Step 2: Apply formula = 3,50,00,000 ÷ 50,000 = 700 persons/sq km
Example 2: Finding Sex Ratio In a district, male population is 5,00,000 and female population is 4,80,000. Calculate the sex ratio.
Step 1: Apply formula = (4,80,000 ÷ 5,00,000) × 1000 Step 2: = 0.96 × 1000 = 960 females per 1000 males
Example 3: Decadal Growth Rate A city's population was 20 lakh in 2001 and 25 lakh in 2011. Find the decadal growth rate.
Step 1: Increase = 25 − 20 = 5 lakh Step 2: Growth rate = (5 ÷ 20) × 100 = 25%
Common Mistakes
- Confusing sex ratio definitions: Indian sex ratio = females per 1000 males; Western/UN definition = males per 100 females. TNPSC uses the Indian definition. Always check which is asked.
- Mixing up density rankings: Students often confuse "most populous" with "most dense." UP is most populous but Bihar has highest density. Remember: density = people per area, not total people.
- Using outdated figures: Some sources cite Census 2001 or projected figures. Stick strictly to Census 2011 official data unless the question explicitly mentions projections.
- Ignoring Tamil Nadu specifics: TNPSC frequently tests TN's superior indicators (higher sex ratio, literacy, urbanization than national average). Don't assume national figures apply to TN.
- Misunderstanding urbanization percentage: 31.16% urban does not mean "most people live in cities." India remains predominantly rural. Urban growth rate being higher than rural doesn't change this yet.
Quick Reference
- India's population (2011): 121 crore; 17.7% decadal growth; density 382/sq km
- Tamil Nadu: 7.21 crore; sex ratio 996; literacy 80.33%; 48.4% urban
- Kerala leads in sex ratio (1084) and literacy (93.91%)
- Bihar has highest density (1106/sq km); Arunachal lowest (17/sq km)
- Child sex ratio (919) is worse than overall sex ratio (943) — indicates female foeticide concern
- India's urban population crossed 30% for the first time in Census 2011