Natural Resources and Their Conservation
Exam focus
Classification of resources, their limits, and conservation methods with Indian and West Bengal examples.
Core rules
- Renewable resources regenerate on a human timescale (solar, wind, forest biomass, groundwater under recharge); non-renewable resources are exhaustible (coal, petroleum, minerals).
- Renewable does not mean unlimited: groundwater can be mined faster than recharge, and forests can degrade.
- Resource conservation means wise use; preservation means non-use. Sustainable use keeps the resource base for future generations.
- Soil conservation: contour ploughing, terracing, check dams, strip cropping, afforestation and organic matter addition.
- Water conservation: rainwater harvesting, watershed management, drip irrigation and recharge pits.
- Energy conservation: efficient appliances, LEDs, public transport, solar water heaters and biogas.
Worked example
A school roof is 200 m². Annual rainfall is 1,200 mm (1.2 m) and the runoff coefficient is 0.8. Potential harvest = area × rainfall × coefficient = 200 × 1.2 × 0.8 = 192 m³ = 1,92,000 litres per year. Reasoning: 1 m³ = 1,000 litres; the coefficient accounts for evaporation, splashing and first-flush losses.
Traps
- Calling groundwater non-renewable everywhere; it is renewable but often mined faster than recharge.
- Confusing conservation with a complete ban.
- Forgetting that dams and canals can cause waterlogging and salinisation.
- Mixing renewable energy with clean energy: large hydropower is renewable but has ecological costs.