Natural Resources: Land, Soil, Water, Energy and Forests
What this domain tests
Natural Resources: Land, Soil, Water, Energy and Forests tests resource classification (renewable, non-renewable, potentially renewable), causes of land degradation, soil erosion and conservation, water harvesting, energy alternatives and forest resources, with Rajasthan examples. Questions often ask you to distinguish a cause from a consequence and to calculate a harvesting or efficiency figure.
Core rules and concepts
- Land degradation in Rajasthan is driven by wind erosion, overgrazing, saline and alkaline soils, waterlogging in canal commands and mining.
- Soil conservation: contour bunding, terracing, shelterbelts, check dams, crop rotation, mulching, reclamation of saline soils by gypsum and drainage.
- Water harvesting: roof-top harvesting, tanka, khadin, johad, baori, watershed treatment; the Indira Gandhi Canal is a major water-transfer and waterlogging case.
- Energy: solar (Bhadla, Jodhpur), wind (Jaisalmer), biogas; distinguish conventional and non-conventional sources.
- Forests: Aravalli ranges, Ranthambore, Kumbhalgarh, Sariska; functions include watershed protection, biodiversity and livelihood.
- Resources are not merely physical stocks; technology, institutions and access determine whether a stock is a resource.
Worked example
A roof of 100 m² receives 300 mm of rain in a season; runoff coefficient 0.8. Volume = area × rainfall × coefficient = 100 × 0.300 × 0.8 = 24 m³ = 24,000 litres. Reasoning: 1 mm of rain on 1 m² gives 1 litre, so 300 mm gives 300 L m⁻²; multiply by area and coefficient. Losses (first flush, evaporation) reduce the usable amount.
Traps
Mixing units (mm with m² without converting); calling soil a renewable resource without qualification; confusing waterlogging with drought; naming a technology without its purpose. In Rajasthan, khadin is a runoff-farming system, not a dam type.