UPSC Mains 2026 GS1 Q6: model answer
Discuss the role of aeolian processes in desertification and land degradation.
What the question wants
Explain wind erosion, transport and deposition, and show how each worsens desertification, with Indian examples and remedies.
How to structure it
Intro: aeolian processes defined. Body: deflation, abrasion, deposition and their effects; Indian context. Conclusion: control measures.
- 1Deflation, abrasion, deposition and their effects
- 2Indian context
Model answer
Aeolian processes are the work of wind: erosion, transport and deposition of fine particles. Where vegetation is thin and soil dry, wind becomes the main agent of land degradation.
How they drive degradation
- Deflation blows away fertile topsoil and organic matter, leaving coarse, infertile ground and hollows.
- Abrasion by sand blasting damages crops and young plants.
- Deposition: moving dunes bury farmland, roads and canals; sand sheets spread the desert's edge.
- Dust storms carry nutrients away and affect health far from the source.
India: ISRO's Desertification Atlas puts close to a third of India's land under degradation; wind erosion dominates in western Rajasthan and parts of Gujarat. Overgrazing and ploughing marginal land expose soil to wind.
Control: shelterbelts and windbreaks, sand-dune stabilisation with native grasses (CAZRI's work in Jodhpur), strip cropping, and grazing control.
India's target of restoring 26 million hectares by 2030 depends on stopping wind erosion first.
Keywords, cases and data to drop in
deflation abrasion sand dunes shelterbelts CAZRI Desertification Atlas
Where most answers lose marks
- Writing only about water erosion
- No Indian example
Same theme in Prelims
Which of the following statements with regard to Green Hydrogen is/are correct ?
- 1. It is decarbonized hydrogen obtained from natural gas reforming combined with carbon capture and storage (CCS).
- 2. It is produced using electrolysis of water with electricity generated by renewable energy.
- 3. National Green Hydrogen Mission of India aims for abatement of nearly 50 MMT of annual greenhouse gas emissions by 2030.
Select the answer using the code given below :
Answer (b) & explanation
Statements 2 and 3 are correct (b). Statement 2 is right: green hydrogen comes from splitting water by electrolysis, using renewable power. Statement 3 is right: the National Green Hydrogen Mission (2023) targets 5 MMT of green hydrogen a year by 2030 and about 50 MMT of avoided CO₂-equivalent emissions each year. Statement 1 is wrong: hydrogen from natural gas with carbon capture is blue hydrogen. So options (a), (c) and (d) fail.
Notice the colours: grey hydrogen from gas without capture (most hydrogen today), brown from coal, and pink from nuclear power. The mission's SIGHT programme supports electrolyser making. Uses include fertilisers, refineries, steel and shipping fuel.
1 says "decarbonized", which sounds green. Gas with CCS is blue.
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Answer as per the official UPSC answer key.
Which of the following statements in relation to NIRANTAR (National Institute for Research and Application of Natural Resources to Transform, Adapt and Build Resilience), a platform of institutions under the Ministry of Environment, Forest and Climate Change, is/are correct ?
- 1. Ecosystem Survey and Analysis is a vertical under this platform, the lead institute of which is Botanical Survey of India, Kolkata.
- 2. Research and Management of Ecosystem Service is a vertical under this platform, the lead institute of which is Central Zoo Authority, New Delhi.
- 3. Capacity Development Support is a vertical under this platform, the lead institute of which is Indian Institute of Forest Management, Bhopal.
Select the answer using the code given below :
Answer (b) & explanation
Statements 1 and 3 are correct (b). NIRANTAR groups the Environment Ministry's institutes into verticals. Statement 1 is right: Ecosystem Survey and Analysis is led by the Botanical Survey of India, Kolkata, with bodies like the FSI and ZSI. Statement 3 is right: Capacity Development Support is led by the Indian Institute of Forest Management, Bhopal. Statement 2 is wrong: Research and Management of Ecosystem Service is led by ICFRE, Dehradun; the Central Zoo Authority is only a member. So options (a), (c) and (d) fail.
Notice the purpose: pooling institutes avoids duplicate work and links research to climate adaptation and resilience. Other Ministry bodies include the Wildlife Institute of India (Dehradun) and GBPNIHE for the Himalaya.
the Central Zoo Authority does sit in that vertical, but as a member, not the lead.
Answer as per the official UPSC answer key.
Consider the following statements :
- Statement I : Studies indicate that carbon dioxide emissions from cement industry account for more than 5% of global carbon emissions.
- Statement II : Silica-bearing clay is mixed with limestone while manufacturing cement.
- Statement III : Limestone is converted into lime during clinker production for cement manufacturing.
Which one of the following is correct in respect of the above statements?
Answer (b) & explanation
Both II and III are correct, but only III explains I (b). Statement I is right: cement gives about 7–8% of the world's CO₂. Statement II is right: silica-bearing clay is mixed with limestone to make cement, but that step releases no carbon. Statement III is right and is the reason: heating limestone (CaCO₃) in a kiln gives lime (CaO) and CO₂. This calcination step, plus the fuel burnt for the high heat, causes most of the emissions. So options (a), (c) and (d) fail.
Notice the fixes: blending in fly ash or slag, LC3 (limestone calcined clay cement), and carbon capture. India is the world's second-largest cement producer after China, and its carbon market covers cement.
Answer as per the official UPSC answer key.
Fresh examples from current affairs
Desertification and Drought Day workshop
Land degradation is linked to farm practices.
UPSC angle: Prelims: AFRI.
17 Jun 2025
Aravalli landscape restoration plan
Aravallis check desert spread.
UPSC angle: Prelims: Aravalli.
21 May 2025Question text as printed in the official UPSC question paper: https://www.upsc.gov.in/sites/default/files/QP-CSM-26-010926-GENERAL%20STUDIES%20PAPER%20-%20I.pdf The model answer is original Battle IAS work; use it to learn structure, not to memorise.