Revision summary
Deflation and abrasion are the two wind-erosion tools. Hollows, ventifacts, mushroom rocks, yardangs, and desert pavement are erosional forms. Barchans, seifs, transverse, parabolic, and star dunes are depositional. Loess is wind-laid silt in sheets. The Thar shows both erosion hollows and a full dune suite.
Model answer
Introduction
Wind works where vegetation is thin, sediment is dry and loose, and a pressure gradient drives sand and dust—above all in hot deserts and rain-shadow plains. Erosion carves rock and sweeps fines; deposition builds dunes and loess sheets.
Body
Wind erosion landforms
- Deflation lowers a surface by lifting loose silt and sand; blowouts and deflation hollows (some later salt pans or playas) mark the Thar and other arid basins.
- Abrasion (sandblast) polishes and facets pebbles into ventifacts and cuts mushroom rocks (goura) and zeugen where a harder cap sits over softer rock.
- Yardangs are streamlined ridges parallel to the dominant wind; desert pavement (reg, gibber) is the lag of coarse stones left after fines blow away.
- Inselbergs and residual hills in arid India are often joint-controlled granite or sandstone leftovers after long deflation and weathering, not wind alone.
Wind deposition landforms
- Sand dunes are the main depositional suite: barchans (crescentic, horns downwind) on open plains with limited sand; transverse ridges where sand is more abundant; seifs or longitudinal dunes parallel to the wind; parabolic dunes with horns upwind, often fixed by vegetation.
- Star dunes form at wind-direction junctions; climbing and falling dunes drape escarpments.
- Loess is wind-laid silt in thick blankets (classic China and Europe; thinner dusty sheets on India’s desert margins).
- Ripples on dune faces, and sand sheets without slip faces, complete the depositional family.
Indian illustration
- The Thar in western Rajasthan and Gujarat shows barchans, parabolic dunes, and deflation hollows; Rann margins add salt-deflation flats.
- Process is dry-season monsoon-wind and western disturbances moving sand, then a brief wet season that may fix parabolic forms with scrub.
Flow diagram
flowchart TD W[Wind dry loose sand] --> E[Deflation abrasion] E --> F[Hollows ventifacts yardangs] W --> D[Dunes loess] D --> T[Thar barchan parabolic]
Conclusion
Wind erosion produces deflation hollows, ventifacts, mushroom rocks, yardangs, and lag pavements; wind deposition produces dunes of several plans and loess. The Thar is India’s working museum of both suites.
Quick related
Students also ask
-
Write a systematic essay on the ocean currents of the northern Atlantic Ocean with their reasons of origin.
Next question in the 2019 paper (Q19). View answer →
-
Do all deserts have barchans?
Barchans need limited sand and a fairly steady wind. Sand-rich ergs build transverse and seif fields instead.
-
Is a mushroom rock only a wind form?
Wind abrasion undercuts the base, but salt weathering and a hard cap rock usually help. Wind is the main shaper, not the only process.
PYQ trend
When UPSC asked this
Related PYQs from other years, newest first. Open a question to read it.
-
2023 · Q20 · UPGS1 · 12 marks
Discuss India’s mineral development policy. -
2020 · Q1 · UPGS1 · 8 marks
Write a note on the town planning of Harappan civilization period. -
2020 · Q3 · UPGS1 · 8 marks
Write a critical note on the Foreign Policy of Mussolini, the leader of Fascism in Italy. -
2020 · Q11 · UPGS1 · 12 marks
Critically examine the impacts of West on the field of Indian education. -
2019 · Q2 · UPGS1 · 8 marks
Describe the role of Iron mineral in socio-economic development of human beings during 600-300 B.C. -
2018 · Q9 · UPGS1 · 8 marks
Write a note on Global Warming. -
2018 · Q10 · UPGS1 · 8 marks
Give a geographical account of Bundelkhand as a cultural region. -
2018 · Q18 · UPGS1 · 12 marks
What is an air mass? Describe its chief characteristics.
More from this paper
Q1 · UPSC Mains 2019 · UPGS1 · 8 marks
Describe the cultural significance of 'Prayagraj' in ancient India.
Indian culture
Prayaga’s ancient fame is the Ganga–Yamuna–Sarasvati sangam treated as Tirtharaja. Epic memory places Bharadvaja’s ashrama and Rama’s halt at the confluence. Xuanzang records a great gathering, so the tirtha was a public fair. The Prayaga pillar joins Ashokan writing to Samudragupta’s Harishena prasasti. Kaushambi and middle-Ganga Buddhist–Jaina circuits sit next to the Hindu tirtha.
Q2 · UPSC Mains 2019 · UPGS1 · 8 marks
Describe the role of Iron mineral in socio-economic development of human beings during 600-300 B.C.
History of Indian Culture
Iron axes and ploughshares opened Ganga-plain forest and raised agrarian surplus about 600–300 BCE. That surplus fed towns, crafts, and Buddhist–Jaina households. Magadha’s iron hinterland helped its armies among the mahajanapadas. NBPW, punch-marked coins, and second urbanisation are contemporary with this ferrous kit. Iron changed the material budget of states; it did not by itself invent kingship.
Q3 · UPSC Mains 2019 · UPGS1 · 8 marks
Critically examine the effects of British Industrial Revolution on India's economic life.
World history
Post-1813 trade rules and Lancashire mills displaced Indian handloom exports. Nationalists named this deindustrialisation and a drain of wealth. Agriculture was pushed into indigo, opium, cotton, and jute, with famine risk. Railways and a few Bombay–Ahmedabad mills were a thin modern overlay. The ledger is infrastructure without a balanced industrial revolution for India.
Toppers' copies
Toppers' copies for this question will be uploaded soon.