UPSC Prelims 2001 Q8: Geography – Physical Geography & Geomorphology
Identify the correct order of the processes of soil erosion from the following:
- (a) Splash erosion, Sheet erosion, Rill erosion, Gully erosion
- (b) Sheet erosion, Splash erosion, Gully erosion, Rill erosion
- (c) Rill erosion, Gully erosion, Sheet erosion, Splash erosion
- (d) Gully erosion, Rill erosion, Sheet erosion, Splash erosion
Answer: (a) Splash erosion, Sheet erosion, Rill erosion, Gully erosion
Explanation
Correct order of the processes of soil erosion
| Stage | Process |
|---|---|
| 1. Splash erosion | Raindrops strike bare soil and detach particles |
| 2. Sheet erosion | A thin film of water removes a uniform layer of topsoil |
| 3. Rill erosion | Water gathers into small channels a few centimetres deep |
| 4. Gully erosion | Rills deepen into large gullies and ravines (as in the Chambal) |
Soil erosion by water goes from the smallest scale to the largest: raindrop splash first, then sheet wash, then small rills, and finally deep gullies.
Answer: (a) Splash erosion, Sheet erosion, Rill erosion, Gully erosion.
Why each option is right or wrong
- (a) CORRECT. Splash, sheet, rill, gully is the sequence of soil erosion by water.
- (b) Incorrect. Splash comes before sheet erosion, and rills come before gullies.
- (c) Incorrect. This puts the later rill and gully stages first.
- (d) Incorrect. This is the reverse order.
Key point
Gully erosion makes badlands and ravines — the Chambal ravines are the classic Indian example.
Remember
Splash → Sheet → Rill → Gully.
Common mistakes
- Reversing the order and starting with the most visible stage, gullies.
- Putting sheet erosion before splash erosion.
- Mixing rill (small channel) with gully (large channel).
Exam tip
Order the erosion stages by size of the channel: drop, sheet, rill, gully.
Sources
- NCERT Class XI — India: Physical Environment, chapter 'Soils' (soil erosion)
- D. R. Khullar — India: A Comprehensive Geography, chapter on soils and soil erosion