---
title: "Erosional feature of running water and wind"
subject: "Engineering Geology I"
chapter: 6
key: "semester_3/engineering_geology_i:erosional-feature-of-running-water"
source: https://www.bctengineer.com/q/semester_3/engineering_geology_i/erosional-feature-of-running-water
site: BCT Engineering
---

# Erosional feature of running water and wind

Engineering Geology I · Chapter 6: Physical Geology

- Asked in: 2079 Bhadra, 4 marks
- Video: [Erosional Landforms created by Running Water - landforms and Their Evolution | Class 11 Geography](https://www.youtube.com/watch?v=Yb6YoU-43U8) — Smart Tute
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/engineering_geology_i/erosional-feature-of-running-water
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-6

## Question

Describe an erosional feature developed by running water and wind.

## Short answer

Running water creates V-shaped valleys, gorges, waterfalls, potholes, meanders, and ox-bow lakes through vertical and lateral erosion. Wind erosion forms deflation hollows, mushroom rocks, yardangs, ventifacts, and zeugen by deflation and abrasion.

## Answer

#### Running water
**Erosional work** of a river is done by hydraulic action, abrasion, attrition and solution. Features:

- **V-shaped valley:** formed by vertical (downward) cutting in the youth stage, in the hills.
- **Gorge and canyon:** deep, narrow valley in hard rock, e.g. the Kali Gandaki gorge.
- **Waterfall and rapids:** form where hard rock lies over soft rock; a plunge pool forms at the base.
- **Potholes:** circular holes drilled in the bed by swirling pebbles.
- **River terraces:** step-like old floodplain levels left after the river cuts down again.
- **Meanders and ox-bow lakes:** formed by lateral (side) cutting in the old stage.
- **Interlocking spurs:** ridges of the valley sides that project alternately into the winding valley of a young river.

#### Wind
- **Deflation hollows (blowouts):** wind lifts loose fine particles and lowers the ground, e.g. the Qattara depression.
- **Mushroom (pedestal) rocks:** wind-blown sand abrades the base of a rock more than its top.
- **Yardangs:** streamlined ridges of rock parallel to the wind.
- **Ventifacts:** pebbles with polished, flat faces cut by sand blast.
- **Zeugen:** tabular ridges of hard rock over softer layers.
- **Desert pavement:** gravel left after fine particles are blown away.
- **Inselbergs:** isolated residual hills.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. A gorge forms in:
   A. Soft soil only
   B. Hard rock as a deep, narrow valley
   C. Glacial valley
   D. Desert
   Answer: B. E.g. Kali Gandaki gorge. (Key point: Gorge)

2. River terraces are:
   A. Fan deposits
   B. Wind ridges
   C. Step-like old floodplain levels left after the river cuts down
   D. Cave deposits
   Answer: C. They remain after downcutting. (Key point: Terraces)

3. How do mushroom rocks form?
   A. Frost shatters the top
   B. Rivers undercut them
   C. Glaciers pluck them
   D. Sand abrades the base more than the top
   Answer: D. Wind-blown sand is concentrated near the ground. (Key point: Mushroom rock)

4. Deflation hollows form when:
   A. Wind lifts loose fine particles and lowers the ground
   B. Rivers deposit
   C. Ice melts
   D. Sand piles up
   Answer: A. E.g. Qattara depression. (Key point: Deflation)

5. Ventifacts are:
   A. Streamlined ridges
   B. Pebbles with polished flat faces cut by sand blast
   C. Isolated hills
   D. Gravel layers
   Answer: B. Yardangs are the streamlined ridges. (Key point: Ventifacts)

## Related in Engineering Geology I

- [Erosional features of underground water](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aerosional-features-of-underground-water) — Engineering Geology I, chapter 6
- [Geological work of running water and its landforms](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Ageological-work-of-running-water) — Engineering Geology I, chapter 6, asked 5×
- [Erosional features of glacier and underground water](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aerosional-features-of-glacier-and) — Engineering Geology I, chapter 6
- [Geological agent and features of running water](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Ageological-agent-and-features-of) — Engineering Geology I, chapter 6
- [Geological work of wind and its landforms](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Ageological-work-of-wind-and) — Engineering Geology I, chapter 6, asked 6×

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