Contour bunding is a method of soil conservation used in
Contents9
- Adesert margins, liable to strong wind action
- Blow flat plains, close to stream courses, liable to flooding
- Cscrublands, liable to spread of weed growth
- DNone of the above
Show answer
Answer: (D) None of the above
Contour bunding (or contour bundling) involves placing lines of stones or earth embankments along the natural rises (contours) of a sloping landscape.
It is used on HILLY or SLOPING terrain to:
- (1) Capture and hold rainfall before it becomes runoff,
- (2) Slow down the speed of water flowing downhill, and
- (3) Reduce soil erosion and retard overall water loss.
Now check the given options:
(a) Desert margins with strong wind action — contour bunding is for WATER erosion on slopes, not wind erosion in flat deserts.
(b) Low flat plains near streams — contour bunding is for slopes, not flat flood-prone plains.
(c) Scrublands with weed growth — contour bunding has nothing to do with weed control.
Since none of the three options describes sloping land, the correct answer is (d) — None of the above.
Contour bunding works specifically on sloping terrain to reduce water erosion by following natural land contours, not on flat lands or for wind erosion.
UPSC designed this as a trap question where all three given options describe flat or irrelevant terrains, testing whether students know contour bunding requires slopes.
Contour Bunding
Geography contour bunding
Contour Bunding: Technique, Application & UPSC Traps
Contour bunding is used on hilly/sloping terrain to control water erosion
Involves placing stone/earth embankments along natural contours (rises)
Primary functions: capture rainfall, slow water flow, reduce soil erosion
NOT used in deserts (wind erosion), flat plains (flooding), or for weed control
What is Contour Bunding
Contour bunding places lines of stones or earth embankments along the natural rises (contours) of sloping landscapes. It works specifically on hilly or sloping terrain where water flows downhill.
How It Works
%%{init: {"flowchart": {"wrappingWidth": 460}}}%%
flowchart TD
s1["`**Rainfall hits sloping land**
Water starts flowing downhill as runoff`"]
s2["`**Contour bunds capture water**
Stone/earth barriers placed along slope contours`"]
s3["`**Water speed slows down**
Bunds reduce velocity of flowing water`"]
s4["`**Soil erosion reduced**
Slower water carries less soil particles`"]
s5["`**Water infiltration increases**
More time for water to soak into ground`"]
s1 --> s2
s2 --> s3
s3 --> s4
s4 --> s5Where Contour Bunding is Used vs Not Used
Terrain Type | Contour Bunding Used? | Reason | Alternative Method |
|---|---|---|---|
Hilly/sloping land | ✓ YES | Controls water erosion on slopes | Terracing, check dams |
Desert margins (wind action) | ✗ NO | Designed for water, not wind erosion | Shelter belts, sand dunes |
Flat plains (flooding) | ✗ NO | Needs slopes to work effectively | Drainage, embankments |
Scrublands (weeds) | ✗ NO | Not a weed control technique | Manual removal, herbicides |
Key Technical Points
Bunds are placed perpendicular to the slope direction
Works best on slopes with 2-10% gradient
Common in rainfed agriculture areas of India
Often combined with vegetative barriers like grasses
Reduces sheet erosion and rill formation
Question Analysis
This 2013 question tested whether students understand contour bunding is specifically for sloping terrain and water erosion control. All three given options described wrong terrains - deserts (wind erosion), flat plains (flooding), and scrublands (weed growth).
Trap: Confusing wind erosion (desert margins) with water erosion (slopes)
Trap: Thinking flat plains need contour bunding - they need drainage systems instead
Trap: Mixing up soil conservation (contour bunding) with weed control methods
Trap: Not recognizing that 'None of the above' can be correct when all options are wrong
Soil Conservation Methods
Geography
Soil Conservation Methods: Types & Applications
Water erosion methods: contour bunding, terracing, check dams for slopes
Wind erosion methods: shelter belts, sand dune stabilization for flat areas
Each method targets specific terrain and erosion type
Flooding control: drainage systems, embankments for low-lying plains
Soil Conservation by Terrain & Erosion Type
Terrain | Main Erosion Type | Conservation Methods | Examples in India |
|---|---|---|---|
Hilly/Sloping | Water erosion | Contour bunding, terracing, check dams | Western Ghats, Himalayas |
Desert/Arid | Wind erosion | Shelter belts, sand dune fixation | Rajasthan, Gujarat |
Flat Plains | Flooding, waterlogging | Drainage systems, embankments | Gangetic plains, deltas |
Coastal Areas | Saltwater intrusion | Mangrove planting, sea walls | Kerala, Sundarbans |
Agricultural Land | Sheet/rill erosion | Crop rotation, mulching | Punjab, Haryana |
Soil Conservation Classification
# Soil Conservation Methods
## Mechanical Methods
- Contour bunding
- Terracing
- Check dams
- Gully plugging
## Biological Methods
- Afforestation
- Grass planting
- Crop rotation
- Agroforestry
## Agronomic Methods
- Strip cropping
- Mulching
- Cover crops
- FallowingTrap: Mixing up methods for water vs wind erosion control
Trap: Applying slope methods (contour bunding) to flat terrain
Trap: Confusing soil conservation with pest/weed control methods