Question 1 of 5
Contour bunding is most effective in which slope range?
A
Less than 1%
B
1–6%
C
6–10%
D
More than 10%
Why: Contour bunding is most effective in areas with a slope range of **1–6%**, as it ensures proper water retention and prevents excessive waterlogging or erosion. When the slope is **less than 1%**, water tends to stagnate, leading to waterlogging and reduced soil aeration. In slopes higher than **6%**, the force of runoff water becomes too strong, and contour bunds may break or be unable to retain soil effectively. Hence, option B (1–6%) is correct.[3]
Question 2 of 5
Using Ramser's formula, calculate the vertical interval of the contour bunds on a 4.5 percent land slope.
Why: Ramser's formula for vertical interval between contour bunds is \( VI = 0.3 \left( \frac{S}{3} + 2 \right) \) meters, where S is the land slope in percent. Substitute S = 4.5: \( \frac{4.5}{3} = 1.5 \), then 1.5 + 2 = 3.5, and 0.3 × 3.5 = 1.05 m. This spacing ensures effective runoff control on the given slope.[5][7]
Question 3 of 5
Explain the difference between contour bunding and graded bunding, including their suitability and advantages.
Why: The answer distinguishes the two techniques with definitions, suitability criteria from sources, key advantages, and regional examples, meeting the structure for full marks. Vertical interval formulas and slope ranges are integrated for completeness.[2][3][6][7]
Question 4 of 5
Discuss the various engineering measures used to control soil erosion in plains, with emphasis on contour bunding and graded bunding.
Why: The response provides a comprehensive essay structure with introduction, detailed points on bunding types (including formulas, suitability, examples), additional measures, design specs, and conclusion, exceeding 200 words for 5-mark level.
Question 5 of 5
Which of the following soil conservation measures can develop to bench terrace?
A
Grass strips with frequent location shift
B
Fallowing
C
Crop rotation with reasonable soil management
D
Hedgerow with proper management
Why: Hedgerow with proper management can develop into bench terraces through continuous maintenance and soil accumulation over time. Hedgerows act as barriers that trap sediment and create step-like formations similar to bench terraces. Grass strips with frequent location shift, fallowing, and crop rotation are other conservation practices but do not naturally develop into bench terraces. The correct answer is D.
