Question

Which of the following statements regarding land levelling methods are correct
A. Plane method is most commonly used method of land levelling
B. Profile method is usually well adopted to leveling design of very flat land with undulating topography
C. Plan inspection method does not give quick estimate
D. Contour method is adapted to smoothening of steep lands that are to be irrigated
Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, B and C only
• C. B, C and D only
• D. B and D only

Hint:

To remember the methods:
- Plane Method $\rightarrow$ Most common, uses least-squares to balance cuts and fills.
- Plan Inspection $\rightarrow$ Quick and subjective.
- Contour Method $\rightarrow$ Used on steep, sloping lands.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Land leveling is the process of shaping the land surface to ensure uniform water distribution during surface irrigation.
Engineers use different mathematical and graphical design methods based on the field's topography and slope requirements.
Detailed Explanation:
Let us evaluate each statement:
- Statement A:
The plane method (also called the least-squares method) is a mathematically rigorous approach.
It calculates a uniform, flat plane of best fit that balances the volumes of cut and fill.
Because of its accuracy and efficiency, it is the most commonly used design method.
Thus, Statement A is correct.
- Statement B:
The profile method involves plotting elevation profiles along grid lines.
It is highly effective for designing fields with very flat slopes and minor, undulating terrain variations.
Thus, Statement B is correct.
- Statement C:
The plan inspection method is a rapid, subjective trial-and-error approach.
Because it relies on visual inspection of the grid map rather than complex calculations, it is used specifically to get a quick, rough estimate.
Thus, Statement C is incorrect.
- Statement D:
The contour adjustment method is used on steeper terrains.
Instead of leveling the entire field, it smooths the land along contour lines to minimize soil movement while still allowing for furrow or contour irrigation.
Thus, Statement D is correct.

Step 2: Final Answer:
The correct statements are A, B, and D only.