Question

While constructing a lysimeter, what are the factors on which it depends
A. The heat advection through walls is to be kept minimum by using circular tanks
B. To maintain a moisture gradient representative of the surroundings, adequate drainage facilities must be provided
C. The heat advection through walls should be maximum by using rectangular tanks
D. No need to maintain moisture gradient in lysimeter
Choose the correct answer from the options given below:

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

Hint:

Lysimeter design criteria: Minimize thermal wall conduction (circular shape, non-conducting walls) + maintain natural drainage moisture gradient.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Lysimeter design engineering aims to eliminate boundary heat conduction and rim edge effects to ensure the contained soil monolith accurately simulates surrounding field conditions.

Step 2: Detailed Explanation:
Key engineering guidelines for representative lysimeter installation:
1. Thermal Advection Control (A): Heat transfer through the lysimeter side walls creates artificial soil temperature gradients. Circular cylindrical tanks minimize wall perimeter area per unit surface volume, reducing edge heat conduction artifacts.
2. Representative Moisture Profile (B): The bottom boundary must provide controlled drainage or tension suction to maintain natural hydraulic gradients identical to the adjacent field.
Thus, factors A and B only are valid scientific requirements.

Step 3: Final Answer:
Hence, the correct answer is A and B only, corresponding to option (B).