Question

In the infiltration moisture profile, the saturation zone is followed by

• A. Wetting zone
• B. Drying zone
• C. Transition zone
• D. Wetting front

Hint:

Remember the downward sequence of Bodman and Colman's infiltration zones: Saturation $\to$ Transition $\to$ Transmission $\to$ Wetting $\to$ Wetting Front. This profile is a classic topic in soil physics exams.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
When water is applied to the soil surface, it infiltrates downwards, creating a distinct moisture profile with depth.
Bodman and Colman (1943) characterized this profile into several distinct zones based on moisture content and hydraulic gradients.

Step 2: Detailed Explanation:
The zones of an infiltration moisture profile from the surface downward are:
1. Saturation Zone: A thin layer of soil at the very surface that is completely saturated with water.
2. Transition Zone: A narrow zone directly beneath the saturation zone characterized by a rapid decrease in water content with depth.
3. Transmission Zone: A relatively stable, unsaturated zone where water content remains nearly constant as water is transmitted downward.
4. Wetting Zone: A zone below the transmission zone where water content decreases rapidly with depth toward the initial dry state of the soil.
5. Wetting Front: The sharp boundary separating the wet soil above from the dry soil below.
Therefore, the zone immediately following the saturation zone is the Transition zone.

Step 3: Final Answer:
The saturation zone is followed by the Transition zone, which corresponds to option (C).