Question

The saturated thickness of an unconfined aquifer is defined by the distance between

• A. the ground surface and the water table
• B. the water table and the underlying confining layer
• C. the water table and the mean sea level
• D. the ground surface and the underlying confining layer

Answer 1

The Correct Option is B

Step 1: Understanding the Concept of Saturated Thickness in an Unconfined Aquifer 

An unconfined aquifer is one where the upper boundary is defined by the water table. The saturated thickness is the vertical distance between the water table (upper boundary) and the underlying confining layer (lower boundary).

Step 2: Explanation of Options

• (A): Incorrect. This defines the depth of the unsaturated zone, not the saturated thickness.
• (B): Correct. Saturated thickness is the vertical distance between the water table and the confining layer beneath.
• (C): Incorrect. This refers to an arbitrary reference (mean sea level), not the aquifer’s boundaries.
• (D): Incorrect. This would include both saturated and unsaturated zones, which is not the definition of saturated thickness.

Final Answer:

Hence, the correct option is: (B).