Question

Given below are two statements:

Statement (I): Isotropic and homogeneous aquifers seldom occur in nature.

Statement (II): Water level measurements during pumping test are made in observation wells installed close to the well or at some distance away from it.

In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are correct.
• B. Both Statement (I) and Statement (II) are incorrect.
• C. Statement (I) is correct but Statement (II) is incorrect.
• D. Statement (I) is incorrect but Statement (II) is correct.

Hint:

Think about whether real geological materials are ever perfectly uniform and directionless, and recall the standard layout of observation wells around a pumping test.

Answer 1

The Correct Option is A

Step 1: Statement (I) claims that isotropic and homogeneous aquifers seldom occur in nature. In real aquifers, hydraulic conductivity commonly varies with position (heterogeneity) and with direction at a point (anisotropy), because of layered deposition, varying grain size, fractures and geological history. The isotropic, homogeneous aquifer is a simplifying idealisation used mainly to make the governing groundwater flow equations solvable, not something actually found in the field. So Statement (I) is correct.
Step 2: Statement (II) describes how a pumping test is actually carried out: while the main well is pumped at a steady rate, water level drawdown is measured over time in observation wells, some placed close to the pumped well and others farther away, so that the drawdown pattern with distance and time can be used to estimate aquifer transmissivity and storativity. This matches standard pumping test procedure, so Statement (II) is correct too.
Step 3: Both statements agree with accepted groundwater hydrology practice, so the correct choice is that both Statement (I) and Statement (II) are correct, option 1.