Groundwater Hydrology MCQ with answer and solution

Concept

Groundwater measurement instruments

Step-by-step solution

1. Identify the purpose of each instrument given in the options. 2. Tensiometer is used for measuring soil suction or moisture tension in the unsaturated zone. 3. Rain gauge measures rainfall depth. 4. Piezometer is installed in the ground to measure the piezometric head or groundwater table level. 5. Lysimeter measures percolation and evapotranspiration from a vegetative soil column.

Explanation

A piezometer is a specialized instrument used to measure the pressure head of groundwater at a specific point, which directly helps in determining the groundwater table or piezometric level. Other options serve different hydrological purposes: a tensiometer measures soil moisture tension, a rain gauge measures precipitation, and a lysimeter measures evapotranspiration.

Why the other options are wrong

A: Tensiometer measures soil moisture tension in unsaturated soil. B: Rain gauge measures precipitation amount. D: Lysimeter measures evapotranspiration.

Shortcut

Remember 'Piezometer' starts with 'P' for Pressure head / Piezometric level of groundwater.

Common mistake

Confusing a tensiometer (used in agriculture/soil mechanics for unsaturated soil suction) with a piezometer.