The 'radius of influence' of a pumping well in a confined aquifer is the distance at which:
Choose the correct answer
The well starts pumping
Drawdown becomes zero — water table (or piezometric level) returns to pre-pumping level
Velocity becomes infinite
Soil becomes impermeable
Correct Answer
B. Drawdown becomes zero — water table (or piezometric level) returns to pre-pumping level
AI Detailed Explanation & IS Code Reference
Unlock the reasoning, formula path and code-linked notes inside your student dashboard.
Radius of influence R: distance from pumping well where drawdown = 0 (piezometric level returns to static level). For confined aquifer (Thiem equation): s = (Q/2πT)×ln(R/r). R depends on: aquifer T (transmissivity), pumping duration, storativity S. Empirical: R = 3000s_w√(KH) (Kusakin) or from pumping test. Beyond R: no impact of pumping detectable.
ScoreCardAI links this solution with subject, topic and difficulty signals so your scorecard can identify weak areas after a full mock test.
Practice more Civil Engineering questions
This MCQ belongs to JE Level Premium Test Series. Full tests include timed attempts, rank comparison and subject-wise analysis.