Subtopic: Overview of groundwater recharge estimation and artificial recharge techniques
Question Statement:
Which of the following techniques represent artificial and induced groundwater recharge methods applied in watershed management?
Options:
(A) Induced recharge, where high-capacity pumping wells installed adjacent to a perennial river draw surface water through the riverbed sand into the aquifer
(B) Percolation tanks and check dams constructed across ephemeral seasonal streams to impound runoff and augment unconfined water tables
(C) Subsurface dykes (groundwater dams) constructed across alluvial riverbeds down to impermeable bedrock to arrest subsurface outflow
(D) Recharge shafts and injection wells designed to introduce clean water directly into deep confined aquifers
Answer Key:
A, B, C, D
Step-by-Step Solution & Explanation
All four techniques are established artificial and induced recharge mechanisms in groundwater engineering (Todd & Michael):
- A: Induced filtration creates a cone of depression intersecting surface water bodies.
- B: Percolation ponds extend surface water infiltration time.
- C: Subsurface dykes dam the invisible subterranean baseflow escaping through permeable river channel sands.
- D: Deep injection shafts bypass upper aquitards to replenish pressure in confined aquifers.