Match the basic terms used in the runoff given in the first column with their meanings in the second column.
| List-I | List-II |
|---|---|
| A.Surface runoff | 1.Delayed sub-surface flow at shallow depth |
| B.Interflow | 2.Unconfined flow of water over the ground surface |
| C.Base flow | 3.Portion of water that moves laterally in the upper part of the soil |
- AA-1, B-2, C-3
- BA-2, B-3, C-1Correct
- CA-1, B-3, C-2
- DA-2, B-1, C-3
Solution
Concept
Runoff has three parts: surface runoff (overland flow), interflow (lateral flow in the upper soil), and base flow (delayed groundwater flow).
Step-by-step solution
1. Surface runoff is water flowing freely over the ground surface. So A-2. 2. Interflow is water that moves sideways in the upper soil layers and reaches the stream. So B-3. 3. Base flow is delayed sub-surface (groundwater) flow that feeds the stream slowly. So C-1. 4. The match is A-2, B-3, C-1. Answer: B.
Explanation
Surface runoff flows over the land. Interflow moves laterally just below the surface in the upper soil. Base flow is the slow, delayed groundwater contribution that keeps rivers flowing in dry periods.
Why the other options are wrong
A: surface runoff is not delayed sub-surface flow. C: base flow is not overland flow. D: interflow is lateral flow in the upper soil, not delayed base flow.
Shortcut
Surface = over the ground, Inter = in the upper soil, Base = delayed groundwater.
Common mistake
Mixing up interflow and base flow, because both are sub-surface flows.
Correct answer: B) A-2, B-3, C-1