Difficulty: Easy
Correct Answer: If both (R1) and (R2) are reasons for the assertion (A).
Explanation:
Introduction / Context:
Flood seasonality in North Indian plains reflects dual inputs: Himalayan snowmelt and monsoon rainfall. The item asks if both reasons explain observed summer flooding.
Given Data / Assumptions:
Concept / Approach:
Hydrographs in snow–monsoon regimes show combined contributions. When both inputs overlap temporally, peak flows and flood probability rise.
Step-by-Step Solution:
Verification / Alternative check:
Historical flood records align with monsoon onset and elevated melt periods.
Why Other Options Are Wrong:
A/B understate the dual-driver nature; D contradicts hydrology.
Common Pitfalls:
Treating snowmelt and monsoon as mutually exclusive.
Final Answer:
If both (R1) and (R2) are reasons for the assertion (A).
Discussion & Comments