An Intensity-Duration-Frequency (IDF) curve for a station is derived from:
Choose the correct answer
Monthly rainfall averages only
Annual maximum rainfall data at various durations analyzed for different return periods using frequency analysis (Gumbel, log-Pearson)
Stream gauge data
Groundwater levels
Correct Answer
B. Annual maximum rainfall data at various durations analyzed for different return periods using frequency analysis (Gumbel, log-Pearson)
AI Detailed Explanation & IS Code Reference
Unlock the reasoning, formula path and code-linked notes inside your student dashboard.
IDF curves: from recording raingauges, extract annual maximum intensities for various durations (5 min, 10 min, 30 min, 1 h, 2 h, 6 h, 24 h). Fit Gumbel or other distribution to each duration separately. IDF equation: I = K T^a / (t + b)^c (Sherman), where T = return period, t = duration. Used for storm sewer and small drainage design.
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 AE Level Premium Test Series. Full tests include timed attempts, rank comparison and subject-wise analysis.