Flood Frequency Analysis MCQ with answer and solution

Concept

Probability distribution used to model extreme values, specifically annual maximum floods in hydrology.

Step-by-step solution

1. Identify the purpose of flood frequency analysis in hydrology. 2. Recognize that Gumbel's Extreme Value Distribution is standard for analyzing extreme events like annual maximum floods. 3. Match with the correct option.

Explanation

The Gumbel distribution, also known as the Extreme Value Type-I distribution, is widely used in hydrology for predicting extreme hydrological events such as annual maximum floods, maximum rainfall, and maximum wind speeds.

Why the other options are wrong

A: Daily rainfall is typically modeled using Log-Pearson Type III or normal distributions. B: Monthly temperature follows a normal distribution. D: Daily evaporation is usually modeled using normal or log-normal distributions.

Shortcut

Gumbel = Greatest/Maximum flood.

Common mistake

Confusing Gumbel distribution with normal distribution used for mean values.