Question

If \( n \) is the number of years, \( T \) is recurrence interval in years and \( m \) is ranking of rainfall event, then the recurrence interval given by Weibull formula is:

• A. \( m = \dfrac{T}{n+1} \)
• B. \( T = \dfrac{m}{n+1} \)
• C. \( n = \dfrac{m+1}{T} \)
• D. \( T = \dfrac{n+1}{m} \)

Hint:

The Weibull formula is one of the most important hydrology formulas: \[ \boxed{T = \frac{n+1}{m}} \] where:
• \( n \) = total number of observations
• \( m \) = rank of event Important observation:
• Larger rainfall events have smaller rank \(m\)
• Smaller rank gives larger recurrence interval Thus, extreme events occur less frequently and therefore have higher return periods.

Answer 1

The Correct Option is D