Hydrology and Runoff

For annual maximum flood records with mean $\bar{x} = 500\text{ m}^3/\text{s}$ and standard deviation $\sigma_x = 100\text{ m}^3/\text{s}$, the Gumbel frequency factor for a 50-year return period is $K = 2.5$. The 50-year design flood $x_{50} = \bar{x} + K \sigma_x$ in $\text{m}^3/\text{s}$ is: