Table 2 PDF and CDF of the functions used in the study.

From: Hydrological projections in the upper reaches of the Yangtze River Basin from 2020 to 2050

Function

PDF

CDF

Gamma

\(f_{G} (x) = \frac{{\alpha^{ - \beta } }}{\Gamma (\beta )}x^{\beta - 1} \exp ( - \frac{x}{\alpha })\)

\(F_{G} (x) = \int_{0}^{x} {\frac{{\alpha^{ - \beta } }}{\Gamma (\beta )}x^{\beta - 1} \exp ( - \frac{x}{\alpha })dx}\)

Exponential

\(f_{E} (x) = \frac{1}{\alpha }\exp ( - \frac{x}{\alpha })\)

\(F_{E} (x) = 1{\text{ - exp}}( - \frac{x}{\alpha })\)

GEV

\(f_{V} (x) = \frac{1}{\alpha }(1 + \beta ( - \frac{x - \tau }{\alpha })^{ - 1/\beta - 1} )\exp ( - (1 + \beta (\frac{x - \tau }{\alpha })^{ - 1/\beta } ))\)

\(F_{V} (x) = \exp ( - (1 + \beta (\frac{x - \tau }{\alpha })^{ - 1/\beta } ))\)

Gumbel

\(f_{U} (x) = \frac{1}{\alpha }\exp ( - \frac{x - \tau }{\alpha })\exp ( - \exp ( - \frac{x - \tau }{\alpha }))\)

\(F_{U} (x) = 1 - \exp ( - \exp ( - \frac{x - \tau }{\alpha }))\)

GP

\(f_{P} (x) = \frac{1}{\alpha }(1 + \beta (\frac{x - \tau }{\alpha })^{ - 1/\beta - 1} )\)

\(F_{P} (x) = 1 - (1 + \beta (\frac{x - \tau }{\alpha })^{ - 1/\beta } )\)