Non-Stationary and Mutually Dependent Rainfall Input and Its Stochastic Response

Abstract

Observed rainfall is a non-stationary and mutually dependant random variable. Based on the condition that the stochastic characteristics of rainfall are known, we derived dierential equations whose solutions provide the ®rst four moments of discharge output from a storage function runo model. The validity of the derived dierential equations was cross-checked by a simulation method. The results showed that it is possible to obtain the probability density function of discharge from the calculated ®rst four moments of discharge.