Monthly Runoff Series Research Articles

Stochastic models applied to evaluating hydrologic changes

Simple statistical tests for equality of means and variances, and Box—Jenkins univariate and input—output models are shown to be tools to detect hydrologic changes. The structural decomposition of monthly runoff series into periodic and stochastic components, and the step response function of monthly runoff processes in relation to monthly rainfall processes provide parameters that form a basis for evaluating the changes in the hydrologic environments.