Simulation of the rainfall runoff process using a hysteretic infiltration redistribution model

Abstract

The significance of the soil profile and its accompanying water status in deterministic catchment models is discussed in relation to the current use of the soil-store concept. An alternative numerical approach is described in which the movement of water into and through the soil profile (together with the determination of runoff volumes) is continuously monitored during any pattern of rainfall and non-rainfall events. A significant component in the approach is the use of a comprehensive domain-type hysteresis model for the analysis of infiltration-redistribution sequences. The simulation is illustrated by using a rainfall hyetograph of 7 h duration (including one non-rainfall period of 1 h) as the flux input into a homogeneous profile of a sandy loam of uniform initial water content. The time-dependent relationships of rate of surface flux, depression storage and runoff volume are calculated for the duration of the hyetograph period. Profiles of water content are also presented.