Calibration of a Daily Rainfall-Runoff Model to Estimate High Daily Flows

Flood estimation can be performed on the basis of event-based simulation or continuous simulation. A model with continuous water balance accounting has the attractive feature that dynamic factors affecting runoff production may be represented explicitly (Lamb 1999). In particular, a conceptual rainfall-runoff model can simulate the changing antecedent moisture conditions that determine the catchment runoff response for a given rainfall event, and the problem of baseflow estimation in event-based approach can be circumvented. In addition, the design flood estimate need not be associated with specific design storm, instead it is derived directly from continuous rainfall records, or from Monte-Carlo simulation using stochastic rainfall data. With the advent of computing capability, flood frequency estimation by continuous modelling approach has been widely applied (e.g. Lamb 1999, Cameron et al. 2000).