ABSTRACT

In hydraulic modelling of floods, estimating the potential flood extent, i.e. inundation map, and maximum water levels, i.e. flood profile, corresponding to a river discharge with a given return period, i.e. design flood, is an important step for assisting decision makers in flood risk management. A traditional representation of simulated results in flood modelling is based on a single simulation used as the best estimate. This approach, which can be called as "deterministic", does not explicitly account for the uncertainties in both the estimation of the design flood and the hydraulic modelling process and may lead to an inaccurate hazard assessment as highlighted in the recent literature. For design flood profile, this uncertainty is sometimes accounted for by adding arbitrary freeboard heights to the simulated maximum water levels. The accuracy in developing flood inundation map and prediction of design flood profile are important in flood hazard management.