Discussion of Modelling Issues Paul Samuels HR Wallingford 4th I M P A C T W O R K S H O P Zaragoza, 3-5 November 2004

Some Discussion Issues Assess accuracy and robustness, i.e. reliability of flood propagation models by comparison with actual data What should we compare? Timing of arrival, rate of rise and fall, time of peak Water level, water depth or inundation extent? Peak discharge only or influence of hydrograph shape? Understand the differences in topography - fixed bed assumption? Estimate uncertainty of model output Can we explain the differences - models, modellers, mesh size Implications of these results for the Uncertainty Analysis Gain insight into modeling problems and difficulties encountered in real life situations What can we learn about data collection and management issues Roughness estimation for extreme flood conditions How would a 1-D model perform? What guidance can we give to the professional community? 4th I M P A C T W O R K S H O P Zaragoza, 3-5 November 2004