A REGIONAL MODEL FOR ESTIMATING THE PROBABILITY-DISTRIBUTION OF ROUTED PEAK DISCHARGES

A regional model is proposed for estimating the probability distributi on of routed peak discharges. The model is composed of two parts: the distribution of the annual maxima of peak discharges Q(p) and the cond itional joint distribution, given the peak discharge q(p), of three of the four parameters (peak discharge q(p), baseflow discharge q(b), st orm runoff v and time to peak t(p)) assumed to represent a flood event hydrograph. The model is based on some simplifications and approximat ions. Analysis of the model behaviour in flood routing simulations, ho wever, suggests that it may be considered reasonably accurate, at leas t in the range of accuracy accepted for design purposes.