The procedure for the determination of Synthetic Design Hydrographs (SDHs), proposed in previous works, is validated by comparing the peak discharges obtained by routing a long series of historical floods and the synthetic floods at different stations along a complex river system.

At this aim, the 60 km long terminal stretch of the Dora Baltea river (Northern Italy) has been modelled according to fully 2D high resolution hydrodynamic approach. The fluvial branch is of considerable complexity due to a strong contraction induced by the presence of a narrow Roman bridge, which, during the most important flood events, causes the reactivation of a paleochannel and the flooding of a part of the city of Ivrea. The hydraulic model has been calibrated on the basis of the main historical floods. Then, all the historical floods over a period of more than 80 years (1939-2020) and the SDHs derived by the same series have been routed. Historical and synthetic peak discharges at two downstream stations have been then compared in probability plots. The results show that the peak discharge distributions derived by routing the historical floods and the SDHs compare well. This suggests that SDHs construction procedure is reliable and has statistical significance.

确定综合设计水位线 (SDH) 的程序，在以前的工作中提出，通过比较通过计算一系列历史洪水和复杂河流系统不同站点的合成洪水获得的峰值流量来验证。

为此，根据全二维高分辨率流体动力学方法对 Dora Baltea 河（意大利北部）60 公里长的终端河段进行了建模。由于狭窄的罗马桥的存在引起的强烈收缩，河流支流相当复杂，在最重要的洪水事件中，这导致古河道的重新激活和伊夫雷亚市部分地区的洪水。水力模型在历史主要洪水的基础上进行了标定。至此，80余年（1939-2020年）的历史洪水和同系列派生的SDH全部被路由。然后在概率图中比较了两个下游站的历史和合成峰值流量。结果表明，通过计算历史洪水和 SDH 得出的峰值流量分布比较好。这表明SDHs构建过程是可靠的并且具有统计意义。