Connecting geologically mapped data to numerical modelling can help in understanding river landscape evolution. This study focuses on flood-induced breaching of the coversand ridge in the IJssel valley floodplain (Rhine delta, the Netherlands). The development of the breach would explain why this river branch came into existence in early medieval times. Prior to the breaching, the coversand ridge formed a barrier for the Rhine River to discharge towards the north. A palaeoflood model was coupled to a local sediment transport model to predict sediment transport rates in two competing coversand ridge breaches. The results show that the breach at the current IJssel River location was expected to expand earlier and faster in time for various upstream discharge waves and initial breach dimensions. This provides quantitative argumentation for the IJssel river avulsion case to have been triggered by the breaching of the coversand ridge during a large palaeoflood.

将地质图数据与数值模型联系起来有助于理解河流景观演变。本研究侧重于艾瑟尔河谷泛滥平原（荷兰莱茵河三角洲）中由洪水引起的覆盖物和山脊的破坏。裂缝的发展可以解释为什么这条河支流在中世纪早期就出现了。在破裂之前，覆盖沙脊形成了莱茵河向北排放的屏障。古洪水模型与局部沉积物输送模型相结合，以预测两个相互竞争的覆盖层和山脊破裂处的沉积物输送速率。结果表明，对于各种上游泄洪波和初始裂缝尺寸，目前艾瑟尔河位置的裂缝预计会更早、更快地扩大。