Abstract The concurrence of flash floods and debris flows is of particular concern, because it may amplify the hazard corresponding to the individual generative processes. This paper presents a coupled modelling framework for the predictions of flash flood response and of the occurrence of debris flows initiated by channel bed mobilization. The framework combines a spatially distributed flash flood response model and a debris flow initiation model to define a threshold value for the peak flow which permits identification of channelized debris flow initiation. The threshold is defined over the channel network as a function of the upslope area and of the local channel bed slope, and it is based on assumptions concerning the properties of the channel bed material and of the morphology of the channel network. The model is validated using data from an extreme rainstorm that impacted the 140 km 2 Vizze basin in the Eastern Italian Alps on August 4–5, 2012. The results show that the proposed methodology has improved skill in identifying the catchments where debris-flows are triggered, compared to the use of simpler thresholds based on rainfall properties.

中文翻译：

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山洪响应与泥石流发生耦合预测：在一次高山特大洪水事件中的应用

摘要 山洪暴发和泥石流的同时发生尤其值得关注，因为它可能会放大与个体生成过程相对应的危害。本文提出了一个耦合建模框架，用于预测山洪响应和由河床动员引发的泥石流的发生。该框架结合了空间分布的山洪响应模型和泥石流引发模型来定义峰值流量的阈值，该阈值允许识别渠道化泥石流的引发。阈值在渠道网络上定义为上坡面积和局部渠道床坡度的函数，它基于关于渠道床材料特性和渠道网络形态的假设。