Debris flows tend to erode sediment from or deposit sediment on the bed, which changes their volume and, thus, in turn, affects their rheological properties. However, previous modeling studies on debris flows mostly ignore sediment erosion/deposition. Here, three models are presented: a debris model without bed deformation, which is similar to traditional models in that it does not consider sediment erosion/deposition but uses the Herschel–Bulkley formulation to describe the non-Newtonian nature; a debris model with bed deformation, which is better improved than the traditional model in that it considers sediment erosion/deposition; and a turbidity current model, which is further simplified from the debris model with bed deformation by ignoring the non-Newtonian nature. These models, formulated in the same modeling framework, are solved by a shock-capturing finite volume method. These models were firstly validated against three laboratory experiments, which indicated that the debris models with and without bed deformation with reasonably well-specified parameters can give satisfactory agreements with the measurements, whereas the turbidity current model overestimated the experimental result due to its lack of yield stress and dynamic viscosity. Moreover, a hypothetical field application was used to explain the difference between a turbidity current and debris flows with and without bed deformation. It was shown that debris flows and turbidity currents are capable of impacting the bed significantly. However, turbidity currents have thinner tails, less shear stress, and form horizontal deposits on the bed, while debris flows have a thicker tail, high shear stress, and form vertical deposits on the bed. Finally, sensitivity analyses were carried out to study the impact of sediment size, bed slope, concentration, and porosity on the deformation of the bed after debris flow where they all showed a positive correlation.

中文翻译：

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泥沙侵蚀/沉积对泥石流传播影响的数值研究

碎屑流倾向于从床上侵蚀沉积物或沉积沉积物，这会改变它们的体积，从而影响它们的流变特性。然而，以前对泥石流的建模研究大多忽略了沉积物侵蚀/沉积。这里介绍了三个模型： 没有床变形的碎屑模型，与传统模型相似，它不考虑沉积物侵蚀/沉积，而是使用 Herschel-Bulkley 公式来描述非牛顿性质；具有床层变形的碎屑模型，在考虑泥沙侵蚀/沉积方面比传统模型有更好的改进；浊流模型，通过忽略非牛顿性质，进一步简化了带床变形的碎屑模型。这些模型在相同的建模框架中制定，由冲击捕获有限体积法求解。这些模型首先在三个实验室实验中得到验证，表明具有合理指定参数的有床变形和无床变形的碎屑模型与测量结果具有令人满意的一致性，而浊流模型由于缺乏屈服而高估了实验结果应力和动态粘度。此外，假设现场应用被用来解释浊流和泥石流之间的差异，有和没有床变形。结果表明，泥石流和浊流能够显着影响床层。但浊流尾部较细，剪应力较小，在床层形成水平沉积，而泥石流尾部较粗，剪应力高，并在床上形成垂直沉积物。最后通过敏感性分析研究泥沙粒径、床层坡度、浓度、孔隙度对泥石流后床层变形的影响，均呈正相关。