Abstract：
Snow avalanches are gravitational processes characterised by the rapid movement of a snow mass, threatening inhabitants and damaging infrastructure in mountain areas. Such phenomena are complex events, and for this reason, different numerical models have been developed to reproduce their dynamics over a given topography. In this study, we focus on the two-dimensional numerical simulation tools RAMMS::AVALANCHE and FLO-2D, aiming to compare their performance in predicting the deposition area of snow avalanches. We also aim to assess the employment of the FLO-2D simulation model, normally used in water flood or mud/debris flow simulations, in predicting the motion of snow avalanches. For this purpose, two well-documented avalanche events that occurred in the Province of Bolzano (IT) were analyzed (Knollgraben, Pichler Erschbaum avalanches). The deposition area of each case study was simulated with both models through back-analysis processes. The simulation results were evaluated primarily by comparing the simulated deposition area with the observed one through statistical indices. Subsequently, the maximum flow depth, velocity and deposition depth were also compared between the simulation results. The results showed that RAMMS::AVALANCHE generally reproduced the observed deposits better compared to FLO-2D simulation. FLO-2D provided suitable results for wet and dry snow avalanches after a meticulous calibration of the rheological parameters, since they are not those typically considered in avalanche rheology studies. The results showed that FLO-2D can be used to study the propagation of snow avalanches and could also be adopted by practitioners to define hazard areas, expanding its field of application.
摘要：
雪雪崩是重力过程，其特征是雪团的快速运动，威胁山区居民和破坏山区基础设施。这种现象是复杂的事件，出于这个原因，已经开发了不同的数值模型来再现它们在给定地形上的动力学。在这项研究中,我们专注于二维数值模拟工具RAMMS::AVALANCHE和FLO-2D，旨在比较它们在预测雪崩沉积面积方面的表现。我们还旨在评估FLO-2D模拟模型的使用情况，通常用于水淹或泥浆/泥石流模拟，预测雪雪崩的运动。为此,分析了在博尔扎诺省(IT)发生的两个有据可查的雪崩事件(Knollgraben，PichlerErschbaum雪崩）。通过反分析过程，用两种模型模拟了每个案例研究的沉积区域。模拟结果主要是通过统计指数将模拟沉积面积与观察到的面积进行比较来评估的。随后，最大流动深度,速度和沉积深度也进行了比较模拟结果。结果表明，与FLO-2D模拟相比，RAMMS::AVALANCHE通常更好地再现了观察到的沉积物。FLO-2D在对流变参数进行精心校准后，为干湿雪雪崩提供了合适的结果，因为它们不是雪崩流变学研究中通常考虑的那些。然而,结果表明，FLO-2D可以用来研究雪雪崩的传播，也可以被从业者用来定义危险区域，扩大其应用领域。
