*5.3. Parameter Selection*

The dynamics of high speed and long runout landslides have been studied by researchers. The analysis of landslide dynamics depends, to a large extent, on the choice of parameters and the knowledge level of the author [23]. In this paper, the simulation parameters of the Panjinbulake loess landslide were mainly obtained by the field survey data and the existing research results [23,49–51]. For the Voellmy model, the main parameters were ξ = 400 m/s2 (the software provides a range of 200–500 m/s2) and f = 0.05. When rain and snow melt water infiltrates, the groundwater level rises, and pore water pressure rises. The sliding body is close to the flow state, so the friction coefficient decreases gradually. The influence of underground groundwater on sliding body motion is realized by changing the friction coefficient in DAN-W (see Section 7.1). For the frictional model, the dynamic friction angle ϕ<sup>b</sup> was set to 19◦ according the literature [23,49–51]. Due to the infiltration of ice and snow meltwater, the excess pore water pressure increases, and Ru was set to 0.7. Finally, according to the indoor geotechnical test and the engineering analogy method, the typical strength testing index ϕi was set to 20◦ and the unit weight (γ) was set to 18 KN/m3. As shown in Table 2, based on the trial and error method and the existing research results, these rheological model combinations and parameters were used to simulate the dynamic hazard effects of the Panjinbulake loess landslide.

**Table 2.** Parameters of the Frictional–Voellmy model used for the Panjinbulake landslide.

