A New Approach for Landslide Modeling: Application to the Scilla 1783 Tsunamigenic Landslide, South Italy

Abstract

In this study, we present a new 2D numerical model, UBO-Inter, able to simulate the motion of a body sliding down a generic surface. Such a body is represented as a mechanical system of a finite number of point masses, where the points can be viewed as the projections on the sliding surface of the centers of mass of the elements which the system is discretized into. The masses are strictly adherent to the surface and interact with the neighbor masses through internal forces. The entire system can be seen as a 2D irregular grid where the masses occupy the nodes of the grid, and each grid side connects a pair of interacting masses. The external forces acting on the masses are gravity, which is the driving force, the reaction force of the sliding surface, the basal friction and the drag exerted by the environmental fluid (typically water, for a slide moving partially or totally underwater). The system is governed by a set of differential equations that are solved through a fourth-order Runge–Kutta scheme. After providing the formulation of the problem and a simple example admitting an exact solution that serves to illustrate the internal forces, we validate the model on the 1783 Scilla (Calabria region, Italy) landslide, that is a well-known catastrophic event that caused a lethal tsunami killing more than 1500 people. This case has been already widely studied and thus can be used as a benchmark for landslide models. The outputs of the model UBO-Inter in terms of time-histories of point-mass velocities, run-out and final deposit, are found to be in agreement with observations and with results published in literature and obtained through different numerical techniques.