Modelling the probability of occurrence of shallow landslides and channelized debris flows using GEOtop‐FS

Abstract

Abstract:This paper describes a coupled, distributed, hydrological-geotechnical model, GEOtop-FS, which simulates the probability of occurrence of shallow landslides and debris flows. We use a hydrological distributed model, GEOtop, which, models latent and sensible heat fluxes and surface runoff, and computes soil moisture in 3-D by solving Richards'equation numerically, together with an infinite-slope geotechnical model, GEOtop-FS. The combined model allows both the hydraulic and geotechnical properties of soil to be considered and realistically modelled. In particular, the model has been conceived to make direct use of field surveys, geotechnical characteristics and soil moisture measurements. In the model the depth of available sediments is also used to characterize the hydraulic properties of the area examined.To account for the uncertainty related to the natural variability in the factors influencing the stability of natural slopes, the safety factor is computed with a probabilistic approach. In order to determine the likelihood of slope failures, soil parameters are assigned distributions instead of single deterministic values.The analysis presented was carried out for an alpine watershed, located in the Friuli region, Italy, for which some geological and geotechnical data were available. In the past, this watershed experienced landslides and debris flows during intense storms following long and moderate intensity rainfall events. The distributed coupled GEOtop-FS model was calibrated by reproducing some of these events and validated in order to map future failure probabilities.

HIRESSS: a physically based slope stability simulator for HPC applications

“…The basic tool is a grid-based model, a combination of C++ programs and ARC/INFO AML scripts intended to be used within an ESRI-ArcGIS software environment. This model has been classified as spatially predictive because it is not suited to forecast the timing of landslide triggering (Simoni et al, 2008).…”

“…GEOtop-FS is one of the most advanced models for distributed slope stability and was recently proposed by Simoni (2008). This model uses the hydrological distributed model GEOtop (Rigon et al, 2006) to compute pore pressure distribution by an approximate solution of the Richards equation and an infinite slope stability analysis to compute the distributed factor of safety.…”

Towards a definition of a real-time forecasting network for rainfall induced shallow landslides

“…This method has the advantage of being relatively simple to implement. However, if both a spatial and a temporal forecasting of shallow landslide occurrence are desirable, the most effective approach is to use deterministic models that couple water infiltration schemes with a one-dimensional slope stability analysis (Montgomery and Dietrich, 1994;Wu and Sidle, 1995;Montgomery et al, 1998;Pack et al, 1998;Borga et al, 1998;Burton and Bathurst, 1998;Baum et al, 2002;Casadei et al, 2003;Crosta and Frattini, 2003;Simoni et al, 2008). If the rainfall characteristics of the triggering event are known, these models become useful tools for modelling where and when shallow landslides are likely to occur at a basin scale.…”

A comparison of linear and nonlinear model performance of shia_landslide: a forecasting model for rainfall-induced landslides

“…A similar approach, using the analytical approximate solution of the Richards equation, is called HIRESSS (High REsolution Slope Stability Simulator) [33]. Recently, a model called GEOtop-FS was proposed [34]; and tRIBS (TIN-based Real-Time Integrated Basin Simulator), an infinite slope and movement module in a physically based, distributed hydrological model [35,36].…”