Probabilistic landslide susceptibility analysis in tropical mountainous terrain using the physically based r.slope.stability model

Abstract

Abstract. Landslides triggered by rainfall are very common phenomena in complex tropical environments such as the Colombian Andes, one of the regions of South America most affected by landslides every year. Currently in Colombia, physically based methods for landslide hazard mapping are mandatory for land use planning in urban areas. In this work, we perform probabilistic analyses with r.slope.stability, a spatially distributed, physically based model for landslide susceptibility analysis, available as an open-source tool coupled to GRASS GIS. This model considers alternatively the infinite slope stability model or the 2.5-D geometry of shallow planar and deep-seated landslides with ellipsoidal or truncated failure surfaces. We test the model in the La Arenosa catchment, northern Colombian Andes. The results are compared to those yielded with the corresponding deterministic analyses and with other physically based models applied in the same catchment. Finally, the model results are evaluated against a landslide inventory using a confusion matrix and receiver operating characteristic (ROC) analysis. The model performs reasonably well, the infinite slope stability model showing a better performance. The outcomes are, however, rather conservative, pointing to possible challenges with regard to the geotechnical and geo-hydraulic parameterization. The results also highlight the importance to perform probabilistic instead of – or in addition to – deterministic slope stability analyses.

Landslide Susceptibility Analysis on the Vicinity of Bogotá-Villavicencio Road (Eastern Cordillera of the Colombian Andes)

“…Finally, Pradhan et al [51] and Ramos-Cañon et al [59] catalogued rock falls, avalanches, rotational and translational landslides, earth-mud flows and debris flows. In other parts of the country, such as the Western and Central Cordilleras, shallow slides, falls, debris flows and mud-flows have been identified [5,[24][25][26][27]29,45,50,55]; in the southern Colombian Massif, specifically in Mocoa, debris flows, debris avalanches and shallow slides have been found [8,21,30,31].…”

“…For hazard, there are numerous deterministic and probabilistic methods, the latter of which are generally the most applied for extensive areas due to the lack of precise and exhaustive data in such areas. Within the deterministic methods, different hydrological models [21,22] or stability analysis methods such as infinite slope [23], r.slope.stability of GRASS [24], FOSM [25][26][27], SLIP [26,27], PEM point estimates [25] or deformation analysis [28] have been applied. These models have been used in high-impact landslides such as the Mocoa debris flow in the southern part of the country [21,[29][30][31], hillslopes around Medellin [22] and San Eduardo in Boyacá [28] or watersheds such as La Arenosa and La Liboriana [24][25][26][27] in the department of Antioquia in the Western Cordillera.…”

iHydroSlide3D v1.0: an advanced hydrological-geotechnical model for hydrological simulation and three-dimensional landslide prediction

“…More recently, progress has been made in a more sophisticated software r.slope.stability (Mergili et al, 2014a;Mergili et al, 2014b) that have the capacity to perform on a regional scale via a parallel computational technique. More importantly, the 3D slope-stability model demonstrates to be effective on both shallow and deep landslides, thus better behaves as a robust geotechnical tool and has a potential for wide applications (Zieher et al, 2017;Palacio Cordoba et al, 2020).…”

Cost estimation for the monitoring instrumentalization of Landslide Early Warning Systems

“…EO-derived data capture the shape of the terrain and the natural and built elements on it. Such information can be used to estimate landslide susceptibility at different regions and scales (Cantarino et al, 2019;Palacio Cordoba et al, 2020;Ospina-Gutiérrez and Aristizábal, 2021).…”