Modelling of Rainfall Induced Landslides in Puerto Rico

Modeling vegetation effects on hydrological and mechanical mechanisms of shallow landslides

Effects of vegetation in improving slope stability can be recognized on both hydrological and mechanical mechanisms. With regard to the hydrological effect, vegetation leads to lower porewater pressure and soil moisture due to interception by foliage of rainfall, which reduces the amount of water available for infiltration, or uptake by root system of soil moisture. With regard to the mechanical aspects, root system, due to their tensile strength and frictional or adhesive properties, reinforce the soil and thus increase the resistance of soil. This mechanical effect is at times the most significant and in slope stability analysis is taken into account by means of the apparent root cohesion…

Accounting for soil parameter uncertainty in a physically based and distributed approach for rainfall-triggered landslides

In this study we propose a probabilistic approach for coupled distributed hydrological-hillslope stability models that accounts for soil parameters uncertainty at basin scale. The geotechnical and soil retention curve parameters are treated as random variables across the basin and theoretical probability distributions of the Factor of Safety (FS) are estimated. The derived distributions are used to obtain the spatio-temporal dynamics of probability of failure, in terms of parameters uncertainty, conditioned to soil moisture dynamics. The framework has been implemented in the tRIBS-VEGGIE (Triangulated Irregular Network (TIN)-based Real-time Integrated Basin Simulator-VEGetation Generator fo…

A physically-based and distributed approach to analyze rainfall-triggered landslides at a watershed scale

A spatially distributed and physically based tool to modelling rainfall-triggered landslides

Landslides are a serious threat to lives and property throughout the world. Over the last few years the need to provide consistent tools and support to decision-makers and land managers have led to significant progress in the analysis and understanding of the occurrence of landslides. The causes of landslides are varied. Multiple dynamic processes are involved in driving slope failures. One of these causes is prolonged rainfall, which affect slope stability in different ways. Water entering the ground beneath a slope always causes a rise of the piezometric surface, which in turn involves an increase of the pore-water pressure and a decrease of the soil shear resistance. For this reason, kno…

Hydrological and mechanical effects of roots in shallow landslide analysis: A physically-based approach

This study provides the first insights of a methodology for estimating the additional cohesion exercised by vegetation roots in a hillslope landslide analysis within a coupled ecohydrological-stability model. The existing coupled system is able to simulate the spatial distribution and temporal dynamics of Factor of Safety (FS) as a function of soil moisture dynamics. The model takes into account the hydrological effects of vegetation which, through the root water uptaking, contributes in reducing the soil water content and, thus, in increasing the slope stability. The additional mechanical root cohesion is estimated in a Fiber Bundle Model (FBM) framework that allows for the evaluation of t…

Evaluation of fine soil moisture data from the IFloodS (NASA GPM) Ground Validation campaign using a fully-distributed ecohydrological model

Modeling the mechanical and hydrological controls of vegetation in shallow landslides

Rainfall Induced Landslides in Puerto Rico

Landslides are a major geologic hazard in the United States, typically triggered by rainfall, earthquakes, volcanoes and human activity. Rainfall-induced landslides are the most common type in the island of Puerto Rico, with one or two large events per year. We performed an island-wide determination of static landslide susceptibility and hazard assessment as well as dynamic modeling of rainfall-induced shallow landslides in a particular hydrologic basin. Based on statistical analysis of past landslides, we determined that reliable prediction of the susceptibility to landslides is strongly dependent on the resolution of the digital elevation model (DEM) employed and the reliability of the ra…

Rainfall Induced Landslides in Puerto Rico

MODELING THE TERRAIN EVOLUTION AT BASIN SCALE: THE GEOMORPHIC COMPONENT OF TRIBS HYDROLOGICAL MODEL

Coupled stability and eco-hydrological model to predict shallow landslides

Modeling the hydrological and mechanical effect of roots in shallow landslide analysis

The additional cohesion exercised by vegetation roots (cr) provides an important contribution to the slope stability. This study proposes a methodology for estimating the cr term in a hillslope landslide analysis within a coupled ecohydrological-stability model. The coupled model simulates the spatial distribution and temporal dynamics of the Factor of Safety (FS) as a function of soil moisture dynamics, by taking into account the hydrological effects of vegetation through the root water uptaking. The additional mechanical root cohesion is estimated in a Fiber Bundle Model framework that allows for the evaluation of the root strength as a function of stress-strain relationships of populatio…

Implementing the erosion component of a physically based and distributed model (tRIBS). A first application to an experimental basin.

Effects of initialization conditions in distributed hydrological response: spatio-temporal dependencies on rainfall forcing, watershed topography and soils