Search results for "Landslides"

Modeling vegetation effects on hydrological and mechanical mechanisms of shallow landslides

2012

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

2016

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

2009

Derivation of critical rainfall thresholds for landslide in Sicily

2015

Rainfall is the primary trigger of shallow landslides that can cause fatalities, damage to properties and economic losses in many areas of the world. For this reason, determining the rainfall amount/intensity responsible for landslide occurrence is important, and may contribute to mitigate the related risk and save lives. Efforts have been made in different countries to investigate triggering conditions in order to define landslide-triggering rainfall thresholds. The rainfall thresholds are generally described by a functional relationship of power in terms of cumulated or intensity event rainfall-duration, whose parameters are estimated empirically from the analysis of historical rainfall e…

Landslides and gully slope erosion on the banks of the Gauja River between the towns of Sigulda and Līgatne

2013

This study examines contemporary and past slope erosion processes in the Gauja River valley and adjoining area between the towns of Sigulda and Līgatne. In the field survey landslides and gullies were mapped. Spatial landslide and gully data were correlated with the landslide- and gully-related features (local relief, slope lithology, slope form, slope angle and density of gullies). A novel approach was applied to establish the relationships between slope processes and factors influencing them. This approach uses correlation between raster values of landslide-related factors in specific slope sections and the number of slope processes in these sections to determine the areas prone to slope …

Submarine canyons of north-western Sicily(Southern Tyrrhenian Sea): Variability in morphology, sedimentary processes and evolution on a tectonically …

2014

Determining the optimal pixel size of topographical parameters for the prediction of hazardous geomorphological phenomenons of different magnitude: g…

2013

Mass movements (landslides) and environmental features in an area Of Alto Belice Destro (High Right Belice) Western Sicily - Italy

2007

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

2009

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…

Modelling landslides in unsaturated slopes subjected to rainfall infiltration using material point method

2016

This paper presents a dynamic fully coupled formulation for saturated and unsaturated soils that undergo large deformations based on material point method. Governing equations are applied to porous material while considering it as a continuum in which the pores of the solid skeleton are filled with water and air. The accuracy of the developed method is tested with available experimental and numerical results. The developed method has been applied to investigate the failure and post-failure behaviour of rapid landslides in unsaturated slopes subjected to rainfall infiltration using two different bedrock geometries that lie below the top soil. The models show different failure and post-failur…