1,721,015 research outputs found
ONE OF THE HAZARDOUS NEIGHBOURS OF THE VAJONT LANDSLIDE: THE HISTORICAL M. SALTA ROCK-BLOCK SLIDE-ROCK FALL
Full text linkIn the Vajont Valley (north-eastern Alps), the everlasting interactions between endogenic (tectonic, seismic, isostatic) and exogenic (glacial, slope, anthropogenic) processes have resulted in a hazardous environment. The most striking geomorpho-logical feature of the valley is the evidence of several landslide processes of different type, age, and size. The October 1963 catastrophic landslide is undoubtedly the most notorious one. However, the Pineda and Salta landslide events have left enduring signatures in the landscape of the valley. In particular, the wide landslide deposit upslope Casso, on the southern slope of M. Salta, derives from multiple overlapping events. Rock planar slides, topples, and rock falls occur since centuries, displaying a complex-composite style of activity. Nowadays, in this area, slope processes are still active and are threatening the village of Casso and the visitors of the 1963 disaster site
Editorial: Developments of remote sensing and numerical modeling applications for landslide analysis
Full text linkEditorial on the Research Topic
Developments of remote sensing and numerical modeling applications for landslide analysi
Multi-temporal analysis of the geomorphic evolution of the failure surface of the Vajont landslide
Full text linkLandslides are among the most common type of hazard that affect mountainous regions. While the impact of the single landslide is often localized and limited to the influence area, in some cases, the occurrence of major events can result in significant and long-lasting social, economic, and environmental impacts that extend beyond the area directly affected by the event. These major landslides involve the sudden detachment of large volumes of rock mass and cause significant disturbance of in-situ stress field due to slope debuttressing and reduction in lateral support, which often result in conditions of limit equilibrium affecting the remaining part of the slope. Effects of such limit equilibrium conditions can range from a long term, gradual morphological evolution of the slope due to progressive detachment of material, to the development of multistage landslides, involving the failure of volumes of rock mass similar in magnitude and impacts to the original event. In this work, we investigate the post-failure morphological evolution of the daylighting rupture surface and deposit of one of the most important historical landslides, the 1963 Vajont Slide. A preliminary investigation of a pair of airborne laser scanner (ALS) datasets, collected in 2017 and 2023, is undertaken to assess and compute the change in elevation across selected areas within the rupture surface. Based on a three-dimensional change detection analysis, the observed volumetric changes of selected, inferred rockfall events are estimated. Terrestrial and airborne photographs are also used to identify the unstable volumes that have progressively detached, as well as the damage features that outlined these unstable blocks. Finally, we discuss the long-term evolution of the slope with focus on progressive damage accumulation and its spatial relationship with inherited, tectonic structures. Ultimately, this contribution is intended to highlight the important role of post-slope failure damage accumulation on the long-term stability of rock slopes, emphasizing the critical role that post-failure monitoring and analysis can play in outlining the residual landslide hazard and, in some instances, the potential development of multi-stage landslides
Using pre-failure and post-failure remote sensing data to constrain the three-dimensional numerical model of a large rock slope failure
Full text linkFactors governing rock slope stability include lithology, geological structures, hydrogeological conditions, and landform evolution. When certain conditions are met, rock slopes may become unstable, inducing deformation and failure. In the present study, an integrated remote sensing-numerical modeling approach investigates the deformation mechanisms leading to the 1965 Hope Slide, BC, Canada and the effect of slope kinematics on the long-term evolution of the slope. Pre- and post-failure datasets were used to perform a large-scale geomorphic and structural characterization, including kinematic and block-theory analyses. Extensive data collection was also undertaken using state-of-the-art remote sensing techniques, including digital photogrammetry (Structure-from-Motion), laser scanning (aerial and terrestrial), and infrared thermography. New evidence is provided that one or more prehistoric failures caused the removal of a key-block, and the initiation of long-term slope deformation and cumulative slope damage ultimately resulting in the catastrophic 1965 event. Detailed characterization of the rock slope has allowed the first three-dimensional, distinct element numerical model of the Hope Slide to be conducted. The results of the numerical simulations involving gradual reduction of the rupture surface shear strength indicate that 1965 slope failure may represent the outcome of a long-term, progressive failure mechanism that initiated after a prehistoric landslide. This combined field mapping–remote sensing–numerical modeling study clearly highlights the role of 3D slope kinematics on the geomorphic evolution of the slope, along with the associated failure mechanisms
Linking stratigraphy, mineralogy and geotechnical properties of claystones involved in the Lacedel landslide, Cortina d’Ampezzo (Dolomites, Italy)
No full textA remote sensing approach for the derivation of numerical modelling input data: insights from the Hope Slide, Canada
No full textIn this paper, we describe an integrated remote sensing approach for the collection of geomechanical data to be used as input for continuum, discontinuum, and hybrid numerical analyses. Ground-based and aerial remote sensing techniques, including terrestrial digital photogrammetry (TDP), terrestrial laser scanning (TLS), structure-from-motion photogrammetry (SfM), and terrestrial infrared thermography (IRT) may be used for collecting rock mass data appropriate for input into varied numerical modelling approaches. To demonstrate our suggested approach, we have used the 1965 Hope Slide, British Columbia, Canada. We present the mapping of rock discontinuities for numerical modelling using a hierarchical geological structure order. Large-scale geological structures which were identified and mapped on the pre-failure and present-day topography are used in a preliminary analysis of the rock slope to investigate their influence on kinematic freedom and in bounding keyblocks. Detailed geomechanical mapping is performed on three-dimensional TDP models. IRT data is used to characterize surface water seepage. Unmanned aerial vehicle (UAV) SfM imagery of the landslide debris was used to analyse the block size distribution. Preliminary numerical discontinuum 3D-DEM modelling based on this data and assigned mechanical properties shows that with detailed planning and systematic field data collection techniques, the geological engineer can obtain the data necessary to reduce both model and parameter uncertainty and allow more reliable and realistic numerical slope simulations
Landslide-geomorphosite assessment in the Dolomites (Italy): Application of a newly implemented method
Full text linkThis paper aims at the definition of new geoheritage criteria to identify and assess landslides as geomorphosites. As first application of a newly implemented methodological approach, we propose a comparative evaluation of landslide geomorphosites in the Dolomites, north-eastern Italy. We quantitatively assess each site by using standard criteria well-established in geoheritage studies and newly defined ones related to risk perception, anthropic signature, and climate change. These new criteria aid in defining the most useful geomorphosites for educating visitors regarding themes such as landslide hazard and risk, the consequences of human activities on landslide triggering and development, and landslide activity in response to warming climatic conditions. In previous studies, geomorphosite assessment was not performed for landforms of one kind as opposed to any kinds of landforms within a specific geographic area. For the first time, we analyse a landform of a kind – namely landslides, as geomorphosites in a defined region, using old and newly defined criteria that can be applied to a variety of other landforms. Our methodology highlights the scientific importance of the definition of landslides as geomorphosites, emphasises how their consequences on human activities and the environment can be disseminated to the public, and can be applied for geomorphosite assessment of any other geomorphological landform
La formazione per disoccupati nel nuovo sistema nazionale di politiche per l’impiego
No full textIl saggio, inserito in un agile volume sul ruolo della formazione professionale nelle politiche attive del lavoro, descrive, nella prima parte, l’evoluzione dal secondo dopoguerra della legislazione italiana a sostegno della formazione professionale dei lavoratori disoccupati e, nella parte finale, le principali novità rinvenibili nel d. lgs. n. 150/2015 (Riordino della normativa in materia di servizi per il lavoro e di politiche attive del lavoro) e nella legge n. 26/2019 (istituzione del Reddito di cittadinanza)
Coastal cliff retreat and landslide processes: a preliminary quantitative characterization at Portonovo-Trave cliffs (Conero, Ancona, Italy)
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