The Use of Gigapixel Photogrammetry for the Understanding of Landslide Processes in Alpine Terrain
The work illustrates an experimental application for geosciences by coupling the Gigapixel Photogrammetry, Structure-from-Motion technique (SfM), and semi-automatic rock mass characterization. The aim was to perform a stereographic analysis based on 3D model obtained from two-dimensional images acquired by GigaPan device. Field test was carried out at the Ingelsberg slope (Bad Hofgastein, Austria), which hosts one of the most dangerous landslides in the Salzburg Land.
The Contribution of Terrestrial Laser Scanning to the Analysis of Cliff Slope Stability
In this work, we describe a comprehensive approach aimed at assessing the slope stability conditions of a tuff cliff located below the village of Sugano (Central Italy) starting from remote geomechanical analysis on high-resolution 3D point clouds collected by terrestrial laser scanner (TLS) surveys. The results from the remote investigation of the cliff slope provided geometrical information of the blocks more susceptible to instability and pointed out that limit equilibrium condition can be achieved for potential triggering scenarios in the whole outcropping slope.
Digital Image Correlation (DIC) Analysis of the 3 December 2013 Montescaglioso Landslide
The objective of this article is to apply the proposed in-depth calibration and validation analysis, referred to as the Digital Image Correlation technique, to measure landslide displacement. The availability of a multi-dataset for the 3 December 2013 Montescaglioso landslide, characterized by different types of imagery (LANDSAT 8 OLI, high-resolution airborne optical orthophotos and COSMO-SkyMed, DTM) allows for the retrieval of the actual landslide displacement field. Furthermore, comprehensive sensitivity analyses and statistics-based processing approaches are used to identify the role of the background noise that affects the whole dataset. The accuracy of the environmental-instrumental background noise evaluation allowed the actual displacement measurements to be correctly calibrated and validated, thereby leading to a better definition of the threshold values of the maximum Digital Image Correlation sub-pixel accuracy and reliability (ranging from 1/10 to 8/10 pixel) for each processed dataset.
Thermal Response of Jointed Rock Masses Inferred from Infrared Thermographic Surveying
In order to evaluate the thermal response of a densely jointed rock-block, monitoring has been in operation since 2016 by direct and remote sensing techniques in an abandoned quarry in Acuto (central Italy). Monthly InfraRed Thermographic (IRT) surveys were carried out. The results highlight the daily and seasonal cyclical behavior of the rock mass. The temperature time-series revealed the effect of sun radiation and exposure on thermal response of the rock-block, which mainly depends on the seasonal conditions. The influence of opened joints in the heat propagation is revealed by the differential heating experienced across it, which was verified under 1D and 2D analysis. IRT has proved to be a valid monitoring technique in supporting traditional approaches, for the definition of the surficial temperature distribution on rock masses or stone building materials.
Imaging Multi-Age Construction Settlement Behaviour by Advanced SAR Interferometry.
This paper focuses on the application of Advanced Satellite Synthetic Aperture Radar Interferometry (A-DInSAR) to subsidence-related issues, with particular reference to ground settlements due to external loads. The paper refers to an analysis carried out in the coastal/deltaic plain west of Rome (Rome and Fiumicino municipalities) affected by subsidence and related damages to structures. The results of A-DInSAR analyses conducted from 1992 to 2015 have been interpreted in light of high-resolution geological/geotechnical models, the age of the construction, and the types of foundations of the buildings on which the PSs are located.
Experimental analysis of a masonry chimney.
The Ciminiera del Tannino is a double pipe brickwork chimney, tall about 45 m and based on a cilindrical base tall 2.25 m (also this made of brickwork). The chimney was built in the early twentieth century and has the same symptoms of degradation as the other brickwork chimneys built in Italy in the same years. The symptoms are due to the weather and the frost cycles that are no longer counteracted by the time of disuse, including the mortar washout, exfoliation of the bricks and the deviation from the vertical. We have made linear tests in static and dynamic field and, after describing the survey campaign, the results of the analysis are discussed.
Discussion to: ‘Guidelines on the use of inverse velocity method as a tool for setting alarm thresholds and forecasting landslides and structure collapses’ by T. Carlà, E. Intrieri, F. Di Traglia, T. Nolesini, G. Gigli and N. Casagli.
The present discussion addresses three different topics of landslide forecasting: (1) data filter selection according to the features of monitoring instrument; (2) the importance of data sampling frequency for the forecasting analysis and (3) the influence of the Starting Point for the application of INV analysis. Moreover, based on this matter, a new method is proposed to update the INV analysis on an ongoing basis.
International Course on Geotechnical and Structural Monitoring: past, present and future.
After four successful events involving more than 450 participants from 49 countries and 100 partners, John Dunnicliff, Paolo Mazzanti and the NHAZCA's staff are organizing the 5thIcGSM, the 21st – 25th May 2018, in Rome. Take a tour of the new websites www.geotechnicalmonitoring.eu and find out all the key information!
Toward transportation asset management: what is the role of geotechnical monitoring?
Geotechnical assets are vital for the efficiency of transportation corridors. Geotechnical monitoring can be a powerful tool for an effective maintenance of transportation assets and for safety purposes. Thanks to the technological evolution that has occurred during recent years, several monitoring technologies are now available to perform geotechnical monitoring. Ranging from remote satellite systems to contact instrumentation, it is now possible to perform a multi-scale approach in space and time, thus effectively supporting management and decision making actions. In this paper, three main categories of geotechnical monitoring are considered on the basis of the “monitoring purpose”: knowledge monitoring, control monitoring and emergency monitoring. STN (space–time-need) diagrams are proposed as a simple and useful graphic tool for the design of an effective monitoring plan that accounts for both the technical capabilities of the available monitoring technologies and the specific monitoring needs. Effective monitoring programs, suitable tools for data collection, management and processing combined with efficient models to support decision making leads to “Smart Geotechnical Asset Management” (SGAM). SGAM is a program that takes advantage of sensors collecting data in order to make risk assessment continuously updated over time.
Ground effects triggered by the 24th August 2016, Mw 6.0 Amatrice (Italy) Earthquake: Survey and Inventorying to update the CEDIT catalogue
This work presents the methodological approach used for efficiently recognizing and inventorying ground effects triggered by the 24th August 2016 (Mw 6.0) Amatrice earthquake, as well as for managing and sharing results online on a global, pre-existing and public geo-database (CEDIT)
The InSAR Feasibility Tool
Negli ultimi anni, l’aumento delle missioni SAR satellitari ha fornito l'opportunità di eseguire analisi A-DInSAR a livello globale. Allo stesso tempo, la ricerca di immagini satellitari negli archivi dei diversi distributori sta diventando sempre più complessa e dispendiosa. Per far fronte alla necessità di individuare rapidamente le aree coperte da acquisizioni SAR, NHAZCA S.r.l. e Geocento Ltd hanno sviluppato l’InSAR Feasibility Tool, una piattaforma web in grado di valutare rapidamente la disponibilità di immagini satellitari adatte per le analisi A-DInSAR (ossia gli stack interferometrici).
L’Interferometria SAR Terrestre per il monitoraggio geotecnico e strutturale
The article aimed at describing the potential and limitations of Terrestrial SAR Interferometry (TInSAR) for geotechnical and structural monitoring, describing the operating principles of the technique and presenting some example of applications.
Mechanism of the Montescaglioso Landslide Inferred by Geological Survey and Remote Sensing
Montescaglioso village is located in southern Italy (Matera, Basilicata region), on a hill top, at about 350 m a.s.l., along the left bank of the Bradano River. Several landslides involved this area, some of them classified as relict; the latest one occurred on December 3rd, 2013 on the south-western slope of Montescaglioso hill. A review of the geological setting of this slope is presented, aimed at defining the failure mechanism of the slope. Sub-pixel cross-correlation analysis based on SAR images was performed to infer the co-failure displacement pattern and A-DInSAR was carried out to detect the spatial-temporal deformational pattern before and after the failure. The field surveys confirmed the main role played by geological setting in structurally constraining the landslide mechanism and its complex kinematic, featured by three main distinct “kinematic blocks” with different direction of movement. The 3rd December landslide has been recognized as a partial reactivation along a slope affected by a long-lasting sequence of landslides, the last one triggered by a transient action.
The Experimental Landslide Monitoring Site of Poggio Baldi Landslide
On 19th March 2010, a 4 million m3 landslide was re-activated in Poggio Baldi. The landslide severely damaged some private houses, a regional road and dammed the Bidente River. The landslide can be classified as a complex movement started as a rotational slide and then evolved into an earthflow. The 2010 event was a re-activation of an ancient landslide, whose previous catastrophic activation is dated back to March 1914. Starting from 2010, the landslide has been monitored by permanent inclinometers, piezometers and extensometers. Then, from 2015 an Experimental Landslide Monitoring Site has been developed mainly for research purposes and several multi-temporal surveys have been performed by using different remote sensing techniques, such as Terrestrial Laser Scanning, Global Positioning System, Unmanned Aerial Vehicles Photogrammetry, Digital Image Correlation, Terrestrial Interferometric SAR.
Il monitoraggio dinamico delle strutture e delle infrastrutture con Interferometria Radar Terrestre
Nell’ultimo decennio si è assistito ad un crescente sviluppo di soluzioni tecniche innovative per la caratterizzazione delle proprietà dinamiche di strutture ed infrastrutture e per il monitoraggio periodico dello stato di conservazione delle stesse, noto nella letteratura scientifica come “Structural Health Monitoring” (SHM) (Balageas et al., 2006). In particolare, tra le tecnologie emergenti in tale ambito, i sistemi di telerilevamento (Mazzanti, 2012) hanno avuto un ruolo predominante. Tra le tecniche di telerilevamento più efficaci per lo SHM figura l’Interferometria Radar Terrestre (Brunetti & Mazzanti, 2015; Mazzanti et al., 2015; Mazzanti et al., 2013; Bernardini et al., 2007; Hanssen, 2001), la cui efficacia è oggigiorno pienamente comprovata. Grazie agli evidenti vantaggi offerti da tale tecnica (come la rapidità di installazione della strumentazione e di acquisizione dei dati, l’elevata risoluzione spaziale e temporale di campionamento, ecc.), questa viene sempre più frequentemente impiegata soprattutto per la valutazione speditiva di alcune caratteristiche strutturali (come le frequenze proprie di vibrazione, le forme modali e le ampiezze di oscillazione, i fattori di smorzamento, ecc.) di ponti, viadotti, edifici ed altre tipologie di strutture civili ed industriali, fornendo risultati del tutto paragonabili a quelli ottenuti attraverso altre tecniche convenzionali di monitoraggio “da contatto” come, ad esempio, reti di sensori velocimetrici e/o accelerometrici installati sulle strutture (Pieraccini et al., 2008; Atzeni et al., 2010; Gentile & Bernardini, 2010; Cunha et al., 2001; Mazzanti et al., 2014).
Analisi Geostrutturale 2.0: Caratterizzazione Di Un Ammasso Roccioso Attraverso Nuvole Di Punti
Gli ammassi rocciosi presenti sulla superficie terrestre risultano per la maggior parte discontinui e pertanto largamente condizionati nel loro comportamento meccanico dalle discontinuità. Per prevedere e prevenire fenomeni gravitativi su versanti in roccia è essenziale quindi che sia la struttura dell’ammasso roccioso che la natura delle sue discontinuità siano attentamente descritte. Uno dei primi a comprendere l’importanza delle discontinuità strutturali sul comportamento degli ammassi rocciosi fu Josef Stini, docente di “Technical Geology” alla “Università tecnica di Vienna” a partire dal 1920. A seguito degli eventi catastrofici che hanno interessato la diga di Malpasset, quella del Vajont e la miniera di Coalbrook, furono in molti ad applicarsi nell’ideazione di criteri di classificazione di versanti in roccia. Le procedure proposte da Piteau (1970, 1973), Robertson (1970) e Patton & Deere (1971) furono integrate e rielaborate nel 1978 dall’International Society for Rock Mechanics (I.S.R.M, 1978). Le raccomandazioni “Suggested Methods for the Quantitative Description of Discontinuities in Rock Masses” proposte dall’I.S.R.M., universalmente considerate come linee guida per il rilevamento geomeccanico, consentono ancora oggi di descrivere ed interpretare in modo razionale e quantitativo quello che in natura appare disordinato e casuale permettendo di effettuare ciò che sinteticamente è denominato “rilievo geostrutturale” (Moretta et al, 2012). Tuttavia, le complessità geomorfologiche e la difficile accessibilità dei versanti in roccia rendono, in molti casi, difficile l’acquisizione sistematica dei parametri previsti dalle raccomandazioni dell’I.S.R.M. e quindi la caratterizzazione dell’ammasso roccioso. Negli ultimi anni l’avvento di tecniche di telerilevamento, quali la fotogrammetria o le scansioni laser, hanno aperto nuovi scenari nell’analisi geostrutturale grazie alla loro capacità di ricostruire modelli tridimensionali del versante con elevato dettaglio. È proprio questa la nuova frontiera che denominiamo “analisi geostrutturale 2.0”.
Nuovo Sito Sperimentale di Monitoraggio Geotecnico: la Frana di Poggio Baldi (Santa Sofia, FC)
Il presente lavoro tratta la caratterizzazione di un grande fenomeno franoso che ha interessato l'abitato di Poggio Baldi (in sinistra idrografica del fiume Bidente, nel comune di Santa Sofia, provincia di Forlì-Cesena), il 19 marzo 2010. Si presentano di concerto le attività di ricerca e sviluppo svolte sul sito a partire dal 2015. La frana del marzo 2010 ha causato numerosi danni alle abitazioni private circostanti e alle infrastrutture, provocando inoltre lo sbarramento naturale del Fiume Bidente. Considerato come la riattivazione di un più antico movimento franoso, avvenuto nel marzo 1914, l’evento del 2010 è stato innescato dall’incremento della pressione dell’acqua nel terreno, probabilmente correlata ad un rapido scioglimento della copertura nevosa accumulatasi nel periodo invernale. Dal 2010, subito dopo l’evento, rilievi geologici, geomorfologici e geomeccanici di sito, sono stati effettuati al fine di approfondire la conoscenza della complessa cinematica della frana. Sono state inoltre condotte diverse attività di monitoraggio, impiegando sia tecniche di campo (inclinometri, estensimetri, piezometri), sia da remoto (laser, radar, fotogrammetria e GPS). Grazie al contributo congiunto di NHAZCA S.r.l., spin-off Sapienza - ’Università di Roma, il Dipartimento di Scienze della Terra Sapienza - Università di Roma, il Parco Nazionale delle Foreste Casentinesi, Monte Falterona e Campigna, il comune di Santa Sofia e Romagna Acque – Società delle Fonti S.p.A., è stato possibile instaurare un vero e proprio Sito Sperimentale di Monitoraggio Frana nell’area di Poggio Baldi. Qui, attività di monitoraggio ed avanzate tecniche di telerilevamento si fondono in un vero e proprio laboratorio di campo. Dal 2015, molti ricercatori e aziende leader nella produzione di strumentazione di monitoraggio geotecnico e geomatico, incontrano annualmente la comunità tecnica e scientifica per dimostrazioni dal vivo, sul campo, delle proprie tecnologie.
Assessment of Landslide Pre-Failure Monitoring and Forecasting Using Satellite SAR Interferometry
In this work, the ability of advanced satellite interferometry to monitor pre-failure landslide behaviours and the potential application of this technique to Failure Forecasting Methods (FFMs) are analysed. In this study, two of the major limitations affecting the technique have been explored: (1) the low data sampling frequency and (2) the phase ambiguity constraints. We explored the time series of displacements for 56 monitored landslides inferred from the scientific literature and from different in situ and remote monitoring instruments. Furthermore, several forecasting techniques have been applied to the monitoring data of the selected landslides. To analyse the reliability of the FFMs based on the InSAR satellite data, the time series have been sampled based on different satellite features, simulating the satellite revisit time and the constraints due to the SAR signal features.
Basin Scale Assessment of Landslides Geomorphological Setting by Advanced InSAR Analysis
An extensive investigation of more than 90 landslides affecting a small river basin in Central Italy was performed by combining field surveys and remote sensing techniques. Basic information, such as landslides mapping and landslides type definition, have been acquired thanks to geomorphological field investigations and multi-temporal aerial photos interpretation, while satellite SAR archive data (ERS and Envisat) have been analysed by means of A-DInSAR (Advanced Differential Interferometric Synthetic Aperture Radar) techniques, techniques to evaluate landslides past displacements patterns. Multi-temporal assessment of landslides state of activity has been performed basing on geomorphological evidence criteria and past ground displacement measurements obtained by A-DInSAR.
VALANCA: A Cellular Automata Model for Simulating Snow Avalanches
Numerical modelling is a major challenge in the prevention of hazards related to the occurrence of catastrophic phenomena. Cellular Automata methods were developed for modelling large scale (extended for kilometres) dangerous surface flows of different nature such as lava flows, pyroclastic flows, debris flows, rock avalanches, etc. This paper presents VALANCA, a first version of a Cellular Automata model, developed for the simulations of dense snow avalanches. VALANCA is largely based on the most advanced models developed for flow-like landslides, and adopts some innovations such as outflows characterized by the position of mass centre and explicit velocity. First simulations of well documented snow avalanches occurred in the Davos region, Switzerland (i.e. the 2006 Rüchitobel and the 2006 Gotschnawang snow avalanches) show a satisfying agreement concerning the avalanche path, snow cover erosion depth, deposit thickness and areal distribution. Furthermore, preliminary simulations of the Gotschnawang snow-avalanche, by considering the presence of mitigation structures, were performed.
First insights on the potential of Sentinel-1 for landslides detection
This paper illustrates the potential of Sentinel-1 for landslide detection, mapping and characterization with the aim of updating inventory maps and monitoring landslide activity. The study area is located in Molise, one of the smallest regions of Italy, where landslide processes are frequent. The results achieved by integrating Differential Synthetic Aperture Radar Interferometry (DInSAR) deformation maps and time series, and Geographical Information System (GIS) multilayer analysis (optical, geological, geomorphological, etc.) are shown.
Inferring the high velocity of landslides in Valles Marineris on Mars from morphological analysis.
The morphologies of the landslides are described, especially concerning those characteristics that can provide information on the dynamics and velocity.
Quarrying - induced subsidence investigated by combining contact and remote monitoring systems.
An urban area located 20 km east of Rome, affected by subsidence, has been investigated by using both contact and remote sensing methodologies. This comprehensive set of data allowed us to describe the space and time distribution of the subsidence process induced by dewatering related to quarrying activities.
Monitoring an unstable road embankment for public safety purposes by terrestrial SAR interferometry
In this paper describe an innovative approach to instability problems of a road embankment, based on Terrestrial SAR Interferometric (TInSAR) monitoring. This technique was useful for the support to the management of the emergency, the design of stabilisation countermeasures and for the control of the slope stability during the works for the stabilisation of the structure. The monitoring has been performed also after the end of the activities to test the efficacy of the performed works.
Understanding the subsidence process of a quaternary plain by combining geological and hydrogeological modelling with satellite InSAR data: The Acque Albule Plain case study
In the frame of the multidisciplinary study, advanced Satellite InSAR data have been integrated with the geological and hydrogeological model of an area near Rome, affected by strong subsidence phenomena. The achieved results allowed for the detailed characterization of such processes, that caused major damages to buildings and infrastructures.
Rock fall instabilities and safety of visitors in the historic rock cut monastery of Vardzia (Georgia)
To envisaging the stability conditions of a slope, both contact and remote sensing technique (3D Terrestrial Laser Scanning survey) have been carried out. Potential rockfalls has been simulated by a 3D modelling code, obtaining a model useful for the recognition of most critical sectors belonging to the upper part of the cliff and to support designing both short and long-term mitigation measures.
Terrestrial Laser Scanning survey of the Sugano cliff (Orvieto, Italy) for slope stability analyses.
The Terrestrial Laser Scanner (TLS) survey of the Sugano (TR, Italy) cliff has been performed, in only two days, to investigate geometrical and mechanical features of the rock mass. The results from the remote investigation allowed to perform a security analysis and an evaluation of the susceptibility to several conditions.
New data and interpretation of the huge clastic deposit of “La Pineda hill” (Vajont valley, northern Italy)
This paper focuses on a detailed study of the huge landslide deposit of “La Pineda” hill (Vajont Valley, northern Italy) through field investigations, stratigraphic borehole data and bibliographic data. Geometrical, sedimentological, morphological and morphometric features of the deposit allowed to obtain the geometrical relationship between the landslide deposit and the bedrock and the evolution of the landslide.
Landslide monitoring by Terrestrial SAR Interferometry: critical analysis of different data processing approaches.
The aim of this work is to present a critical analysis of Terrestrial Synthetic Aperture Radar Interferometry (TInSAR) technique, providing information about its reliability and the accuracy in its different kind of applications. In the frame of this work, two case studies of landslides monitored with a continuous acquisition mode have been investigated.
Structural Health Characterization of an Old Riveted Iron Bridge By Remote Sensing Techniques.
A 45 m long single span truss road bridge, built in 1930 in Southern Italy, is still serving the local community while no regular maintenance operations have been performed since its construction. In order to estimate its actual static and dynamic behavior, to predict its load carrying capacity and to preliminary estimate its remaining service life, an extensive campaign assessment is carried out by Terrestrial Radar Interferometry. In one only field work, all necessary data were collected allowing a few impact on the local traffic and a reduction of the costs.
Dynamic characterization of tower structures by means of interferometry measurements
The Aurelian Column has been investigated by the ENEA Research Center and NHAZCA S.r.l. (Spin-off company of “Sapienza” University of Rome). In order to characterize its dynamic properties for the assessment of its health status, a seismometric array made up of 24 short period (1 s) single channel sensors and two interferometric coherent radar sensors were temporary installed in one day field work.
Structural Health Monitoring of Dams by Advanced Satellite SAR Interferometry: Investigation of Past Processes and Future Monitoring Perspectives.
This paper describes three successful case histories where A-DInSAR techniques have been applied for the structural health monitoring of dams; specifically, the Three Gorges Dam (China), the Plover Cove Dam (Hong Kong) and the San Liberato Dam (Italy) have been investigated. In various geographical context, type of structure, kind of satellite sensor used, A-DInSAR technique showed its great potential for reaching specific purposes for every case-study.
A New Approach Based on Terrestrial Remote-sensing Techniques for Rock Fall Hazard Assessment.
Terrestrial remote-sensing techniques represent a great opportunity for investigating inaccessible cliffs from a remote position. In this paper, a new approach for the investigation of rock cliff and the prioritization of rock fall hazard based on the integration of remote-sensed data (ground-based SAR, Terrestrial Laser Scanner and Infrared Thermography) has been developed and applied to a real coastal cliff. A prioritizations map of the cliff in terms of stability interventions is achieved that can be easily used by local authorities in charge of land management.
The Ligosullo (UD, Italy) Landslide, Revisiting of Past Data and Prospects from Monitoring Activities.
Field surveys and monitoring activities by innovative remote sensing techniques have been performed for the characterization of the Ligosullo (UD, Italy) landslide. Specifically, Terrestrial SAR Interferometric, Satellite Interferometric and Topographic monitoring have been performed in last years for the identification of the present and historical ground deformation of the slope, also to assess the efficacy of recent remediation works for the mitigation of the phenomenon.
Terrestrial SAR Interferometry Monitoring of Natural Slopes and Man-Made Structures.
Terrestrial Synthetic Aperture Radar (SAR) Interferometry (TInSAR) is one of the most innovative techniques for the remote monitoring of displacements. It promises to be a very effective solution, which will be extensively used in the near future in the field of geotechnical engineering and geology. Thanks to its features and the advantages offered respect to conventional monitoring techniques, TInSAR has been successfully used for investigation and diagnostic purposes (e.g. landslide and structural movement monitoring).
Advanced Characterization of a Landslide-Prone Area by Satellite a-DInSAR.
A multidisciplinary approach based on conventional and innovative surveying approaches, has been lead for the characterization of an area in Central Italy heavily affected by landslide processes. Multi-temporal aerial photogrammetry and Advanced Differential Satellite Interferometric (A-DInSAR) analyses have been performed in order to provide information about historical ground deformations for the characterization of the present and past dynamic evolution of the slopes.
Analysis of a Subsidence Process by Integrating Geological and Hydrogeological Modelling with Satellite InSAR Data.
A multidisciplinary study was carried out in an urban area affected by subsidence induced by dewatering processes linked to quarry activities. Persistent Scatterer Interferometric SAR (InSAR) analyses were performed to assess the historical ground deformation and to analyse the relation among ground displacements and groundwater level variations, geological setting and geotechnical properties of subsoil.
Integrating Contact and Remote Sensing Techniques For Quick Recognition Of Bridge Dynamic Behaviour.
Detection of past slope activity in a desert area using multi-temporal DInSAR with Alos Palsar
Coastal slope involved in the construction of a road in the Sultanate of Oman was affected during the period 2011-2012 by instability processes. Satellite SAR interferometry has been chosen to investigate the past evolution of the slope. SAR images acquired by the ALOS PALSAR sensor have been analysed using a hybrid approach based on the classical dif¬ferential interferometry (DInSAR) and Quasi-Persistent Scatter¬ers (QPS) techniques. Some ground deformation processes have been detected and measured. One of them has been localised within the area affected by the recent landslide phenomenon. Thanks to this approach the deformation processes have been defined in time and the related displacements have been quantitatively estimated.
Integrating geomechanical surveys and remote sensing for sea cliff slope stability analysis: the Mt. Pucci case study (Italy)
By the integration of remote sensing technologies (Laser Scanner, Terrestrial Interferometry and Infrared Thermography), the geostructural characterization of a coastal cliff has been quickly and safely performed, thus allowing the identification of unstable sectors of the rock mass.
Furthermore, the main rock mass parameters (collected on site) allowed a full geomechanical characterization and the assessment of the safety factors according to different triggering scenarios (such hydrostatic water pressure and seismic pseudo-static action).
New insights into the temporal prediction of landslides by a terrestrial SAR interferometry monitoring case study
A slope was continuously monitored 24/7 for 4 years by Terrestrial Interferometry and other traditional techniques during the works for the realization of a highway tunnel.
The case study was a 1:1 scale experiment for the calibration of methods of landslides forecasting analysis based on the Voight semi-empirical method, applied to the different processes of instability observed. The continuous monitoring also allowed the interaction between the slope dynamic evolution and the working activities to be evaluated.
A field experiment for calibrating landslide time-of-failure prediction functions
This study demonstrates the great potential of Terrestrial Interferometry in the landslide risk forecasting. Thanks to a continuous monitoring (more than 40 months) and to the high sampling frequency of data collection (about 5 minutes), it was possible to remotely study the evolution of 10 small rock-slides since their first triggering stages till to the end of phenomenon evolution. Thanks to collected displacement data and the development of the method ADF (Average Date Fukuzono), based on the creep theory, it was demonstrated the possibility to predict the collapse of the landslides with an accuracy of about 2 hours.