The results from both techniques were finally compared and discussed. Surface fissures are potential indicators of slope instabilities and considerably influence infiltration characteristics of the soil. The increasing availability of unmanned aerial vehicles UAVs enables the observation of surface features at unprecedented detail and this study develops an image processing method combining Gaussian filters and object-oriented image analysis to map such features in very-high resolution VHR aerial images largely automatically.
At three different time steps the results of the technique are compared with expert elaborated maps. The paper presents the concept, design and construction of new ring shear apparatus, ICL The new apparatus is, compared to previous ones DPRI-5, 6, 7 , much smaller in dimensions and has higher performances.
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It can keep undrained condition up to 1 MPa of pore water pressure up to two times more than in previous versions of apparatus and load normal stress up to 1 MPa. This makes it suitable for investigation of large- scale and deep seated landslides. Speed control test and undrained cyclic loading tests were performed to show experimental procedures in details.
Typical test results are presented to show the efficiency of this ring shear apparatus. The need of living together with landslides in a sustainable way requires a strong effort in terms of landslide analysis.
Traditional methods used for mapping and monitoring mass movements can benefit from the application of remote sensing techniques coupled with GIS analysis. The use of remote sensing technologies, whether air, satellite or ground based allows a rapid acquisition of quantitative data over wide areas, reducing the field work and, as a consequence, the costs.
Differential Interferometry Synthetic Aperture Radar is a mature remote sensing technique broadly used for the measurement of slow deformations with major application in several fields. In the last years, the application to slow moving landslides has grown quickly and several examples of the monitoring capability can be found in the literature. Main goal of this work is the description of the advances in terms of products that can be achieved from both an innovative methodological approach to DInSAR data analysis and the technological improvements related to the last generation of sensors.
Among several weathering processes that may contribute to rock fall generation, a particular issue is related to freeze-thaw cycles. Several studies claim that many rock falls originate from thawing of the fractured bedrock during seasonal freezing Matsuoka and Marton Permafrost Periglac Process 19 2 —, ; Matsuoka Cold Reg Scid Technol 17 3 —, Other authors have recently suggested that ice segregation is the real cause behind bedrock fracturing Hallet Science —, ; Murton et al.
Permafrost Periglac Process 12 3 —, , Science —, Consequently, freeze and thaw processes will be deeply investigated in order to discover possible relationships between triggering mechanisms concerning rockfalls and monitoring datasets. Laboratory tests have been carried out to investigate the rupture process caused by the abovementioned cycles.
Volume 6: Risk Assessment, Management and Mitigation
Preliminary analyses were performed both in lab and on the field with the aim of testing the capability of different transducers to register micro seismic signals. It can be installed rapidly and it can rapidly provide results in the form of displacement maps. However, it has never been thoroughly tested in radar-hostile conditions such as these posed by large-scale earth slides — earth flows covered by a canopy of trees bushes and meadows, that are the typical landslides in Emilia Romagna Apennine.
To test the possibility to achieve improved surveillance capability in case of attention needed, a series of GB-InSAR spot campaigns lasting from a week to a month, was carried out in —11 in several landslides of Emilia Romagna Apennine using a commercial interferometric radar. The aim was to evaluate the performance of the technique for rapid assessment of landslide activity, even in case of partly vegetated soil coverage conditions.
The paper deals with the results obtained in 3 out of the 11 monitored sites. At Heumoes slope, Austria, the locations of slide quakes are clustered in the mid-part of the slope exhibiting lower displacement rates than the remaining slope. In contrast, at the mudslide in Super-Sauze, France, the epicenters of located slide quakes correlates well with areas of highest displacement rates.
These different behaviors are caused by the completely different layout of bedrock topography which directly influences dilatation and stress relief within the slope material. The ongoing slope instability affecting the Castagnola area is a complex and still poorly understood phenomenon which in the last few decades has undergone numerous reactivations leading to damage to buildings and civil infrastructures.
The results of the space-borne inteferometric data analysis have been compared both with the deformation measured at the head of 10 inclinometric tubes and with the openings of some cracks on buildings. The interpretation of the results has allowed to derive a multi-temporal deformation maps of the landslide, showing the up-to-date displacement field and the mean landslide velocity.
We analyze a long term monitoring dataset collected for a deep-seated rockslide Ruinon, Lombardy, Italy , which activity is documented by ground-based and remote sensing data since The monitoring data allowed to set-up and update the geological model, to identify rockslide complexities e. Displacement time series extracted from GB-InSAR provide a large amount of data even in debris-covered areas, when ground-based instrumentation fails.
Such spatially-distributed, improved information, validated by selected ground-based measurements, allowed to establish new velocity and displacement thresholds for early warning purposes. Daunia includes many small hill-top towns affected by landslides and is of particular interest for the Civil Protection — Regione Puglia Authority, one of the end users of the PSI deformation maps.
The SPINUA algorithm is used to perform interferometric analysis and detect, with mm precision, the presence of ground surface movements. We present a new procedure that allows retrieving in near-real-time 3D surface deformation models starting from data acquired via Robotized Total Stations RTS.
The RTS measurements are first pre-processed and then implemented on 3D maps that include vector arrows representative of the intensities and of the real directions of motion in a given system of coordinates. We discuss an example of application to an active large-scale landslide located in the area of Montaguto southern Italy, ca.
In this complex landslide scenario, the use of 3D representations of the surface deformation simplified the understanding of the evolution of the landslide phenomenon and received positive feedbacks from operators of the Italian Civil Protection Department.
The availability of surface displacement time series for all the radar benchmarks identified makes it also possible to change the scale of the analysis from regional to local, allowing an in depth study of the evolution of single instability phenomena, supporting the design of traditional monitoring networks, and even verifying the efficiency of remedial works. By combining results obtained in both ascending and descending acquisition geometries, it was possible to retrieve both vertical and E-W components of surface displacements.
A correlation with the results of the geophysical investigations will be proposed, with a preliminary interpretation of the surface displacement trends in the upper part of the slope. The quick K. The paper illustrates the capability of SDMT to identify remoulded zones, symptom of instability, and slip surfaces in the investigated slopes. Moreover, the paper presents the possibility to use the DMT blade as a piezometer, to monitor rapidly the variation of the ground water level in relation to weather trend.
This paper reports in situ test results and monitoring performed to characterise the development of a gravitational phenomenon. Analysis made it possible to create a 3D subsoil model to identify the main preferential paths of groundwater seepage, the boundaries of the subsidence area and the relationships between rainfall and displacements. The results of seepage and stability analyses highlight some aspects that characterise the kinematical mechanism of the slope. Displacements show a constant increase over time independently from the pluviometric regime.
Landslide Science and Practice : Volume 6: Risk Assessment, Management and Mitigation
Stratigraphic sections and geophysical investigations highlight that the subsidence basin was formed just above a morphological bedrock depression and was filled with weathered gypseous arenite and sandy silt. The slow and constant sinking of the cover may be ascribed to the progressive collapse of the voids created through karstification within the gypseous rock mass and which attract loose material from above causing vertical and horizontal movements. The phenomenon of rockfall along slopes is an environmental risk that frequently occurs in mountainous regions.
In this phenomenon are directly involved infrastructures railways, ordinary roads or highway but also residential areas as well as individual structures are also interested in prevention and defense. Among different types of action taken into account to reduce the risk of rockfall, passive defenses are solutions widely adopted.
In this field, the most frequently used are the elasto-plastic steel barriers, while greater resistance are offered by reinforced earth. The unsaturated zone buffers precipitation and controls groundwater recharges. Quantification of groundwater recharges is important for the improvement of hydrogeomorphological hazard analysis. The importance of fast preferential flow is recognized in literature, but its quantification remains difficult.
The aim of the experiments was to study the hydrological system within three morphological units characterized by different displacement rates and possible hydrological conditions. Special attention was given to identify and characterise the preferential flow patterns with the attempt for its quantification. The infiltration process was monitored with hydrological observations and hydrochemical tracers Br. Based on the analysis of all available field data, conceptual models of the hydrological responses were proposed.
Radar interferometry InSar techniques using images from several radar satellites are increasingly being used in slope stability assessment. During the past year there were at least 25 media reports of landslides, some fatal, occurring in various areas in Canada. The high-resolution InSAR images are very effective in characterizing differential motion within these low velocity coastal landslides.
Field measurements are exposed to daily and seasonal temperature variations due to meteorological and hydrological events. This paper presents the obvious influence of temperature on strain measurements with DTSS. Tests with wide range temperature variations inside the reference section and the strained section were performed.
Moreover, temperature effects on different system configuration relating reference section types are investigated. Results show temperature compensated as well as uncompensated strain of DTSS measurements. Finally, a manual temperature compensation was accomplished for comparison to DTSS temperature compensated strain. Distributed Fibre Optic Temperature sensing DTS system allows the monitoring of geo-hydrological changes of boundary conditions due to rainfall.
Based on the heat transport in soils the temperature distribution is closely correlated with the presence and movement of water in soils.
http://mail.maier.de/libraries/florida/bookingcom-flash-deals-ireland.php Therefore rainfall infiltration as well as the degree of saturation as common landslide triggers can be monitored in a distributed way. The advantage of continuous measurements over several kilometers of cable and its robustness allows a long-time and early warning monitoring for landslide occurrence.
This paper represents the potential and installation of DTS for monitoring of infiltration processes and degree of saturation in soil.
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