numerical models for planning landslide risk mitigation strategies in iconic but unstable landscapes the case of cinque torri dolomites italy abstract this study deals with the numerical modelling of large deep seated instability processes affecting the cinque torri group dolomites italy which is a unesco world heritage site the aim is to evaluate the role of intrinsic causal factors and to assess the failure mechanism proposed in previous investigations the geological model is based on topographic geological and geomechanical surveys complemented with mineralogical physical and geotechnical lab analyses for parameters determination the numerical simulations have been carried out using a distinct element method code on conceptual and site specific slope models a series of parametric analyses have been performed to characterize the role of the different predisposing factors potentially related with the ongoing rock spreading i load of the rocky pinnacles ii lithology stratigraphy and attitude of the geological units iii discontinuity sets in the rock mass iv degradation of the mechanical properties the results of this study suggest that the shear zone initiation is controlled by stress concentration due to the loading of the dolomitic pinnacles whereas its shape appears to be structurally controlled by the dip slope attitude of bedding in clay rich mudstones the interpretation of the modelling results has provided a better understanding of the ongoing deformation process which can help in targeting effective and low impact landslide risk mitigation strategies in this iconic landscape

a field experiment for calibrating landslide time of failure prediction functions over the last decades time of failure semi empirical prediction functions have been developed and applied to different landslides with mixed results in this study a field experiment was carried out to calibrate these functions with the simultaneous consideration of small size landslides and landslides that occur on slopes modified by human activities four years of continuous monitoring using an integrated platform consisting of both traditional sensors i e inclinometers piezometers load cells topographic measurement and innovative remote sensing equipment i e terrestrial sar interferometer resulted in the collection of a notably large amount of data several landslides affecting different slopes i e cut slopes cut slopes covered by spritz beton and slopes stabilised by anchored bulkheads were observed as part of the experiment thus facilitating the inference of detailed information for the pre failure behaviour nine landslides were back analysed thus allowing for calibration of the failure prediction functions for different types of slopes from these observations it was found that events occurring on slopes modified by human interventions could be effectively predicted using the voight function if suitable parameters are used as a general remark the landslides that originate from cut slopes in natural terrain behave similar to large landslides reported in the literature similar values of a and while landslides that originate from cut slopes covered by spritz beton and slopes stabilised by anchored bulkheads show values that are significantly lower and a values that are significantly higher than those of landslides on natural terrains

monitoring landslide displacements by using ground based synthetic aperture radar interferometry application to the ruinon landslide in the italian alps 1 synthetic aperture radar sar data are collected by a ground based radar system forming the synthetic aperture by the sliding of the antennas on a linear rail coherent sar processing converts the raw data into a complex image the phase of each image pixel contains information on the target sensor distance and can be exploited as a ranging tool the interferometric technique based on the comparison between paired and coherent sar images taken at different times permits the quantitative extraction of this information thus allowing the monitoring of the morphological changes the portable device used in this application was developed by the joint research center ispra italy specifically for measurements in the field it is known as linear sar and it is able to provide 17 ghz measurements with a 2 8 m synthetic aperture a measurement campaign lasting about 1 week was performed between july and august 2000 for monitoring superficial displacements at the ruinon landslide a 30 million m3 rockslide in the italian alps two sequences of interferograms are presented and discussed the interpretation of the sequences has allowed us to derive multitemporal deformation maps of the test area thus showing the entire displacement field of those landslide sectors characterized by higher radar reflectivity and coherence displacement rates up to 1 2 mm h 1 have been measured with a pixel resolution of 5 m and a measurement precision of 0 75 mm the results have been validated by using ground truth data obtained through automatic extensometers and topographic measurements discrepancies are limited to a few millimeters

analysis of a complex high strain zone at cap de creus spain abstract the structural analysis of a high strain zone developed in medium to high grade metamorphic micaschists from the cap de creus area spain provides an example of the complex relationships between geometry strain and kinematics to be found in deep crustal shear zones this high strain zone is composed of e w trending structural domains characterized by different strain intensities and associated with syntectonic emplacement of pegmatite dykes the main phase of deformation discussed here d2 affects steeply dipping bedding boudinaged quartz veins and s1 developed parallel to bedding d2 deformation of these features and of syn d2 pegmatite dykes gives rise to fold boudin structures in map view a d2 high strain zone coincides with a km scale dextral flexure of s0 s1 and s2 although all small scale structures on outcrop surfaces close to horizontal indicate a prevalent sinistral shear sense in addition a subvertical stretching lineation is present approximately parallel to the axis of the foliation deflection and thus normal to the apparent displacement direction in the high strain zone it is proposed that this high strain zone did not form by horizontal dextral simple shear with a flow plane parallel to the boundaries of high and low strain zones but acted as a zone of highly vortical sinistral non coaxial flow with a strong vertical extension component the dextral flexure of s0 s1 and s2 can be explained by considering that sinistral non coaxial flow in the low strain zones was either slower or earlier that in the high strain core this example stresses the necessity of being careful when interpreting displacement directions from the deflection of older fabric elements in deep seated high strain zones

a paleoecological analysis of a southern permafrost peatland charlevoix quebec the southernmost site where permafrost has been located in the quebec labrador peninsula is in a peatland on the subalpine summit of lac des cygnes mountain 47 41 n 70 36 w because of the thickness of its peat deposit this site contains rich ecological information about the history of the peatland and its surrounding subalpine environment we conducted a detailed macrofossil analysis to reconstruct the 6000 year history of the peatland in general the development of the lac des cygnes mountain peatland has followed the classic succession of rich fen poor fen bog found in other peatlands in subarctic boreal and temperate environments an abrupt decline in all tree macrofossils ca 4000 bp suggests that a major deforestation event occurred on the summit of lac des cygnes mountain the exact cause of this deforestation event is unknown but fire is a possible factor the lack of absolute chronological resolution near the top of the macrofossil record precludes proper dating of permafrost inceptio

remote sensing as tool for development of landslide databases the case of the messina province italy geodatabase abstract landslide geodatabases including inventories and thematic data today are fundamental tools for national and or local authorities in susceptibility hazard and risk management a well organized landslide geo database contains different kinds of data such as past information landslide inventory maps ancillary data and updated remote sensing space borne and ground based data which can be integrated in order to produce landslide susceptibility maps updated landslide inventory maps and hazard and risk assessment maps italy is strongly affected by landslide phenomena which cause victims and significant economic damage to buildings and infrastructure loss of productive soils and pasture lands in particular the messina province southern italy represents an area where landslides are recurrent and characterized by high magnitude due to several predisposing factors e g morphology land use lithologies and different triggering mechanisms meteorological conditions seismicity active tectonics and volcanic activity for this area a geodatabase was created by using different monitoring techniques including remote sensing e g sar satellite ers1 2 envisat radarsat 1 terrasar x cosmo skymed data and in situ measurements e g gbinsar damage assessment in this paper a complete landslide geodatabase of the messina province designed following the requirements of the local and national civil protection authorities is presented this geo database was used to produce maps e g susceptibility ground deformation velocities damage assessment risk zonation which today are constantly used by the civil protection authorities to manage the landslide hazard of the messina province

integration of advanced monitoring and numerical modeling techniques for the complete risk scenario analysis of rockslides the case of mt beni florence italy on december 28 2002 a landslide occurred on the eastern flank of mt beni florence italy on a slope where jointed basalts and ophiolitic breccias overlie mesozoic limestones calcari a calpionelle formation the collapse was preceded by several forewarning signals the evolution of the slope deformation was the most important of them and its analysis was the starting point for a risk scenario assessment in fact during the management of the emergency period which began on april 13 2002 in effort to evaluate the actual extension of the landslide the distribution of the displacements within the mass its kinematical characteristics and its spatial and temporal evolution data obtained by means of geomechanical surveys laboratory analyses geotechnical investigations geophysical surveys seismic and gbinsar monitoring systems distometric and automatic and distinct element numerical modeling were integrated thus it has been possible to provide public authorities with all necessary information to plan suitable measures for risk management and reduction after the event the study was completed with a runout back analysis that highlighted successes and failures of the predictive investigations

determination of the seismic signatures of landslides in soft soils a methodology based on a field scale shear box abstract we present a novel field experimental setup that can be used for studying the characteristics of landslide seismicity the setup consists of a concrete filled with soil cylinder that moves along a surficial soil corridor the emitted seismic signals are due to soil friction the cylinder acts as an upscaled sheer box allowing control over a number of parameters the magnitude of normal stress on the failure plane the degree of saturation and the type of soil this allows for the simulation of soil friction within or between different geological layers under different conditions results are site specific but can be easily reproduced for any geological environment we validate this methodology by comparing the spectral characteristics of the signals emitted by the movement of the cylinder to those induced by a controlled failure of a 2 5 m high vertical face at a nearby site with very similar geology we find a very good agreement between the two this methodology can be used as a site investigation tool for the optimization of the deployment geometry of seismic networks for landslide monitoring as well as to inform machine learning algorithms on automatic detection and classification of recorded signals during seismic monitoring of landslides

integration between ground based and satellite sar data in landslide mapping the san fratello case study abstract the potential use of the integration of psi persistent scatterer interferometry and gb insar ground based synthetic aperture radar interferometry for landslide hazard mitigation was evaluated for mapping and monitoring activities of the san fratello landslide sicily italy intense and exceptional rainfall events are the main factors that triggered several slope movements in the study area which is susceptible to landslides because of its steep slopes and silty clayey sedimentary cover in the last three centuries the town of san fratello was affected by three large landslides developed in different periods the oldest one occurred in 1754 damaging the northeastern sector of the town in 1922 a large landslide completely destroyed a wide area in the western hillside of the town in this paper the attention is focussed on the most recent landslide that occurred on 14 february 2010 in this case the phenomenon produced the failure of a large sector of the eastern hillside causing severe damages to buildings and infrastructures in particular several slow moving rotational and translational slides occurred in the area making it suitable to monitor ground instability through different insar techniques ps insar permanent scatterers sar interferometry techniques using ers 1 ers 2 envisat radarsat 1 and cosmo skymed sar images were applied to analyze ground displacements during pre and post event phases moreover during the post event phase in march 2010 a gb insar system able to acquire data continuously every 14 min was installed collecting ground displacement maps for a period of about three years until march 2013 through the integration of space borne and ground based data sets ground deformation velocity maps were obtained providing a more accurate delimitation of the february 2010 landslide boundary with respect to the carried out traditional geomorphological field survey the integration of gb insar and psi techniques proved to be very effective in landslide mapping in the san fratello test site representing a valid scientific support for local authorities and decision makers during the post emergency management

the thermal regime of a permafrost body at mont du lac des cygnes quebec a low peat plateau in the alpine forest tundra at mont du lac des cygnes 100 km northeast of quebec city contains a permafrost body 2 m thick at an elevation of 960 m this is the southernmost k

reconstructing the late holocene history of a subalpine environment charlevoix quebec using fossil insects in southern quebec charlevoix canada reconstructions of the subalpine insect assemblages were made in environments that were transformed by fire during the late holocene since 4500 bp the ecological requirements of beetle species likely to be found as fossils were studied by collecting living beetles in pitfall traps in forest suibalpine and alpine environments the late holocene changes of insect assemblages were reconstructed by recovering fossil insects from 13 peat sections modem beetle assemblages are valuable indicators of tree cover well developed podzol soils under peat as well as numerous spruce charcoal remains overlaying the podzol in all sampling sites suggest that a dense spruce cover was present before the beginning of the accumulation of peat and was eliminated by fire 4570 800 bp ground beetle and bark beetle assemblages at the base of the peat sections contained a mixture of forest and open environment species indicating that the postfire environment was a subalpine one w

on the application of sar interferometry to geomorphological studies estimation of landform attributes and mass movements this paper presents two examples of application of synthetic aperture radar sar interferometry insar to typical geomorphological problems the principles of insar are introduced taking care to clarify the limits and the potential of this technique for geomorphological studies the application of insar to the quantification of landform attributes such as the slope and to the estimation of landform variations is investigated two case studies are presented a first case study focuses on the problem of measuring landform attributes by interferometric sar data the interferometric result is compared with the corresponding one obtained by a digital elevation model dem in the second case study the use of insar for the estimation of landform variations caused by a landslide is detailed

a model for the runout analysis of rapid flow slides debris flows and avalanches runout analyses are used for risk assessment and design of remedial measures against rapid landslides such as debris flows debris avalanches rockslide avalanches large scale liquefaction failure

understanding the kinematic behavior of the active gascons rockslide from in situ and satellite monitoring data abstract the monitoring of the 410 000 m3 coastal gascons rockslide began in 2009 this paper presents and analyzes combined in situ and satellite based monitoring data to interpret the kinematic behavior of the slide and the evolution of the rockslide and the possible mechanisms that can lead to an accelerating phase of movement the available data are 1 relative displacements measured by thirteen crackmeters and manually with an extensometer tape 2 absolute displacements obtained from inclinometers and vertical shape accelerometer arrays in boreholes total station surveys and satellite based point target analysis insar pta 3 the settlement of the railway ballast monitored by two horizontal shape accelerometer arrays 4 groundwater pressures from nine vibrating wire piezometers and 5 weather conditions the study indicates that the role of water on displacements varies spatially within the rockslide the rockslide s kinematic behavior enables us to develop evolution scenarios of the rockslide which could be useful to conduct a risk analysis this leads to the identification of critical zones for railroad safety the unique set of monitoring data helps to elucidate the complexity of the rockslide s behavior

reconstruction of deformation and flow parameters from deformed vein sets abstract in any homogeneously deformed material sets of material lines with a similar stretch history occupy sectors with a scale and orientation that depend on finite strain area change rate and vorticity of the parent flow if the size and shape of these material line sectors are known they can be used to determine the sense of shear and to calculate deformation and flow parameters even if actual stretches along material lines are unknown in rocks which have undergone near homogeneous deformation on a large scale the orientation of sets of boudinaged folded and folded boudinaged or boudinaged folded veins can be used for such calculations a general theoretical background to the problem is presented and a mohr circle construction to carry out the deformation and flow analysis is introduced among other statements the theory predicts that shortened or folded boudins must develop in non coaxial monophase deformation with considerable area change in the plane of observation or in polyphase deformation

a review of terrestrial radar interferometry for measuring surface change in the geosciences this paper presents a review of the current state of the art in the use of terrestrial radar interferometry for the detection of surface changes related to mass movement different hardware types and acquisition concepts are described which use either real or synthetic aperture for radar image formation we present approaches for data processing procedures paying special attention to the separation of high resolution displacement information from atmospheric phase variations recent case studies are used to illustrate applications in terrestrial radar interferometry for change detection applications range from detection and quantification of very slow moving millimeters to centimeters per year displacements in rock walls from repeat monitoring to rapid processes resulting in fast displacements 50 m yr acquired during single measurement campaigns with durations of only a few hours fast and episodic acting processes such as rockfall and snow avalanches can be assessed qualitatively in the spatial domain by mapping decorrelation caused by those processes a concluding guide to best practice outlines the necessary preconditions that have to be fulfilled for successful application of the technique as well as in areas characterized by rapid decorrelation empirical data from a ku band sensor show the range of temporal decorrelation of different surfaces after more than two years for rock surfaces and after a few seconds to minutes in vegetated areas during windy conditions the examples show that the displacement field can be measured for landslides in dense grassland ice surfaces on flowing glaciers and snowpack creep copyright 2014 john wiley sons ltd

large scale brittle and ductile toppling of rock slopes slow ductile toppling of rock masses commonly creates large scale mountain slope deformations in some cases rock toppling can initiate an extremely rapid catastrophic landslide this theoretical and field based study was aimed at distinguishing the two alternative modes of toppling the idea that certain key parameters of the undeformed rock mass may influence failure behaviour in a quantifiable way was examined through a parametric study of a large rock slope using the universal distinct element code udec the slope was modelled using variations of rock mass strength discontinuity orientation and persistence and toe over steepening the results indicated two distinct types of failure behaviour i ductile self stabilizing flexural toppling in weak rock with a single dominant joint set and ii brittle catastrophic block toppling in strong rock containing persistent down slope oriented or horizontal cross joints which act as surfaces of separation at the base of the toppling blocks the two m

a crack induced stress approach to describe the tensile strength of transversely isotropic rocks rocks are generally more or less anisotropic depending on their structure at the scale of interest in engineering applications the magnitude of such anisotropy must often be determined for compressive as well as tensile loading conditions in this paper the authors present the results of an investigation on tensile failure of transversely isotropic rocks based on inglis analytical solution for the stress at the boundary of an elliptical flaw the strength of transversely isotropic rocks is assumed to be controlled by the maximum tensile local stress along the crack boundary equations are developed and compared with tensile test data taken from the literature the results show that the proposed formulations represent well the direct and indirect tensile strength of anisotropic rocks as a function of bedding plane orientation it is also shown that the proposed physical model correlates well with the results obtained from more empirical formulations key words rock mechanics anisotropy transverse i

application of an integrated geotechnical and topographic monitoring system in the lorano marble quarry apuan alps italy abstract accurate slope stability analysis is essential for human activity in high risk geological contexts this may however not be enough in the case of quarrying where the dynamic and evolving environment also requires effective monitoring a well designed monitoring system requires the acquisition of a huge dataset over time improving knowledge of the study area and helping to refine prediction from stability analysis this paper reports the implementation of an integrated monitoring system in a marble quarry in the apuan alps italy and some of the results obtained the equipment consists of a traditional geotechnical monitoring system extensometers crackmeters and clinometers and two modern topographic monitoring systems a terrestrial interferometer and a robotic total station this work aims to provide in depth knowledge of the large scale rock mass behaviour as a result of marble exploitation thereby allowing continuous excavation the results highlight the importance of integrating different monitoring systems

landslide monitoring by using ground based sar interferometry an example of application to the tessina landslide in italy abstract an innovative technique based on radar interferometry and implemented using ground based instrumentation has been applied for monitoring the tessina landslide italy belluno the technique has allowed us to derive multitemporal surface deformation maps of the entire depletion zone of the landslide with a high spatial resolution and accuracy the portable device used in this application is known as linear sar lisa and it is able to provide measurements at 17 ghz with a synthetic aperture of up to 2 8 m the results have been validated by comparing the recorded pixel displacements with independent measurements carried out by a motorized theodolite and electronic distance meter edm on two benchmarks

the tancitaro debris avalanche characterization propagation and modeling abstract the tancitaro volcano 3860 m is an andesitic dacitic stratovolcano located in the western portion of the trans mexican volcanic belt within the state of michoacan mexico the tectonic activity of this area has likely contributed to a large sector collapse of the volcano the first findings of a multidisciplinary investigation into this debris avalanche are presented here geomorphological analyses based on the interpretation of orthophotos satellite imagery and on gis elaborations had the objective of determining the main morphometric features of the landslide the collapse structure is an east facing horseshoe shaped crater 4 km wide and 5 3 km long while the deposit forms a large fan that is 66 km long covers an area of approximately 1155 km2 and has an estimated volume of 18 km3 event volume was established by reconstructing the paleo edifice in a gis and taking into account volumetric expansion cross sections measured in the field were also used for this purpose field investigations also highlighted the presence of two texturally distinct units which are referred to as the block facies and the matrix facies respectively the first is responsible for the typical hummock morphologies found in the proximal area a transitional zone contains a mixed block and matrix facies while in the distal portion blocks and megablocks some of which have a jigsaw puzzle texture gradually decrease in size until they disappear entirely a number of matrix samples were collected to conduct direct shear tests granulometric analyses and classification of the materials the data and analyses described above were used to discuss the mechanism controlling the long runout of the avalanche based on the comparison between the tancitaro debris avalanche and similar events we propose that mechanical fluidization was the mechanism responsible for the remarkable mobility of the landslide the predisposing factors leading to the collapse were also considered field observations suggest that these are mainly related to weakening processes operating both in volcanoes and in non volcanic areas the runout of the tancitaro debris avalanche was numerically modeled using dan w the geotechnical parameters determined in the field and from the laboratory analyses were used as input the dan w code models longitudinal spreading and the thickness and velocity of the failed mass by opportunely selecting a specific rheological model voellmy frictional bingham thus it was determined that the two parameter voellmy model provided the best simulation of the tancitaro debris avalanche movement and the best fitting rheological parameters have been found through back analysis

transferability of a calibrated numerical model of rock avalanche run out application to 20 rock avalanches on the nuussuaq peninsula west greenland long run out rock avalanches are one of the most hazardous geomorphic processes and risk assessments of the potential threat they pose are often reliant on numerical modelling of their potential run out distance the development of such models requires a thorough understanding of past flow behaviour inferred from deposits emplaced by previous events despite this few records exist of multiple rock avalanches that occurred in conditions sufficiently consistent to develop a set of more generalised and hence transferrable rules we conduct field and imagery based mapping and use numerical modelling to investigate the emplacement of 20 adjacent rock avalanches on the southern flanks of the nuussuaq peninsula west greenland the rock avalanches run out towards the vaigat strait and are sourced from a range of coastal mountains of relatively uniform geology we calibrate a three dimensional continuum dynamic flow code volcflow with data from a modern well constrained event that occurred at paatuut ad 2000 the best fit model assumes a constant retarding stress with a collisional stress coefficient simulating run out to within 0 3 of that observed this calibration was then used to model the emplacement of deposits from five other neighbouring rock avalanches before simulating the general characteristics of a further 14 rock avalanche deposits on simplified topography our findings illustrate that a single calibration of volcflow can account for the observed deposit morphology of a uniquely large collection of rock avalanche deposits emplaced by a series of events spanning a large volume range although the prevailing approach of tuning models to a specific case may be useful for detailed back analysis of that event we show that more generally applied models even using a single pair of rheological parameters can be used to model potential rock avalanches of varied volumes in a region and therefore to assess the risks that they pose

integrating radar and laser based remote sensing techniques for monitoring structural deformation of archaeological monuments ground based synthetic aperture radar interferometry gbinsar and terrestrial laser scanning tls were purposely integrated to obtain 3d interferometric radar point clouds to facilitate the spatial interpretation of displacements affecting archaeological monuments the paper describes the procedure to implement this integrated approach in the real world situations of surveillance of archaeological and built heritage targeted tests were carried out on the case study of the domus tiberiana sited along the northern side of the palatino hill in the central archaeological area of rome italy and displacements of the monument were monitored over almost one year of acquisition the gbinsar tls integration provided updated information about the condition of the archaeological structures in relation to their history of instability mechanisms and did not highlighted a general worsening for the stability of the entire monument point wise and prompt detection of displacement anomalies and or sudden changes in displacement trends proved the suitability of the method to support early warning procedures also to evaluate effects on the masonry due to human activities