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Since the beginning of the 1960s, the urban area of Bologna has experienced land subsidence due to excessive groundwater withdrawals. Ground deformation reached its peak during the 70s of the last century when maximum displacement rates of about 10 cm/year were documented, and significant damage to structures and infrastructures occurred. This process has been intensively monitored over the years, and extensive ground displacement measurements were collected employing increasingly sophisticated techniques, ranging from topographic levelling to GNSS surveys and, since 1992, satellite interferometry. Satellite data, in particular, has given a substantial contribution to the reconstruction of the subsidence process in more recent times, with a progressively higher spatial and temporal resolution towards the newer surveys. The available interferometric data are the results of four consecutive SAR campaigns undertaken by local authorities: 1992 – 2000 (ERS), 2002 – 2006 (ENVISAT), 2006 – 2011 (RADARSAT), 2011 – 2016 (RADARSAT and COSMO-SkyMed), and a fifth survey performed by the UniBo spin-off “Fragile” from the free SENTINEL1 2014 – 2020 data. As long-term data are essential to comprehensively understand the ongoing subsidence process evolution, within this work, a methodology was developed to integrate ground-based and remotely sensed monitoring data collected over the years, and produce continuous cumulative ground displacement time series and maps, depicting the long-term temporal evolution and spatial distribution of the subsidence process, respectively. The results obtained through the adopted processing chain highlight that the long-term ground displacement field well agrees with the 3D geological model of the area and that the cumulative subsidence and displacement rates temporal evolution nicely matches the pluriannual trend of the piezometric and groundwater pumping time series.

In mountain regions, debris flows are responsible for major damage to infrastructure and many casualties every year. Early Warning Systems (EWSs) based on sensor networks installed along the debris-flow channel have been implemented in some catchments around the world, including the Alps. Detecting the early phase of debris flows would allow expanding the lead time of an EWS compared to the monitoring of channelized flows upstream a vulnerable site. In this study, monitoring data gathered from 2019 to 2022 in the headwaters of the Gadria catchment, eastern Italian Alps, are analyzed. One active channel located at 2200 m a.s.l. was instrumented with a time-lapse video camera, a tipping-bucket rain gauge, and a 4.5-Hz vertical geophone. The dataset includes 5 debris-flow events that propagated from the monitored channel to the basin outlet and a large number of signals produced by other seismic sources (e.g., rockfalls, earthquakes, animals, wind). The peak amplitude, the duration and the frequency content of the seismic signals were analyzed with the support of video images to identify the different seismic sources. Results show that different seismic sources produce signals with different characteristics and that it is possible to discriminate the most intense channel processes by analyzing seismic data only. Adopting an approach similar to the rainfall thresholds, debris-flow and runoff events have been bounded by means of a power relationship between peak amplitude and signal duration. The next step of the research would be the development of an algorithm able to automatically classify the seismic sources and identify intense channel processes that can generate debris flows. A similar approach will be applied to the Blé catchment (Val Camonica, central Italian Alps) to study the triggering mechanisms and dynamics of debris flows and analyse whether the proposed approach is valid in other locations. The analysis of seismic data will be combined with the identification of triggering rainfall thresholds and the analysis of infrasound signals to develop reliable EWSs for debris flows.

Late Quaternary paleovalley systems are sedimentary bodies, tens of m thick and a few km wide, that are typically buried beneath modern deltas and coastal plains and that have no obvious geomorphological expression. Paleovalley systems are increasingly studied worldwide as they are considered possible amplifiers of earthquake damage due to the sharp contrast between their soft and unconsolidated sediment fill and the adjacent substrate. In this study, using previous high-resolution stratigraphic reconstructions of the Pescara and Manfredonia paleovalleys in the Adriatic coastal plain (Italy), we investigate the potential of the microtremor-based horizontal-to-vertical spectral ratio technique (mHVSR) to identify these sediment bodies in the subsurface. We acquired 23 microtremor measurements in the Pescara area and 54 at Manfredonia along two transects transversal to the paleovalley axes. At both sites, we were able to detect resonance peaks that we correlated with stratigraphic data. In the Pescara paleovalley system, we identified low-amplitude resonance peaks at frequencies varying between 0.9 and 4 Hz, clearly denoting a U-shaped feature with lower frequencies in the central part. At Manfredonia, the resonance peaks are more prominent (with mHVSR amplitude up to 7), and the paleovalley system is denoted by resonance frequencies between 0.9 and 2.5 Hz, with a more complex geometry shaped by the interactions of the Candelaro, Cervaro, and Carapelle rivers. Using the well-known facies architecture as a guide, we constrained the mHVSR resonance peaks to create a Frequency-Depth model and transformed the mHVSR curves from the frequency to the spatial domain to reconstruct paleovalley geometries and infer Vs models. We thus obtained the 2D models of the paleovalleys profiles. The Pescara mHVSR model shows a sedimentary cover thickness varying from 10 m (on the interfluves) to 40 m (in the depocentre). At Manfredonia, the sedimentary cover has similar thickness, in the range of 10-45 m, with variations that reflect its complex internal geometry. At both sites, paleovalley fills are characterized by low Vs velocities: comparable Vs values were obtained from the two depocentres (about 180 m/s at Pescara and 140 m/s at Manfredonia), which places paleovalley fills into the ground type D of the Standard Eurocode 8. The fundamental resonance frequencies show considerable variability along the investigated transects on very short distances (few hundred meters), in a range of frequencies that can interact with the most common building types. We mapped this variability and observed excellent correlation with the geologic cross-sections, proving the mHVSR to be an effective tool for mapping these particular sediment bodies. The 2D models obtained will serve as a basis for future seismic response simulations.

Numerical models have become a useful tool for predicting the potential risk caused by debris flows. Although a variety of numerical models have been proposed for the runout simulation of debris flows, the performances of these models in simulating specific events generally vary due to the difference in solving methods and the simulation of the entrainment/deposition processes. In this paper, two typical depth-averaged models have been used to analyze a well-documented debris-flow event that occurred in the Cancia basin on 23 July 2015. The simulations with and without bed entrainment are conducted to investigate the influence of this process on the runout behavior of the debris flow. Results show that the actual runout can be reproduced only by considering bed entrainment. If basal erosion is not taken into account, part of the debris mass deviates from the main path and both models predict unrealistic bank overflows not observed in the field. Moreover, the comparison between measured and simulated inundated areas shows that both models perform generally well in the terms of simulating the erosion-deposition pattern, although the DAN3D model predicts a greater lateral spreading and a thinner depositional thickness compared to Shen’s model. A simple numerical experiment obtains similar consequences and further illustrates the possible reasons that cause these differences.

Since their launch on the market in the late 1970s, Dual Mobility Cups (DMCs) have shown encouraging results both in terms of stability and of restoration of wide hip joint amplitude. Therefore, the use of DMCs is mainly indicated for patients at risk of dislocation, such as those with neuro-muscular diseases, femoral neck fractures, or complex situations like failed hip osteosynthesis, as well as being indicated in the setting of revisions.The objective of this review is to provide indications and recommendations for orthopedic surgeons using DMCs in complex primary and revision settings. An overview of the tech- nical and theoretical requirements necessary to achieve a successful DMC implantation is presented. According to the literature, indications have been expanded thanks to the constant improvement and development of materials and implants. Nowadays, the use of DMCs is no longer limited to revision surgery alone; on the contrary, increasingly complex cases may be approached. Long-term studies are needed before any formal conclusions can be drawn an before the promising results that have been obtained in difficult cases are consolidated.

Background: The trapeziometacarpal joint is the second joint affected by osteoarthritis in the hand. The symptoms and clinical presentation are characterized by pain, limited range of motion, muscle weakness with loss of strength, bone deformities and disability. The symptomatology often is not related to the radiographic grade of osteoarthrosis. Therefore, in addition to the radiographic stage of the disease, the treatment is influenced by multiple variables such as age, functional requirement, symptoms and stability of the joint. Objective: There are several options of surgical treatments. Although trapeziectomy and its technical variation is the gold standard for treatment, prosthesis replacement can be used with good results. This case report discusses the case of a 70-year-old male who presents bilateral trapeziometacarpal osteoarthrosis treated with two different techniques with different timelines. Methods: The patient underwent a trapeziectomy on the right hand and arthroplasty with implant on the left. In both TMC the stage of the disease was grade III according to the Eaton Litter classification and the results were evaluated according to clinical and radiographic criteria. The NPRS pain scale and the Quick Dash functional scale were used in subsequent checks. The mean follow-up was 12 months. Conclusion: There were no significantly different results with respect to pain, activities of daily living, mobility or strength. No complications were observed. The patient is satisfied with the treatment having found a better and earlier resumption of daily activity of the left hand treated with prosthesis replacement.

Some flow-like landslides tend to lose materials while moving on a relatively dry sliding surface. This phenomenon is called bed deposition. In contrast to the bed entrainment phenomenon, bed deposition is relatively poorly understood. Therefore, an improved depth-averaged model is proposed to quantify this phenomenon. The deposition depth is calculated according to the momentum conservation of the deposited mass, and the rheological property of the sliding mass on the bottom is modified considering an abrupt increase in the depth of the sliding surface after deposition. Utilizing the proposed model, the Gaolou andslide, a typical flowlike landside occurring on October 6th, 2006 with an obvious bed deposition phenomenon in Shaanxi Province of China, is simulated to investigate the influence of bed deposition on its propagation process. The results indicate that the proposed model can effectively depict the bed deposition phenomenon in the Gaolou landslide. Bed deposition dissipates part of the kinetic energy of this lndslide; thus, the simulated debris inundation area would likely be overestimated when this effect is neglected. On the other hand, the thin liquefied layer formed by the bed deposition process reduces the friction energy dissipation, contributing to the high mobility of this landslide.

Complete and accurate DNA replication requires the progression of replication forks through DNA damage, actively transcribed regions, structured DNA and compact chromatin. Recent studies have revealed a remarkable plasticity of the replication process in dealing with these obstacles, which includes modulation of replication origin firing, of the architecture of replication forks, and of the functional organization of the replication machinery in response to replication stress. However, these specialized mechanisms also expose cells to potentially dangerous transactions while replicating DNA. In this Review, we discuss how replication forks are actively stalled, remodelled, processed, protected and restarted in response to specific types of stress. We also discuss adaptations of the replication machinery and the role of chromatin modifications during these transactions. Finally, we discuss interesting recent data on the relevance of replication fork plasticity to human health, covering its role in tumorigenesis, its crosstalk with innate immunity responses and its potential as an effective cancer therapy target.

Humeral shaft fractures represent approximately 3% of all long-bone fractures and have historically been treated successfully in a non-operative way, but surgical management is indicated in several conditions. Although there are numerous randomized clinical trials and meta-analyses that have attempted to guide surgeons, there is little evidence and no consensus as to the most suitable treatment. Every treatment has its advantages and its complications, and many factors must be considered: not only the features of the fracture, but also patient compliance and surgeon experience.

Landslide risk is one of the most relevant hazard that affects the Emilia-Romagna Region. Almost 80,000 landslides were mapped in the mountainous part, and the percentage of land covered by landslides exceeds in some areas 25%. Although most of the regional landslides are relatively slow, the economic impact is critical: in 2019, 1 million euros was allocated for urgent safety interventions, and it is estimated that at least another 80 would be needed to complete the plan. These numbers place the Emilia-Romagna Region among the areas with the highest landslide risk in the world. The geological characteristics of the Region, combined with the growing exploitation of the territory and the climatic changes underway, are making this problem more and more dramatic. It is now clear that emergency responses are no longer sufficient and that they must be accompanied by prevention actions devoted to mitigate the risk. The main objective of this work is to develop Artificial Intelligence models for the prediction of landslides in the Emilia-Romagna Region. The idea is to exploit the data collected by the University of Bologna in the last 15 years, as part of the research activities carried out in collaboration with the Regional Agency for Civil Protection and the Geological Survey of the Emilia-Romagna Region.Available data consist of time series of rainfall, soil moisture, snow cover and displacement of some active landslides that have occurred in the region in recent years. The displacement data comes from permanent GPS stations, wire strain gauges, and robotic total stations installed in several landslides for emergency purposes. These data show clear relationships between precipitation and rate of movement. However, such relationships are difficult to reproduce using physically-based approaches.The proposed machine learning approach was applied to the Emilia-Romagna Region of Italy taking advantage of the historical landslide archive, which includes more than 2210 rainfall events that triggered 2363 landslide, and of the genetic classification algorithm TPOT (Tree-based Pipeline Optimization Tool) with more than 1million combinations of hyperparameters. The results show that landsliding in the study area is strongly related to rainfall event parameters (Precipitation during the event, The day of the event and in which location happened) while antecedent rainfall seems to be less important (Precipitation 30 and 60 days before the rainfall event). The distribution of landslides in the rainfall precipitation - day of the year chart shows that after the dry summer season a rain event of at least 90-100 mm is necessary to trigger a landslide. However, this number decreases as the day of the year increases, and then arrives in spring where many landslides are shown have been triggered with modest rain events (15-30 mm). The algorithm also provided an F1 test result score of 0.825, which means that it can predict a true positive (rainfall event triggers landslide) with a 70% of precision and with 95.5% about true negative (rainfall event do not triggers landslide).

Numerical models have become a useful tool for predicting the potential risk caused by debris flows. Although a variety of numerical models have been proposed for the runout simulation of debris flows, the differences and performances of these models are unknown. To this end, in this paper, two typical depth-averaged models have been selected to analyze the debris-flow event that occurred in the Cancia basin on July 23rd, 2015. The simulations with and without entrainment are conducted to analyze the influence of entrainment on the runout behavior of the debris flow. The simulated results are compared and discussed in detail. In the scenario without entrainment, a part of the debris mass deviates from the main path during propagation, while the debris mass propagates along the channel if entrainment is considered. This conclusion illustrates that entrainment cannot be ignored in this case. Additionally, the comparison between measured and simulated results shows that both models perform generally well in the terms of simulating the erosion-deposition distribution, but the DAN3D model will present a greater lateral spreading and a thinner depositional thickness than Shen’s model.

Since the beginning of the 1960s, the urban area of Bologna has experienced land subsidence due to excessive groundwater withdrawals. Sinking reached its peak in the 70s of the last century when the subsidence rate attained the maximum value of about 10 cm/year, and significant damages to structures and infrastructures occurred. This process has been intensively monitored over the years, and extensive ground displacement data were collected employing various increasingly sophisticated techniques, ranging from topographic levelling to GNSS surveys and, since 1992, to satellite interferometry. Satellite data, in particular, allowed an accurate reconstruction of the land subsidence process. The available interferometric data are the results of three different SAR campaigns undertaken by local authorities in which the PSInSAR technique was adopted: 1992 – 2000 (ERS), 2002 – 2006 (ENVISAT) and 2006 – 2011 (RADARSAT). Within this work, a new InSAR survey from the free SENTINEL1 2014 – 2020 ascending and descending orbits data was undertaken by the UniBo spin-off “Fragile”. The software GMTSAR was used to process each interferogram and then a Small Baseline (SBAS) approach was followed to resolve the ground displacements over time. Great attention was paid to the choice of reference pixels on the existing buildings and structures, in order to maximise their density in the study area, and to the definition of the considered time span ranging from 6 to 365 days, allowing to analyse both quicker and slower ground movements. Compared to previous surveys, the displacement map obtained by Sentinel has a much higher spatial and temporal resolution, thus leading to a detailed interpretation of the ongoing subsidence. Results show that the displacement field well agrees with the 3D geological model of the area and that the temporal evolution of the subsidence rate nicely matches the piezometric level and groundwater pumping temporal series.

One of the most damaging side effects associated with seismic shaking within a certain distance from the seismogenic source are possible landslide movements. Seismic-induced landslide movements can cause serious problems to local communities even if the seismic shaking is of low intensity. To face these problems, local administrators are often forced to take unpopular planning decisions that affect the population. Therefore, detailed knowledge of landslide behavior to seismic shaking appears crucial.In this study, we analyze the seismic response of a slow-moving landslide, which mainly affects clay soils. This landslide is located along a built-up area of about one thousand inhabitants (Gaggio Montano, northern Apennines, Italy), in a zone classified as medium seismic risk and its hazard potential has been assessed by considering geomorphological, geological, hydrological and seismic issues.Firstly, we compiled a database of the existent geognostic investigations (cores, inclinometers, piezometers and CPT) and of the new geophysical surveys (HVSR and MASW) specifically acquired for this study. This allowed us to realize a detailed geological model of the slope and of the landslide body. Secondly, we run a 2D-numerical model of the seismic response of the slope. This allowed to evaluate the topographic and stratigraphic effects in response to hypothetical earthquakes with return period of 475 years. Finally, we applied the Newmark method to estimate the seismic-induced landslide movements.A detailed sensitivity analysis was performed to account for the strong uncertainty in the data, especially regarding the geotechnical input parameters. The results show a dramatic influence of the shear strength parameters on the seismic-induced displacements. For example, by changing the effective friction angle by just 1°, the displacements vary more than 30 cm. This highlights the limitations of the conventional approach and the difficulty to predict the response of existing landslides to seismic shaking.

Landslides, a forest disturbance, mobilize carbon (C) sequestered in vegetation and soils. Mobilized C is deposited either onto hillslopes or into the water, sequestering C from and releasing C to the atmosphere at different time scales. The C-dense old-growth temperate forests of SE Alaska are a unique location to quantify C mobilization rate by frequent landslides that often evolve into saturated moving masses known as debris flows. In this study, the amount of C mobilized by debris flows over historic time scales was estimated by combining a landslide inventory with maps of modeled biomass and soil carbon. We analyzed SE Alaskan landslides over a 55-year period where a total of 4.69±0.21 MtC was mobilized, an average rate of 2.5 tC km−2yr−1. A single event in August 2015 mobilized 57,651±3,266 tC, an average of 63 tC km−2. Depositional fate was inferred using two methods, a standard stream intersection analysis and a second novel approach using simulated debris flow deposition modeling calibrated to the study area. Approximately 60% of debris flow deposits intersected the stream network (9% into mainstem channels, 91% into small tributaries), consistent with long-term modeled connectivity, suggesting that debris flows are likely to contribute to globally significant amounts of C buried in local fjord sediments. Our results are consistent with an emerging consensus that landslide disturbances that mobilize organic carbon may play an important role in the global carbon cycle over geologic time, with coastal temperate forests being hotspots of potential carbon sequestration.

The importance of soil moisture conditions in the initiation of landslides has been widely recognized. This study takes advantage of the distributed hydrological model to derive the soil wetness index. The derived soil wetness index is then used to determine soil wetness thresholds for landslide occurrences. In order to predict landslides based on alert zones, a zone threshold is introduced together with the soil wetness threshold to constitute the integrated threshold. We evaluate the prediction performance of the integrated thresholds with the use of skill scores and the receiver operating characteristic (ROC) curves. This study is carried out in a sub-region of the Emilia-Romagna region, Northern Italy. Results show that the derived soil wetness index could account for the hydrological process that is controlled by meteorological conditions and topographic properties. The proposed integrated threshold shows a better predictive capability than the rainfall threshold, demonstrating the effectiveness of applying the soil wetness index in landslide predictions. The optimal threshold is also determined by compromising the correct predictions and incorrect predictions, it is found that the optimal integrated threshold is more advantageous in reducing false alarms compared with the optimal rainfall threshold. This study highlights the potential of applying hydrological simulations in landslide prediction studies and provides a new way to make use of high-resolution data in zone-based landslide predictions.

Debris flow events, generated by surface runoff, occur with great frequency in the Dolomites (Northeastern Italian Alps) during the summer season. Summer thunderstorms, which are common in the region, can quickly generate runoff at the base of rocky cliffs, which then entrains and propagates downstream the underlying unconsolidated material. In the past, the main atmospheric feature considered in evaluating the initiation of debris flow events was rainfall. Observations led to the development of rainfall intensity–duration thresholds for sediment mobilization, which compared incoming severe rainfalls with the potential for triggering debris flows. This study works toward the examination of another characteristic of the atmosphere, the atmospheric electric field. In particular, the behavior of the electric field prior to convective rainfall is investigated as an indicator of rainfall intensities capable of triggering debris flows, in a basin near Cortina d’Ampezzo (Italy). Results suggest that prior to bursts of intense rainfall, the electric field derivative frequency distribution exhibits a recurrent pattern roughly half the time. When it occurs, the amplitude of derivative frequency distribution intersects the zero axis twice before rainfall reaches maximum intensity. A regression model is designed which considers the amplitude maximum and the difference in time between the crossings of the zero axis. The validation of this model suggests a mild relationship between electric field and rainfall intensity in an alpine environment.

Chen et al. show that XLF functions to limit fork reversal during DNA replication. H2AX prevents MRE11-dependent replication stress in XLF-deficient cells, suggesting that H2AX prevents the resection of regressed arms at reversed forks., XRCC4-like factor (XLF) is a non-homologous end joining (NHEJ) DNA double strand break repair protein. However, XLF deficiency leads to phenotypes in mice and humans that are not necessarily consistent with an isolated defect in NHEJ. Here we show that XLF functions during DNA replication. XLF undergoes cell division cycle 7–dependent phosphorylation; associates with the replication factor C complex, a critical component of the replisome; and is found at replication forks. XLF deficiency leads to defects in replication fork progression and an increase in fork reversal. The additional loss of H2AX, which protects DNA ends from resection, leads to a requirement for ATR to prevent an MRE11-dependent loss of newly synthesized DNA and activation of DNA damage response. Moreover, H2ax−/−:Xlf−/− cells exhibit a marked dependence on the ATR kinase for survival. We propose that XLF and H2AX function in series to prevent replication stress induced by the MRE11-dependent resection of regressed arms at reversed replication forks.

Open fractures management has always been one of the main challenges in traumatologic surgery: definition of the most appropriate therapeutic protocol is a research and debate topic. Infectious risk minimisation, soft-tissue damage resolution, fracture reduction and fixation are the main objectives in order to recover anatomical and functional integrity of the involved district. Management protocols are characterized by the contrast between an early total care approach and a gradual damage control approach. Gustilo-Anderson classification is still the most widely used in order to set open fractures management, but its limitations have led to the development of other important classifications. This article, through a literature review, aims at summarising main classifications and state of the art on open fractures treatment and at highlighting latest protocols and technical solutions adopted: negative wound pression therapy, antibacterial coated nails and other innovative devices.

With this note, we show a three-dimensional reconstruction of the basal surface of a large-scale and deep-seated rock-slide located in Northern Apennines (Northern Italy), obtained by integrating direct observations from boreholes and data from multi-methods geophysics. This type of landslides is so intrinsically complex and extended, that borehole investigations alone are generally insufficient to fully characterize the inner structures. To overcame such limitations, geophysical surveys are employed extensively (Bogoslovsky and Ogilvy 1977; Bruno and Marillier 2000; Bichler et al. 2004; Jongmans and Garambois 2007). In this study, we integrated multi-parameter data derived from 400 m of DC electrical resistivity tomography (ERT), 466 m of P-wave seismic refraction tomography (SRT), 420 meters of P-wave seismic reflection profile (SRF) together with 156 HVSR seismic noise recordings processed with spectral ratio methodology (Nakamura 1989). To constrain the inversion of the HVSR and migrate to the spatial domain the SRF, the P-wave velocity domains from SRT profiles were used after comparison with stratigraphic data. Moreover, the ERT profile fitted the geometrical features depicted by SRF profile. By means of all these data, we managed to map the surface exhibiting the highest acoustic impedance and the most relevant spatial continuity, which, according to the stratigraphic data, is to be ascribed to the basal interface between the fractured flysch rock masses involved in deep-seated sliding and the underlying undamaged bedrock. Comparison with inclinometer data also showed, presently, the active sliding surfaces match the mapped interface only in some locations, whereas in other they are shallower. This indicates that the mapped basal surface can be considered the envelope of the maximum volume involved, in the past, by the mass movement, and that part of such volume is nowadays no longer moving. The integration of multi-geophysical surveys, in this case, proved to be a valuable way to spatialize evidences collected by boreholes, providing the basis for a three-dimensional geological model of the slope that can later on be used for modelling purposes.ReferencesBichler, A., P. Bobrowsky, M. Best, M. Douma, J. Hunter, T. Calvert, and R. Burns. 2004. “Three-Dimensional Mapping of a Landslide Using a Multi-Geophysical Approach: The Quesnel Forks Landslide.” Landslides 1 (1): 29–40. https://doi.org/10.1007/s10346-003-0008-7.Bogoslovsky, V A, and A A Ogilvy. 1977. “GEOPHYSICAL METHODS FOR THE INVESTIGATION OF LANDSLIDES.” GEOPHYSICS 42 (3): 562–71. https://doi.org/10.1190/1.1440727.Bruno, F., and F. Marillier. 2000. “Test of High-Resolution Seismic Reflection and Other Geophysical Techniques on the Boup Lanslide in the Swiss Alps.” Surveys in Geophysics 21 (4): 333–48.Jongmans, Denis, and Stéphane Garambois. 2007. “Geophysical Investigation of Landslides: A Review.” Bulletin de La Societe Geologique de France 178 (2): 101–12. https://doi.org/10.2113/gssgfbull.178.2.101.Nakamura, Y. 1989. “Method for Dynamic Characteristics of Subsurface Using Microtremor on the Ground Surface.” Proc. 20th JSCE Earthquake Eng. Symposium.

Rainfall is the most significant factor for debris flows triggering. Water is needed to saturate the soil, initiate the sediment motion (regardless of the mobilization mechanism) and transform the solid debris into a fluid mass that can move rapidly downslope. This water is commonly provided by rainfall or rainfall and snowmelt. Consequently, most warning systems rely on the use of rainfall thresholds to predict debris flow occurrence. Debris flows thresholds are usually empirically-derived from the rainfall records that caused past debris flows in a certain area, using a combination of selected precipitation measurements (such as event rainfall P, duration D, or average intensity I) that describe critical rainfall conditions. Recent years have also seen a growing interest in the use of coupled hydrological and slope stability models to derive physically-based thresholds for shallow landslide initiation.In both cases, rainfall thresholds are affected by significant uncertainty. Sources of uncertainty include: measurement errors; spatial variability of the rainfall field; incomplete or uncertain debris flow inventory; subjective definition of the “rainfall event”; use of subjective criteria to define the critical conditions; uncertainty in model parameters (for physically-based approaches). Rainfall measurement is widely recognized as a main source of uncertainty due to the extreme time-space variability that characterize intense rainfall events in mountain areas. However, significant errors can also arise by inaccurate information reported in landslide inventories on the timing of debris flows, or by the criterion used to define triggering intensities.This study analyzes the common sources of uncertainty associated to rainfall thresholds for debris flow occurrence and discusses different methods to quantify them. First, we give an overview of the various approaches used in the literature to measure the uncertainty caused by random errors or procedural defects. These approaches are then applied to debris flows using real data collected in the Dolomites (Northen Alps, Itay), in order to estimate the variabilty of each single factor (precipitation, triggering timing, triggering intensity..). Individual uncertainties are then combined to obtain the overall uncertain of the rainfall threshold, which can be calculated using the classical method of “summation in quadrature” or a more effective approach based on Monte Carlo simulations. The uncertainty budget allows to identify the biggest contributors to the final variability and it is also useful to understand if this variability can be reduced to make our thresholds more precise.

Runoff-generated debris flows are a significant hazard in steep mountain ranges across the world. During intense rainfall storms, runoff can rapidly form in small steep basins and mobilise large volumes of sediment triggering debris flows which can damage infrastructure and endanger lives. A common method for forecasting debris flows is deriving empirical rainfall intensity–duration (ID) thresholds from previously recorded debris flow events in a given area. However, the storms which trigger debris flows usually are short and intense with high spatial variation making an accurate recording of the conditions responsible for initiation difficult.In this study, we investigate the impact of the spatial variability of rainfall on debris flow initiation in small, steep, and debris flow prone catchments in the eastern Italian Alps (Dolomites) using the SWEHR (Shallow Water Equation Hairsine-Rose) numerical model. The modelled catchments are monitored by multiple rain gages which we use to quantify the uncertainty of the rainfall ID thresholds due to the spatial variation of rainfall by comparing empirical and numerically modelled thresholds. We also compare simulated triggering discharges for debris flows with available field observations in the study area. This study will help to improve the quality of hazard forecasting of debris flows in mountainous regions

The complete understanding of the mechanisms controlling debris-flow initiation is still an open challenge in landslide research. Most debris-flow models assume that motion suddenly begins when a large force imbalance is imposed by slope instabilities or the substrate saturation that causes the collapse of the channel sediment cover. In the real world, the initiation of debris flows usually results from the perturbation of the static force balance that retains sediment masses in steep channels. These perturbations are primarily generated by the increasing runoff and by the progressive erosion of the deposits. Therefore, great part of regional early warning systems for debris flows are based on critical rainfall thresholds. However, these systems are affected by large spatial-temporal uncertainties due to the inadequate number and distribution of rain gauges. In addition, rainfall analysis alone does not explain the dynamics of sediment fluxes at the catchment scale: short-term variations in the sediment sources strongly influence the triggering of debris flows, even in catchments characterized by unlimited sediment supply.In this work, we present multi-parametric observations of debris flows at the headwaters of the Gadria catchment (eastern Italian Alps). In 2018, we installed a monitoring network composed of geophones, three soil moisture probes, one tensiometer and two rain-triggered videocameras in a 30-m wide steep channel located at about 2200 m a.s.l. Most sensors lie on the lateral ridges of this channel, except for the tensiometer and the soil moisture probes that are installed in the channel bed at different depths. This network recorded four flow events in two years, two of which occurred at night. Specifically, the debris flows that occurred on 21 July 2018 and 26 July 2019 produced remarkable geomorphic changes in the monitored channel, with up to 1-m deep erosion. For all events, we measured peak values of soil water content that are far from saturation (These results, although still preliminary, show the relevance of a multi-parametric detection of debris-flow initiation processes and may have valuable implications for risk management. Alarm systems for debris flows are becoming more and more attractive due the continuous development of compact and low-cost distributed sensor networks. The main challenge for operational alarm systems is the short lead-time, which is few tens of seconds for closing a transportation route or tens of minutes for evacuating settlements. Lead-time would significantly increase installing a detection system in the upper part of a catchment, where the debris flow initiates. The combination of hydro-meteorological monitoring in the source areas and seismic detection of channelized flows may be a reliable approach for developing an integrated early warning - alarm system.

Landslides are widespread landscape features in the Northern Apennine mountain chain and their activity frequently cause damages to settlements and infrastructures. In such context, slow-moving landslides are very common and typically affect fine-grained weathered rocks. Long periods of sustained slow-movements (cms/year) can be interrupted by rapid acceleration and catastrophic failures (ms/day) that are caused by intense rainfall events. Space-borne synthetic aperture radar interferometry (InSAR) proved effective to detect actively deforming phenomena and monitor their evolution in the periods before and after failures. We present InSAR results derived from the Sentinel 1 satellite constellation for landslide cases that underwent reactivation during 2019. In all cases, the catastrophic failures were unexpected and no ground-based monitoring data are available. We processed pre- and post-failure interferograms of SAR images acquired by Sentinel 1 A/B with time spans ranging from 6 to 24 days, removing those having low coherence by manual inspection. The conventional 2-pass technique allowed us to obtain measurements of surface displacement despite the fact that sparse to none infrastructures nor bare rock outcrops are present on the landslide bodies. Our interferograms show that surface displacements are visible well in advance of the actual failure. They display nearly continuous downslope motion with seasonal velocity changes. Time series between 2015 and 2019 shows that surface displacements can be appreciated throughout most part of the year with snow cover and summer peak of vegetation being the most notable exceptions. Distinct accelerations can be detected in space and time during the weeks and months preceding the reactivation.We compare time-dependent deformations to precipitation patterns to explore their relationship and to document the transition from stable to unstable deformation. Our work suggests that InSAR interferometry can be successfully used to measure pre-failure displacements and detect slow-moving landslides that are more prone to reactivation in case of rainfall events.

Earthflows are clay-rich, slow-moving landslides subjected to periodic accelerations. During the stage of rapid movement, most earthflows exhibit a change in behavior from a solid to a fluid-like state. Although this behavior has been extensively documented in the field, the mechanism leading to the rapid acceleration of earthflows is still poorly understood. Some studies suggest that earthflows essentially behave as Coulomb plastic solids, attributing the flow-like appearance to distributed internal shearing; others believe that these landslides can be treated as viscous fluids, pointing out that the material undergoes a phase transition by increasing its moisture content. Minimal data are currently available to support these different findings. In this study, we present the results of periodic and continuous measurements of Rayleigh wave velocity carried out in an active earthflow located in the northern Apennines of Italy. Our data indicate that the material undergoes significant changes in shear stiffness and undrained strength during rapid movements. In particular, the material exhibits a substantial drop of Rayleigh wave velocity as the earthflow accelerates, followed by a slow return to predisturbance Rayleigh velocities as the landslide decelerates. Soon after a surge, the earthflow material is extremely soft and the estimated gravimetric water content is above the liquid limit. In the following months, the shear stiffness gradually increases and the water content decreases to the plastic limit following a nonlinear trend typical of a consolidation process. These data demonstrate that the earthflow transforms into a viscous fluid by softening of the material and by water entrainment.

Landslide is one of the repeated geological hazards during rainy season, which causes fatalities, damage to property and economic losses in Korea. Landslides are responsible for at least 17% of all fatalities from natural hazards worldwide, and nearly 25% of annual casualties caused by natural hazards in Korea. Due to global climate change, the frequency of landslide occurrence has been increased and subsequently, the losses and damages associated with landslides also have been increased. Therefore, accurate prediction of landslide occurrence, and monitoring and early warning for ground movements are very important tasks to reduce the damages and losses caused by landslides. Various studies on landslide prediction and reduction in landslide damage have been performed and consequently, much of the recent progress has been in these areas. In particular, the application of information and geospatial technologies such as remote sensing and geographic information systems (GIS) has greatly contributed to landslide hazard assessment studies over recent years. In this paper, the recent advances and the state-of-the-art in the essential components of the landslide hazard assessment, such as landslide susceptibility analysis, runout modeling, landslide monitoring and early warning, were reviewed. Especially, this paper focused on the evaluation of the landslide susceptibility using probabilistic approach and physically based method, runout evaluation using volume based model and dynamic model, in situ ground based monitoring techniques, remote sensing techniques for landslide monitoring, and landslide early warning using rainfall and physical thresholds.

In dolomitic headwater catchments, intense rainstorms of short duration produce runoff discharges that often trigger debris flows on the scree slopes at the base of rock cliffs. In order to measure these discharges, we placed a measuring facility at the outlet (elevation 1770 m a.s.l.) of a small, rocky headwater catchment (area ∼ 0.032 km2, average slope ∼ 320%) located in the Venetian Dolomites (North Eastern Italian Alps). The facility consists of an approximately rectangular basin, ending with a sharp-crested weir. Six runoff events were recorded in the period 2011-2014, providing a unique opportunity for characterizing the hydrological response of the catchment. The measured hydrographs display impulsive shapes, with an abrupt raise up to the peak, followed by a rapidly decreasing tail, until a nearly constant plateau is eventually reached. This behavior can be simulated by means of a distributed hydrological model if the excess rainfall is determined accurately. We show that using the Soil Conservation Service Curve-Number (SCS-CN) method and assuming a constant routing velocity invariably results in an underestimated peak flow and a delayed peak time. A satisfactory prediction of the impulsive hydrograph shape including peak value and timing is obtained only by combining the SCS-CN procedure with a simplified version of the Horton equation, and simulating runoff routing along the channel network through a matched diffusivity kinematic wave model. The robustness of the proposed methodology is tested through a comparison between simulated and observed timings of runoff or debris flow occurrence in two neighboring alpine basins. This article is protected by copyright. All rights reserved.

We investigated relations between geomorphic structures, movement velocity, and basal-slip surface geometry within individual kinematic domains of two large earth flows in the Apennine Mountains of southern Italy: the “Montaguto” earth flow and the “Mount Pizzuto” earth flow. Our analyses indicated that the earth flows are composed of distinct kinematic zones characterized by specific deformational patterns and longitudinal velocity profiles. Variations in velocity within individual kinematic zones is controlled by the geometry of the basal-slip surface, and, in particular by local variations in slope angle. Slip-surface geometry and slope also seem to control the density of extensional structures in driving earth-flow elements.

Chromatin ubiquitination by the ubiquitin ligase RNF168 is critical to regulate the DNA damage response (DDR). DDR deficiencies lead to cancer-prone syndromes, but whether this reflects DNA repair defects is still elusive. We identified key factors of the RNF168 pathway as essential mediators of efficient DNA replication in unperturbed S phase. We found that loss of RNF168 leads to reduced replication fork progression and to reversed fork accumulation, particularly evident at repetitive sequences stalling replication. Slow fork progression depends on MRE11-dependent degradation of reversed forks, implicating RNF168 in reversed fork protection and restart. Consistent with regular nucleosomal organization of reversed forks, the replication function of RNF168 requires H2A ubiquitination. As this novel function is shared with the key DDR players ATM, γH2A.X, RNF8, and 53BP1, we propose that double-stranded ends at reversed forks engage classical DDR factors, suggesting an alternative function of this pathway in preventing genome instability and human disease.

The Montevecchio landslide is an active earthflow in the province of Forli-Cesena (Northern Apennines of Italy). In the last few years, this landslide reactivated several times. In order to investigate the landslide dynamics, two monitoring systems were installed by combining 3 permanent GPS stations (to measure landslide movement) and 4 geophones (to evaluate surface-wave velocity). In this paper we present the monitoring data collected during the last reactivation of the landslide (24th – 25th of May 2015). The geophones data show a clear relationship between surface-wave velocity (Vr) and displacement rate. In particular, a decrease of Vr value was observed just before an increase of velocity, while higher Vr values were detected when the landslide was slowing down. Moreover, a pressure sensor, buried at low depth beside the geophones, showed an increase in pore water pressure before the failure in correspondence of the critical rainfall event, and while the displacement rate increased the pore water pressure had a positive value (above the ground level), probably due to the undrained compression of the landslide material.

We used GPS surveys, boreholes, seismic profiles and field observations to investigate the cross sectional geometry, kinematics and sediment discharge of the Mount Pizzuto earth flow in southern Italy. This earth flow is characterized by several kinematic zones, characterized by an area of stretching with normal faults upslope and an area of shortening with thrust faults downslope. Our results indicate that: (i) during surging episodes, earth flow acceleration propagate from the head toward the toe with constant sediment discharge inducing a cascade effect between consecutive kinematic zones, (ii) change in mechanical behavior of the material might occur due to the presence of a well-defined neck influencing movement propagation, (iii) during ordinary movements, sediment discharge varies along the flow and the activity of kinematic zones seems to be independent from each other. Implications are that it is not correct to consider sediment discharge as constant but rather as a function of the earth flow activity.

The transport and deposition mechanisms of debris flows are still poorly understood due to the complexity of the interactions governing the behavior of water–sediment mixtures. Empirical–statistical methods can therefore be used, instead of more sophisticated numerical methods, to predict the depositional behavior of these highly dangerous gravitational movements. We use widely accepted semi-empirical scaling relations and propose an automated procedure (DFLOWZ) to estimate the area potentially inundated by a debris flow event. Beside a digital elevation model (DEM), the procedure has only two input requirements: the debris flow volume and the possible flow-path. The procedure is implemented in Matlab and a Graphical User Interface helps to visualize initial conditions, flow propagation and final results. Different hypothesis about the depositional behavior of an event can be tested together with the possible effect of simple remedial measures. Uncertainties associated to scaling relations can be treated and their impact on results evaluated. Our freeware application aims to facilitate and speed up the process of susceptibility mapping. We discuss limits and advantages of the method in order to inform inexperienced users.

Many flow-like landslides entrain material from their paths during motion. At the flow front and along the lateral margins the sliding mass can plow into the path material pushing or entraining the existing soil. Although plowing can be a dominant mechanism for landslide mobility, little attention has been paid to this phenomenon in comparison with other entraining mechanism such as basal scouring. Therefore, establishing a suitable mathematical description is still a challenge. In this paper, a two-layer finite difference model is proposed to simulate frontal plowing. The frontal erodible mass and the sliding mass are simplified as two separate layers based on the assumption that they are immiscible in their propagation processes. The interaction (i.e., thrusting and shear) between the two layers is simulated by the normal force and shear force acting on the two-layer interface. The governing equations for the two-layer model are deduced from the mass and momentum conservations of a soil column and transformed into a finite difference form for numerical solving. Then the proposed model is tested in the back analysis of the Ximiaodian landslide which is a typical loess flow-like landslide located at the south bank of the Jing River, China. The modeling results show that frontal plowing has significant influence on the propagation of this landslide, especially on the final topography of the deposit. Without considering this effect, the thickness of the final deposit tends to be underestimated, while the propagation duration, area and distance are likely to be overestimated. The proposed model can provide more accurate and reliable simulations for rapid flow-like landslides with frontal plowing phenomenon.

The possibility to rapidly deploy a continuous monitoring system in and around an active landslide during an emergency is crucial in order to gather information for hazard and risk scenarios updates. This paper deals with the use of an optimized portable and self-powered array of continuous GPS receivers that has been used for rapid deployment in several landslides during 2013 and 2014 emergency events in Emilia Romagna. In order to optimize the array of GPS receivers, so to make it a sort of plug-and-play system that can be operative in a few hours only and provide data in near-real time,, several technical and logistic issues had to be pre-evaluated and solved in the configuration of the system. These issues are illustrated in the short note together with some of the results obtained in the monitored sites.

Landscape evolution in active mountain chains can be dominated by gravitational slope movements. This is observed in a large portion of the Reno river catchment, Apennines, Italy, where weak rocks, such as clayshales, are subject to earthflows that control hillslope morphology and supply sediments to the channel network. In this paper, we evaluate the sediment flux generated by earthflows and compare it with Holocene-averaged deposition rates to assess the contribution of mass movements to landscape evolution. Present-day hillslope sediment flux is estimated by combining measured displacement rates (72 inclinometers) and spatial attributes of earthflows and historical frequency of reactivations. Averaged sediment yield (~ 1.6 x 10 3 t/km 2 /yr) compares well with similar studies on earthflow-dominated landscapes, despite notable differences in methodology. In the study area, the connectivity between hillslopes and the stream network is well developed and no significant sediment sinks influence the sediment transport processes. We document best estimates of regional sediment fluxes and related uncertainties, based on available data. Coarse limestone fragments, present in the clayshales, are used as a natural sediment tracer to allow a comparison with sedimentation rates taking place at the mouth of the intramontane catchment. Here, available borehole logs, 14 C datings and stratigraphic correlations of the alluvial fan are used to obtain an estimate of the deposition that took place during Holocene times. Taking also into account the role of solute transport, sedimentation rates are compared to earthflow sediment production rates. Results show a good agreement and demonstrate that earthflows are the primary mass wasting process in these weak rock lithologies. We document best estimates of regional sediment fluxes and related uncertainties. Present earthflow sediment production outpaces Holocene-averaged sedimentation rates by a factor of two. The gap between sediment production and deposition can be partly justified by uncertainties associated with our estimates and by time-scale differences. With this respect, the dynamic equilibrium between erosion and deposition, is likely affected by intra-Holocene oscillations at a short time scale (10 to 1 ky) attributable to climate variability. Terraced deposits documenting sedimentary episodes would also support such interpretation.

SAR interferometry has proven capable of measuring surface displacements in various situations including ground-settlement, landslides and excavations. We present a case study that consists of a tunnel excavation under a slope where dormant deep seated landslides are recognized. We take advantage of the high resolution images of the COSMO SkyMed Satellite system, that has a high sampling frequency, to measure the distribution of displacements in space and time. Our results are compared to ground-based InSAR data, surface geophysical techniques, GPS and inclinometer measurements. The data were acquired between 2011 and 2015 during the construction phase of the highway that will connect Bologna with Florence across the Northern Apennines. The tunnel passes under the small villages of Ripoli and Santa Maria Maddalena. The geological conditions are characterized by highly sheared flysch sandstones that belong to the LigurianMonghidoro Formation, a unit that is well known for its poor geomechanical properties and high landslide susceptibility. The work on the tunnel started in 2011 and, with the advance of the tunnel front, severe surface displacements were induced, causing damage to houses and infrastructure. The deformation slowed down after the tunnel was completed in November 2014, and low displacement rates were registered during the spring of 2015. The data illustrate the evolution of ground deformations as the excavation proceeds. In particular the InSAR results obtained with the Stanford Method of Persistent Scatterers (StaMPS) for the X-Band data of COSMO SkyMed give interesting insights into the nature of observed surface deformations that include clear downslope movements. 55 SAR scenes were analyzed that had been acquired in ascending and descending orbits, between December 2012 and February 2015. Together with the new findings from combined HVSR-MASW techniques and a detailed remapping of the area, a new conceptual geological model of the slope is developed.

Statistical and deterministic methods are widely used in geographic information system based landslide susceptibility mapping. This paper compares the predictive capability of three different models, namely the Weight of Evidence, the Fuzzy Logic and SHALSTAB, for producing shallow earth slide susceptibility maps, to be included as informative layers in land use planning at a local level. The test site is an area of about 450 km2 in the northern Apennines of Italy where, in April 2004, rainfall combined with snowmelt triggered hundreds of shallow earth slides that damaged roads and other infrastructure. An inventory of the landslides triggered by the event was obtained from interpretation of aerial photos dating back to May 2004. The pre-existence of mapped landslides was then checked using earlier aerial photo coverage. All the predictive models were run on the same set of geo-environmental causal factors: soil type, soil thickness, land cover, possibility of deep drainage through the bedrock, slope angle, and upslope contributing area. Model performance was assessed using a threshold-independent approach (the ROC plot). Results show that global accuracy is as high as 0.77 for both statistical models, while it is only 0.56 for SHALSTAB. Besides the limited quality of input data over large areas, the relatively poorer performance of the deterministic model maybe also due to the simplified assumptions behind the hydrological component (steady-state slope parallel flow), which can be considered unsuitable for describing the hydrologic behavior of clay slopes, that are widespread in the study area.

A method proposed for delineating lahar-hazard zones in volcanic valleys is adapted to debris flows. The original method is based on two predictive equations that relate the lahar volume to the cross-sectional inundated area and to the planimetric inundated area. These predictive equations were derived by combining a scaling analysis of lahar kinematics with the statistical analysis of data for 27 historical lahars. This paper tests the applicability of this approach to debris flow fans. Forty debris flow basins in the Italian Alps were surveyed, and data on 27 historical debris flow events were collected in the field or by means of aerial-photo analysis. Collected data reveal that the flow area ( A ) and the planimetric area ( B ) of a debris flow are linearly correlated to the debris flow volume ( V ) on a logarithmic scale, with high statistical significance. Moreover, the computed regression equations are very similar to those obtained from other published datasets on debris flows, leading to the global fitting equations A = 0.08 V 2 / 3 and B = 17 V 2 / 3 . These predictive equations are then implemented in an automated code (DFLOWZ) that delineates the inundated area on a debris flow fan on the basis of a user-specified debris flow volume, taking the statistical uncertainty in the prediction into account. DFLOWZ is simple reproducible, and it can handle both confined and unconfined flow. The model is tested against 10 historical debris flow events, providing a satisfactory agreement between observed and computed inundated areas. In spite of the limitations due to DEM accuracy and statistical uncertainty of the regression parameters, test results show that the method can be useful for practical applications.

Genotoxic treatments in human cells consistently induce uncoupling of replication forks and their remodeling into four-way junctions by the RAD51 recombinase., Replication fork reversal protects forks from breakage after poisoning of Topoisomerase 1. We here investigated fork progression and chromosomal breakage in human cells in response to a panel of sublethal genotoxic treatments, using other topoisomerase poisons, DNA synthesis inhibitors, interstrand cross-linking inducers, and base-damaging agents. We used electron microscopy to visualize fork architecture under these conditions and analyzed the association of specific molecular features with checkpoint activation. Our data identify replication fork uncoupling and reversal as global responses to genotoxic treatments. Both events are frequent even after mild treatments that do not affect fork integrity, nor activate checkpoints. Fork reversal was found to be dependent on the central homologous recombination factor RAD51, which is consistently present at replication forks independently of their breakage, and to be antagonized by poly (ADP-ribose) polymerase/RECQ1-regulated restart. Our work establishes remodeling of uncoupled forks as a pivotal RAD51-regulated response to genotoxic stress in human cells and as a promising target to potentiate cancer chemotherapy.

The replication-stress response enables the DNA replication machinery to overcome DNA lesions or intrinsic replication-fork obstacles, and it is essential to ensure faithful transmission of genetic information to daughter cells. Multiple replication stress–response pathways have been identified in recent years, thus raising questions about the specific and possibly redundant functions of these pathways. Here, we review the emerging mechanisms of the replication-stress response in mammalian cells and consider how they may influence the dynamics of the core DNA replication complex.

In this work we describe the deployment of a probabilistic model for landslide occurrence to support the decisional process within the Civil Protection Agency of the Emilia-Romagna Region (Italy). The model is based on the Bayes’ theorem and computes the conditional probability to have a landslide in response to a rainfall event of given duration and intensity. Unlike most the methods used to date to define rainfall thresholds, our probabilistic approach takes into account of the uncertainty in the data and provides a quantitative assessment of the threshold reliability. The model was recently applied to evaluate the landslide probability in the Emilia-Romagna region, taking advantage of the landslide historical archive that includes about 3,000 landslides whose date of occurrence is known with daily accuracy. For the operational use, we fitted the isolines of landslide probability on the rainfall duration-intensity plane and created two easy-to-read probability charts useful at two different scales: the rain gauge reference area (about 65 km2) and the regional alert zone (about 2,600 km2). The user combines the rainfall data recorded by the automated rain gauge network and the rainfall forecasts to characterize the rainfall event, and plot the rainfall path on the probability charts to evaluate the probability of failure. A sample application of the model is described.

Three tunnels for hydraulic purposes were excavated by tunnel-boring machines (TBM) in mostly hard metamorphic rocks in Northern Italy. A total of 14 km of tunnel was surveyed almost continually, yielding over 700 sets of data featuring rock mass characteristics and TBM performance. The empirical relations between rock mass rating and penetration rate clearly show that TBM performance reaches a maximum in the rock mass rating (RMR) range 40–70 while slower penetration is experienced in both too bad and too good rock masses. However, as different rocks gives different penetrations for the same RMR, the use of Bieniawski's classification for predictive purpose is only possible provided one uses a normalized RMR index with reference to the basic factors affecting TBM tunneling. Comparison of actual penetrations with those predicted by the Innaurato and Barton models shows poor agreement, thus highlighting the difficulties involved in TBM performance prediction.

We present an automated time series analysis of InSAR data for the characterization of ground subsidence induced by longwall mining at Metropolitan mine (New South Wales, Australia). The dataset derives from SqueeSAR™ processing of two Envisat radar data stacks of 44 images acquired from the ascending orbit and 43 from a descending orbit, acquired on a 35-day repeat interval in the period June 2006 to September 2010. Automated time series classification was carried out with PSTime, a specifically designed software that employs a sequence of statistical tests to classify the time series into the six different classes: uncorrelated, linear, quadratic, bilinear, discontinuous without constant velocity and discontinuous with change in velocity. Results highlight a cluster of bilinear trends with acceleration at the front of longwall panel progression and a cluster of bilinear trends with deceleration at the back. Linear trends are found at the centre of the subsidence bowl while outside most trends are uncorrelated. This picture is consistent with the evidence of acceleration in deformation trend when mining is approaching and a deceleration after extraction is completed and an essentially constant while mining takes place just underneath a specific point. Thus, time series analysis proved to be valuable for subsidence dynamics characterization, constraining in space and time the patterns of deformation trend in mining applications.

n n n n n n n n n n n n n LandSLIdE MonItorIng In thE EMILIa roMagna aPEnnInES Alberto Rosi, Matteo Berti, Nicola Bicocchi, Gabriella Castelli, Alessandro Corsini, Marco Mamei, and Franco Zambonelli Universita di Modena e Reggio Emilia Matteo Berti Universita di Bologna I taly’s Emilia Romagna Apennines are characterized by widespread landslide phenomena that pose a potential danger to villages and infrastructures. Existing monitoring technologies are coarse-grained, discontinuous, and costly. To overcome these limitations, we’ve started an interdisciplinary collaboration to study wireless sensor networks in this context. We’ve developed and deployed the first prototype in a steep landslide area near the village of Calita. The network’s infrastructure was first deployed in late 2008, and it’s been working ever since. It currently exploits 13 Crossbow Micaz motes with TinyOS software and covers a surface of approximately 500 square meters. The nodes embed accelerometer boards to capture slope movements and environmental boards to monitor ambient parameters such as temperature, pressure, humidity, and light depth. In-node processing and eventbased data delivery minimize communications and save energy. A base station delivers data to a central server every 15 minutes to support near-realtime analysis (see Figure 1). Analysis of the data collected so far proves the system’s capability to detect slope movements with high accuracy. In fact, comparisons between the sensor-network data and the data collected from the preexisting instrument sensors, such as strain gauges and inclinometers, show a good match. The wireless networks could therefore potentially act as an effective compleEnvironmental Monitoring and Task-Driven Computing

A debris flow event occurred in June 1997 in the Dolomites (Eastern Alps, Italy). The phenomenon was directly observed in the field and recorded by a video camera near its initiation area. The debris flow originated shortly after an intense rainstorm (25 mm in 30 min) whose runoff mobilised the loose coarse debris that filled the bottom of the channel in its upper part. The analysis of the steep headwater basin indicates a very short concentration time (9–14 min) that fits the quick hydrological response observed in the field. The debris flow mobilisation was not contemporaneous with the arrival of the peak water discharge in the initiation area probably due to the time required for the saturation of the highly conductive channel-bed material. Channel cross-section measurements taken along the flow channel indicate debris flow peak velocity and discharge ranging from 3.1 to 9.0 m/s and from 23 to 71 m3/s, respectively. Samples collected immediately after deposition were used to determine the water content and bulk density of the material. Channel scouring, fines enrichment and transported volume increase testify erosion and entrainment of material along the flow channel. Field estimates of the rheological properties based on open channel flow of Bingham fluid indicate a yield strength of 5000±400 Pa and relatively low viscosity (60–326 Pa s), probably due to a high percentage of fines (approx. 30%).

This paper illustrates research addressing the subject of the earthquake-induced surface effects by means of a multidisciplinary approach: tectonics, neotectonics, seismology, geology, hydrogeology, geomorphology, soil/rock mechanics have been considered. The research is aimed to verify in areas affected by earthquake-triggered landslides a methodology for the identification of potentially unstable areas. The research was organized according to regional and local scale studies. In order to better emphasise the complexity of the relationships between all the parameters affecting the stability conditions of rock slopes in static and dynamic conditions a new integrated approach, Rock Engineering Systems (RES), was applied in the Northern Apennines. In the paper, the different phases of the research are described in detail and an example of the application of RES method in a sample area is reported. A significant aspect of the study can be seen in its attempt to overcome the exclusively qualitative aspects of research into the relationship between earthquakes and induced surface effects, and to advance the idea of beginning a process by which this interaction can be quantified.

Diverse sources of information, which describes landslide movement, hillslope-channel connectivity and sedimentation rates, are analyzed to detect trends that took place during the last 12,000 years. We estimate the landslide-related sediment production rates by combining measured landslide velocities and geometries and historical landslide frequency. Coarse sediment deposition rates are measured throughout the Holocene by means of dating and stratigraphy of the alluvial fan and terraced deposits. The comparison between present-day hillslope sediment production and Holocene averaged sediment deposition rates confirms that landsliding is the main agent conveying sediments to higher order trunk streams. The connectivity between hillslopes and the stream network is well developed and no significant sediment sinks influence the sediment transport process. However fluctuations of sediment delivery rates at the outlet of the catchment took place during Holocene and are likely associated to periods of increased hillslope sediment production and channel discharge caused by climatic forcing.