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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.

Procida Island, located in the Gulf of Naples (southern Italy), is characterized by steep cliffed coasts, articulated in a succession of headlands and small embayments with narrow pocket beaches, such as Ciraccio and Chiaia, often characterized by instability. In this study, a methodology for coastal cliff susceptibility assessment has been conceived based on hydraulic and geomorphological characteristics, which supported the construction of a Cliff Stability Index (CSI). The geomorphological characteristics are related to the whole cliff face, the cliff material resistance, and the cliff failure mechanisms. The hydraulic actions on the cliff are related to the wave impact which is exerted by the breaking waves once the wave run-up distance exceeds the beach width. The index takes into account the slope of the cliff, the rock strength, the wave energy at the cliff base produced by the broken wave and the presence of defence structures at the cliff base. The resulting index classification, obtained by addition of the partial sub-indices, has been compared with the observed coastal cliff evolution from 1954 to 2021.

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.

In mountain environments, landslide sediment supply is one of the main factors that can affect fluvial morphodynamics. In settings underlain by clay-rich lithologies, where earthflows are the dominant agents of hillslope sediment transfer, limited quantitative information is available on the contribution of these processes to the sediment budget. This is a critical aspect both for addressing basic scientific questions on landscape evolution, as well for tackling more applied issues on river sediment management.This study focuses on the mountain portion of the Sillaro River basin (138 km2), a fluvial system underlain by argillites and siltstones of the Ligurian domain, Northern Apennines (Italy). Here, earthflows are the most common landslide type. Through the compilation of a multi-temporal earthflow inventory (1954-2019), we aim to: (i) characterize earthflow source-to-sink sedimentary pathways, with special reference to sediment delivery to ephemeral and perennial streams; (ii) explore possible litho-topographic controls on earthflow size, frequency and recurrence; (iii) examine historical trend of earthflow activity in relation to rainfall variability and land use changes. Finally, the high and extended temporal resolution of the inventory, will offer the opportunity to test how relevant information could complement the existing inventory of the Emilia-Romagna region, for evaluating earthflow hazard and risk potential.Data collection entailed inspection of 12 sequential aerial photo sets (1954, 1969, 1976, 1988, 1996, 2000, 2006, 2008, 2011, 2014, 2016, and 2018), through which earthflows were classified and mapped in GIS environment. This remotely-based activities were complemented by confirmatory field visits on a subset of most recent events. Overall, we have mapped a total of 506 earthflows, which collectively extend over an area of 4.1 km2.Preliminary results show that earthflow size (i.e., total disturbed area) ranges from 400 m2 to 98000 m2, with frequencies peaking around 10000 m2. In terms of source-to-sink pathways, we find that earthflows chiefly tend to deliver sediment to ephemeral gully channels (61%) and perennial tributaries (25%). Whereas, 5% of the events remain on the slopes, and another 5% are buffered by roads and similar anthropogenic barriers. Only a very limited proportion of earthflows (4%) makes it directly to the Sillaro River main stem.This work, as part of the projects BEDFLOW and BEFLOW PLUS, is partially funded by Fondazione Cassa di Risparmio in Bologna.

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

Landslides are widespread geological features in Italy’s Northern Apennines, with slow-moving earthflows among the most common types. They develop in fine-grained rocks and are subject to periodic rainfall-induced reactivations alternating to phases of dormancy. In this paper, we use radar interferometry (InSAR) and information about landslide activity to investigate deformation signals on an areal basis and to assess the dynamics of recently reactivated earthflows. We use traditional two-pass interferometry by taking advantage of the short revisit time of the Sentinel 1 satellite to characterize 4 years of slope deformations over the 60 km2 study area, where 186 landslides are mapped. Our results show that most intense and sustained deformation signals are associated with phenomena on the verge of reactivation, indicating that radar interferometry may have a potential for early warning purposes. By focusing on three specific earthflow reactivations, we analyze their dynamics through the years that preceded their failure. Despite inherent uncertainties, it was possible to retrieve the deformation signal’s temporal evolution, which displayed seasonally recurring accelerations, peaking during the major precipitation episodes in the area.

The Rendiconti Online della Società Geologica Italiana is a journal of the Italian Geological Society. It is published every four months in December, April and August.

This casebook deals with the basic principles of the Italian business law and focuses on certain recent and pivotal cases in which important rules governing the modern public company have been applied. After a short overview of the main corporate and securities laws and regulation applicable to Italian listed companies, certain leading cases which triggered the application of such rules are analyzed. The main interrelationships between and among the economic and legal elements are scrutinized for the purpose of highlighting the economic logic underlying corporate law. In the financial markets’ dynamics, the public company plays a vital role since it attracts the public savings coming from the investors in order to finance business plans and strategies which create growth and welfare. In such a scenario, financial intermediaries must act in the interest of the investors, selecting among the potential issuers those who are the most attractive for their clients. When companies are structurally organized to attract standardized equity or debt investments, by issuing listed shares, bonds or other financial instruments, their operational and governance rules change in order to safeguard the public savings coming from the investors. In the end, what makes this branch of law so interesting to students, practitioners, and scholars alike is the open-textured relationship between corporate law and securities regulation which plays a crucial role in such context. The cases selected in the second part of this book deal with significant topics in the Italian market practice and are briefly commented making reference to an updated set of laws and references. Therefore, this book can be used also with a focus on comparative legal systems for corporations taught in Italy or abroad.

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.

Rainfall thresholds for the occurrence of debris flows are commonly defined by Intensity-Duration curves (ID thresholds). Interestingly, many empirical ID thresholds show up as straight lines in a log-log plot and therefore can be expressed by power-law functions of the form I=α⋅Dβ, where α is the scaling coefficient and β is the exponent of the power function. The different values of α and β reflect the variability of geological and hydrological conditions in the different areas. In most cases, however, field conditions are so complex that a quantitative interpretation of the empirical rainfall threshold is impossible and the physical meaning of α and β remains obscure. In this work, we provide a physical interpretation of the rainfall thresholds that characterize an active debris flow catchment in the Eastern Italian Alps (the Dimai Basin, Belluno Province). The catchment is affected by frequent debris flows generated by surface-water runoff and has been monitored since 2010 to investigate the initiation process. Monitoring data allowed for the detection of two rainfall thresholds: a lower one that identifies the arrival of water in the initiation area (Catchment Outflow Threshold) and an upper one that identifies the initiation of debris flows by channel runoff (Debris Flow Threshold). We demonstrate that these two thresholds can be satisfactorily reproduced by a simple physically based model in which the excess rainfall is routed over the catchment using a kinematic-wave scheme. This simple analysis provides a sound explanation of the observed thresholds and can be used to develop physically based thresholds for runoff-generated debris flows.

In the Dolomitic region, abundant coarse hillslope sediment is commonly found at the toe of rocky cliffs. Ephemeral channels originate where lower permeability bedrock surfaces concentrate surface runoff. Debris flows initiate along such channels following intense rainfall and determine the progressive erosion and deepening of the channels. Sediment recharge mechanisms include rock fall, dry ravel processes and channel-bank failures. Here we document debris flow activity that took place in an active debris flow basin during the year 2015. The Cancia basin is located on the southwestern slope of Mount Antelao (3264 m a.s.l.) in the dolomitic region of the eastern Italian Alps. The 2.5 km2 basin is incised in dolomitic limestone rocks. The data consist of repeated topographic surveys, distributed rainfall measurements, time-lapse (2 s) videos of two events and pore pressure measurements in the channel bed. During July and August 2015, two debris flow events occurred, following similarly intense rainstorms. We compared rainfall data to existing rainfall triggering thresholds and simulated the hydrological response of the headwater catchment with a distributed model in order to estimate the total and peak water discharge. Our data clearly illustrate how debris entrainment along the channel is the main contributor to the overall mobilized volume and that erosion is dominant when the channel slope exceeds 16°. Further downstream, sediment accumulation and depletion occurred alternately for the two successive events, indicating that sediment availability along the channel also influences the flow behaviour along the prevailing-transport reach. The comparison between monitoring data, topographical analysis and hydrological simulation allows the estimation of the average solid concentration of the two events and suggests that debris availability has a significant influence on the debris flow volume. © 2020 John Wiley & Sons, Ltd.

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.