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Growing and uncontrolled urbanization and climate change (with an associated increase in the frequency of intense meteoric events) have led to a rising number of flooding events in urban areas due to the insufficient capacity of conventional drainage systems. Nature-Based Solutions represent a contribution to addressing these problems through the creation of a multifunctional green infrastructure, both in urban areas and in the countryside. The aim of this work was to develop a methodology to define Green Infrastructure for stormwater management at the municipal level. The methodology is defined on the basis of three phases: the definition of the territorial information needed, the production of base maps, and the production of a Suitability Map. In the first phase, we define the information needed for the identification of non-urbanized areas where rainwater can potentially infiltrate, as well as areas with soil characteristics that can exclude or limit rainwater infiltration. In the second phase, we constructed the following base maps: a “map of green areas”, a “map of natural surface infiltration potential” and a “map of exclusion areas”. In phase 3, starting from the base maps created in phase 2 and using Geographical Information Systems’ (GIS) geoprocessing procedures, the “Green area compatibility map to realize Green Infrastructure”, the “map of areas not suitable for infiltration” and the final “Green Infrastructure Suitability Map” are created. This methodology should help municipal authorities to set up Green Infrastructure Suitability Maps as a tool for land-use planning.
Giulio Senes; Paolo Ferrario; Gianpaolo Cirone; Natalia Fumagalli; Paolo Frattini; Giovanna Sacchi; Giorgio Valè. Nature-Based Solutions for Storm Water Management—Creation of a Green Infrastructure Suitability Map as a Tool for Land-Use Planning at the Municipal Level in the Province of Monza-Brianza (Italy). Sustainability 2021, 13, 6124 .
AMA StyleGiulio Senes, Paolo Ferrario, Gianpaolo Cirone, Natalia Fumagalli, Paolo Frattini, Giovanna Sacchi, Giorgio Valè. Nature-Based Solutions for Storm Water Management—Creation of a Green Infrastructure Suitability Map as a Tool for Land-Use Planning at the Municipal Level in the Province of Monza-Brianza (Italy). Sustainability. 2021; 13 (11):6124.
Chicago/Turabian StyleGiulio Senes; Paolo Ferrario; Gianpaolo Cirone; Natalia Fumagalli; Paolo Frattini; Giovanna Sacchi; Giorgio Valè. 2021. "Nature-Based Solutions for Storm Water Management—Creation of a Green Infrastructure Suitability Map as a Tool for Land-Use Planning at the Municipal Level in the Province of Monza-Brianza (Italy)." Sustainability 13, no. 11: 6124.
Natural gas in clathrate hydrates is regarded as a potential energy source that has received increased attention to optimize production strategies with controllable impacts on the environment. This paper investigates possible instability of a gently sloping reservoir of oceanic hydrates induced by gas production using the huff-puff method through a horizontal well. The geomechanical stability of the slope is analyzed within the framework of the limit equilibrium method by considering the dynamic change in the pore pressure and the strength parameters of the slope during gas production. The production process is simulated by a coupled analysis of heat and flow transport considering thermal effects of hydrate dissociation and formation, and the time-dependent pore pressure and strength parameters are attained from this analysis and passed to the slope stability analysis. Parametric studies are performed to screen the optimal production scenario under different site conditions. Being part of the huff-puff production process, thermal stimulation during the huff stage poses a risk of production-induced instability to the slope. Overpressure is the dominant cause for slope failure, and strength reduction due to hydrate dissociation plays a secondary role in the studied scenario. The production-induced slope failure likely takes place at a site with interbedded geological structures that promote overpressure expansion in a laterally extending band beneath the potential failure surface. Thus, the geological structures should be properly modelled in reservoir simulations, as they could impact the production effectiveness and geomechanical response of the reservoir remarkably. This study demonstrates a need for a multi-objective optimization procedure to seek the overall optimal production strategy, since the economically optimal option is not necessarily free of risk of production-induced geo-hazards.
Lin Tan; Fang Liu; Yu Huang; Giovanni Crosta; Paolo Frattini; Xueqi Cen. Production-induced instability of a gentle submarine slope: Potential impact of gas hydrate exploitation with the huff-puff method. Engineering Geology 2021, 289, 106174 .
AMA StyleLin Tan, Fang Liu, Yu Huang, Giovanni Crosta, Paolo Frattini, Xueqi Cen. Production-induced instability of a gentle submarine slope: Potential impact of gas hydrate exploitation with the huff-puff method. Engineering Geology. 2021; 289 ():106174.
Chicago/Turabian StyleLin Tan; Fang Liu; Yu Huang; Giovanni Crosta; Paolo Frattini; Xueqi Cen. 2021. "Production-induced instability of a gentle submarine slope: Potential impact of gas hydrate exploitation with the huff-puff method." Engineering Geology 289, no. : 106174.
Attaining a comprehensive and reliable water balance of snow-dominated alpine catchments is fundamental for a holistic representation of the hydrological and hydrogeological processes. A major limitation to the elaboration of this balance in alpine terrain is the difficultly of data acquisition as well as the limited presence of meteorological stations. Remotely sensed data can provide valuable information for the balance elaboration at a regional scale. We exploited Sentinel-satellite data to estimate the groundwater storage for one hydrologic year in an extensive Alpine catchment located in northern Italy. Evapotranspiration (ET) and Snow Water Equivalent (SWE) were estimated once weekly with the combined use of Sentinel data, at a spatial resolution of 20 m and 30 m, respectively. Finally, the groundwater storage was estimated by means of the residual water balance approach. The results show that the adopted satellite-based methods allow obtaining consistent and physically realistic values to describe the groundwater storage dynamics, with a relatively low uncertainty (36%). For the studied hydrologic year, a positive storage occurred only in the snowmelt period and the overall storage was negative, leading to a lowering of the groundwater level in the floodplain. In addition, the influence of physiographic parameters (altitude, slope, and aspect) and the seasonal conditions on the estimates of ET and snow-depth were investigated. For SWE estimates, an altitude-dependent effect and a lower accuracy in the snowmelt phase were observed. Finally, the estimated values of ET and the SWE-linked components were verified for a gauged tributary valley with negligible groundwater storage.
Roberta PericoiD; Philip Brunner; Paolo Frattini; Giovanni Battista Crosta. Water balance in Alpine catchments by Sentinel data. 2021, 1 .
AMA StyleRoberta PericoiD, Philip Brunner, Paolo Frattini, Giovanni Battista Crosta. Water balance in Alpine catchments by Sentinel data. . 2021; ():1.
Chicago/Turabian StyleRoberta PericoiD; Philip Brunner; Paolo Frattini; Giovanni Battista Crosta. 2021. "Water balance in Alpine catchments by Sentinel data." , no. : 1.
Time series of rock glaciers (RG) movements in the European Alps indicate an acceleration in permafrost creep in recent decades in relation to an increase in ground temperatures and water content. In this work, we analyse the geomorphological changes of an active RG located in the Western European Alps, in Valtournenche Valley (AO, Italy).
Five photogrammetric surveys were realized on the RG between 2015 to 2019, using a senseFly eBee RTK and a DJI Phantom 4 UAVs. During UAV acquisitions, 21 ground control points were placed all over the study area and their coordinates were measured in GNSS RTK mode, for georeferencing each photogrammetric model. The monitoring activity also includes GNSS campaigns, carried out annually since 2012, which provides high accurate surface displacement measurements but limited to 54 points. In addition, in July 2015 two Electrical Resistivity Tomography profiles were performed, with the Wenner-Schlumberger configuration, to identify the internal structure and potential ground ice content inside the main body of the RG.
The Structure-from-Motion technique was used to generate orthophotos and digital surface models with a resolution of 5 cm/px. Successively, we estimated the three-dimensional change of the surface displacements (surface lowering and accumulation processes) of the RG comparing pairs of point clouds, using the Multiscale Model to Model Cloud Comparison (M3C2 plug-in). A first evaluation of the horizontal surface velocity was computed identifying corresponding features manually on the orthophotos through time and a second assessment was performed based on repeated GNSS campaigns. Surface velocity obtained by orthophotos manual identifications is validated against repeated GNSS measurements. The analysis shows a good correlation at all magnitudes with a R2 equal to 0.988 and RMSE of 26 cm.
The RG shows a clear distinction in creep dynamics between a faster western part (values up to 1.8 m/y) and a slower eastern part, with values below 0.1 m/y in the most upstream part. Considering the period 2012-2020, maximum peak of surface velocity is reached in 2015, followed by a velocity decrease until 2017-2018 when the smallest movements are recorded. However, the following two years (2018-2019 and 2019-2020) are marked by a gradual increase in surface horizontal velocity. The absence of significant of any significant movement in the upstream part is related to the lack of permafrost consecutive to the development and advance of a local glacier during the Little Ice Age. The slower eastern part is almost gently inclined and corresponds to a currently degrading part of the RG, with an ice melt-induced subsidence of up to 5 cm/year. The faster area is also the steepest, where the driving stress is also the largest. The presence of the frozen ground at depth, probably its structure and thermal state, but also the topographical settings are the main factors explaining the current RG flow pattern.
Francesca Bearzot; Roberto Garzonio; Biagio Di Mauro; Christian Hauck; Reynald Delaloye; Umberto Morra Di Cella; Edoardo Cremonese; Paolo Pogliotti; Giovanni Battista Crosta; Roberto Colombo; Paolo Frattini; Micol Rossini. Monitoring the dynamics of an alpine rock glacier with repeated UAV and GNSS data. 2021, 1 .
AMA StyleFrancesca Bearzot, Roberto Garzonio, Biagio Di Mauro, Christian Hauck, Reynald Delaloye, Umberto Morra Di Cella, Edoardo Cremonese, Paolo Pogliotti, Giovanni Battista Crosta, Roberto Colombo, Paolo Frattini, Micol Rossini. Monitoring the dynamics of an alpine rock glacier with repeated UAV and GNSS data. . 2021; ():1.
Chicago/Turabian StyleFrancesca Bearzot; Roberto Garzonio; Biagio Di Mauro; Christian Hauck; Reynald Delaloye; Umberto Morra Di Cella; Edoardo Cremonese; Paolo Pogliotti; Giovanni Battista Crosta; Roberto Colombo; Paolo Frattini; Micol Rossini. 2021. "Monitoring the dynamics of an alpine rock glacier with repeated UAV and GNSS data." , no. : 1.
Rockfalls are severe and common dangerous events in mountain areas which are strongly controlled by geological and weather conditions. Remotely sensed data allows to identify slowly moving block volumes and to characterize the evolution towards collapse. The commonly adopted approaches for time to failure estimations generally rely on the inverse velocity approach. In this study we investigate the capabilities of a viscoplastic model to simulate the progressive evolution of the block instability with time. We use the monitored time series to calibrate the model parameters and then we pass to the modeling of the entire rockfall events and to the design of mitigation countermeasures. To this aim we study the May 29th 2018 Gallivaggio rock fall (San Giacomo Filippo, Sondrio, Italy) when about 5,000 m3 of rock detached from a 400 m high cliff, causing considerable damage to the area of the Sanctuary of Gallivaggio and closure of the main mountain route (S.S.36).
The area was monitored by the Regional Environmental Protection Agency since 2011 by using a ground-based radar (GB-InSAR, LisaLab srl), and it was affected by a 150 m3 rockfall event in the last months of 2019.
GB-InSAR data, multiple laser scanner surveys and drone images of the rock cliff recorded before the event allow to identify the source area, to define and characterize the potentially detachable block volumes and their evolution through time. Thanks to the continuous GB-InSAR monitoring which started well before the event, we calibrated the parameters of a 1d multi-block model whose behaviour is governed by time-dependent visco-plastic constitutive law based on the Perzyna’s approach. This model is subsequently employed to reproduce the mechanical response of the block masses until their detachment from the vertical wall by using different constitutive laws.
At the same time, the comparison between the size distributions of the detached and the deposited blocks and the dust sampling and characterization allowed us to evaluate the degree of comminution due to fragmentation. This information, which is rarely available, made possible to calibrate the fragmentation algorithm of the code HY-STONE, which simulates fragmentation of the falling blocks overcoming a certain energy threshold and the dynamic behaviour of the resulting fragments. We first applied the code to replicate the rockfall events, being able to simulate the large spreading of the block that was impossible to simulate without the fragmentation algorithm. Then we applied this modelling approach for the design of a ditch-embankment countermeasure, simulating different scenarios with and without fragmentation. The results show that fragmentation induces an increase in the number of blocks impacting the embankment, in the heights, and in the velocity, but a decrease of the kinetic energy since each fragment has a smaller mass than the original blocks.
Andrea Valagussa; Giuseppe Dattola; Paolo Frattini; Elena Valbuzzi; Alberto Villa; Federico Agliardi; Giovanni Crosta. Accelerating phase displacement prediction and 3D rockfall modelling of the large Gallivaggio rockfall. 2021, 1 .
AMA StyleAndrea Valagussa, Giuseppe Dattola, Paolo Frattini, Elena Valbuzzi, Alberto Villa, Federico Agliardi, Giovanni Crosta. Accelerating phase displacement prediction and 3D rockfall modelling of the large Gallivaggio rockfall. . 2021; ():1.
Chicago/Turabian StyleAndrea Valagussa; Giuseppe Dattola; Paolo Frattini; Elena Valbuzzi; Alberto Villa; Federico Agliardi; Giovanni Crosta. 2021. "Accelerating phase displacement prediction and 3D rockfall modelling of the large Gallivaggio rockfall." , no. : 1.
Large slow rock-slope deformations are widespread in alpine environments and mountainous regions worldwide. They evolve over long time by progressive failure processes, resulting in slow movements that impact infrastructures and can eventually evolve into catastrophic rockslides. A robust characterization of the activity of these phenomena is thus required to cope with their long-term threats.
Displacement rates measured by remote sensing and ground-based techniques only provide a snapshot of long-term, variable trends of activity and are insufficient to capture the behavior of slow rock slope deformations in a long-term risk management perspective. We thus propose to adopt a more complete approach based on a re-definition of “style of activity”, including displacement rate, segmentation/heterogeneity, kinematics, internal damage and accumulated strain. To this aim, we developed a novel approach combining persistent-scatterer interferometry (PSI) and systematic geomorphological mapping, to obtain an objective semi-automated characterization and classification of 208 slow rock slope deformations in Lombardia (Italian Central Alps). Through a peak analysis of displacement rate distributions we characterized the degree of internal segmentation of mapped slow rock slope deformations and highlighted the presence of nested sectors with differential activity. Then, we used an original approach to automatically characterize the kinematics of each landslide (translational, compound, or rotational) by combining a 2DInSAR velocity vector decomposition and a supervised machine learning classification. Finally, we combined Principal Component and K-medoid Cluster multivariate statistical analyses to classify slow rock slope deformations into groups with consistent styles of activity. We classified DSGSDs and large landslides respectively in five and two representative groups described by different degree of internal segmentation and kinematics that significant influence the evolutionary behavior and affect the definition of representative displacement rates. Our results provide a statistical evidence that phenomena classified as “Deep-Seated Gravitational Slope deformations” (DSGSD) and “large landslides” actually have different mechanisms and/or evolutionary stages, mirrored by different morphological features that testify higher accumulated internal deformation for large landslides with respect to DSGSDs. Our statistical classification of rock-slope deformation style of activity further highlighted the different risk potentials associated to each one of the seven descriptive groups in a practical perspective, taking into account the most significant parameters (rate, volume and heterogeneity) to assess risks related to the interaction between slow movements and sensitive elements.
Our analysis benefits from both deterministic and statistical components to perform a complete regional screening of slow rock slope deformations and to prioritize site-specific, engineering geological analyses of critical slopes depending on the most important factors conditioning their long-term style of activity. Our methodology is readily applicable to different datasets and provides an objective and cost-effective support to land planning and the prioritization of local-scale studies aimed at granting safety and infrastructure integrity.
Chiara Crippa; Elena Valbuzzi; Paolo Frattini; Giovanni B. Crosta; Margherita C. Spreafico; Federico Agliardi. Semi-automated regional classification of the style of activity of slow rock slope deformations using PS InSAR and SqueeSAR velocity data. 2021, 1 .
AMA StyleChiara Crippa, Elena Valbuzzi, Paolo Frattini, Giovanni B. Crosta, Margherita C. Spreafico, Federico Agliardi. Semi-automated regional classification of the style of activity of slow rock slope deformations using PS InSAR and SqueeSAR velocity data. . 2021; ():1.
Chicago/Turabian StyleChiara Crippa; Elena Valbuzzi; Paolo Frattini; Giovanni B. Crosta; Margherita C. Spreafico; Federico Agliardi. 2021. "Semi-automated regional classification of the style of activity of slow rock slope deformations using PS InSAR and SqueeSAR velocity data." , no. : 1.
We present an analysis of subsidence phenomena and mechanisms affecting urban areas developed on soft volcanic rock where sinkholes frequently occur. The study focuses on the metropolitan area of Naples (Southern Italy), an important example of an urbanized area affected by instability issues. The sub-surface of Naples is characterised by tunnels and cavities excavated in Neapolitan Yellow Tuff (NYT) through history for aqueducts and sewer systems, as places of worship or to extract building materials. The study was carried out in the UNESCO area (about 31 km2) considering ground surface measurements acquired by C-band radar sensors on board the ESA platforms ERS-1/2 and ENVISAT, as well as the X-band sensors of the COSMO-SkyMed (CSK) constellation and the TerraSAR-X/Tandem-X (TSX) satellites (processed by TRE Altamira). SAR data show different wavelengths, spatial/temporal resolution, revisit time and monitored period. ERS-1/2 and ENVISAT are both characterized by revisit time of 35 days and spatial resolution of 5x20m, while second-generation X-band sensors determine an extremely high resolution and PS (Persistent Scatterer) density distribution (TSX PS density is 26769 PS/km2). Data from CSK and TSX show spatial resolution of few km2 and reduced revisit time (8 days for CSK and 11 days for TSX). SAR data are capable of detecting ground subsidence or uplift deformations on urban areas. The available cavities and sinkholes (Guarino et al., 2018) inventories were considered as well as available thematic maps (piezometric level, NYT roof depth, water supply, sewerage, waterwork and historical buildings). The cavity dataset, counting 888 polygons, was related to the PS mean velocities to detect possible correlations between them. Finite Element Analysis (FEA) for three-dimensional modelling were performed using MIDAS GTS NX code to simulate failure mechanisms of real cavities. Numerical results highlight that the cavity planimetry and its height, the overburden thickness and the mechanical properties of the tuff material are the most influencing parameters. Saturation effect and tuff degradation were evaluated computing the safety factor by means of the strength reduction method. The role played by pillars in complex cavities in terms of stress distribution and stability conditions was investigated. Numerical results and InSAR measurements of subsiding areas are in agreement, although some differences due to local effects are encountered, variation in properties and the assumptions of a constant length of the cavities. Finally, an example of a structural collapse occurred on 8th January 2021 affecting the Ospedale del Mare parking lot, in the Ponticelli district, was examined. Ground displacement pattern and time series comprised between January 2016 and December 2019 obtained with the TSX data display downward trends, clearly showing that the area experienced “subsidence” over at least the past two years. This study demonstrates the usefulness of numerical analysis combined with InSAR measurement technology to assess cavity stability conditions and the study of subsidence phenomena in urban areas.
Guarino, P. M., Santo, A., Forte, G., De Falco, M., Niceforo, D. M. A. (2018). Analysis of a database for anthropogenic sinkhole triggering and zonation in the Naples hinterland (Southern Italy). Natural Hazards, 91(1), 173-192.
Serena Rigamonti; Fernando Bellotti; Giuseppe Dattola; Paolo Frattini; Paolo Maria Guarino; Giovanni Battista Crosta. Analysis of subsidence in the metropolitan area of Naples based on SAR data. 2021, 1 .
AMA StyleSerena Rigamonti, Fernando Bellotti, Giuseppe Dattola, Paolo Frattini, Paolo Maria Guarino, Giovanni Battista Crosta. Analysis of subsidence in the metropolitan area of Naples based on SAR data. . 2021; ():1.
Chicago/Turabian StyleSerena Rigamonti; Fernando Bellotti; Giuseppe Dattola; Paolo Frattini; Paolo Maria Guarino; Giovanni Battista Crosta. 2021. "Analysis of subsidence in the metropolitan area of Naples based on SAR data." , no. : 1.
Rainfall is one of the most significant triggering factors for shallow landslides. The early warning for such phenomena requires the definition of a threshold based on a critical rainfall condition that may lead to diffuse landsliding. The developing of these thresholds is frequently done through empirical or statistical approaches that aim at identifying thresholds between rainfall events that triggered or non-triggered landslides. Such approaches present several problems related to the identification of the exact amount of rainfall that triggered landslides, the local geo-environmental conditions at the landslide site, and the minimum rainfall amount used to define the non-triggering events. Furthermore, these thresholds lead to misclassifications (false negative or false positive) that always induce costs for the society. The aim of this research is to address these limitations, accounting for classification costs in order to select the optimal thresholds for landslide risk management.
Starting from a database of shallow landslides occurred during five regional-scale rainfall events in the Italian Central Alps, we extracted the triggering rainfall intensities by adjusting rain gouge data with weather radar data. This adjustment significantly improved the information regarding the rainfall intensity at the landslide site and, although an uncertainty related to the exact timing of occurrence has still remained. Therefore, we identified the rainfall thresholds through the Receiver Operating Characteristic (ROC) approach, by identifying the optimal rainfall intensity that separates triggering and non-triggering events. To evaluate the effect related to the application of different minimum rainfall for non-triggering events, we have adopted three different values obtaining similar results, thus demonstrating that the ROC approach is not sensitive to the choice of the minimum rainfall threshold. In order to include the effect of misclassification costs we have developed cost-sensitive rainfall threshold curves by using cost-curve approach (Drummond and Holte 2000). As far as we know, this is the first attempt to build a cost-sensitive rainfall threshold for landslides that allows to explicitly account for misclassification costs. For the development of the cost-sensitive threshold curve, we had to define a reference cost scenario in which we have quantified several cost items for both missed alarms and false alarms. By using this scenario, the cost-sensitive rainfall threshold results to be lower than the ROC threshold to minimize the missed alarms, the costs of which are seven times greater than the false alarm costs. Since the misclassification costs could vary according to different socio-economic contexts and emergency organization, we developed different extreme scenarios to evaluate the sensitivity of misclassification costs on the rainfall thresholds. In the scenario with maximum false-alarm cost and minimum missed-alarm cost, the rainfall threshold increases in order to minimize the false alarms. Conversely, the rainfall thresholds decreases in the scenario with minimum false-alarm cost and maximum missed-alarm costs. We found that the range of variation between the curves of these extreme scenarios is as much as half an order of magnitude.
Paolo Frattini; Gianluca Sala; Camilla Lanfranconi; Giulia Rusconi; Giovanni Crosta. How to account for misclassification costs in shallow-landslide rainfall thresholds? 2021, 1 .
AMA StylePaolo Frattini, Gianluca Sala, Camilla Lanfranconi, Giulia Rusconi, Giovanni Crosta. How to account for misclassification costs in shallow-landslide rainfall thresholds? . 2021; ():1.
Chicago/Turabian StylePaolo Frattini; Gianluca Sala; Camilla Lanfranconi; Giulia Rusconi; Giovanni Crosta. 2021. "How to account for misclassification costs in shallow-landslide rainfall thresholds?" , no. : 1.
Earthquakes are – amongst many others – one type of triggering factors for mass movements in mountainous regions such as landslides, deep-seated gravitational slides (DSGSD), rockfalls, mudflows, etc. Hence, the emerging hazard would require an area-wide assessment of seismogenic impact to better apprehend the interplay of different triggering factors contributing to mass movement activity. However, seismicity itself is difficult to assess for several reasons. On the one hand, there are various parameters describing ground motion, and not all of them are suitable for area-wide assessments due to their availability or complexity. On the other hand, phenomena such as attenuation and topographic amplification must be taken into account, especially when the region of interest is an orogen.
Considering the criteria mentioned above and aiming for a mapping approach ascribing one value of seismogenic impact to one geographic location, we developed a strategy based on two empirical laws approximating Arias Intensity: the first law estimates Arias Intensities for a particular location as a function of earthquake magnitudes and focal depths; the second law corrects these estimated Arias Intensities in relation to the height differences to the nearest channel beds. Finally, we sum all corrected Arias Intensities resulting from different earthquakes in one particular location. Values obtained in this last step do not represent a physical entity; nevertheless, they allow for quantitative assessment of seismic exposure with respect to a given earthquake dataset covering a specific time frame, also allowing for color coding and comparative mapping approaches in GIS for other factors triggering mass movements.
In our case study, we assess the seismic exposure of a set of several hundreds of landslides, DSGSD, and rockfalls located in a rectangular area in the Italian Central Alps. In a first step, the area was discretized using a quadratic grid with increments of 1 km in order to assign points of evaluation to the previously mapped polygons representing landslides, DSGSD, and rockfalls. Additionally, to each polygon, a centroid point was attributed to avoiding the loss of polygons smaller than 1x1 km. In a second step, we computed the seismic exposure in each point resulting from two earthquake datasets covering the Alps, including a 500 km wide buffer zone: instrumental earthquake data of the ISC Bulletin covering a period from 1900 to 2019; macro-seismic earthquake data of the SHARE European Earthquake Catalog covering a period from 1000 to 2006.
The study serves as a preliminary test for assessing wider areas across the Alps, which either geologically or geographically belong together. We illustrate our mapping approach in a series of maps discussing the effects of the number of earthquakes, magnitudes, distances, topography, and time frame.
Gisela Domej; Paolo Frattini; Elena Valbuzzi; Giovanni B. Crosta. Quantifying the seismogenic impact on mass movements in the Alps in terms of Arias Intensity. 2021, 1 .
AMA StyleGisela Domej, Paolo Frattini, Elena Valbuzzi, Giovanni B. Crosta. Quantifying the seismogenic impact on mass movements in the Alps in terms of Arias Intensity. . 2021; ():1.
Chicago/Turabian StyleGisela Domej; Paolo Frattini; Elena Valbuzzi; Giovanni B. Crosta. 2021. "Quantifying the seismogenic impact on mass movements in the Alps in terms of Arias Intensity." , no. : 1.
Despite their centrality to rockfall risk management, two issues are frequently overlooked: the role of forests in rockfall dynamic and the fragmentation phenomenon. To investigate the importance of these issues we have developed advanced modelling case studies in two representative sites that have been recently affected by rockfall events in the Aosta Valley Region (Western Italian Alps). In the Saint Oyen case study, about 17,500 m3 of rock detached in March 2019 and reached a service road and the sport center in the lower part of the slope, passing through a mature fir forest. The presence of the forest has significantly influenced the rocks distribution along the slope, increasing the lateral dispersion of trajectories and reducing the mobility. For the design of defensive works, 3D rockfall models of three future potential risk scenarios were therefore performed by using the tree-impact algorithm of the code HY-STONE (Frattini et al., 2012). This algorithm provides the location of impacts on trees, the absorbed energy, and the deviation angle. The input parameters (i.e., the value of diameter at breast height and the forest density) were based on direct measurements of the fir forest. Compared with a traditional simulation without the protective role of forests, the results of 3D numerical modelling with tree-impact algorithm show a decrease in the number of blocks impacting the barriers (91%), no variations in the bouncing heights (for 95th percentile), and an increase in the kinetic energies due to a filter effect by the forest (85% for 95th percentile). In the Roisan case study, about 1,050 m3 of rock toppled in October 2019. While the main body of the rockfall stopped in a relatively flat area close to the failure, two blocks were exceptionally able to reach the foot of the slope causing the interruption of a municipal road. An attempt to back-calibrate this event with HY-STONE showed difficulties to describe the behaviour of these isolated blocks with respects to the main landslide body. A possible explanation for this behaviour is that the detached volume fragmented soon after impacting the slope, giving rise to flying fragments with higher mobility. To test this hypothesis we accounted for fragmentation through a specific algorithm of HY-STONE that fragments the falling blocks when their energy overcomes a certain threshold and simulate the behaviour of the resulting fragments. This approach allowed to accurately replicate the rockfall event. We therefore adopted this approach for defensive-works design, simulating all the unstable volumes overhanging the municipal road. Compared with a traditional simulation, the results of 3D numerical modelling with fragmentation algorithm show an increase in the number of blocks impacting the barriers (86%) and in the bouncing heights (96% for 95th percentile), with a decrease of the kinetic energy due to comminution (39% for 95th percentile). These two case studies demonstrate the importance of accounting for the forest or for fragmentation in the design of cost-effective defensive works.
Frattini P, Crosta GB, Agliardi F (2012) Rockfall characterization and modeling. Landslides: types, mechanisms and modelling 22:267-281
Camilla Lanfranconi; Paolo Frattini; Giovanni Battista Crosta; Gianluca Sala; Davide Bertolo; Marco Paganone; Michel Stra; Patrick Thuegaz. Advanced rockfall modelling for risk mitigation: tree impact and fragmentation. 2021, 1 .
AMA StyleCamilla Lanfranconi, Paolo Frattini, Giovanni Battista Crosta, Gianluca Sala, Davide Bertolo, Marco Paganone, Michel Stra, Patrick Thuegaz. Advanced rockfall modelling for risk mitigation: tree impact and fragmentation. . 2021; ():1.
Chicago/Turabian StyleCamilla Lanfranconi; Paolo Frattini; Giovanni Battista Crosta; Gianluca Sala; Davide Bertolo; Marco Paganone; Michel Stra; Patrick Thuegaz. 2021. "Advanced rockfall modelling for risk mitigation: tree impact and fragmentation." , no. : 1.
Attaining a comprehensive and reliable water balance of snow-dominated alpine catchments is fundamental for a holistic representation of the hydrological and hydrogeological processes. In fact, their contribution to the water balance is extremely important for the water resources management and for a reliable estimation of groundwater recharge. A major limitation to the elaboration of these balances in alpine terrain are the difficultly of data acquisition as well as the limited presence of meteorological stations. These two factors considerably increase the uncertainty of water balances. Remotely sensed data can provide valuable information for the balance elaboration at a regional scale. Among the satellite data available, the Sentinel data, collected in the ESA missions in the last 6 years, has provided free and global access of observations including optical, thermal, and microwave sensors with high spatial and temporal resolutions.
In the present work, we estimated groundwater recharge (R) for the last two hydrologic years (from March 2018 to March 2020), based on satellite data. For this purpose, the most recent methods and databases based on satellite observations were tested: time series of the precipitation (P), the snow water equivalent (SWE), and the evapotranspiration (ET) were retrieved in an extensive Alpine catchment (26,000 km2) located in northern Italy. Daily precipitation was calculated from PERSIANN-Cloud Classification System (PERSIANN-CCS, Hong et al. 2004) database at the resolution of 4.0 km. ET was estimated with the combined use of Sentinel 2 and 3 satellites (Guzinski et al., 2020) at a resolution of 20 m and with weekly return period. The weekly SWE was calculated starting from Sentienl 1 (C-SNOW database, Lievens et al., 2019) and Sentienl 2, at the spatial resolution of 30 m.
Based on available measurements of P, ET, and snow depth in the catchment, the uncertainty of the hydrologic estimations was quantified. We further carried out a sensitivity analysis, considering the physiographic parameters (altitude, slope, and aspect) and the seasonal conditions. For SWE estimates, an altitude-dependent effect and a lower accuracy in the snowmelt phase have been observed. The results show that the adopted satellite-based methods allow obtaining consistent and physically realistic values of recharge, with relatively low uncertainty.
References:
Roberta Perico; Paolo Frattini; Giovanni Battista Crosta; Philip Brunner. Establishing a water balance of an Alpine catchment using satellite data. 2021, 1 .
AMA StyleRoberta Perico, Paolo Frattini, Giovanni Battista Crosta, Philip Brunner. Establishing a water balance of an Alpine catchment using satellite data. . 2021; ():1.
Chicago/Turabian StyleRoberta Perico; Paolo Frattini; Giovanni Battista Crosta; Philip Brunner. 2021. "Establishing a water balance of an Alpine catchment using satellite data." , no. : 1.
The project “Geo-information Services for Landslides in the Alps (eo4alps-landslide)” has the main objective of exploiting the potential of new satellite data coupled to advanced modelling for gravitational hazards assessment in the Alpine region. The two-year project starts in early 2021 and consists of a broad consortium of universities, geological consultancies, ICT companies and geological services. More than 20 authorities and other stakeholders responsible for landslide disaster risk management are actively involved in all project phases. “eo4alps-landslide” aims at ensuring that satellite-based Earth Observation (EO) products are increasingly and more efficiently used in practice for science and operational DRM procedures. “eo4alps-landslide” produces harmonised and advanced landslide inventories and susceptibility/hazard maps for the Alps based on InSAR and optical ground motion services and landslide-specific models embedded in the Geohazards Exploitation Platform (GEP). These EO-based services and products can be complemented by local datasets and terrain data from the end users directly in GEP. Planned products of “eo4alps-landslide” includes 1) automatic landslide detection using satellite optical and InSAR-based services, 2) harmonised and advanced landslide catalogues resulting from the satellite based detection and local inventories, 3) susceptibility/hazard maps consisting of possible landslide source areas and landslide type-specific runout modelling. Further fields of application and products will be adapted to the needs of end users. The methods will be generic in order to be used at several spatial scales from Tier 1 (region) to Tier 2 (municipality) and Tier 3 (local slope). Furthermore, the products of “eo4alps-landslide” will be compatible with products and services of other “eo4alps” initiatives, as well as with the European Ground Motion Service (EGMS).
Jean-Philippe Malet; Clément Michoud; Thierry Oppikofer; Giovanni B. Crosta; Paolo Frattini; Fabrizio Pacini; Javier Garcia Robles; Michaelis Foumelis. Landslide Geo-Information Services for the Alps. 2021, 1 .
AMA StyleJean-Philippe Malet, Clément Michoud, Thierry Oppikofer, Giovanni B. Crosta, Paolo Frattini, Fabrizio Pacini, Javier Garcia Robles, Michaelis Foumelis. Landslide Geo-Information Services for the Alps. . 2021; ():1.
Chicago/Turabian StyleJean-Philippe Malet; Clément Michoud; Thierry Oppikofer; Giovanni B. Crosta; Paolo Frattini; Fabrizio Pacini; Javier Garcia Robles; Michaelis Foumelis. 2021. "Landslide Geo-Information Services for the Alps." , no. : 1.
Slow rock slope deformations are widespread in alpine environments. They affect giant volumes and evolve over thousands of years by progressive failure, resulting in long-term slow movements threatening infrastructures and potential evolution into massive collapses. In the alpine sector of Lombardia (Italian Central Alps), 208 mapped slow rock slope deformations affect a total area exceeding 580 km2 and interact with a variety of elements at risk including settlements, hydroelectric facilities and lifelines characterized by different vulnerability to both slow and progressive deformations. In this context, a systematic, reliable and cost-effective approach is required to classify slow rock slope deformations on the regional scale for landplanning, prioritization and analysis of interactions with elements at risk, depending on their style of activity, including not only mean deformation rate, but also their kinematics and spatial complexity. In this work, we implemented a toolbox that integrates different approaches to classify a large dataset of slow rock slope deformations in discrete groups, according to the deformation style and morpho-structural expression of individuals, mapped on regional scale and characterized through remote sensing techniques. The landslide dataset used in this study was obtained by a “semi-detail” geomorphological and morpho-structural mapping on aerial imagery and DEM, performed on regional scale yet including local-scale information (e.g. tectonic lineaments, morpho-structures, landforms, nested deep-seated landslides) and a full set of geological and morphometric attributes. To characterize landslide activity, we use Persistent-Scatterer Interferometry (PSI) data, including PS-InSARTM and SqueeSARTM acquired by different sensors (ERS, Radarsat, Sentinel 1A/B) over different time periods from 1992 to 2017. Since Line-of-Sight velocity of point like data can hamper a correct evaluation of both landslide kinematics and deformation rates, for each phenomenon we automatically selected the most complete PSI datasets. From these, through a 2DSAR decomposition procedure, we derived 2D velocity components and computed the magnitude and orientation of the 2D total displacement vector T. We then applied a supervised machine learning procedure to automatically classify the kinematics of each landslide (i.e. translational, roto-translational, rotational) depending on the statistical distribution of the T vector orientation. As the evaluation of a representative landslide mean deformation rate is strongly affected by spatial heterogeneity and landslide mass segmentation, we implemented an original peak analysis of the velocity distribution in each landslide to calculate a modal velocity of the main body and automatically outline nested sectors with differential displacement rates. Finally, we classified landslides in types, representative of different styles of activity and potential interaction with elements at risk, by combining PSI analysis results with geological, morpho-structural and morphometric variables in a multivariate statistical analysis framework including sequential Principal Component and K-medoids Cluster Analysis. The entire analysis workflow runs in a semi-automated way through a set of GIS and MatlabTM tools. Our procedure can be applied to different large landslide datasets, providing a fast and cost-effective support to landslide classification, risk analysis, landplanning and prioritization of local-scale studies aimed at granting safety and infrastructure integrity.
Chiara Crippa; Federico Agliardi; Paolo Frattini; Margherita C. Spreafico; Giovanni B. Crosta; Elena Valbuzzi. Semi-automated regional classification of slow rock slope deformations integrating kinematics, activity and spatial complexity. 2020, 1 .
AMA StyleChiara Crippa, Federico Agliardi, Paolo Frattini, Margherita C. Spreafico, Giovanni B. Crosta, Elena Valbuzzi. Semi-automated regional classification of slow rock slope deformations integrating kinematics, activity and spatial complexity. . 2020; ():1.
Chicago/Turabian StyleChiara Crippa; Federico Agliardi; Paolo Frattini; Margherita C. Spreafico; Giovanni B. Crosta; Elena Valbuzzi. 2020. "Semi-automated regional classification of slow rock slope deformations integrating kinematics, activity and spatial complexity." , no. : 1.
Following the 7.8 Mw earthquake that struck Nepal on April 25th, 2015, a high-resolution earthquake-induced landslide inventory was prepared. 21,151 landslides have been mapped using Google Earth’s pre- and post-earthquake images, helicopter footage and Google Crisis data. For a representative subset of landslides (~7%), the main scar area was manually distinguished from the landslide transport and deposition areas. Starting from this subset of scar areas, six different relationships between scar area and total landslide area were attained for six different intervals of the landslide aspect ratio (AR, i.e. ratio between landslide length and width) which is used as a proxy of landslide mobility. These relationships were used to estimate the scar area for the entire dataset. For landslides with AR lower than 3 (i.e. low-mobility landslides) the total volume was calculated with the equations proposed by Larsen et al. (2010) by using the total landslide area values. For landslides with an AR larger than 3 (i.e. high-mobility landslides) the volume was computed by applying the equation by Larsen et al. (2010) to landslide scar area only, and considering a constant thickness for the runout area (1m based on field activities). By comparing the landslide denudation and mass wasting to uplift and subsidence measured by InSAR (ALOS-2 satellite data) following the Nepal earthquake, the net volume change in the earthquake-affected area was calculated.
Paolo Frattini; Andrea Valagussa; Elena Valbuzzi; Giovanni B. Crosta. 2015 Nepal Earthquake: A Mass Wasting Balance. 2020, 1 .
AMA StylePaolo Frattini, Andrea Valagussa, Elena Valbuzzi, Giovanni B. Crosta. 2015 Nepal Earthquake: A Mass Wasting Balance. . 2020; ():1.
Chicago/Turabian StylePaolo Frattini; Andrea Valagussa; Elena Valbuzzi; Giovanni B. Crosta. 2020. "2015 Nepal Earthquake: A Mass Wasting Balance." , no. : 1.
The acquisition of high-resolution topographic data is a widely used tool for studies related to the processes and dynamics of the Earth's surface. In this work, we present the results of the repeated acquisition of photogrammetric data by Unmanned Aerial Vehicle (UAV) in order to detect the topographic evolution of an alpine rock glaciers located in Valtournenche (AO, Italy). Field monitoring conducted in recent years has shown significant variations in the behaviour of these landforms, with an increasing trend of their dynamism, raising questions about their stability in changing climatic conditions.
The photogrammetric shots were taken with a DJ Phantom 4 UAV equipped with a compact RGB digital camera. The acquisitions were performed yearly from 2012 up to 2019 with a ground sampling distance never exceeding 5 cm/px. Contemporary to the acquisitions, approximately 20 Ground Control Points were placed on the rock glacier and on the surrounding areas and their coordinates were measured with a differential GPS (dGPS) for georeferencing UAV images. Moreover, in 2014, 2015 and 2019 geophysical campaigns were carried out for the detection of ice lenses under the debris cover of the rock glacier.
Structure-from-motion techniques were applied on overlapping images to create high-density point clouds, than converted in orthophotos and digital surface models of the Earth’s surface.
The point clouds were analysed using the M3C2 (Multiscale Model to Model Cloud Comparison) plug-in, freely available in the CloudCompare software. Maps of surface changes between acquisition pairs in the period from 2015-2019 have been created. The comparison allowed the identification of "material supply" and "material removal" zones, slightly variable from one year to the next. The major accumulation zones are concentrated along the frontal sector of the rock glacier, more focused on the western sector (black lobe) and secondly on the right side of the rock glacier (white lobe). The removal of material is mainly concentrated on the higher altitude of the body but also in correspondence to the systems of crevasses and scarps and on the central part of the black lobe.
The surface displacement analysis of the rock glacier was also performed selecting manually several clearly identifiable features on the orthomosaics collected. Blocks and ridges-and-furrows complex were marked on the 2019 orthomosaic and found them on the 2015 orthomosaic. This approach allows improving and quantifying the dynamics of the different portions of the individual apparatus.
The velocity fields’ patterns highlight non-homogeneous displacements between the West (black lobe) and East part (white lobe) of the whole rock glacier. Specifically, the black lobe showed an average horizontal displacement of around 1 m/y while the white lobe moved significantly slower than the previous one (approximately 0.5 m/y). Overall, the rock glacier moved downslope at an average horizontal velocity of 0.60 m/y in the frontal tongue, 0.48 m/y in the central portion and 0.30 m/y in the upper zone.
Francesca Bearzot; Roberto Garzonio; Biagio Di Mauro; Umberto Morra Di Cella; Edoardo Cremonese; Paolo Pogliotti; Paolo Frattini; Giovanni B. Crosta; Roberto Colombo; Micol Rossini. Geomorphological mapping of an alpine rock glacier with multi-temporal UAV-based high density point cloud comparison. 2020, 1 .
AMA StyleFrancesca Bearzot, Roberto Garzonio, Biagio Di Mauro, Umberto Morra Di Cella, Edoardo Cremonese, Paolo Pogliotti, Paolo Frattini, Giovanni B. Crosta, Roberto Colombo, Micol Rossini. Geomorphological mapping of an alpine rock glacier with multi-temporal UAV-based high density point cloud comparison. . 2020; ():1.
Chicago/Turabian StyleFrancesca Bearzot; Roberto Garzonio; Biagio Di Mauro; Umberto Morra Di Cella; Edoardo Cremonese; Paolo Pogliotti; Paolo Frattini; Giovanni B. Crosta; Roberto Colombo; Micol Rossini. 2020. "Geomorphological mapping of an alpine rock glacier with multi-temporal UAV-based high density point cloud comparison." , no. : 1.
Three landslide inventories were prepared for the area affected by the 7.8 Mw Nepal earthquake (April 25, 2015). The first inventory contains 21,151 earthquake-induced landslides (EQL), directly associated to the 7.8Mw earthquake, mapped by using Google Earth’s pre and post-earthquake images, helicopter footage and Google Crisis data. Landslides were classified as debris flows, shallow translational landslides and rotational landslides. This last class included a relatively small number of events. The second inventory includes only pre-event shallow landslides (PESL) to evidence those landslides which were already active before the 2015 earthquake. This inventory includes more than 2,500 landslides. The third inventory includes almost 20,000 large landslides (LL), consisting mostly of rock avalanches, slumps, rockslides, and deep-seated gravitational slope deformations (DSGSD). The spatial distribution of the three inventories was analysed with respect to land surface parameters. The EQL inventory shows in general a different spatial distribution with respect to the other two inventories. This is probably related to the seismic triggering and to the characteristics of the geographic area. A joint analysis of the LL and the EQL inventories shows that only a few earthquake-induced landslides (about 15 %) are directly associated to reactivation of LL.
A Principal Component Analysis (PCA) and a Discriminant Analysis were performed to analyse the controlling parameters on EQL and PESL. The analyses were based on: 1) land surface parameters, 2) hydrological parameters, 3) seismic parameters, 4) lithological parameters, 5) land cover, and 6) meteorological parameters. The statistical analyses show that the most critical variables for landslide triggering during an earthquake are associated to the land surface parameters, in association with the cosesimic displacement and the PGA, that show an effect on the landslide size and density respectively. PESL seem to be mainly controlled by land surface parameters, with some of them (e.g. elevation) showing a slightly inverse relationship with landslide density. Agricultural land use, slope gradient and rainfall (reference period 1980-2000) show a high correlation with the PESL landslide triggering in absence of earthquakes.
Andrea Valagussa; Paolo Frattini; Elena Valbuzzi; Malcolm Billinge-Jones; Giovanni Battista Crosta. 2015 Nepal Earthquake: A Comparison between Landslide Inventories. 2020, 1 .
AMA StyleAndrea Valagussa, Paolo Frattini, Elena Valbuzzi, Malcolm Billinge-Jones, Giovanni Battista Crosta. 2015 Nepal Earthquake: A Comparison between Landslide Inventories. . 2020; ():1.
Chicago/Turabian StyleAndrea Valagussa; Paolo Frattini; Elena Valbuzzi; Malcolm Billinge-Jones; Giovanni Battista Crosta. 2020. "2015 Nepal Earthquake: A Comparison between Landslide Inventories." , no. : 1.
The vulnerability of buildings to the impact of rockfalls is a key component of Quantitative Risk Assessment for rockfall phenomena. Only a few attempts to quantitatively assess vulnerability have been presented in the literature due to the lack of high-quality rockfall and damage data. For processes such as debris flows, snow avalanches or earthquakes, well-established methods for the estimation of physical vulnerability are already available.
The present work aims to develop an empirical rockfall vulnerability function by coupling rockfall back-analysis modelling of several damaging events occurred in different lithological and geomorphological settings. A sound database of damage to specific categories of structures impacted by rockfalls is build up by archive research of historical events and high-quality field observations of recent events. Damages are classified according to four damage types: superficial (degree of loss: 0.1-0.2) to structural (degree of loss: 1.0). The back-analysis of rockfalls and the interaction with element at risk is performed with the 3D numerical model Hy- STONE. The code uses a hybrid modelling approach and random sampling of input parameters from different probability density distributions (uniform, normal, exponential) to account for the complexity of the rockfall process and influencing factors. The elements at risk are integrated as lines to the model, impact points being able to be displayed and extracted as point vector data. This enables a precise analysis of simulated energies and observed damage for each building impacted in the past to define an empirical vulnerability function. The empirical vulnerability function is established by fitting damage-energy data through a sigmoidal function. This empirical vulnerability function for buildings is fundamental to compute the expected degree of loss for each element of risk, especially in areas where no detailed rockfall or damage data is available.
Sandra Melzner; Paolo Frattini; Federico Agliardi; Giovanni Battista Crosta. Back-analysis of rockfalls for the definition of an empirical vulnerability function for buildings. 2020, 1 .
AMA StyleSandra Melzner, Paolo Frattini, Federico Agliardi, Giovanni Battista Crosta. Back-analysis of rockfalls for the definition of an empirical vulnerability function for buildings. . 2020; ():1.
Chicago/Turabian StyleSandra Melzner; Paolo Frattini; Federico Agliardi; Giovanni Battista Crosta. 2020. "Back-analysis of rockfalls for the definition of an empirical vulnerability function for buildings." , no. : 1.
The recognized evidence of global warming demands assessment of the present and future water cycle in Europe and worldwide. Recently, evidence of modified hydrological regime in the Alps under climate change has been documented. In particular, several studies (e.g. Bocchiola, 2014; Soncini et al. 2016) indicated an increase in hydrological flows in autumn and winter in response to snowfall trading with intense rainfall, shorter snow cover during winter, as well as decreased flows during dry spring and summer and large shrinking of glaciers at high altitude. However, according to the IPCC Fifth Assessment Report, it is still necessary to deepen our understanding of the impact of climate change and land use on groundwater recharge and levels in the alpine catchment areas (Cochand et al. 2019).
For this purpose, a water balance of the last three hydrogeological years (March 2017 - March 2020) was carried out on the Valtellina catchment (northern Italy, Central Italian Alps). This basin is a perfect case study for its wide unconfined aquifer in the floodplain, which makes it highly sensitive to this type of change. Moreover, the management of the water resource is of considerable importance, being crucial in a wide range of sectors (tourism, irrigation, domestic use, energy and industry).
Due to the extensive and diversified study area (26,000 km2) and the low ground data density (7 meteorological stations, 4 surface-water monitoring points, and 9 groundwater monitoring points), the water balance terms were estimated by exploiting and combining Earth Observation data products with ground data, also taking into account the geological and geomorphological characteristics of the basin. In particular, the evapotranspiration and the snow cover were provided, by MOD16A2 (MODIS/Terra Evapotranspiration 8-Day Level-4 Global 500m SIN Grid) and MOD10A2 (MODIS/Terra Snow Cover 8-Day L3 Global 500m SIN Grid, Version 6) satellite data, respectively.
As a result, the groundwater storage of a wet hydrogeological year compared with the groundwater storage of a dry hydrogeological year allowed analysing the sensitivity of groundwater resources to climate change.
Bocchiola, D.: Long term (1921–2011) Hydrological regime of Alpine catchments in Northern Italy. Advances in Water Resources, 70, 51-64, 2014.
Cochand, M., Christe, P., Ornstein, P., & Hunkeler, D.: Groundwater storage in high alpine catchments and its contribution to streamflow. Water Resources Research, 55(4), 2613-2630, 2019.
Soncini, A., Bocchiola, D., Confortola, G., Minora, U., Vuillermoz, E., Salerno, F., Viviano, G., Shrestha, D., Senese, A., Smiraglia, C. and Diolaiuti, G.A.: Future hydrological regimes and glacier cover in the Everest region: The case study of the upper Dudh Koshi basin. Science of the Total Environment, 565, 1084-1101, 2016.
Roberta Perico; Paolo Frattini; Marco Celesti; Roberto Colombo; Giovanni Battista Crosta. Water balance of an extensive alpine catchment area under the effect of climate change. 2020, 1 .
AMA StyleRoberta Perico, Paolo Frattini, Marco Celesti, Roberto Colombo, Giovanni Battista Crosta. Water balance of an extensive alpine catchment area under the effect of climate change. . 2020; ():1.
Chicago/Turabian StyleRoberta Perico; Paolo Frattini; Marco Celesti; Roberto Colombo; Giovanni Battista Crosta. 2020. "Water balance of an extensive alpine catchment area under the effect of climate change." , no. : 1.
In mountainous areas, rockfall phenomena cause damages and safety problems in residential areas and along transportation facilities. Forests that lay upslope the elements at risk can mitigate rockfall hazard by reducing the kinetic energy of blocks and the probability of impact. Nevertheless, the effects of rockfall protection forests is usually quantified only at local scale.
In order to assess the forest efficiency for different combinations of forest (tree size, forest density, forest position, forest length), morphological (slope gradient) and lithological (expected block volume) conditions, we performed a large set of parametric simulations by using the HY-STONE rockfall simulator (Crosta et al, 2004) with a tree impact algorithm that allows calculating the probability of impact, the loss of energy and the lateral deviation of the trajectories based on forest density, tree size and block volume. For each simulation, we therefore quantified the forest efficiency by using a new energy-based efficiency index (EEI) that measure the reduction of rockfall kinetic energy along the forest.
The results of the parametric simulations show that the block volume, the slope inclination, the tree size, and the forest density are, in decreasing order of relevance, the most sensitive parameters for rockfall efficiency. Due to its importance, the volume of blocks associated to different lithologies found in Central Italian Alps have been analysed through a statistical analysis of talus deposits. This allowed to obtain volume frequency distributions for the different lithologies, and the associated percentiles of expected block volume.
Starting from the parametric simulations, we developed a multiple linear regression that allows to predict an EEI index value (efficiency of protection forest) as a function of forest, morphological and lithological parameters. This regression function has been eventually applied to all the protection forest of Central Italian Alps, providing regional scale maps of rockfall-protection forest efficiency for different block volume percentiles.
Crosta, G. B., and F. Agliardi. (2004) Parametric evaluation of 3D dispersion of rockfall trajectories.” Natural Hazards and Earth System Science 4.4: 583-598.
Gianluca Sala; Camilla Lanfranconi; Paolo Frattini; Giovanni B. Crosta. Regional scale mapping of rockfall-protection forest efficiency. 2020, 1 .
AMA StyleGianluca Sala, Camilla Lanfranconi, Paolo Frattini, Giovanni B. Crosta. Regional scale mapping of rockfall-protection forest efficiency. . 2020; ():1.
Chicago/Turabian StyleGianluca Sala; Camilla Lanfranconi; Paolo Frattini; Giovanni B. Crosta. 2020. "Regional scale mapping of rockfall-protection forest efficiency." , no. : 1.
Landslide size controls the destructive power of landslides and is related to the frequency of occurrence, with larger landslides being less frequent than smaller ones. For this reason, the analysis of landslide size is essential for landslide hazard assessment. We analyse six earthquake-induced landslide inventories with earthquake magnitude ranging between 6.6 and 7.9 Mw (Papua New Guinea, 1993; ChiChi 1999; Northridge, 1994; Niigata–Chuetsu, 2004; Iwate–Miyagi Nairiku, 2008; Wenchuan, 2008). For each inventory, we developed magnitude–frequency curves to analyse the size distribution of landslides as a function of ground motion, distance from the seismic source (both fault trace and epicentre), local relief, and lithology. For three earthquakes, we observed a clear relationship between the landslide size and ground motion, with larger landslides associated with higher ground motion. We investigate different possible causes for such observation, and propose that the main mechanical reason is that stronger shaking induces higher stresses that may overcome the strength, which increases with depth, triggering larger landslides. We also show that landslide size decreases with distance from the fault trace, whereas, this trend is not clear for distance from the epicentre. Local relief does not seem a first order control on landslide size for the earthquake-induced landslides considered here. Some lithologies do influence landslide size, but we were unable to identify a general behaviour for different lithologies.
A. Valagussa; O. Marc; P. Frattini; G.B. Crosta. Seismic and geological controls on earthquake-induced landslide size. Earth and Planetary Science Letters 2018, 506, 268 -281.
AMA StyleA. Valagussa, O. Marc, P. Frattini, G.B. Crosta. Seismic and geological controls on earthquake-induced landslide size. Earth and Planetary Science Letters. 2018; 506 ():268-281.
Chicago/Turabian StyleA. Valagussa; O. Marc; P. Frattini; G.B. Crosta. 2018. "Seismic and geological controls on earthquake-induced landslide size." Earth and Planetary Science Letters 506, no. : 268-281.