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Francesco RONCHETTI

Professore Associato
Dipartimento di Scienze Chimiche e Geologiche - Sede Dipartimento di Scienze Chimiche e Geologiche

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Pubblicazioni

2023 - Analysis of the Potential Effectiveness and Efficiency of Mobile Terrestrial LiDAR to Survey and Monitor Rockfall Areas Along 15 km of Highway E45 [Relazione in Atti di Convegno]
Ferro, E.; Cemin, F.; De Rosa, L.; Corsini, A.; Ronchetti, F.; Lelli, F.; Vitti, A.; Simeoni, L.
abstract

A method was developed in a GIS environment to assess the potential effectiveness and efficiency of a mobile terrestrial LiDAR survey at detecting the geometrical changes due to rockfalls from the cliffs facing a 15 km stretch of a highway in an alpine valley. The elements exposed to rockfalls were automatically classified as viaduct or open-sky ground supported road by comparing the DTM with the DSM. The most critical cliffs were then identified through the analysis of the rockfall trajectories. For these cliffs two mobile terrestrial LiDAR surveys from a vehicle travelling on the highway were simulated: a stop&go survey and a kinematic survey. The effectiveness of the surveys was assessed in terms of sensed area and density of the measured points. Their efficiency was specified in terms of feed rate. For both surveys at least 70% of the cliffs was visible with a point density higher than 400 points/m2. The proportion of sensed area and density of the points provided by the stop&go survey was slightly higher compared with the kinematic survey, but the feed rate for the kinematic survey was higher.

2023 - Contamination exposure assessment of a well field through Null-Space Monte Carlo method [Articolo su rivista]
Critelli, Vincenzo; Ronchetti, Francesco; Mulas, Marco; Corsini, Alessandro; Brozzo, Giampiero
abstract

2023 - Geophysical techniques for monitoring the climate change effects on groundwater availability and quality [Abstract in Atti di Convegno]
Sabattini, Marco; Ronchetti, Francesco; Arosio, Diego; Brozzo, Gianpiero; Panzani, Andrea
abstract

2023 - Water isotope analyses and flow measurements for understanding the stream and meteoric recharge contributions to the Poiano evaporite karst spring in the North Apennines, Italy [Articolo su rivista]
Ronchetti, F.; Deiana, M.; Lugli, S.; Sabattini, M.; Critelli, V.; Aguzzoli, A.; Mussi, M.
abstract

The Poiano karst spring is located in the North Apennines (Italy) and it drains Triassic evaporite rocks with a mean discharge of hundreds of liters/second. Two hydrogeological conceptual models have been proposed (and published) for the spring based on tracer tests. Both models highlighted the contribution of the local streams to recharge of the karst aquifer system, through sinking-stream processes, as well as recharge through rainfall; however, those studies differed in the water courses selected to monitor the recharge processes. The aim of the present research is to increase knowledge about the groundwater recharge processes of the Poiano karst spring with new surveys and analyses, resulting in a large dataset of temporal water stable isotope analyses (δ18O, δ2H), temporal stream discharge measurements, and temporal water tritium isotope data (T). A new hydrogeological conceptual model for the Poiano karst spring is proposed, within which a new list of streams becomes involved in the recharge-processes model based on different sources of water. In addition, the research identifies and confirms the occurrence of groundwater flow processes inside the karst system, such as the piston effect.

2022 - A strontium isoscape of Italy for provenance studies [Articolo su rivista]
Lugli, F.; Cipriani, A.; Bruno, L.; Ronchetti, F.; Cavazzuti, C.; Benazzi, S.
abstract

We present a novel database of biological and geological 87Sr/86Sr values (n = 1920) from Italy, using literature data and newly analysed samples, for provenance purposes. We collected both bioavailable and non-bioavailable (i.e. rocks and bulk soils) data to attain a broader view of the Sr isotope variability of the Italian territory. These data were used to build isotope variability maps, namely isoscapes, through Kriging interpolations. We employed two different Kriging models, namely Ordinary Kriging and Universal Kriging, with a geolithological map of Italy categorized in isotope classes as external predictor. Model performances were evaluated through a 10-fold cross validation, yielding accurate 87Sr/86Sr predictions with root mean squared errors (RMSE) ranging between 0.0020 and 0.0024, dependent on the Kriging model and the sample class. Overall, the produced maps highlight a heterogeneous distribution of the 87Sr/86Sr across Italy, with the highest radiogenic values (>0.71) mainly localized in three areas, namely the Alps (Northern Italy), the Tuscany/Latium (Central Italy) and Calabria/Sicily (Southern Italy) magmatic/metamorphic terrains. The rest of the peninsula is characterized by values ranging between 0.707 and 0.710, mostly linked to sedimentary geological units of mixed nature. Finally, we took advantage of the case study of Fratta Polesine, to underscore the importance of choosing appropriate samples when building the local isoscape and of exploring different end-members when interpreting the local Sr isotope variability in mobility and provenance studies. Our user-friendly maps and database are freely accessible through the Geonode platform and will be updated over time to offer a state-of-the-art reference in mobility and provenance studies across the Italian landscape.

2022 - Multidisciplinary non-invasive investigations to develop a hydrogeological conceptual model supporting slope kinematics at Fontana Cornia landslide, Northern Apennines, Italy [Articolo su rivista]
Aguzzoli, Alessandro; Arosio, Diego; Mulas, Marco; Ciccarese, Giuseppe; Bayer, Benedikt; Winkler, Gerfried; Ronchetti, Francesco
abstract

A multidisciplinary approach focusing on the integration of diverse and non-invasive investigations is presented to define the hydrogeological conceptual model of the complex Fontana Cornia landslide in the Northern Apennines, Italy. The results of seismic refraction tomography and electrical resistivity tomography investigations indicate that the landslide has a curvilinear sliding surface dividing the shallow calcarenite debris layer from the deeper pelitic bedrock. The surface presents undulations in which water can be stored and supports the application of the fill and spill hypothesis that is seldom used in landslide studies. The joint interpretation of the geophysical outcomes and of the hydrogeological and hydro-chemical analyses of a spring located on the slope allows the definition of the landslide hydrogeological conceptual model. Four specific hydrologic stages with different groundwater flows though the landslide body were identified. The developed hydrogeological model may explain the displacements of the landslide that were detected with In-SAR monitoring. The isotopes analyses, the displacement monitoring, and the hydrogeological measurements confirm that periods with significant precipitations and snowmelt can cause an increase in landslide saturation that in turn triggers larger displacements. Conversely, the landslide slowly moves at a steady rate during periods with limited recharge water.

2021 - MICROPILES TRIPODS SHIELDS (MTS) AS UNCONVENTIONAL BREAKERS FOR THE CONTROL OF MODERATELY RAPID EARTHFLOWS (SASSI NERI LANDSLIDE, NORTHERN APENNINES) [Articolo su rivista]
Corsini, Alessandro; Giovanna, Baiguera; Francesco, Capuano; Ciccarese, Giuseppe; Diena, Michela; Mulas, Marco; Ronchetti, Francesco; Rossi, Gianluca; Truffelli, Giovanni
abstract

The paper deals with the idea, design and implementation of unconventional one-of-a-kind Micropiles Tripods Shields (MTS) intended to break and decelerate moderately rapid earthflows surges in the track zone of the Sassi Neri landslide (Nure Valley, Northern Apennines, Province of Piacenza, Italy). The MTS are inspired to floating anchors and “chevaux de fries” used in wartime. The basic elements are tripods of 193 mm diameter steel micropiles laid out at triangle, driven into the stable bedrock and emerging some meters aboveground. Each tripod consists of a vertical upslope central pile and two lateral oblique piles, linked by two transversal beams and connection plates aboveground. Multiple tripods are spaced along transversal rows to form Micropiles Tripods Shields (MTS) to advancing earthflows. The design of MTS has been based on field investigations such as boreholes and geophysics, that indicated a limited thickness of landslide deposits in the track zone where MTS have been installed. The forces resulting from active earthflows fronts have been estimated both with geotechnical and hydraulic computations. The analysis of vertical and transversal forces as well as bending moments acting on a single tripod versus the characteristic resistances was carried out using a bi-dimensional scheme with finite-elements software Plaxis, that indicated that the stress levels were compatible with the structural resistance of the tripods. The construction of MTS took place in 2018, involving working site preparation with partial lime-treatment of the surficial layers, underground micropiles drilling and installation, aboveground micropiles welding, tripods completion with connection beams and plates. Some tripods have been instrumented with load cells for monitoring earth pressures against micropiles, electric transducers for groundwater monitoring next to the piles, tiltmeters for tripods rotations and a total station for slope and tripods movements monitoring. Results show that the acceleration of slope movements corresponds to a generalized increase of pore water pressure at all the monitored tripods and to temporary slight tilting of the tripods which has so far being fully recovered when the landside slowed down and pressure decreased. This pioneering application indicates that once the characteristics of the earthflows are carefully considered, the depth to the bedrock in the installation zone is limited, and the logistical conditions in the field during construction are adequate, the MTS can be taken into consideration as a possible unconventional solution to break down and control moderately rapid earthflows.

2021 - Nuove evidenze sulla circolazione idrica sotterranea delle fonti carsiche di Poiano (Appennino reggiano) [Monografia/Trattato scientifico]
Ronchetti, Francesco; Deiana, Manuela; Lugli, Stefano; Critelli, Vincenzo; Arosio, Diego; Mussi, Mario; Longoni, Laura; Ivov Ivanov, Vladislav; Taruselli, Marco; Brambilla, Davide; Curotti, Alessandra; Bergianti, Stefano; Ercolani, Massimo; Sansavini, Baldo
abstract

2020 - Contribution of water geochemistry and isotopes (δ18O, δ2H, 3H, 87Sr/86Sr and δ11B) to the study of groundwater flow properties and underlying bedrock structures of a deep landslide [Articolo su rivista]
Deiana, M.; Mussi, M.; Pennisi, M.; Boccolari, M.; Corsini, A.; Ronchetti, F.
abstract

A comprehensive understanding of bedrock lithology and groundwater circulation is necessary to identify areas prone to landslide initiation and reactivation. This necessity is particularly required in the case of outcroppings of weak rocks such as gypsum that, due to their high solubility and low mechanical strength, can promote slope deformation with the development of caves and collapses. In the Upper Secchia River Valley, where gypsum outcrops extensively and is covered by landslide deposits, an accurate identification of the gypsum outcrops and their distribution is needed to reduce the damage to urbanized slopes. In this paper, a hydrologic and geochemical approach is used in the Montecagno landslide to identify the origin, flow paths and transit time of groundwater circulating inside the landslide body and to identify gypsum deposits and their distribution in the bedrock. The results of groundwater-level monitoring, δ18O-δ2H and 3H isotope analyses and FLOWPC modelling suggest a local and recent origin of the groundwater hosted in shallow flow paths inside the landslide. Chemical and isotope (87Sr/86Sr, δ11B) analyses offer evidence of the presence inside the landslide of small blocks of gypsum that, due to their dimensions, probably have a minor influence on landslide stability. This research demonstrates that the methodology used can provide satisfactory information about bedrock structures and their hydrological aspects.

2020 - Redundancy and coherence of multi-method displacement monitoring data as key issues for the analysis of extremely slow landslides (Isarco valley, Eastern Alps, Italy) [Articolo su rivista]
Simeoni, Lucia; Ronchetti, Francesco; Costa, Carlo; Joris, Paolo; Corsini, Alessandro
abstract

The paper describes the study of two extremely slow, active-continuous, deep-seated landslides located in the Isarco Valley (Eastern Alps, Italy): a Multiple Rotational Rock Slide (MRRS) and partial reactivation of a Deep-Seated Gravitational Slope Deformation (DSGSD). Both landslides interact with viaducts on the E45 highway. Extensive multi-method field investigation, monitoring of surface and subsurface displacements and limit equilibrium stability analyses were adopted to fully characterize slope dynamics. In order to overcome the limitations due to the systematic errors affecting each single monitoring system and analysis method, an operative framework based on redundancy and coherence tests was introduced to check the reliability of the data and results. In this framework, the geological and geotechnical models of the investigated slopes were progressively refined. This allowed assessment of the type of interaction between the slopes and the highway viaducts.

2020 - Tracer test to assess flow and transport parameters of an earth slide: The Montecagno landslide case study (Italy) [Articolo su rivista]
Ronchetti, Francesco; Piccinini, Leonardo; Deiana, Manuela; Ciccarese, Giuseppe; Vincenzi, Valentina; Aguzzoli, Alessandro; Malavasi, Gianluca; Fabbri, Paolo; Corsini, Alessandro
abstract

Subsurface water processes are principle triggering and driving factors during slope movements. However, thehydraulic properties that drive groundwaterflow along the slope remain poorly understood. Moreover, landslidedeposits are often characterized by layering andfissures that cause high heterogeneity in the distribution ofhydraulic properties. This heterogeneity leads to great uncertainty in the prediction of groundwaterflow paths.This study aimed to improve understanding of hydraulic and transport properties of deep earth slides and toidentify preferentialflow directions inside the landslide body. A dye tracer test was used to estimate transportparameters and characterize groundwaterflow paths. The results indicate that in the studied landslide, twogroundwaterflow types exist and are related to the presence offissured rock blocks and debris horizons em-bedded in afine matrix. The estimated low groundwaterflow velocity has rarely been estimated in other studiesof this landslide type. The groundwaterflow direction appears to be mainly influenced by the failure surfaceshape and differs from the sliding direction. Our results differ from those in other landslide studies and improveour knowledge of groundwaterflow properties in deep earth slides; furthermore, they offer a new contribution toslope stability analyses and formula, and to the effective design of mitigation strategies.

2019 - Estimating the Isotopic Altitude Gradient for Hydrogeological Studies in Mountainous Areas: Are the Low-Yield Springs Suitable? Insights from the Northern Apennines of Italy [Articolo su rivista]
Tazioli, Alberto; Cervi, Federico; Doveri, Marco; Mussi, Mario; Deiana, Manuela; Ronchetti, Francesco
abstract

Several prior studies investigated the use of stable isotopes of water in hydrogeological applications, most on a local scale and often involving the isotopic gradient (evaluated by exploiting the so-called altitude effect), calculated on the basis of rainwater isotopes. A few times, this gradient has been obtained using the stable isotopic contents of low-yield springs in a limited time series. Despite the fact that this method has been recognized by the hydrogeological community, marked differences have been observed with respect to the mean stable isotopes content of groundwater and rainwater. The present investigation compares the stable isotopic signatures of 23 low-yield springs discharging along two transects from the Tyrrhenian sea to the Po Plain of Italy, evaluates the different isotopic gradients and assesses their distribution in relation to some climatic and topographic conditions. Stable isotopes of water show that groundwater in the study area is recharged by precipitation and that the precipitation regime in the eastern portion of the study area is strongly controlled by a shadow effect caused by the Alps chain on the air masses from central Europe. Stable isotopes (in particular the d18O and deuterium excess (d-excess) contents together with the obtained isotopic gradients) allow us to identify in the study area an opposite oriented orographic effect and a different provenance of the air masses. When the windward slope is located on the Tyrrhenian side, the precipitation shows a predominant oceanic origin; when the windward slope moves to the Adriatic side, the precipitation is characterized by a continental origin. The main results of this study confirm the usefulness of low-yield springs and the need for a highly detailed survey-scale hydrological investigation in the mountainous context.

2019 - New isotopic surveys on the Poiano karst system [Abstract in Atti di Convegno]
Ronchetti, Francesco; Critelli, Vincenzo; Deiana, Manuela; Corsini, Alessandro; Lugli, Stefano; Mussi, Mario; Ercolani, Massimo; Curotti, Alessandra
abstract

2018 - Chemical and isotopic investigations (δ18O, δ2H, 3H, 87Sr/86Sr) to define groundwater processes occurring in a deep-seated landslide in flysch [Articolo su rivista]
Deiana, Manuela; Cervi, F.; Pennisi, M.; Mussi, M.; Bertrand, C.; Tazioli, A.; Corsini, A.; Ronchetti, F.
abstract

Deep-seated landslides are complex systems. In many cases, multidisciplinary studies are necessary to unravel the key hydrological features that can influence their evolution in space and time. The deep-seated Berceto landslide, in the northern Apennines of Italy, has been investigated in order to define the origin and geochemical evolution of groundwater (GW), to identify the slope system hydrological boundary, and to highlight the GW flow paths, transit time and transfer modalities inside the landslide body. This research is based on a multidisciplinary approach that involves monitoring GW levels, obtaining analyses of water chemistry and stable and unstable isotopes (δ18O-δ2H, 3H, 87Sr/86Sr), performing soil leaching tests, geochemical modelling (PHREEQC), and principal component analysis (PCA). The results of δ18O-δ2 H and 87Sr/86Sr analyses show that the source of GW recharge in the Berceto landslide is local rainwater, and external contributions from a local stream can be excluded. In the landslide body, two GW hydrotypes (Ca-HCO3 and Na-HCO3) are identified, and the results of PHREEQC and PCA confirm that the chemical features of the GW depend on water–rock interaction processes occurring inside the landslide. The 3H content suggests a recent origin for GW and appears to highlight mixing between shallow and deep GW aliquots. The 3H content and GW levels data confirm that shallow GW is mainly controlled by a mass transfer mechanism. The 3H analyses with GW levels also indicate that only deep GW is controlled by a pressure transfer mechanism, and this mechanism is likely the main influence on the landslide kinematics.

2018 - Slope dynamics and streambed uplift during the Pergalla landslide reactivation in March 2016 and discussion of concurrent causes (Northern Apennines, Italy) [Articolo su rivista]
Mulas, Marco; Ciccarese, Giuseppe; Ronchetti, Francesco; Truffelli, Giovanni; Corsini, Alessandro
abstract

On March 28, 2016, the toe zone of the apparently dormant Pergalla earthslide-earthflow (Northern Apennines, Italy) had a paroxysmal reactivation. In the course of 2 days, displacements up to almost 8 m severely damaged several houses and roads. At the bottom of the slope, the emersion of rotational sliding surfaces determined the uplift of almost 3 m of the Nure river streambed that was consequently partially dammed. The paper describes the landslide event on the basis of field surveys and analysis of post-event aerial photos, as well as data from geophysical surveys and pre- to post-failure displacement monitoring. It also discusses the possible concurrent causes of the event, including antecedent rainfall, the migration of active streambed channels of Nure river toward the landslide toe in the previous year, and the existence of long-term pre-failure slow movements. It is concluded that these factors, together with the presence of sliding surfaces extending beneath the valley floor, should be primarily considered if a preventive assessment of river damming potential due to streambed uplift should be made for other similar landslides in the Apennines.

2017 - CROP EVAPOTRANSPIRATION VARIATION UNDER CLIMATE CHANGE IN SOUTH EAST EUROPE DURING 1991-2050 [Articolo su rivista]
Nistor, Mărgărit Mircea; Ronchetti, Francesco; Corsini, Alessandro; Cheval, Sorin; Dumitrescu, Alexandru; Kumar Rai, Praveen; Petrea, Dănuţ; Dezsi, Ştefan
abstract

The crop evapotranspiration computing is a complex matter from many points of view, but also it represents a useful parameter in hydrological and climate studies. Due to climate changes, the natural systems are coming to be negatively affected. The seasonal and annual crop evapotranspiration under current climate (1991-2020) and future climate (2021-2050) were analysed using the mean annual temperature, mean annual precipitation, and mean monthly potential evapotranspiration for average of 30 years. The spatial distribution of crop evapotranspiration was calculated considering the evapotranspiration coefficients taken from literature using four stages of crops growth. Additionally, the absolute and relative changes of the annual crop evapotranspiration were carried out. The annual crop evapotranspiration varies in the actual period from 56 mm to 1297 mm, while in the future period the annual crop evapotranspiration varies from 59 mm to 1410 mm, which implies the impact of future climate warming on the crop evapotranspiration in the South East Europe. The heights values were identified in the South of Greece, in the southwestern sides of Romania, in the East sides of Bulgaria, Croatia and European Turkey. The maximum seasonal crop evapotranspiration were found in the mid-season, both for present and future. The minimum values of seasonal crop evapotranspiration were obtained in the cold season, when the mean air temperature and crop coefficients are lower. The absolute and relative changes indicate the high values in the South and southwestern sides of the South East Europe.

2017 - Discharge and environmental isotope behaviours of adjacent fractured and porous aquifers [Articolo su rivista]
Deiana, Manuela; Mussi, M.; Ronchetti, Francesco
abstract

The combined use of hydrogeological and hydrogeochemical methods can provide relevant information about the characteristics of aquifers in studies focused on groundwater protection and management. In the present study, spring discharge monitoring coupled with stable and unstable water isotopes was used to compare the behaviour of adjacent fractured and porous aquifers hosted in a 4.5 km2 area along the same slope in the northern Apennines, Italy. Based on stable isotope analyses of four springs, a plausible local meteoric water line and a local vertical isotopic gradient were identified. Additionally, tritium contents revealed a recent meteoric origin for groundwater via infiltration in the area. The results of monthly stable isotope monitoring, hourly spring discharge monitoring, hourly rainfall monitoring, and statistical analyses (time series analysis) suggested that although the adjacent aquifers exhibited pronounced geological and hydrogeological differences, few discrepancies were observed regarding groundwater infiltration and release processes. Notably, they exhibited similar temporal delays associated with the response to precipitation events due to the roles of macro-fractures and macro-porosity. Groundwater circulation was characterized by piston and memory effects in both the fractured and porous aquifers, and these effects reflect the roles of micro-fractures/fissures and micro-porosity. The study highlights the relevant contributions of isotopes in studies that focus on spring vulnerability and aquifer processes. Moreover, results obtained in the Pietra di Bismantova site are useful to increase hydrological knowledge on the quite relevant aquifers hosted in Epi-ligurian rock slabs and the surrounding slope deposits in the northern Apennines of Italy.

2017 - Groundwater Flow Characterization Using Different Hydraulic Methods in Large and Deep Earth-Slide Rich in Clay [Relazione in Atti di Convegno]
Ronchetti, Francesco; Piccinini, Leonardo; Deiana, Manuela; Fabbri, Paolo; Corsini, Alessandro
abstract

Since 2013, different hydraulic tests have been conducted and replicated in a large earth slide characterized by a landslide body that is rich in clay, has a mean thickness of 30 meters, and is located in the Northern Apennines, Italy. All the tests were performed to estimate the hydrogeological properties of the landslide and to design future mitigation measures. To define the geometry of the sliding mass, the stratigraphy in more than 15 boreholes was analyzed. The boreholes were subsequently equipped with inclinometers and open standpipe piezometers. According to the stratigraphy, the landslide body is characterized by the presence of gravel layers in a clay-rich matrix. This study compares the results from the different techniques applied to 2 boreholes, 5 open standpipe piezometers and 1 well. The number of tests performed for each test type were 31 slug tests (ST), 4 falling head tests (FT), 5 low-flow pumping tests (PT), 1 point dilution (PD) test, and 2 aquifer tests (AT). Moreover, the test data was evaluated with different solutions. The ST data was evaluated with the Hvorslev and KGS solutions; the FT data was evaluated with the AGI and Hvorslev solutions; the PT data was evaluated with the Muskat solutions; the AT data was evaluated with the Theis, Cooper-Jacob, Neuman, Moench and Tartakosky-Neuman solutions; and the PD test data was evaluated with the classical solution where Darcy velocity is calculated as a function of the rate of dilution. The results show that hydraulic conductivity (K), storage (S) and specific storage (Ss) vary in the horizontal plane and with the depth (K ranges between 1.0E-5 and 1.0E-8 m/s; S ranges between 4.0E-3 and 5E-5; and Ss ranges between 1.0E-3 and 3.0E-3 1/m). The horizontal and vertical variability is correlated with the lithologic heterogeneity highlighted by the borehole stratigraphy. Moreover, all the hydraulic tests conducted on the landslide body give highly consistent results. Comparison of results derived from different methods show that they are comparable with each other and they differ by one order of magnitude only in a few cases.

2017 - Landslide Zoning Using the Principal Component Analysis on Monitoring Data: The Sauna Earth Slide—Earth Flow (Parma, Italy) [Relazione in Atti di Convegno]
Mulas, Marco; Bonacini, Francesco; Petitta, Marcello; Ronchetti, Francesco; Truffelli, Giovanni; Diena, Michela; Corsini, Alessandro
abstract

In this contribute, we present the morphodynamic zoning of the Sauna complex earth slide—earth flow (Corniglio municipality, Northern Apennines) obtained by integrating results of field surveys and of Principal Component Analysis (PCA) of continuous displacement monitoring data. Since January 2014, the area is surveyed by an Automated Total Station (ATS) monitoring 30 prisms with duty cycles of 2 h. An evacuation plan has been adopted by the local authorities, which is based on pre-defined movement thresholds. However, during more than 2 years of monitoring, the results have evidenced that in different zones of the slope, differentiate displacement rates and timings of response to precipitations take place. Therefore, in order to fine tune evacuation plans, movement thresholds should be more appropriately tailored on the basis of morphodynamic zones rather than being left spatially generic. The final result is a morphodynamic zonation of the slope that represents a useful document to identify areas in which differentiated movement thresholds can be assessed for alert and alarm.

2016 - 2014-2015 Tritium values in small and shallow aquifers in northern Apennines [Abstract in Rivista]
Deiana, Manuela; Mussi, Mario; Ronchetti, Francesco
abstract

Tritium data relating to actual rainfall in north of Italy and in particular in the northern Apennines are rare or missing. The reasons of this lack of data frequently depends on the high cost of analysis and the necessity of high amount of water to perform the analysis itself. In order to obtain these data a valid alternative can be analyze the amount of Tritium in unconfined, shallow and small aquifer not affect by human activities (such as sewage). Recent studies, applied to the hydrogeology of the Po plain or of the Apennine slopes, highlight, in rainfall water recharging shallow aquifer, tritium values ranging between 6 T.U. and 12 T.U., higher than those detected in other and different areas of Italy or of the South Europe. The aim of this paper is to highlight first results of tritium analyses performed on spring draining shallow aquifers in northern Apennines, characterized by the absence of human activities. The peculiarity of sampling point (spring are characterized by small and well defined catchment areas as well small differences between the infiltration/recharge elevation and the spring elevation) makes results representative of mean tritium value of rainfall recharge in the studied area. In detail, during 2014-2015 three springs located at different elevation in Secchia Valley have been sampled and analyzed. Tritium analyses performed on a total of 5 samples highlight the following results: the maximum value (5.0±0.7 T.U.) is detected in water collected in November whereas the minimum value ( 3.7±0.6 T.U.) is obtained in May. Therefore a mean annual value of 4.2±0.7 T.U. in the studied area have been highlighted.

2016 - A wireless crackmeters network for the analysis of rock falls at the Pietra di Bismantova natural heritage site (Northern Apennines, Italy) [Relazione in Atti di Convegno]
Corsini, Alessandro; Bonacini, Francesco; Deiana, Manuela; Giusti, Riccardo; Russo, M. .; Ronchetti, Francesco; Cantini, C.; Truffelli, G.; Iasio, C.; Generali, M.; Ascari, L.; Chiesi, L. .; Venturi, L.
abstract

The Pietra di Bismantova (Northern Apennines, Italy) is a large calcareous sandstone rock slab which is distinctively bordered by sub-vertical cliffs that are affected by rock falls, a risk for people visiting the area and for key assets located at the foot of this natural heritage site. A wireless sensor network based on wireless nodes, crack meters and thermometers has been made operative in January 2015 in order to study the response of fractures to changing environmental conditions and support the spatial and temporal zonation of rock fall hazard in this natural heritage site. Results from the first eight months of monitoring show that intense snowfall and low temperatures can determine short-term pulses of fracture opening while the increase of temperature throughout summer determines long-term fracture closing trends. Moreover, as soon as February 2015 one of the crack meters monitored the rapid trend of crack opening that occurred prior to the failure of a large rock slab of about 200 cubic meters.

2016 - Hydrogeological investigation of Pietra di Bismantova slab and surrounding slope deposits (northern Apennines, Italy) [Articolo su rivista]
Deiana, Manuela; Cervi, Federico; Bertrand, Catherine; Ronchetti, Francesco
abstract

The recent application of hydrochemistry to unstable slopes reveals the contribution of this technique to better understand hydrological processes, water rock interaction and to outline groundwater flow paths. The aim of this short note is to present results from two years of semi-continuous monitoring (discharge, EC, temperature) of two springs (Eremo and F. Cornia spring) flowing along the SE slope of Bismantova fractured slab, in the stable and unstable portion of the slope respectively. Both springs follow the precipitation pattern with the increase of discharge and decrease of temperature as consequence of rainfall recharge; moreover the increase of EC seems to suggest interaction beetween groundwater and mineral phases hosted along fractures of the slab. Using chemical results a first inverse modeling with PHREEQC have been performed in order to identify the interaction between water infiltrating in host-rock and mineral phases, as well to reconstruct geochemical evolution of groundwater from the upward stable portion to the downward unstable portion of the slope.

2016 - The use of stable water isotopes from rain gauges network to define the recharge areas of springs: Problems and possible solutions from case studies from the northern Apennines [Articolo su rivista]
Cervi, Federico; Ronchetti, Francesco; Doveri, Marco; Mussi, Mario; Marcaccio, Marco; Tazioli, Alberto
abstract

Gli isotopi stabili dell’ossigeno e dell’idrogeno sono ampiamente utilizzati in bibliografia per la definizione degli areali di ricarica delle acque sotterranee in ambienti montani. Nella quasi totalità dei casi, vengono utilizzate relazioni pregresse sviluppate da altri autori che legano la variazione degli isotopi raccolti presso pluviometri campionatori con la quota, ricavando, con le sole analisi delle acque sotterranee, la quota media di infiltrazione delle acque sorgive campionate. Tale approccio, seppur di facile utilizzo, non tiene in considerazione i meccanismi di ricarica delle acque sotterranee, assumendo le acque campionate ai pluviometri come totalmente equiparabili alle acque sorgive. Dal punto di vista idrogeologico, tale assunzione non tiene in considerazione l’equazione del bilancio idrogeologico, trascurando gli effetti dell’evapotraspirazione e del deflusso superficiale. La presente nota riporta una comparazione preliminare tra isotopi stabili in acque meteoriche (1 pluviometro) e sotterranee (2 sorgenti) nel medio-alto Appennino emiliano. I risultati evidenziano come, nel caso in esame, le relazioni comunemente applicate in bibliografia forniscano valori di quote di alimentazione fuorvianti, in entrambi i casi superiori alle rispettive quote massime dei bacini idrogeologici delle sorgenti. Le stime dell’evapotraspirazione potenziale, e la successiva procedura dei weighting del dato isotopico meteorico, sottolineano come la causa principale delle anomalie nella stima della quota di alimentazione sia da ricercare in questo parametro del bilancio, che non consente alle acque meteoriche estive di pervenire alle falde sotterranee.

2016 - Toward a centralized data management center for integrated landslide monitoring in Emilia Romagna Region (Italy) [Relazione in Atti di Convegno]
Corsini, Alessandro; Bonacini, Francesco; Ciccarese, Giuseppe; Mulas, Marco; Ronchetti, Francesco; Nanni, Stefania; Truffelli, Giovani; Caputo, Giuseppe; Pizziolo, Marco; Primerano, Sabrina; Monni, Antonio
abstract

In Emilia Romagna Region, slope monitoring systems have become more widely used for hazard and risk management. However, they are generally non-interoperable. Moreover dispersion of monitoring data in several local databases have made data sharing among the involved institutional actors quite laborious and often untimely. A centralized database and a web-based portal that integrate infor- mation derived by different types of slope monitoring systems has been developed. The paper illustrates the specific features of the developed “SensorNet” and provides examples of its use for visualizing and analyzing in an integrated manner data from different monitoring systems. In perspective it could serve as an every-day operational tool for a timely reporting of landslide monitoring data for surveillance and warning purposes.

2015 - A portable continuous GPS array used as rapid deployment monitoring system during landslide emergencies in Emilia Romagna [Articolo su rivista]
Corsini, A.; Bonacini, F.; Mulas, M.; Ronchetti, F.; Monni, A.; Pignone, S.; Primerano, S.; Bertolini, G.; Caputo, G.; Truffelli, G.; Benini, A.; Berti, M.
abstract

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

2015 - Characterizing the Recharge of Fractured Aquifers: A Case Study in a Flysch Rock Mass of the Northern Apennines (Italy) [Relazione in Atti di Convegno]
Cervi, F.; Corsini, Alessandro; Doveri, M.; Mussi, M.; Ronchetti, Francesco; Tazioli, A.
abstract

12 springs from the northern Apennines of Italy were studied by means of a comprehensive hydrogeological investigation to unravel recharge processes taking place in a highly fractured slab of flysch rock hosting the corresponding aquifers. Several campaigns were carried out during the period 2005–2008 to gather springs’ discharge together with electrical conductivity and temperature data. Water samples were collected and allowed the determination of the major ions (Ca2+, Mg2+, Na+, K+, SO4 2−, HCO3 −, Cl−) and the isotopic content (δ18O). Additionally, groundwater discharge from 3 selected springs was measured continuously using pressure-transducers. Over the same period, reference δ18O values for rainfall and snow-melt water were collected monthly by a rain-gauge. Results highlighted an aquifer-like behavior of this slab of flysch rock. The springs are characterized by a Ca–HCO3 hydro-facies and an increase of groundwater mineralization has been noticed moving toward the base of the slab; the mean discharges are between 0.3 and 0.7 l·s−1 and suffered a marked variability during the year; the total maximum yield is about 155,000 m3 while the total discharge volume is around 320,000 m3·y−1. By processing the δ18O isotope values from springs (mean annual values ranged from −9.67 and −10.42 ‰) and by combining them with rainfalls datasets, results show that the main aliquot of recharge occurs in the winter—spring months and it is principally related to the solid precipitations (snow-melt).

2015 - Geomechanical assessment of the Corvara earthflow through numerical modelling and inverse analysis [Articolo su rivista]
Schädler, W.; Borgatti, L.; Corsini, Alessandro; Meier, J.; Ronchetti, Francesco; Schanz, T.
abstract

This research proposes a conceptual approach for analysis and numerical modelling of the hydromechanical behaviour of large landslides, applied to one of the source areas of the Corvara earthflow (Dolomites, Italy). The approach consists of two steps: forward calculation and inverse analysis. For the forward calculations, the geological model of the slope considering several shear zones delimitating landslide units was developed, based on a detailed dataset of field investigation and monitoring data. A viscoplastic constitutive model was used to describe the time-dependent material behaviour, i.e. the creep, of the shear zones. The transient distribution of pore water pressure in the slope was considered by means of an additional purely hydrogeological model. These results were used as averaged hydraulic boundary conditions in the calculation of stress and deformation fields with the continuum finite element method (FEM). The numerical model was then calibrated against ground surface displacement rates measured by D-GPS, by iteratively varying the material parameters of the shear zones. For this task, an inverse analysis concept was applied, based on statistical analyses and an evolutionary optimisation algorithm. The inverse modelling strategy was further applied to gather statistical information on model behaviour, on the sensitivity of model parameters and on the quality of the obtained calibration. Results show that the calibrated model was able to appropriately simulate the displacement field of the earthflow and allow the requirements, difficulties and problems, as well as the advantages and benefits of the proposed numerical modelling concept to be highlighted.

2015 - Hydrogeology, Hydrochemistry and Isotopic Investigation to Define the Lateral Hydraulic Boundaries of a Deep Rock Slide (Berceto Landslide: Northern Apennines) [Relazione in Atti di Convegno]
Deiana, Manuela; Cervi, F.; Corsini, Alessandro; Ambanelli, A.; Diena, M.; Lopardo, L.; Truffelli, G.; Ronchetti, Francesco
abstract

The Berceto landslide is a deep and active rock slide located in the northern Apennines. It affects a slope characterised by the overlapping of flysch and shale formations. The landslide has been monitored since the 1990s and an inclinometer installed in the head zone shows a sliding surface at the depth of 110 m. The landslide and the adjacent areas are affected by morphological anomalies in the slopes and in the surface drainage patterns. These anomalies are related to the presence of deep landslide or to the presence of faults in the bedrock. In particular, the River Baganza (RB) is situated at about 100 m upstream of the landslide main scarp and it is separated from the landslide by a thin layer of shale. The RB streambed is located at an elevation 70 m higher than the elevation of the active sliding surface. Due to these morphological anomalies, it is possible to speculate that the present extension of the landslide limit is not correct and that the landslide sliding surface could be extended as far as the RB. In this study, hydro-chemical and isotopic investigation have been carried out on the Berceto rock slide in order to define the lateral hydraulic boundary, the geometry of the slide surface and the groundwater flow paths. The ion contents and the δ18O-δ2H values indicate the presence in the landslide body of an external source of groundwater which could be provided by the RB through a sliding surface developed within the shale or by the flysch below the landslide body.

2015 - Interaction of Extremely Slow Landslides with Transport Structures in the Alpine Glacial Isarco Valley [Relazione in Atti di Convegno]
Simeoni, L.; Ronchetti, Francesco; Corsini, Alessandro; Mongiovì, L.
abstract

This paper describes three cases of extremely slow landslides located in the Isarco Valley, and interacting with major transport infrastructures connecting Italy to the central Europe: SS12 State Road, A22 (E45) Motorway, Verona-Brennero railway, high-speed railway network TNT-T5. Field measurements of displacements and pore water pressure were carried out to understand the mechanism of landslide evolution and the interaction with the transport structures. In particular, mobile inclinometers, IPIs, direct pendula and Total Station were used for monitoring the subsurface or structure movements. The landslides were classified as complex landslides. Two of them are associated to DGSDs phenomena. Field and remote measurements of displacements revealed that the interaction with the transport infrastructures was due to deep rotational/translational slides as partial reactivations of the DGSDs. The residual shear strength was developed on the sliding surfaces and therefore these landslides may be classified as active landslides.

2015 - Long-Term Continuous Monitoring of a Deep-Seated Compound Rock Slide in the Northern Apennines (Italy) [Relazione in Atti di Convegno]
Corsini, Alessandro; Bonacini, F.; Mulas, Marco; Petitta, M.; Ronchetti, Francesco; Truffelli, G.
abstract

An automated total station monitored a compound rock slide near the Cerreto Pass (northern Apennines, Italy) for more than three and a half years. The rock slide, which threatens national road SS63, has an estimated volume of more than 3 million m3 and is composed by the overlap of highly fractured limestone on an impermeable and weak clay shale layer. Specifically, a network of more than 30 prisms has been measured every 2 h from October 2009 to May 2013. This dataset provides substantial evidence of displacement rates up to 15 cm/year and gives information about the control of rainfall on slope movements. On the yearly scale the seasonal variation of rainfall regime determines the baseline displacement rate of the rockslide while moving to shorter time spans has been possible to individuate effects of rain episodes calculated on daily and weekly sampling. Results highlight the added value of continuous monitoring for assessing rock slide dynamics and improving hazard assessment.

2015 - MONITORING AND CHARACTERIZATION OF A SPRING IN A FRACTURED SANDSTONE SLAB [Poster]
Deiana, Manuela; Corsini, Alessandro; Mussi, Mario; Ciccarese, Giuseppe; Giusti, Riccardo; Ronchetti, Francesco
abstract

Fractured sandstone by tectonic and gravity actions could be classified as aquitard or aquifer according to the number and aperture of the fractures inside the rock mass. This kind of rock mass outcrops not frequently and sparsely in the Apennine and Alps chains. In the Emilian Apennines, which is mainly composed by sedimentary rocks (rich in clay), this type of rock is part of the Epiligurian Succession that outcrops for a 20 percent of the chain. The paper aims to highlight the first results of the semi-continuous water flow monitoring (discharge, electrical conductivity and temperature) and stable isotopic monitoring (delta18O and delta2H) of the spring that represents the drainage point of a vertical fractures system. This network joint characterizes the vertical scarp of a sandstone slab with thickness of 100 meters. The results show that the spring flow rate, the water electrical conductivity, temperature and isotopic values are influenced by the rainfall distribution pattern. Consequently during every rainfall event the spring discharge and water electrical conductivity increase, while the water temperature decreases and isotopic values become more negative. The new infiltrate water reachs the spring with a delay of 10-60 hours. The discharge variability index is around 270 percent. The fractured system is characterized by replacement effect of the preexistent groundwater. During the infiltration event, dissolution phenomena are observed along the wall of the fractures. A preliminary groundwater budget calculation highlights that only a potential infiltration coefficient higher that 75 percent is admitted to justify the total annual volume discharge from the fractures.

2015 - Partial reactivation of a DGSD of ignimbrite and tuff in an alpine glacial valley in Northern Italy [Relazione in Atti di Convegno]
Simeoni, L.; Ronchetti, Francesco; Corsini, Alessandro; Mongiovì, L.
abstract

This paper describes the surveys, site investigations, field measurements and laboratory tests carried out to analyze the stability of a slope in the Isarco alpine glacial valley, in Northern Italy, where rocks and debris of ignimbrite and tuff outcrop. This valley is crossed by the major transport infrastructures connecting Italy to the central Europe: SS12 State Road,A22 (E45) Motorway, Verona-Brennero railway, high-speed railway network TNT-T5. Recently, large deformations of the pads of a viaduct were identified and were supposed to be caused by the downslope movement of the piers. In effect, subsequent investigations and measurements revealed the existence of sliding surfaces with movements smaller than 1 cm per year. Surveys identified that movements occur at the toe of a DGSD and back-analyses revealed that the residual shear strength estimated with shearbox tests is mobilized on the sliding surfaces.

2015 - Prediction of landslide velocity at given cumulated rainfall values based on analysis of continuous monitoring data using ROC curves : application to the Piagneto landslide ( Northern Apennine , Italy ) [Abstract in Atti di Convegno]
Corsini, Alessandro; Mulas, Marco; Petitta, Marcello; Bonacini, Francesco; Ronchetti, Francesco
abstract

A novel approach to predict landslide velocity at given cumulated rainfall values based on the analysis of continuous displacement and rainfall monitoring data by using ROC curves has been developed and tested in the Piagneto landslide (northern Apennines, Italy). It is an active rock slide for which a velocity dataset covering the period October 2009 to December 2014 is available thanks to a total station that has been monitoring tens of prisms at duty cycles of 2 hours. Over the same time frame, an hourly rainfall dataset is available from rain gauges located just a few km away from the landslide. The ROC curve (Receiver Operating Characteristic) is a well-known and widely used method to assess the efficiency of a binary classifier. In this case, it is used to assess the efficiency of different values of cumulated rainfall to determine a given value of velocity in the landslide. Operatively, the daily velocity distributions of selected monitoring prisms is plotted in order to assess upper values at given levels of occurrence probability, i.e. velocity values at the upper 1st,2nd, 3rd quartile and 2 sigma. These velocity values are then classified with respect to daily rainfall cumulated over different time windows (from 1 to 120 days), that are considered singularly or in combination one another. The area under the ROC curves, as well as the max distance from the random line, is used as indicator of performance in order to assess the cumulated rainfall (in terms of amount and duration) showing the higher performance in predicting a defined landslide velocity level. The values obtained with the retrospective analysis of monitoring data, can then be used for prediction of expected velocity levels. This has been verified by using the conventional approach of dividing the dataset in a training and a validation subsets. Results underline the added value of the analysis of long time-series of continuous landslide monitoring data by mean of operational research tools, such as in this case the ROC curves, for extracting information useful for improving the comprehension and the prediction of slope dynamics that, in specific cases, can be of great support to risk management.

2015 - Preliminary water flow monitoring of a vertical fractures system in a sandstone rock mass [Articolo su rivista]
Deiana, M.; Bonacini, F.; Cilona, F.; Formicola, M.; Nistor, M. M.; Corsini, A.; Ronchetti, F.
abstract

Fractured sandstone by tectonic and gravity actions could be classified as aquitard or aquifer according to the number and aperture of the fractures inside the rock mass. This kind of rock mass outcrops not frequently and sparsely in the Apennine and Alps chains. In the Emilian Apennines, which is mainly composed by sedimentary rocks (rich in clay), this type of rock is part of the Epiligurian Succession that outcrops for a 20% of the chain. The aim of the paper is to highlight the first results of the semi-continuous water flow monitoring (discharge, electrical conductivity and temperature) of the spring that represents the drainage point of a vertical fractures system. This network joint characterizes the vertical scarp of a sandstone slab with thickness of 100 meters. The results shows that the spring flow rate, the water electrical conductivity and temperature are influenced by the rainfall distribution pattern. Consequently every rainfall event the spring discharge and water electrical conductivity increase, while the water temperature decreases. The new infiltrate water reacts the spring with a delay of 10-60 hours. The discharge variability index is around 270%. The fractured system is characterized by replacement effect of the preexistent groundwater. During the infiltration event, dissolution phenomena are observed along the wall of the fractures. A preliminary groundwater budget calculation highlights that only a potential infiltration coefficient higher that 75% is admitted to justify the total annual volume discharge from the fractures.

2015 - Water isotopes in landslide research (WIsLaR) [Abstract in Atti di Convegno]
Deiana, Manuela; Cervi, Federico; Corsini, Alessandro; Mussi, Mario; Pennisi, Maddalena; Ronchetti, Francesco
abstract

In the last decade, the scientific community is trying to integrate multidisciplinary approaches to gain further insights in the knowledge of landslide initiation and evolution. In particular, isotope geochemistry is a useful investigation tool to define landslide groundwater recharge origin, groundwater flow paths, mixing phenomena between different water bodies, type of aquifer, type of groundwater transfer processes (only pressure or pressure and mass). This paper aims at pointing out the potentiality of stable and radiogenic isotopic analyses in the study of large and deep rock landslides located in north Apennines. In the studied landslides, the continuous monitoring of groundwater levels, groundwater flow rate from springs or mitigation works, groundwater electrical conductivity and temperature are coupled with groundwater sampling followed by determination of major and tracers ions (such as: Na+, K+, Mg2+, Ca2+, Cl-, HCO3-, SO42-,Btot, Sr2+), and stable (delta 18O, delta 2H,) and radiogenic isotopes (87Sr/86Sr, 3H). In this study isotopic investigations are decisive to understand hydrological processes in landslide body. More in details delta 18O, delta 2H, 87Sr/86Sr and 3H allow to define subsurface architecture, groundwater origin, groundwater flow paths and mixing phenomena between different groundwater bodies. Recharge zones are identify by means of delta 18O and delta 2H isotopes. 3H gives information about groundwater age and allows to identify deep confined layer characterized by low circulation of water and to investigate subsurface transfer processes. In the current research 3H allows to identify a deep confined aquifer in which pressure transfer prevails on mass transfer. Subsurface layers with prevalent horizontal or vertical flux are identified by means simultaneous application of delta 18O, delta 2H and 3H. The simultaneous application of delta 18O, delta 2H, 3H and 87Sr/86Sr allows to recognize hydraulic connections between groundwater and surface water. Moreover, 87Sr/86Sr coupled with 3H allow to identify multilayer aquifer within the landslide body.

2014 - Determination of the concentration of asbestos minerals in highly contaminated mine tailings: An example from abandoned mine waste of Cretaz and Emarese (Valle d'Aosta, Italy) [Articolo su rivista]
Gualtieri, Alessandro; Pollastri, Simone; Ronchetti, Francesco; Gandolfi, N. B.; Albonico, C.; Cavallo, A.; Zanetti, G.; Marini, P.; Sala, O.
abstract

For the first time, this work reports concentration maps of asbestos minerals in contaminated mine tailings drawn using the results of Rietveld quantitative phase analysis (QPA). The investigated sites are located in the Valle d’Aosta region (Italy): Crètaz, the most important Italian magnetite mine, active until 1979 and Emarèse, one the most important chrysotile asbestos mines in Italy, active until 1968. The results of the study permit to draw the spatial distribution of the asbestos (chrysotile and tremolite in this specific case) concentration, useful to plan reclamation of the sites, with priority given to the areas with the highest asbestos concentration. Because of the complexity of the mineral assemblage, which includes, among the others, antigorite, chlorite, talc, and tremolite, the concentration of chrysotile was cross-checked using different experimental techniques such as X-ray powder diffraction (XRPD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), polarized light optical microscopy (PCOM), and differential thermal analysis (DTA). The accuracy of the results was validated by analyzing standard samples with known concentrations of chrysotile and tremolite. The comparison allowed to point out the advantages and disadvantages of each experimental method. At Crètaz, chrysotile ranges from 4.4 to 22.8 wt% and tremolite from 1.0 to 10.3 wt%, whereas at Emarèse the concentration of chrysotile varies from 3.3 to 39.5 wt% and tremolite from 5.9 to 12.4 wt%. Antigorite and chlorite are the major accompanying phases with variable amounts of other accessory minerals including magnetite, carbonates, talc, olivine, pyroxene, talc, and brucite. The results of our study are of key importance for the local environmental policies as the knowledge of the spatial distribution of the asbestos concentration allows to plan a detailed reclamation agenda of the contaminated sites. The spots with the highest surface contamination of both chrysotile and tremolite were identified and classified as priority areas in the reclamation plan.

2014 - Evidence of deep-water inflow in a tectonic window of the northern Apennines (Italy) [Articolo su rivista]
F., Cervi; L., Borgatti; G., Martinelli; Ronchetti, Francesco
abstract

Water samples from the river network and from some shallow and brackish springs located in a tectonic window of the northern Apennines of Italy were studied in the frame of a comprehensive hydrogeological investigation in order to better understand the origin and the mixing processes between the two water types noticed also in previous studies (Ca–HCO3 and Na–Cl). A sampling campaign covering the drought period during year 2010 was planned to gather electric conductivity, temperature and redox potential data along the river network and on groundwater occurrences located inside the tectonic structure. Additionally, eight water samples were collected for hydrochemical (major anions and cations: Na+, K+, Ca2+, Mg2+, HCO3 −, Cl−, SO4 2− and trace ion Btot) and isotopic (δ18O, δ2H, 3H) analyses and compared with other eighteen samples from shallow and brackish springs collected near the study site during the period 2005–2012. Moreover, river discharge and water balance estimations were carried out. Results confirmed the presence of old Na–Cl water with salinity progressively increasing up to 5.5 g l−1 at the northern termination of the tectonic window. These values are in agreement with the ions contents of the most mineralized spring (Macognano spring: salinity of 7.6 g l−1), which has been considered as having the deepest and longest flow-path. Stable isotopes and trace ions contents are consistent with rainfall and snowmelt water mixed with brines associated with a hydrocarbon reservoir hosted at depth. Considering as end-member the more mineralized Na–Cl water, a cumulate inflow in the range of 12.9 ± 5.9 l s−1 has been estimated. This aliquot is released into the river network with different mixing proportions by the groundwater occurrences discharging from the autochthonous flysch unit.

2014 - Frane a cinematica estremamente lenta in una valle glaciale del corridoio TEN-T5 [Relazione in Atti di Convegno]
Simeoni, L.; Ronchetti, Francesco; Corsini, Alessandro; Mongiovì, L.; Ferro, E.; Ghirardini, G.; Girardi, M. F.
abstract

La memoria descrive tre casi di frane a cinematica estremamente lenta (velocità di spostamento media inferiore a 10 mm/anno) ubicate nella valle glaciale alpina dell’Isarco, tra Bolzano e Bressanone. Le tre frane sono riattivazioni parziali di DGPV, sviluppatesi dopo l’ultima glaciazione in rocce vulcaniche o metamorfiche e si classificano come scorrimenti rotazionali profondi di roccia e detrito. Si descrivono i sistemi di monitoraggio di spostamenti e pressioni interstiziali, attivi da un minimo di 5 anni ad un massimo di 20, che sono stati installati per la definizione dei meccanismi di evoluzione dei movimenti. Si evidenziano i metodi di elaborazione delle misure, finalizzati al controllo dell’affidabilità delle stesse, e si riportano le interpretazioni dei meccanismi di frana effettuate mediante verifiche di stabilità a ritroso.

2014 - Integrazione tra indagini geofisiche e geognostiche per la definizione di un modello geologico e geotecnico di grandi frane profonde: il caso di Berceto nell’Appennino Settentrionale [Relazione in Atti di Convegno]
Ambanelli, A.; Ambrogio, A.; Baldi, A. M.; Bianchi, F.; Corsini, Alessandro; De Luca, J.; Deiana, Manuela; Diena, M.; Larini, G.; Lopardo, L.; Malaguti, C.; Mencarini, S.; Ronchetti, Francesco; Roverselli, D.; Truffelli, G.; Vescovi, P.
abstract

L’Appennino Settentrionale è caratterizzato dalla presenza di numerose frane con Deformazione Gravitativa Profonda di Versante (DGPV), a carattere cinematico lento. Una di queste interessa il versante di Berceto e presenta un’estensione di 3-4 km223 , una profondità di oltre 100 metri e un tasso di movimento nell’ordine di alcuni mm/anno, coinvolgendo l’intero abitato ed un tratto dell’Autostrada della Cisa (A15). La Regione Emilia-Romagna ha avviato, da alcuni anni, campagne di indagini geognostiche e geofisiche per la definizione del modello geologico e geotecnico di tale fenomeno. Le caratteristiche geometriche della massa coinvolta hanno reso necessaria indagini geofisiche di superficie (geoelettrica e sismica) e sondaggi geognostici indispensabili per la taratura puntuale dei dati indiretti e per l’installazione di strumentazioni inclinometriche, estensimetriche-assestimetriche e piezometriche. I risultati, interpretati alla luce delle evidenze stratigrafiche hanno consentito, congiuntamente ai dati idrogeologici e di monitoraggio degli spostamenti, la ricostruzione di un primo modello geologico e geotecnico.

2014 - The Mulino delle vene spring system: hydrogeological features and groundwater balance [Relazione in Atti di Convegno]
Ronchetti, Francesco; G., Panini; A., Tazioli; L., Vizzi; F., Cervi
abstract

The Mulino delle vene spring system...

2014 - Utilizzo d'immagini all'infrarosso termico per l'individuazione di sorgenti minerali nella Finestra Tettonica di Gova [Articolo su rivista]
Ronchetti, Francesco; F., Cervi; Corsini, Alessandro; P., Mora; G., Maragò; S., Taddia
abstract

L’utilizzo di immagini all'infrarosso termico da piattaforma satellitare, aerea e terrestre è oramai consolidato in diverse discipline tra le quali l’ingegneria civile, l’architettura, l’idrologia, l’idrogeologia, l’agronomia e la climatologia. A partire dagli ultimi anni, le termocamere forniscono preziose informazioni per la valutazione della dispersione di energia termica dagli edifici mentre in campo ambientale, vengono impiegate per monitorare vulcani, prevenire e controllare incendi, controllare discariche, rilevare fughe gas, valutare l'umidità del suolo, monitorare/caratterizzare frane e pareti rocciose, classificare l’uso del suolo, controllare la dispersione di inquinanti in fiumi, individuare sorgenti in alveo e stimare la loro portata, indagare la presenza di sorgenti sottomarine lungo le coste (Danielescu et al. 2009). Una trattazione esaustiva delle possibili applicazioni di questa tecnica in campo idrogeologico ed ambientale si trova in Brunner et al. (2007). Nella presente nota viene riportato l'utilizzo dell’infrarosso termico mediante termocamera da piattaforma terrestre per la localizzazione di alcune sorgenti minerali che vengono a giorno in modo diffuso nell’alveo del Torrente Dolo (Comune di Toano, Provincia di Reggio Emilia). Si tratta delle sorgenti fredde e minerali di Quara, già sfruttate fin da epoca romana, ad oggi in larga parte scomparse e sepolte da alluvioni recenti. Il sito è inoltre inserito tra le aree di particolare interesse nell’analisi preliminare per la valutazione del potenziale geotermico in Regione Emilia Romagna.

2014 - Valutare la vulnerabilità dei corpi idrici a scala locale [Articolo su rivista]
Ronchetti, Francesco; Corsini, Alessandro; F., Cervi; M. M., Nistor; F., Petronici; D., Errigo; M., Marcaccio
abstract

Il progetto il progetto ha lo scopo di valutare la vulnerabilità delle risorse idriche potabili in funzione del cambiamento climatico e delle variazioni degli aspetti socio-economici della zona montana dell’Appennino della Regione Emilia Romagna. Tale vulnerabilità è intesa sia in termini quantitativi, come la disponibilità futura della risorsa idropotabile, che in termini qualitativi, intesa come futura potabilità della risorsa stessa. Inoltre il progetto ha lo scopo di valutare la funzione dei servizi ecosistemici relativamente all’azione mitigatrice della vulnerabilità della risorsa idrica sotterranea e di fornire linee guida per una corretta regolamentazione dell’uso del suolo nelle zone di ricarica dei corpi idrici sotterranei in zone montane.

2014 - Vulnerability of groundwater in fractured aquifers, under climate and land use change in northern Apennines [Relazione in Atti di Convegno]
Nistor, M. M.; Ronchetti, Francesco; Corsini, Alessandro; F., Cervi; L., Borgatti; D., Errigo; M., Marcaccio
abstract

Vulnerability of groundwater in fractured aquifers

2013 - Forward simulation of displacement rates variations due to groundwater level changes induced by deep drainage wells in Succiso earth slide (northern Apennines, Italy) [Articolo su rivista]
F., Bonacini; G., Caputo; A. B., Costantino; Ronchetti, Francesco; Corsini, Alessandro
abstract

The Succiso landslide is a large scale active earth slide located in the northern Apennines of Italy, in the upper Enza river basin (Province of Reggio Emilia, Emilia Romagna Region). It extends from 1075 to 800 m a.s.l., affecting an area of about 0.5 km2 for a length of about 1.6 km and a maximum width of 500 m. The landslide area is characterized by flysch and claystone bedrock, by glacial and landslide deposits of various type and by more than 2000 mm rainfall per year. The landslide is named after the village of Succiso, that was damaged by acceleration of earth slide movements in 1951, 1952 and, quite severely, in 1966 and 1972. Succiso was first declared, according to law 445/1908, as “to be consolidated” (DPR n 201 of 14/02/1957) and, later on, as “to be transferred” (DL n°976 of 18/12/1966 – G.U. 24/4/70). From 1972 to 2008 the landslide did not underwent any other particular acceleration event and presumably, it moved at rates in the order of few cm/year, as it does presently. Consequently, the village of Succiso was again re-classified as “to be consolidated” (DGR n° 686 of 12/05/2008). Following such recent administrative act, and in order to define, design and construct consolidation works, the local technical basin service (Emilia Romagna Region) has undertaken an intensive geological, geotechnical investigation and monitoring survey that allowed to define the geological model and the on-going kinematics of the landslide's deposit. This work describes a geotechnical softsoil-creep model, in order to analysing the potential benefits, in terms of decrease in displacement rates, induced by the building of a deep drainage wells in the Succiso earth slide.

2013 - Forward simulation of groundwater level changes induced by deep drainage wells in Succiso earth slide (northern Apennines, Italy) [Articolo su rivista]
M., Righini; G., Caputo; F., Cervi; Corsini, Alessandro; Ronchetti, Francesco
abstract

The Succiso landslide is a large scale active earth slide located in the northern Apennines of Italy, in the upper Enza river basin (Province of Reggio Emilia, Emilia Romagna Region). It extends from 1075 to 800 m a.s.l., affecting an area of about 0.5 km2 for a length of about 1.6 km and a maximum width of 500 m. The landslide area is characterized by flysch and claystone bedrock, by glacial and landslide deposits of various type and by more than 2000 mm rainfall per year. The landslide is named after the village of Succiso, that was damaged by acceleration of earth slide movements in 1951, 1952 and, quite severely, in 1966 and 1972. Succiso was first declared, according to law 445/1908, as “to be consolidated” (DPR n 201 of 14/02/1957) and, later on, as “to be transferred” (DL n°976 of 18/12/1966 – G.U. 24/4/70). From 1972 to 2008 the landslide did not underwent any other particular acceleration event and presumably, it moved at rates in the order of few cm/year, as it does presently. Consequently, the village of Succiso was again re-classified as “to be consolidated” (DGR n° 686 of 12/05/2008). Following such recent administrative act, and in order to define, design and construct consolidation works, the local technical basin service (Emilia Romagna Region) has undertaken an intensive geological, geotechnical investigation and monitoring survey that allowed to define the geological model and the on-going kinematics of the landslide's deposit. This work supports feasibility analysis of a shield of deep drainage wells to be possibly located in the central portion of the landslide (indicatively: 26 wells, diameter 1 m, depth 30 m, inter-axes 7-8 m, total length of shield 200 m, gravity discharge).Specifically, it performs a forward simulation of groundwater level changes induced by this possible deep drainage solution, using an hydrogeological modeling of the landslide based on 3D FEFLOW software, which has been calibrated thank to a continuous piezometric monitoring. A parent paper presented at this conference has complemented the feasibility analysis by using the outputs of this hydrogeological simulation as input to a geotechnical softsoil-creep model, in order to analysing the potential benefits, in terms of decrease in displacement rates, induced by deep drainage wells.

2013 - Hot spots for simplified risk scenarios of the Trafoi rockslide (South Tyrol) [Relazione in Atti di Convegno]
Corsini, Alessandro; Iannacone, J. P.; Ronchetti, Francesco; Salvini, R.; Mair, V.; Nossing, L.; Stefani, M.; Unterthiner, G.; Valentinotti, G.
abstract

The Trafoi rockslide is very similar to the Val Pola landslide before it evolved in a catastrophic rock avalanche in 1987. The Trafoi rockslide was recognized and mapped on the basis of geomorphic evidences such as double crests and detachment niches/scarps as well as geologic proxies such as gravitational offset of distinctive bedrock levels and trenching and fracturing of rock masses. In order to assess the activity status of the landslide, not discernible from field evidences only, periodic GPS monitoring on 11 benchmarks was started in 2007 and continued until 2010 with static-rapid measurements repeated 3 to 4 times per year. Results have shown that portions of the rockslide move at some cm/year rate. This highlights the potential for a possible evolution of the mass movement and the necessity of hazard scenarios mapping and run-out modelling. In order to define volume of possible detachments scenarios, digital aerial photo-interpretation were used together with High Resolution DEM and information collected from geomechanical field survey. The Trafoi rockslide is among the test sites of the ongoing European project “Monitor II”, that is proposing the usage of hot spots in the process domain as a practical mean to describe hazard scenarios. Following such approach, simplified hazard and risk scenarios were schematized on the basis of the data collected with monitoring and analysis of ongoing and potential slope instability processes.

2013 - Improve information provision for disaster management: MONITOR II, EU project [Relazione in Atti di Convegno]
Ronchetti, Francesco; Corsini, Alessandro; Kollarits, S.; Leber, D.; Papez, J.; Plunger, K.; Preseren, T.; Schnetzer, I.; Stefani, M.
abstract

Management of natural hazards constitutes a common challenge in all country of the world. Until now, neither hazard mapping nor contingency planning have been transnationally coordinated and defined. These gaps will be tackled in MonitorII project (founded by the EU - South East Transnational Cooperation Program) with the development of a common methodology about risk assessment and risk management. The project partnership has so far carried out the following activities and achieved the following results: review of best practices in hazard mapping and contingency plans; definition of information needs and information flows in different phases of risk management; definition of novel concepts for the creation of simplified scenario models in the process, damage and intervention domain. In the project will be developed a Continuous Situation Awareness system, a software that support the disaster management in the different phases of the risk cycle. Within the broad range of hazards, MonitorII specifically deals with floods and landslides, but the concepts of the project could be applied to other types of hazards.

2013 - Integrating airborne and multi-temporal long-range terrestrial laser scanning with total station measurements for mapping and monitoring a compound slow moving rock slide [Articolo su rivista]
Corsini, Alessandro; Castagnetti, Cristina; Bertacchini, Eleonora; Rivola, Riccardo; Ronchetti, Francesco; Capra, Alessandro
abstract

A slow moving compound rock slide located in the northern Apennines of Italy was mapped and monitored through the integration of Airborne Laser Scanning (ALS), multi-temporal long-range Terrestrial Laser Scanning (TLS), and Automated Total Station (ATS) measurements. Landslide features were mapped using a High Resolution Digital Terrain Model (HR-DTM) obtained by merging ALS and TLS data in an Iterative Closest Point (ICP) procedure. Slope movements in the order of centimeters to a few decimeters were quantified with Differential TLS (D-TLS) based on a Surface Matching approach and supported by ATS data to define stable reference surfaces. The integrated approach allowed mapping of the composite geomorphic features of the rock slide under examination, revealing its complex dynamic nature and further proving that laser scanning is a versatile and widely applicable tool for slope process analysis

2013 - Landslide displacement monitoring from multi-temporal terrestrial digital images: case of the Valoria landslide site [Relazione in Atti di Convegno]
M., Motta; F., Gabrieli; Corsini, Alessandro; V., Manzi; Ronchetti, Francesco; S., Cola
abstract

This work presents a low-cost method to measure the displacement of some points on the landslide surface. The method uses a sequence of terrestrial digital images. The Image Acquisition System (IAS) consists in a remote connected DSLR camera and controlled by software. The camera is fixed on a stable pillar, inside a transparent box and it periodically takes the pictures of the landslide. In order to rectify the image and to correct the little natural displacement of the image plane with respect to the landslide some fixed reference points are selected in the images. Moreover, some “well recognizable” optical targets are used in order to evaluate the displacement field. The image sequence is analyzed with a home-made digital image correlation code. The colour and size of the optical targets were evaluated in order to get the maximum accuracy of measurements and to improve the auto-matching function between the images. Taking pictures with bracketing function was proved to help the target searching phase for different weather conditions. The possibilities of the method are evaluated with reference to a sequence of images taken at the Valoria landslide site (Northern Apennines, Italy).

2013 - Large-scale slope instability affecting SS63 near the Cerreto Pass (northern Apennines, Italy) [Relazione in Atti di Convegno]
Corsini, Alessandro; Ronchetti, Francesco; Bertacchini, Eleonora; Bonacini, Francesco; Calicetti, P; Capra, Alessandro; Castagnetti, Cristina; Piantelli, E; Caputo, G; Truffelli, G.
abstract

National Road SS63 is endangered by large scale slope instability phenomena few km north of the Cerreto Pass (northern Apennines, Italy). At the Col Piagneto slope, SS63 was closed two times in the past 50 years after landslide events. In 1974, the collapse of portion of a rock slide triggered a debris slide that buried more than 50 m of the road track. In 2008, the reactivation of an earth slide in eastern portion of the slope damaged about 400 m of the “new” track built to by-pass the 1974 risk area. In order to evaluate if it is worthwhile keeping the old track open to traffic, or it is maybe better to repair the new track a comprehensive study was financed by Emilia Romagna Region. Research methods included: high resolution DEM, landslides mapping, continuous displacement and groundwater monitoring. Results allowed to assess different semi-quantitative risk scenario for the road structures or vehicles.

2013 - Rapid assessment of landslide activity in Emilia Romagna using GB‐InSAR short surveys [Relazione in Atti di Convegno]
Corsini, Alessandro; Berti, M.; Monni, A.; Pizziolo, M.; Bonacini, Francesco; Cervi, Federico; Ciccarese, G.; Ronchetti, Francesco; Bertacchini, Eleonora; Capra, Alessandro; Gallucci, A.; Generali, M.; Gozza, G.; Pancioli, V.; Pignone, S.; Truffelli, G.
abstract

Rapid assessment of landslide activity is important in case of adverse climatic conditions leading to civil protection’s alerts that require increased surveillance of risk areas. GB-InSAR is nowadays becoming a consolidated near-sensing monitoring technique for slope movements. It can be installed rapidly and it can rapidly provide results in the form of displacement maps. However, it has never been thoroughly tested in radar-hostile conditions such as these posed by large-scale earth slides – earth flows covered by a canopy of trees bushes and meadows, that are the typical landslides in Emilia Romagna Apennine. As sparse small villages, buildings, roads and other lifelines are often built on these landslide bodies, they are of particular concern for civil protection, especially during prolonged rainfall periods that determine attention/alerting conditions. To test the possibility to achieve improved surveillance capability in case of attention needed, a series of GB-InSAR spot campaigns lasting from a week to a month, was carried out in 2010-11 in several landslides of Emilia Romagna Apennine using a commercial interferometric radar. The aim was to evaluate the performance of the technique for rapid assessment of landslide activity, even in case of partly vegetated soil coverage conditions. The paper deals with the results obtained in 3 out of the 11 monitored sites.

2012 - Origin and assessment of deep groundwater inflow in the Ca' Lita landslide using hydrochemistry and in situ monitoring [Articolo su rivista]
Cervi, Federico; Ronchetti, Francesco; Martinelli, G.; Bogaard, T. A.; Corsini, Alessandro
abstract

Changes in soil water content, groundwater flow and a rise in pore water pressure are well-known causal or triggering factors for hillslope instability. Rainfall and snowmelt are generally assumed as the main sources of groundwater recharge. This assumption neglects the role of deep water inflow in highly tectonized areas, a factor that can influence long-term pore-pressure regimes and play a role on local slope instability. This paper aims to assess the origin of groundwater in the Ca' Lita landslide (northern Italian Apennines) and to qualify and quantify the aliquot attributable to deep water inflow. The research is essentially based on in situ monitoring and hydrochemical analyses. It involved 5 yr of continuous monitoring of groundwater levels, electrical conductivity and temperature and with groundwater sampling followed by determination of major ions (Na+, K+, Mg2+, Ca2+, Cl−, HCO3−, SO42−), tracers (such as Btot and Sr2+), and isotopes (δ18O, δ2H and 3H). Leaching experiments on soil samples, hydrochemical modelling and water recharge estimation were also carried out. Results show that the groundwater balance in the Ca' Lita landslide must take into account an inflow of deep and highly mineralised Na-SO4 water (more than 9500 μS cm−1) with non-negligible amounts of Cl− (up to 800 mg l−1). The chemical and isotopic fingerprint of this water points to oilfield water hosted at large depths in the Apennine chain and that uprises through a regional fault line crossing the landslide area. It recharges the aquifer hosted in the bedrock underlying the sliding surface (at a rate of about 49 000–85 700 m3 yr−1) and it also partly recharges the landslide body. In both the aquifers, the hydrochemical imprint of deep water mixed with rainfall and snowmelt water was observed. This indicates a probable influence of deep water inflow on the mobility of the Ca' Lita landslide, a finding that could be applicable to other large landslides occurring in highly tectonized areas in the northern Apennines or in other mountain chains. The paper demonstrates that hydrochemistry should, therefore, be considered as a valuable investigation method to define hydrogeological limits and the groundwater sources in hillslope and to assess groundwater flow patterns in deep-seated landslides

2011 - Surveillance of landslides risk areas with ground-based interferometric SAR for Civil protection in Emilia Romagna (Italy). [Relazione in Atti di Convegno]
Corsini, Alessandro; F., Cervi; G., Ciccarese; J. P., Iannacone; Ronchetti, Francesco; Bertacchini, Eleonora; Capra, Alessandro; M., Berti; E., Brancaleoni; P., Mora; V., Pancioli; A., Gallucci; G., Gozza; A., Monni; M., Generali; M., Pizziolo; G., Caputo; G., Truffelli; V., Manzi; F., Ghiselli; M., Guida; G., Minardi; C. C., Lucente; A., Bernardi; A., Benini
abstract

Experimental applications of Groune Based SAR to landslides movement/deformation control. The objective was to verify yìthe possibility to apply GBsAR techniques for civil protection activities in Emilia Romagna region relatively to the different types of landslides.

2010 - Comparing predictive capability of statistic and deterministic methods for landslide susceptibility mapping: a case study in the northern Appennines (Reggio Emilia Province, Italy) [Articolo su rivista]
Cervi, Federico; Borgatti, Lisa; M., Berti; Ronchetti, Francesco; F., Manenti; Corsini, Alessandro
abstract

Statistical and deterministic methods are widely used ingeographic information system based landslide susceptibility mapping.This paper compares the predictive capability of three differentmodels, namely the Weight of Evidence, the Fuzzy Logic andSHALSTAB, for producing shallow earth slide susceptibility maps, to be included as informative layers in land use planning at a local level.The test site is an area of about 450 km2 in the northern Apennines ofItaly where, in April 2004, rainfall combined with snowmelt triggeredhundreds of shallow earth slides that damaged roads and otherinfrastructure. An inventory of the landslides triggered by the eventwas obtained from interpretation of aerial photos dating back to May2004. The pre-existence ofmapped landslides was then checked usingearlier aerial photo coverage.All the predictivemodelswere run on thesame set of geo-environmental causal factors: soil type, soil thickness,land cover, possibility of deep drainage through the bedrock, slopeangle, and upslope contributing area. Model performance wasassessed using a threshold-independent approach (the ROC plot).Results show that global accuracy is as high as 0.77 for both statisticalmodels, while it is only 0.56 for SHALSTAB. Besides the limited qualityof input data over large areas, the relatively poorer performance of thedeterministic model maybe also due to the simplified assumptionsbehind the hydrological component (steady-state slope parallel flow),which can be considered unsuitable for describing the hydrologicbehavior of clay slopes, that are widespread in the study area.

2010 - Hydro-mechanical features of landslide reactivation in weak clayey rocks [Articolo su rivista]
Ronchetti, Francesco; L., Borgatti; Cervi, Federico; Corsini, Alessandro
abstract

In the northern Apennines, four representativelarge and deep seated landslides affecting weak rockmasses have been studied before, during and after reactivationevents. Semi-continuous and continuous monitoringin the 2004–2006 period included the dormancy, reactivationand suspension phases, allowing some comments tobe put forward as regards the hydro-mechanical conditionsthat drive the reactivations. The data have highlighted theinteractions between groundwater and displacement ratesin different sections of the slope.

2010 - Integrated displacement and activity analysis at the Valoria landslide (Italian Apennines) through automated topographic monitoring, image correlation velocimetry and surface roughness computation [Relazione in Atti di Convegno]
Daehne, Alexander; Corsini, Alessandro; Ronchetti, Francesco
abstract

ISBN 2-95183317-1-5At the Valoria landslide located in the Italian Apennines, surface monitoring data acquired by an automated total station were analyzed. The system provided short-term information on the behavior of the material during crisis and the duration of reactivations. Long-term displacements and morphometric properties were studied using a geographic information system (GIS). Results from monitoring show a strong correlation between rainfall related triggering of mass wasting in the crown zone and subsequent downslope reactiva-tions. We found that crown-to-toe zone reactivations generally occur within only 6 weeks. Further findings indicate that earth slide materials in the head zone fail almost instantaneous conversely to earth flow materials in the track channel. The findings are complemented by a digital image correlation analysis of multi temporal, high-resolution digital elevation models (DEM) acquired in 2006, 2007 and 2009. We utilized this technique to compute velocities and displacements of pixels in the DEMs between 2006 and 2009. It was found that both azimuth and magnitude of displacements could be reconstructed in for the crown zone, the main track channel and the landslide toe. The results from the image correlation compare well to displacements obtained from independent monitoring methods (GPS and interpreting of shaded reliefs maps). Based on the assump-tion that increased materials movements result in higher terrain roughness, we used LiDAR-derived to per-form a raster based roughness analysis. Different roughness calculation methods were applied to 0.5 m eleva-tion grids using different Kernel sizes. The performance of a supervised and an unsupervised approach was evaluated. Findings from the supervised approach showed that the difference between active and dormant landslides is evident in some cases but also that earth flows and dormant landslides tend to have a similar roughness patterns as stable areas. Results from the unsupervised approach demonstrated that landslide roughness is heterogeneous and that non-landslide areas may have a similar morphometric signature. In this study it was demonstrated that near- and remote sensing techniques are crucial, as well as complimentary in the analysis of landslide hazard. Applying both approaches can yield a more complete picture of the defor-mation history of landslides

2010 - Ipotesi sugli eventi distruttivi rilevati nell’abitato romano di Montegibbio [Capitolo/Saggio]
Borgatti, L.; Cervi, Federico; Corsini, Alessandro; Guandalini, F.; Ronchetti, Francesco; Pellegrini, M.
abstract

Presso la località il Poggio, circa 500 m a N del castello di Montegibbio, in Comune di Sassuolo (Provincia di Modena), la Soprintendenza per i Beni Archeologici dell’Emilia-Romagna ha portato alla luce i resti di una sequenza di insediamenti di età romana (da una villa urbano – rustica del I secolo a. C. sino ad un insediamento del VI secolo d. C.). Una parte delle strutture presentano evidenze di lesioni di rilevante entità, che possono aver portato alla distruzione e al successivo abbandono degli insediamenti stessi. L’edificio più antico rinvenuto negli scavi del 2008, sul quale si focalizza prevalentemente il nostro contributo, aveva un pavimento in opus signinum e un’elevazione in ciottoli e blocchi, talora debolmente arrotondati, e in laterizio. L’obbiettivo di questo lavoro è di indagare le possibili cause che possono avere provocato le deformazioni rinvenute nelle strutture e ricostruire la sequenza di eventi ambientali che hanno accompagnato la vita e l’abbandono dell’insediamento romano di Montegibbio. Le ipotesi di lavoro che sono state hanno la finalità di rispondere a due domande, ovvero: Quali tipologie di eventi possono essere stati responsabili delle deformazioni osservabili sulle strutture? Tali eventi possono essere tanto di origine naturale (dissesto per frana, terremoto, erosione s.l., creep, cedimento e consolidazione dei terreni di fondazione), tanto di origine antropica (cedimento strutturale, asportazioni successive di materiale dovute in particolare alle lavorazioni agricole); Quanti eventi si sono eventualmente susseguiti? Si tratta di un solo evento che ha lesionato tutte le strutture o si tratta di una serie di dissesti? E nel secondo caso, i dissesti sono tutti della stessa natura o di natura differente? Le problematiche esposte sono state affrontate con un approccio multidisciplinare, che vede l’integrazione di diverse discipline oltre all’Archeologia, tra cui la Geologia e la Geologia Applicata.

2010 - Lidar And Hyperspectral Data Integration For Landslide Monitoring: The Test Case Of Valoria Landslide [Articolo su rivista]
Sterzai, P.; Vellico, M.; Berti, M.; Coren, F.; Corsini, Alessandro; Rosi, Alberto; Mora, P.; Zambonelli, Franco; Ronchetti, Francesco
abstract

In the framework of the WISELAND project, funded by MIUR, we tested the integration between Lidar and hyperspectral methodologies in the Valoria landslide (Modena province, Italy), a high risk area with vulnerable elements, subjected to periodic and abrupt reactivations. Multitemporal Lidar Digital Terrain Models (DTMs) allowed the calculation of a differential surface, highlighting absolute height variations, recognizing the main landslide components and identifying depletion and accumulation zones. Hyperspectral data helped in the landslide terrain roughness characterization, performing the Principal Component Analysis (PCA) and correlating the results with Flatness and Organization geomorphometric parameters derived from Lidar DTM.

2010 - Utilizzo dei sistemi di telerilevamento per il monitoraggio di fenomeni franosi: il progetto WISELAND [Relazione in Atti di Convegno]
Vellico, M.; Sterzai, P.; Pietrapertosa, C.; Corsini, Alessandro; Ronchetti, Francesco; Berti, M.; Mora, P.; Coren, F.
abstract

I fenomeni franosi sono ampiamente diffusi in tutto il territorio italiano e sono responsabili di ingenti perdite economiche, stimate nell’ordine dei 2 miliardi di euro l’anno negli ultimi 50 anni. Lo scopo del progetto WISELAND, afferente al Programma di Ricerca Scientifica di Rilevante Interesse Nazionale (PRIN) 2007, finanziato dal Ministero dell’Università e della Ricerca (MIUR), è la creazione di un sistema integrato ed innovativo di sensori wireless ed airborne per il monitoraggio e il controllo di fenomeni franosi a cinematica lenta. La sperimentazione di tale sistema è stata condotta su una frana per scorrimento-colata, tipica dell’Appennino: la frana di Valoria, in provincia di Modena. Nel corso del 2009 e 2010 sono stati condotti diversi rilievi aerotrasportati con sensoristica Lidar e iperspettrale. I primi hanno consentito di ricostruire accurati Modelli Digitali del Terreno (DTM), dalla cui analisi si è stati in grado di caratterizzare le componenti principali di una frana. Inoltre, tramite un’analisi differenziale e geomorfometrica dei DTM (relativi a rilievi effettuati in passato mediante la stessa metodologia), si sono individuati e monitorati gli spostamenti avvenuti in un certo arco temporale. I rilievi iperspettrali hanno contributo anch’essi alla caratterizzazione dei fenomeni franosi; in particolare si è dimostrato che i risultati ottenuti dalla Principal Component Analysis (PCA) sono correlabili con la rugosità del terreno ed il dinamismo di frana e consentono di metterne chiaramente in risalto le zone di accumulo e deplezione. Oltre ai datasets telerilevati, si sono utilizzati dei dati provenienti da una rete sperimentale di sensori wireless (WSN) installata nell’ambito del progetto, che ha permesso di rilevare gli spostamenti differenziali della frana in modo efficace e poco costoso. L’utilizzo combinato della metodologia Lidar, iperspettrale e di reti asensori wireless (WSN) si è dimostrata, pertanto, un valido strumento in grado di monitorareperiodicamente un fenomeno franoso. La potenzialità dei risultati aumenta con l’interpretazionecongiunta dei datasets. Il monitoraggio con queste metedologie può essere inoltre facilmenteprogrammato sia temporalmente che spazialmente, e questo garantisce una specificitàdell’informazione attualmente non garantita da altre metodologie operative.

2009 - Continuous monitoring of active earth flow by means of an integrated GPS-automatic total station approach [Articolo su rivista]
Corsini, A.; Capra, A.; Bertacchini, E; Borgatti, L.; Borghi, A.; Castagnetti, Cristina; Cervi, F.; Daehne, A.; Dubb Ini, M.; Leuratti, E.; Manzi, V.; Pellegrini, M.; Ronchetti, F.; Bonanno, C.; Piantelli, E.
abstract

The research deals with the integration of surface displacement measurements obtained using geodetic and topographic instruments such as GPS, automatic total station and inclinometer sensor in a large-scale active earth flow. The landslide, located in the northern Apennine of Italy, damaged roads and endangered houses during a sequence of reactivations in 2001, 2005 and 2007. Monitoring has been performed by means of: an automatic total station, coupled with inclinometer sensor, measuring about 40 prisms located in the landslide to a maximum distance of 1.650 km; one double-frequency GPS receiver connects in streaming by wireless communication with 4 single-frequency GPS in side the flow. Until December 2007 the monitoring network was operated with periodic static surveyings followed by the data post-processing; while since March 2008 the total station system and GPS were automated in order to allow continuous data acquisition and near-real-time data processing. The monitoring network has been able to cope with displacement rates ranging from millimetres to metres per day, a performance not achieved by borehole systems operated in the slope, such as in-place inclinometers, that were damaged when displacements exceeded some decimetres. The data so far collected, integrated with geomorphic, geologic and borehole data, allowed the complex spatial and temporal pattern of slope movements to be tracked and the relationships between rainfall pattern and acceleration-deceleration phases to be highlighted.

2009 - Coupling geomorphic field observation and Lidar derivatives to map complex landslides [Relazione in Atti di Convegno]
Corsini, Alessandro; Cervi, Federico; Daehne, A.; Ronchetti, Francesco; Borgatti, L.
abstract

High resolution LiDAR DEMs from regional or site specific surveys were used to map complexlandslides such as deep-seated rockslides and earth slides-earth flows. Regional surveys DEMs wereused to produce shaded relief maps that allowed delimiting rock slide units and sub-units at the slope scale.Multitemporal site-specific survey DEMs were used in eath slides-earth flows case studies to derive roughnessmaps that allowed defining the curvature fingerprint of the most active parts of earth flows, and to derivedifferential elevation maps that allowed assessing depletion and accumulation areas occurring in the slope asa consequence of post-failure dynamics.

2009 - Estimating mass-wasting processes in active earth slides – earthflows with time-series of High-Resolution DEMs fromphotogrammetry and airborne LiDAR [Articolo su rivista]
Corsini, Alessandro; Borgatti, L.; Cervi, Federico; Daehne, Alexander; Ronchetti, Francesco; Sterzai, P.
abstract

This paper deals with the use of time-series ofHigh-Resolution Digital Elevation Models (HR DEMs) obtainedfrom photogrammetry and airborne LiDAR coupledwith aerial photos, to analyse the magnitude of recently reactivated large scale earth slides – earth flows located in thenorthern Apennines of Italy. The landslides underwent completereactivation between 2001 and 2006, causing civil protectionemergencies. With the final aim to support hazardassessment and the planning of mitigation measures, highresolution DEMs are used to identify, quantify and visualizedepletion and accumulation in the slope resulting from the reactivation of the mass movements. This information allowsto quantify mass wasting, i.e. the amount of landslide materialthat is wasted during reactivation events due to streamerosion along the slope and at its bottom, resulting in sedimentdischarge into the local fluvial system, and to assessthe total volumetric magnitude of the events. By quantifyingand visualising elevation changes at the slope scale, resultsare also a valuable support for the comprehension of geomorphological processes acting behind the evolution of theanalysed landslides.

2009 - Groundwater processes in a complex landslide, northern Apennines, Italy [Articolo su rivista]
Ronchetti, Francesco; L., Borgatti; Cervi, Federico; Gorgoni, Carlo; L., Piccinini; V., Vincenzi; Corsini, Alessandro
abstract

The hydrogeological characteristics of rototranslationalslides in flysch are complex, due to the inherentanisotropy and heterogeneity of rock masses and related deposits.The paper deals with the hydrogeological characterizationof a reactivated roto-translational slide affecting Cretaceousflysch rocks, located in the northern Apennines ofItaly. Continuous monitoring of groundwater levels, in-situpermeability and pumping tests, hydrochemical and physicalanalyses and Uranine tracers were the adopted prospectingmethods.In this research hydrological monitoring and investigationare summarized in order to define a hydrogeological conceptualmodel of the landslide source area. Results showed thattwo overlaying hydrogeological units exist at the slope scale:the first is unconfined, but highly compartmentalized, andhosted in the fractured and dismembered rock slide body.The second is confined and lays in the undisturbed flyschbelow the sliding surface. The groundwater level in theconfined hydrogeological unit is twenty meters higher thanthe groundwater level in the uppermost one. Moreover, thegroundwater chemistry characterization revealed a rising ofdeep fluids in the landslide area.

2009 - Hydrogeologic characterististics of roto-traslational slides in flysch [Relazione in Atti di Convegno]
Ronchetti, Francesco; Borgatti, L.; Cervi, Federico; Corsini, Alessandro; Gorgoni, Carlo; Piccinini, L.; Truffelli, G.; Vincenzi, V.
abstract

The hydrological characteristics of roto-translational slides in flysch are complex, due to the inherent anisotropy and heterogeneity of rock masses and related deposits. The paper deals with the hydrogeological characterization of a reactivated roto-translational slide affecting Cretaceous flysch rocks, located in the northern Apennines of Italy. Continuous monitoring of groundwater levels, in-situ permeability and pumping tests, hydrochemical analyses and uranine tracers were the adopted prospecting methods. Results showed that two overlaying aquifers exist at the slope scale: the first is unconfined, but highly compartmentalized, and hosted in the fractured and dismembered rock slide body. The second is confined and lays in the undisturbed flysch below the sliding surface. The latter is therefore a relevant factor for the instability of the slope. In this work, hydrologic monitoring and investigation are summarized, in order to support the analysis of landslide trigger mechanisms and to identify and design proper drainage system.

2009 - Hydrogeological characterization of roto-translational slides in flysch rock masses for mitigation proposes: The example of Ca'Lita landslide [Articolo su rivista]
Ronchetti, Francesco; L., Borgatti; F., Cervi; A., Gargini; C., Gorgoni; M., Pellegrini; L., Piccinini; G., Truffelli; V., Vincenzi; Corsini, Alessandro
abstract

The hydrogeological characteristics of rototranslational slides in flysch are complex, due to the inherent anisotropy and heterogeneity of rock masses and related deposits. The paper deals with the hydrogeological characterization of a reactivated roto-translational slide affecting Cretaceous flysch rocks, located in the northern Apennines of Italy. Continuous monitoring of groundwater levels, in-situ permeability and pumping tests, hydrochemical and physical analyses and Uranine tracers were the adopted prospecting methods. In this research hydrological monitoring and investigation are summarized in order to define a hydrogeological conceptual model of the landslide source area. Results showed that two overlaying hydrogeological units exist at the slope scale: the first is unconfined, but highly compartmentalized, and hosted in the fractured and dismembered rock slide body. The second is confined and lays in the undisturbed flysch below the sliding surface. The groundwater level in the confined hydrogeological unit is twenty meters higher than the groundwater level in the uppermost one. Moreover, the groundwater chemistry characterization revealed a rising of deep fluids in the landslide area.

2009 - Integrated Surveying System for Landslide Monitoring, Valoria Landslide (Appennines of Modena, Italy) [Relazione in Atti di Convegno]
Bertacchini, Eleonora; Capitani, Andrea; Capra, Alessandro; Castagnetti, Cristina; Corsini, Alessandro; Dubbini, Marco; Ronchetti, Francesco
abstract

The research object is the study and prevention of landslide risk through the utilization of integrated surveying systems like GPS and Automatic Total Station (Robotic station).The measurements have been applied to Boschi di Valoria landslide, located on Appennines of Modena in the Northern Italy, which relatively large size, about 1.6 square km, required the use of both techniques. The system is made by Automatic Total Station, looking at 45 reflectors and a GPS master station, reference for three rovers on the landslide. In order to monitor "local" disturbing effects, a bi-dimensional clinometer has been applied on the pilaster where the total station is located. In a first periodically measurements were collected, while the system is now performing continuously. The system permitted to evaluate movements from few millimeter till some meters per day in most dangerous areas; the entity of the movements obliged to plan an alert system that was activated after a first phase of phenomenon study. Topographic measurements have been integrated with geotechnical sensors (inclinometers and piezometers) in a GIS for landslide risk management.

2009 - Monitoring, modelling and mitigation of earth slides-earth flows in the northern Apennines [Articolo su rivista]
Borgatti, L.; Corsini, Alessandro; Ronchetti, Francesco
abstract

The article show some experiences about slow moving landslides monitoring and modelling, which are located in northern Appennines.

2009 - Weight of Evidence and Artificial Neural Networks for potential groundwater springs mapping: an application in Mt. Modino area (Northern Apennines, Italy) [Articolo su rivista]
Corsini, Alessandro; Cervi, Federico; Ronchetti, Francesco
abstract

Locations of potential groundwater springs were mapped in an area of 68 km2 in the Northern Apennines of Italy based on Weight of Evidence (WofE) and Radial Basis Function Link Net (RBFLN). A map of more than 200 springs and maps of five causal factors were uploaded to ArcGIS with Spatial Data Modelling extensions. The WofE and RBFLN potential groundwater spring maps had similar prediction rates, allowing about 50% of the training and validation springs to be predicted in about 15 to 20% of the study area. The two maps were merged using a heuristic combination matrix in order to produce two hybrid maps: one representing susceptible areas in both the WofE and RBFLN maps (type A), while the other representing susceptible areas at least in one of the two maps (type B). For small cumulated areas, the success rate of both hybrid maps was higher than that of the parent maps, while for large cumulated areas, only the type B hybrid map performed similarly to the parent maps. This conclusion suggests different applications of these maps to water management purposes.

2008 - Appraise the structural mitigation of landslide risk via numerical modelling: a case study from the northern Apennines (Italy) [Articolo su rivista]
L., Borgatti; Corsini, Alessandro; G., Marcato; Ronchetti, Francesco; L., Zabuski
abstract

The Ca’ Lita landslide is a large and deep-seated mass movement located in the northern Apennines, about 70 km west of Bologna (Northern Italy). It consists of a composite landslide that affects Cretaceous to Eocene flysch rock masses and chaotic complexes. Many of the sectors making up the landslide have resumed activity between 2002 and 2006, threatening some villages and an important road connecting several key industrial facilities located in the upper watershed. This paper presents the management of the emergency, dealing with the investigation campaigns (geological, geomorphological and LiDAR surveys, borehole drillings, seismic surveys), with the monitoring (in situ instrumentation) and with the design and construction of mitigation measures. The whole process, from landslide reactivation to date, has been modelled on a numerical basis with the finite difference code FLAC 2D, to assess the efficiency of the mitigation system and to propose further countermeasure works in different scenarios.

2008 - Collecting a multi-disciplinary field dataset to model the interactions between a flood control reservoir and the underlying porous aquifer (abstract) [Abstract in Atti di Convegno]
Borgatti, L.; Corsini, A.; Chiapponi, L.; D'Oria, M.; Giuffredi, F.; Lancellotta, R.; Mignosa, P.; Moretti, G.; Orlandini, S.; Pellegrini, M.; Remitti, F.; Ronchetti, F.; Tanda, M.; Zanini, A.
abstract

2008 - Large Slow-moving Rock Slides – Earth Flows: the Case Study of Ca’ Lita Landslide (Northern Apennines, Italy) [Relazione in Atti di Convegno]
Borgatti, L.; Corsini, Alessandro; Ronchetti, Francesco; Truffelli, G.
abstract

The Ca’ Lita landslide is a large and deep-seated mass movement located in the northern Apennines of Italy. It consists of a complex-composite landslide that affects Cretaceous to Eocene flysch rock masses and chaotic complexes. The landslide head zone resumed activity in 2002 and in 2004 the landslide was totally reactivated. More than 50 m retrogression of the scarp, and about 400 m advancement of the toe threatened villages and an important road connecting several key industrial facilities located in the upper watershed. A national state of emergency was declared by the Authorities, following the evolution of 2004. A large plan of civil protection interventions was implemented, aimed at the management of risk and at the identification and realisation of structural mitigation. The Ca’ Lita landslide is a noticeable case history both from the geomorphic and the risk management perspectives. The relatively fast evolution undergone by the phenomenon from 2002 to date, and the remarkable advancement of the toe, point out that total and partial reactivations of dormant landslides can cause unexpected consequences in terms of involvement of new areas that, in practice, have no previous hazard rating assigned. Also, the landslide is a test bed for coupled monitoring and mitigation actions that, in a relatively short time, have allowed passing from response, to mitigation and preparedness phases. In this work, the management of the emergency is presented in the frame of monitoring, mitigation and modelling activities that are the result of the shared effort of public offices and research institutes.

2008 - MONITOR – Hazard Monitoring for Risk Assessment and Risk Communication [Articolo su rivista]
Mayer, R.; Plank, C.; Bohner, A.; Kollarits, S.; Corsini, Alessandro; Ronchetti, Francesco; Siegel, H.; Noessing, L.; Mair, V.; Sulzenbacher, U.; Tosoni, D.; Cimarosto, S.; Zanco, A.; Todorov, S.; Krastev, L.; Wergles, N.; Gasperl, W.; Mayerl, M.; Toli, T.; Haradalia, H.; Koutsias, N.; Kreuzer, S.; Liehr, C.; Rachoy, C.; Papez, J.; Jindra, P.
abstract

Protection against natural disasters is an increasing challenge for society. In many areas the frequent occurrence of natural hazards like e.g. floods, landslides and forest fires has become a constant threat for inhabitants, the habitat itself and its resources. The overall magnitude of damaging events in the last decade clearly shows the need for comprehensive and innovative risk management. It is absolutely necessary to implement controlling mechanisms for the protection of population, land use areas, infrastructure and the natural space in endangered areas.Therefore monitoring tools and appropriate simulation procedures are indispensable. They have to provide necessary information for risk evaluation, successful risk management and communication.These are the main tasks the trans-national INTERREG IIIB Cadses Project is dealing with. The report gives an insight into the particular activities and will present some results of MONITOR.

2008 - Modellazione numerica dei meccanismi di riattivazione di grandi frane per scivolamento di terra: l’esempio della frana di Tolara, Appennino settentrionale [Articolo su rivista]
Ronchetti, Francesco; Borgatti, L.; Cervi, Federico; Piccinini, L.; Corsini, Alessandro
abstract

The time and space evolution of large earth slides in weak and complex rockmasses, that characterize thenorthern Apennines, is depending on geological setting and past climate. At the present the reactivation of theselandslides are due to mainly to hydrogeological and geotechnical features. This paper describes the hydrogeological andgeotechnical features of these landslides and the reactivations mechanism using coupled 2D hydrogeological numericalmodel and limit equilibrium analysis (Geoslope, 2004). The case study is the Tolara landslide (Modena Apennines) thatresumed activity in 2002. In this landslide some hydrogeological and geotechnical data have been collected from 2003 todate.

2007 - Analisi della predisposizione al manifestarsi di sorgenti in area appenninica: un approccio statistico applicato all’area del Monte Modino (Provincia di Modena) [Articolo su rivista]
Cervi, Federico; Corsini, Alessandro; Ghinoi, A.; Ronchetti, Francesco; Pellegrini, Maurizio
abstract

Il lavoro,centrato sull’applicazione di codici di calcolo statisticiin ambiente Arc-GIS già utilizzati nel campo dellaricerca geomineraria, intergrati con l’analisi dei complessiidrogeologici, permette l’individuazione delle zonepotenzialmente idonee al reperimento ed eventuale captazionedella risorsa. Il tipo di informazione ottenuta,integrata ad una carta dei complessi idrogeologici, èutile per la pianificazione dello sfruttamento e per latutela della risorsa idrica.

2007 - Consolidamento di versanti instabili mediante opere di contenimento strutturale e tecniche di drenaggio profondo: gli esempi di Acquabona, Cervarezza, Magliatica e Ca’ Lita (Appennino reggiano) [Articolo su rivista]
Sartini, G.; Caputo, G.; De Simone, N.; Truffelli, G.; Borgatti, L.; Cervi, Federico; Corsini, Alessandro; Ronchetti, Francesco
abstract

The consolidation works carried out by the Technical Service of Enza, Panaro and Secchia basins of ReggioEmilia (STB-RE) on four large landslides, located in the Northern Apennines, Italy, are described. These interventions havebeen focused on the use of specialised drainage and containment measures such as modular shields of draining wells andinspectionable draining wells (Ø 1500 mm), large-diameter wells and large-diameter pile (Ø 60 mm) retaining walls with tierods. The interventions carried out have allowed slopes to be consolidated and critical hydro-meteorological events to bemanaged after the implementation of works.

2007 - Hydro-mechanical mechanisms of landslide reactivation in heterogeneous rock masses of the northern Apennines (Italy) [Relazione in Atti di Convegno]
Borgatti, L.; Cervi, Federico; Corsini, Alessandro; Ronchetti, Francesco; Pellegrini, Maurizio
abstract

The prediction of landslide reactivations in space and time is of relevantpractical interest in the northern Apennines. Dormant or active earth slides-earth flows affect,directly or indirectly, about 1800 villages and many km of road networks. Four test sites havebeen studied and monitored in order to analyse hydro-mechanical conditions in and aroundthe landslides, prior or during reactivation events. Data from monitoring systems such aselectric piezometers, spring and stream discharge flow-meters, inclinometers, Time DomainReflectometry (TDR) cables, Differential Global Positioning System (DGPS) networks andwire extensometers have highlighted some interplay between flow and mass transfers fromstable rock masses to the landslide body, and within the landslide itself. Monitoring in the2004-2006 period has covered dormancy, reactivation and suspension phases, allowing someconsiderations to be drawn on the hydro-mechanical mechanisms that drive the reactivationof large and deep seated landslides.

2007 - Primi interventi di consolidamento sulle frane dei Boschi di Valoria, di Tolara e Lezza Nuova (Val Dolo e Val Dragone, Appennino modenese) [Articolo su rivista]
Leuratti, E.; Lucente, C. C.; Medda, E.; Manzi, V.; Corsini, Alessandro; Tosatti, Giovanni; Ronchetti, Francesco; Guerra, M.
abstract

A seguito degli intensi eventi pluviometrici verificatisi a partire dall’autunno 2000, l’Appennino emiliano è stato interessato da una forte ripresa del dissesto idrogeologico, in particolare nelle valli dei torrenti Dolo e Dragone (Prov. di Modena). Il Servizio Tecnico di Bacino ha realizzato numerosi interventi volti alla mitigazione del dissesto ed al ripristino delle infrastrutture danneggiate. Vengono descritte tre località nelle quali si sono concentrati gli interventi di stabilizzazione.

2007 - The Valoria landslide reactivation in 2005-2006 (Northern Apennines, Italy) [Articolo su rivista]
Ronchetti, Francesco; Borgatti, L.; Cervi, Federico; Lucente, C. C.; Veneziano, M.; Corsini, Alessandro
abstract

The research has shown that complex hydrogeological processes play an important role in reactivating the Valoria landslide. The main of these processes was identified and, with the aid of new investigations and monitoring systems, will be analyzed in further details.

2006 - Space-borne and ground-based SAR interferometry as tools for landslide hazard management in civil protection [Articolo su rivista]
Corsini, Alessandro; Farina, P.; Antonello, G.; Barbieri, Massimo; Casagli, N.; Coren, F.; Guerri, L.; Ronchetti, Francesco; Sterzai, P.; Tarchi, D.
abstract

In recent years, SAR interferometry has become one of the most popular emerging techniques for the assessment of ground displacements, and, as such, it is of great interest as a possible operational tool for civil protection institutions having to deal with landslide risk. The paper presents some of the results obtained in northern Italy during a research project aimed at testing the potentiality of the application of C-band space-borne interferometry and Ku-band ground based interferometry during different specific civil protection activities. Main research objectives were the detection of the movements of complex earth and rock slides affecting built-up areas during the 1990s, and the near real-time monitoring of a reactivated rotational earth slide over an emergency period of 15 days. Results of space-borne interferometry did qualitatively fit with the geological interpretation of the mass movements and with ground truths such as damaged buildings and in situ monitoring systems. However, this was not achieved in quantitative terms, suggesting that this technique should be used limitedly for displacement recognition and not monitoring. On the other hand, ground-based interferometry proved valuable both for a qualitative and a quantitative estimate of slope movements. Nonetheless, the research has also enabled the limitations that are still to be tackled in order to bring these systems to an operational usage in civil protection to be highlighted.

2005 - Monitoraggio di grandi frane riattivate e sospese nella valle del Fiume Secchia (Appennino settentrionale) [Articolo su rivista]
Corsini, Alessandro; Borgatti, L.; Pellegrini, M.; Ronchetti, Francesco; con la collaborazione di Borghi, A.; Campagnoli, I.; Caputo, G.; Gatti, A.; Leuratti, E.; Lucente, C. C.; Truffelli, G.; Sartini, G.
abstract

Large complex landslides of prehistoric age, that are coupling multiple roto-traslational rock slides at the crownto earth slides and earth flows in the intermediate and lower part of the slope, are widespread over the Northern Apenninesof Italy. Typically, these landslides alternate decades or centuries long dormancy periods, to shorter periods characterised bythe alternation between reactivation events and phases of suspended activity. This note deals with four landslides of thiskind, that have been repetitively reactivated in the last decade causing damages to key road connections in thesubcatchments of Secchia River. A comparative analysis of data from the four sites collected with monitoring systems suchas inclinometers, TDR cables, wire extensometers, GPS benchmarks networks and automated electric piezometers, has beencarried out. This has enabled the kinematics and hydrogeologic characteristics of the landslide during the suspended activityphases, and during the most recent reactivation phases, to be reconstructed. This has yield indications that can have ageneral validity for these type of mass movements.