In the last two decades, advanced differential interferometric synthetic aperture radar (A-DInSAR) techniques have experienced significant developments, which are mainly related to (i) the progress of satellite SAR data acquired by new... more
In the last two decades, advanced differential interferometric synthetic aperture radar (A-DInSAR) techniques have experienced significant developments, which are mainly related to (i) the progress of satellite SAR data acquired by new missions, such as COSMO-SkyMed and ESA's Sentinel-1 constellations; and (ii) the development of novel processing algorithms. The improvements in A-DInSAR ground deformation time series need appropriate methodologies to analyse extremely large datasets which consist of huge amounts of measuring points and associated deformation histories with high temporal resolution. This work demonstrates A-DInSAR time series exploitation as valuable tool to support different problems in engineering geology such as detection, characterization and modelling of land subsidence mechanisms. The capabilities and suitability of A-DInSAR time series from an end-user point of view are presented and discussed through the analysis carried out for three test sites in Europe: the Oltrepo Pavese (Po Plain in Italy), the Alto Guadalentín (Spain) and the London Basin (United Kingdom). Principal component analysis has been performed for the datasets available for the three case histories, in order to extract the great potential contained in the A-DInSAR time series.
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Recent improvement to Advanced Differential Interferometric SAR (A-DInSAR) time series quality enhances the knowledge of various geohazards. Ground motion studies need an appropriate methodology to exploit the great potential contained in... more
Recent improvement to Advanced Differential Interferometric SAR (A-DInSAR) time series quality enhances the knowledge of various geohazards. Ground motion studies need an appropriate methodology to exploit the great potential contained in the A-DInSAR time series. Here, we propose a methodology to analyze multi-sensors and multi-temporal A-DInSAR data for the geological interpretation of areas affected by land subsidence/uplift and seasonal movements. The methodology was applied in the plain area of the Oltrepo Pavese (Po Plain, Italy) using ERS-1/2 and Radarsat data, processed using the SqueeSAR™ algorithm, and covering time spans, respectively, from 1992 to 2000 and from 2003 to 2010. The test area is a representative site of the Po Plain, affected by various geohazards and characterized by moderate rates of motion, ranging from −10 to 4 mm/yr. Different components of motion were recognized: linear, non-linear, and seasonal deformational behaviors. Natural and man-induced processes were identified such as swelling/shrinkage of clayey soils, land subsidence due to load of new buildings, moderate tectonic uplift, and seasonal ground motion due to seasonal groundwater level variations.
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Land subsidence represents a kind of hazard, which affects an increasing number of worldwide regions, densely populated, causing damage to the environment and infrastructures. Settlements can be related to multiple processes both natural... more
Land subsidence represents a kind of hazard, which affects an increasing number of worldwide regions, densely populated, causing damage to the environment and infrastructures. Settlements can be related to multiple processes both natural and anthropic (i.e. vadose zone processes, soil consolidation, aquifer compaction, solid and fluid extraction and load-induced compaction) which take place at different spatio-temporal scale. Over the last decades, advanced subsidence studies exploited Synthetic-Aperture Radar (SAR) data, a recent remote sensing tool, to investigate land subsidence phenomena around the world. In particular, Persistent Scatterer Interferometry (PSI) technique, allowing a quantitative estimation at high resolution of the surface deformations, has already been successfully applied to monitor the phenomenon evolution; PSI measurements represent the cumulative displacement, deriving from the contribution of natural and anthropic components, both superficial and deep. The...
Since the 1960s, severe groundwater level changes had taken place in the Alto Guadalentín Basin (south-eastern Spain), where the city of Lorca is located. The piezometric level records a lowering around 100 m in a time interval of 40... more
Since the 1960s, severe groundwater level changes had taken place in the Alto Guadalentín Basin (south-eastern Spain), where the city of Lorca is located. The piezometric level records a lowering around 100 m in a time interval of 40 years. The increase of the effective stresses has triggered the man-induced subsidence highest rate (>10 cm/yr-1) of Europe (González et al. 2011). Deformation measurements have become particularly relevant in order to identify the affected area extension, to evaluate the temporal evolution of deformation velocities and to identify the main control mechanisms. The extensive and continuous spatial and temporal monitoring is necessary to prevent the negative effects of such risks on structures and infrastructures. Differential SAR interferometry represents an advanced remote sensing tool, which permits the high spatial resolution back-monitoring of the history displacements. The Persistent Scatterer Interferometry (PSI) technique is a class of SAR inte...
In the last decades, early warning systems have become a precious support in hazard management by helping in reducing the possible damages caused by natural and anthropic hazards. Furthermore, in the last years, thanks to the rapid... more
In the last decades, early warning systems have become a precious support in hazard management by helping in reducing the possible damages caused by natural and anthropic hazards. Furthermore, in the last years, thanks to the rapid advances in science and technology a new concept of innovative early warning systems has been developed taking advantage of the decreasing costs of sensors and the wide diffusion and coverage of internet services (WFS, WMS, WPS, SOS, etc.). In this concept, simulation models can play an important role: in fact, by allowing the objective assessment of the location and intensity of a possible disaster, they can provide valuable information to support decision makers in taking timely and appropriate disaster responses. r.massmov is a new GRASS GIS module for landslide runout simulation over complex topographies developed to meet the expectation of innovative early warning systems modeling services, identified by the authors through four key requirements: i) ...
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ABSTRACT Rainfall-induced shallow landslides are common phenomena in many parts of the world, affecting cultivation and infrastructure and sometimes causing human losses. Assessing the triggering zones of shallow landslides is fundamental... more
ABSTRACT Rainfall-induced shallow landslides are common phenomena in many parts of the world, affecting cultivation and infrastructure and sometimes causing human losses. Assessing the triggering zones of shallow landslides is fundamental for land planning at different scales. This work defines a reliable methodology to extend a slope stability analysis from the site-specific to local scale by using a well-established physically based model (TRIGRS-unsaturated). The model is initially applied to a sample slope and then to the surrounding 13.4 km2 area in Oltrepò Pavese (northern Italy). To obtain more reliable input data for the model, long-term hydro-meteorological monitoring has been carried out at the sample slope, which has been assumed to be representative of the study area. Field measurements identified the triggering mechanism of shallow failures and were used to verify the reliability of the model to obtain pore water pressure trends consistent with those measured during the monitoring activity. In this way, more reliable trends have been modelled for past landslide events, such as the April 2009 event that was assumed as a benchmark. The assessment of shallow landslide triggering zones obtained using TRIGRS-unsaturated for the benchmark event appears good for both the monitored slope and the whole study area, with better results when a pedological instead of geological zoning is considered at the regional scale. The sensitivity analyses of the influence of the soil input data show that the mean values of the soil properties give the best results in terms of the ratio between the true positive and false positive rates. The scheme followed in this work allows us to obtain better results in the assessment of shallow landslide triggering areas in terms of the reduction in the overestimation of unstable zones with respect to other distributed models applied in the past.
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the principal aim of this study is to compare different landslide susceptibility zonation models for predicting areas prone to shallow landsliding using both physically distributed landslide models and artificial neural networks.... more
the principal aim of this study is to compare different landslide susceptibility zonation models for predicting areas prone to shallow landsliding using both physically distributed landslide models and artificial neural networks. Necessary geotechnical and hydrological parameters were obtained coupling sample laboratory analysis and in situ measures; soil thickness was estimated using an empirical model while distribution of rainfall intensity was analyzed by performing a spatial interpolation. The predictive capabilities of these models were finally evaluated using a threshold-independent quantitative method (the ROC plot).
Large landslides are widespread both in the Alps and Apennines; the observed movements are generally from extremely slow to slow, fairly regular with some occasional acceleration, related to rainfall events of high intensity or long... more
Large landslides are widespread both in the Alps and Apennines; the observed movements are generally from extremely slow to slow, fairly regular with some occasional acceleration, related to rainfall events of high intensity or long duration. Rapid and superficial phenomena are often associated and they result in significant socio-economic losses. They are also difficult to characterize in their boundaries and state of activity, to monitor with traditional tools due to their extension and low rates of movement, which are close to the detection limit of traditional monitoring equipment. Nevertheless, their management and prevention require a proper detection of ground movements for land use planning and/or civil protection purposes. Persistent Scatterer Interferometry (PSI) is a powerful tool for studying and monitoring such landslides. This work illustrates the potential of Persistent Scatterer Interferometry (PSI) using SAR (Synthetic Aperture Radar) data for a detailed detection, ...
The paper describes the experiences made in the Interreg Alcotra IIIa RiskNat project by three Italian regions, Liguria, Piemonte and Valle d’Aosta, in the field of landslide assessment by means of persistent scatterers... more
The paper describes the experiences made in the Interreg Alcotra IIIa RiskNat project by three Italian regions, Liguria, Piemonte and Valle d’Aosta, in the field of landslide assessment by means of persistent scatterers radarinterferometry. If a sufficient series of radar images is available, the technique allows, with accuracies in the order of mm a-1, to evaluate the displacement of ground radar targets represented by rocks, buildings and other structures. In a regional scale analysis the density of these points (named PS or DS) may reach several thousands per km2 , thus permitting a very good cinematic characterization of slow-moving landslides. The technique is about twelve years old and, in many Italian regions, is now an ordinary working tool. Within the project, several software tools were developed in order to perform both pre- and post-processing analyses. The technique has numerous advantages, the most important being the possibility of surveying wide areas at minimal cost...
The Po basin has been affected in the last sixty years by a strong subsidence due to groundwater pumping from a shallow well-developed multi-aquifer system and oil & gas production from a number of onshore and offshore reservoirs. Once... more
The Po basin has been affected in the last sixty years by a strong subsidence due to groundwater pumping from a shallow well-developed multi-aquifer system and oil & gas production from a number of onshore and offshore reservoirs. Once this phenomenon was identified, several monitoring campaigns were carried out by different techniques since the 1897 (Arca and Beretta 1985): precise topographic levelling, GPS, SAR and vertical extensometers. The relatively large amount of observations so far acquired offers the opportunity of monitoring the spatial pattern of land subsidence in the Po Plain, especially for the second half of the 20 th century, when the subsidence dramatically increased. The large diffusion of the space geodetic techniques, as GPS and SAR, in the last twenty years has provided two new tools which have a relatively low cost, and can improve significantly the spatial and temporal monitoring of the subsidence phenomena. So currently, the monitoring 134 GNGTS 2014 sessio...
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Cenni N., Loddo F., Zucca F., Meisina C., Baldi P., Belardinelli M.E.., Bacchetti M., Mantovani E., Viti M., Casula G., Stramondo S., Severi P., Pierini L., Bonsignore F.. The spatio-temporal pattern of subsidence in the Po basin moniroed by different techniques. Atti del 33° Convegno Nazionale d...more
The spatio-temporal pattern of subsidence in the Po basin monitored by different techniques N. Cenni12, F. Loddo3, F. Zucca4, C. Meisina4, P. Baldi1 , M.E. Belardinelli1 , M. Bacchetti1, E. Mantovani5, M. Viti5, G. Casula3, S. Stramondo6,... more
The spatio-temporal pattern of subsidence in the Po basin monitored by different techniques N. Cenni12, F. Loddo3, F. Zucca4, C. Meisina4, P. Baldi1 , M.E. Belardinelli1 , M. Bacchetti1, E. Mantovani5, M. Viti5, G. Casula3, S. Stramondo6, P. Severi7, L. Pierini7, F. Bonsignore8 (1)Dipartimento di Fisica ed Astronomia – Università degli Studi di Bologna, Bologna, Italy (2)Dipartimento Scienze Biologiche, Geologiche ed Ambientali – Università degli Studi di Bologna, Bologna, Italy (3) Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, Bologna, Italy (4) Dipartimento di Scienze della Terra e dell'Ambiente, Università degli Studi di Pavia, Pavia, Italy (5) Dipartimento di Scienze Fisiche, della Terra e dell’Ambiente, Università di Siena (6) Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma Italy (7) Servizio Geologico, Sismico e dei Suoli della Regione Emilia-Romagna (8) ARPA Emilia Romagna, Largo Caduti del Lavoro 6, I-40122 Bologna Italy Introducti...
... Some Examples from Southern Lombardia C. Meisina, F. Zucca Department of Earth Sciences, University of Pavia, Via Ferrata n°1, 27100 Pavia, Italy. ... The analysis resulted in the identification of around 95500 descending PS and 3800... more
... Some Examples from Southern Lombardia C. Meisina, F. Zucca Department of Earth Sciences, University of Pavia, Via Ferrata n°1, 27100 Pavia, Italy. ... The analysis resulted in the identification of around 95500 descending PS and 3800 ascending PS. ...
ABSTRACT Measurements of ground deformation with millimetric accuracy and the reconstruction of the history of deformations in the last 20 years with Persistent Scatterer techniques have a high potential for landslides studies. In this... more
ABSTRACT Measurements of ground deformation with millimetric accuracy and the reconstruction of the history of deformations in the last 20 years with Persistent Scatterer techniques have a high potential for landslides studies. In this work we analyze pro and cons of PSI techniques to update the Italian Inventory of Landslides (IFFI) using data from ERS 1/2 (1992-2001) and RADARSAT (2003-2010) satellites. The study area is located in North-Western Italy and belongs to three regions: Piemonte, Lombardia and Liguria.
ABSTRACT This work describes the potentiality of Persistent Scatterers Interferometry (PSI) techniques into mapping, monitoring and characterizing some pattern of deformations related to different slow geological processes: landslides,... more
ABSTRACT This work describes the potentiality of Persistent Scatterers Interferometry (PSI) techniques into mapping, monitoring and characterizing some pattern of deformations related to different slow geological processes: landslides, subsidence, periglacial activity and other processes related to natural or anthropic causes. The study area is located in the NW Italy (>20,000 km2). Radarsat Canadian satellite (2003–2010) and European Remote-Sensing Satellite (ERS) satellite data (1992–2000) processed with advanced algorithm (SqueeSAR™) were used. Some representative case histories are here presented.
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ABSTRACT This paper illustrates the main characteristics of the newly developed landslide model r.massmov, which is based on the shallow water equations, and is capable of simulating the landslide propagation over complex topographies.... more
ABSTRACT This paper illustrates the main characteristics of the newly developed landslide model r.massmov, which is based on the shallow water equations, and is capable of simulating the landslide propagation over complex topographies. The model is the result of the reimplementation of the MassMov2D into the free and open-source GRASS GIS with a series of enhancements aiming at allowing its possible integration into innovative early warning monitoring systems and specifically into Web processing services. These improvements, finalized at significantly reducing computational times, include the introduction of a new automatic stopping criterion, fluidization process algorithm, and the parallel computing. Moreover, the results of multi-spatial resolution analysis conducted on a real case study located in the southern Switzerland are presented. In particular, this analysis, composed by a sensitivity analysis and calibration process, allowed to evaluate the model capabilities in simulating the phenomenon at different input data resolution. The results illustrate that the introduced modifications lead to important reductions in the computational time (more than 90 % faster) and that, using the lower dataset resolution capable of guaranteeing reliable results, the model can be run in about 1 s instead of the 3.5 h required by previous model with not optimized dataset resolution. Aside, the results of the research are a series of new GRASS GIS modules for conducting sensitivity analysis and for calibration. The latter integrates the automated calibration program “UCODE” with any GRASS raster module. Finally, the research workflow presented in this paper illustrates a best practice in applying r.massmov in real case applications.
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The applicability of the Permanent Scatterers Synthetic Aperture Radar Interferometry (PSInSAR) technique for detecting and monitoring ground displacements was tested in the Oltrepo Pavese territory (Northern Italy, southern Lombardia),... more
The applicability of the Permanent Scatterers Synthetic Aperture Radar Interferometry (PSInSAR) technique for detecting and monitoring ground displacements was tested in the Oltrepo Pavese territory (Northern Italy, southern Lombardia), which could be representative of similar geological contexts in the Italian Apennines. The study area, which extends for almost 1100 km2, is characterized by a complex geological and structural setting and the
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Riassunto Il lavoro presenta un'applicazione della Tecnica dei Permanent Scatterers nel territorio dell'Oltrepo Pavese situato nella Lombardia meridionale e rappresentativo dell'ambiente appenninico. L'obiettivo della... more
Riassunto Il lavoro presenta un'applicazione della Tecnica dei Permanent Scatterers nel territorio dell'Oltrepo Pavese situato nella Lombardia meridionale e rappresentativo dell'ambiente appenninico. L'obiettivo della ricerca é stato la verifica dell'applicazione ...
After a large earthquake, a lot of coseismic phenomena can occur in the field, and the spatial distribution is very important to understand the fault geometry. In this framework, the application of terrestrial photogrammetry is a less... more
After a large earthquake, a lot of coseismic phenomena can occur in the field, and the spatial distribution is very important to understand the fault geometry. In this framework, the application of terrestrial photogrammetry is a less expensive and more rapid method to map the micro-morphology of sand volcanoes, compared to (terrestrial/aerial) laser scanning. The centimetric DEMs obtained can be processed and correlated with other datasets later, to create a complete geodatabase of coseismic features. The 3D reconstruction of sand boils ...
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The new generations of Persistent Scatterer data (es. SqueeSAR, Ferretti et al., 2011) allow to have a high density of interferometric data in the alpine area, especially in correspondence of slow landslides, due to the widespread debris... more
The new generations of Persistent Scatterer data (es. SqueeSAR, Ferretti et al., 2011) allow to have a high density of interferometric data in the alpine area, especially in correspondence of slow landslides, due to the widespread debris coverage which help in the geo-hazard assessment. The improvement in the time series quality allows also to understand the behavior of some processes and to have a best comparison with traditional monitoring system and/or rainfall data. In this work we evaluate the potentiality and the ...