MAN OR NATURE? THE ROLE OF NATURAL EVENTS IN THE ABANDONING OF THE ROMAN TOWN OF CARSULAE (TIBER BASIN ITALY)

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Natural and anthropic changes on landscapes: signs and designs in a river system. The study-case of the Potenza River final sector (Porto Recanati, Italy)

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Landslide Susceptibility Using Climatic–Environmental Factors Using the Weight-of-Evidence Method—A Study Area in Central Italy

The Italian territory is subject to a high level of hydrogeological instability that periodically results in the loss of lives, buildings and productive activities. Therefore, the recognition of areas susceptible to hydrogeological instability is the basis for preparing countermeasures. In this context, landslide susceptibility in the mid-Adriatic slope was analyzed using a statistical method, the weight of evidence (WoE), which uses information from several independent sources to provide sufficient evidence to predict possible system developments. Only flows, slides, debris flows and mud flows were considered, with a total of 14,927 landslides obtained from the IFFI (Inventory of Franous Phenomena in Italy) database. Seven climatic–environmental factors were used for mapping landslide susceptibility in the study area: slope, aspect, extreme precipitation, normalized difference vegetation index (NDVI), CORINE land cover (CLC), and topographic wetness index (TWI). The introduction of these factors into the model resulted in rasters that allowed calculation by GIS-type software of a susceptibility map. The result was validated by the ROC curve method, using a group of landslides, equal to 20% of the total, not used in the modeling. The performance of the model, i.e., the ability to predict the presence or absence of a landslide movement correctly, was 0.75, indicating a moderately accurate model, which nevertheless appears innovative for two reasons: the first is that it analyzes an inhomogeneous area of more than 9000 km2 , which is very large compared to similar analyses, and the second reason is the causal factors used, which have high weights for some classes despite the heterogeneity of the area. This research has enabled the simultaneous introduction of unconventional factors for landslide susceptibility analysis, which, however, could be successfully used at larger scales in the future

DSGSDs induced by post glacial decompression in central Apennine (Italy)

During the last 30 years of studies in the field of mass movements located in the calcareous-marly and marly-sandy Apennines (Umbria-Marches and Latium-Abruzzi regions), over to a large number of landslides with different dimensions, even a lot of deep-seated gravitational slope deformations (DSGSDs) have been recognized and analysed. These phenomena are also located in that sector of central Italy affected by a cold climate during the past and actually temperate (central Apennine chain)

Geo-environmental changes and historical events in the area of the Greek archaeological site of Selinunte (Western Sicily, Italy)

Detailed geomorphological and geo-archaeological surveys were carried out in this study at the Greek archaeological site of Selinunte to reconstruct the landscape evolution that occurred before and during the anthropization of the site and to verify the possible correlations between geo-environmental changes and human events that characterized almost four centuries of the history of the city. By using a multidisciplinary approach and different survey techniques, this study testified the role played by climate, geomorphological setting and georesources in conditioning the development of the city and the close relationship sometimes observed between the historical events and natural processes. This included the controversial and never discovered hydraulic work of Empedocles who, according to textual sources, in 444 BC, resolved a public health problem linked to the presence of marshy areas

Step-like displacements of a deep seated gravitational slope deformation observed during the 2016–2017 seismic events in Central Italy

Deep Seated Gravitational Slope Deformations are characterized by low deformation rates although they can experience partial-collapse phases or more rapid movements, especially in presence of active tectonic structures. In the Central Italy, considering the high seismicity rate, seismic activity must be considered to be an important trigger of deep slope movements. We aim to contribute to the research in this field by reporting the results of a monitoring program on a Deep Seated Gravitational Slope Deformation in this region that involves marly calcareous rocks. We documented the pre-earthquakes evolution of the phenomenon and measured its displacements during the seismic sequence in 2016 and 2017 in Central Italy, which largest events were Mw 5.0-to-6.5. A multidisciplinary approach that combines a field geomorphological survey, installation of permanent GPS stations, and InSAR elaborations was adopted for this study. The average ground motion rate of the slope deformation before the earthquakes was very low (< 3 mm/y) and not spatially homogenous, as detected by GPS and InSAR. In detail, the uppermost area of the slope instability likely moves faster than the lowest sector. On the other hand, GPS and InSAR recorded significant step-like movements, one to ten times higher than the normal activity rate, triggered by the M-w 5.0-to-6.5 earthquakes. In detail, the movement mainly depended on the magnitude of the earthquake and the distance from the epicenter, and only secondarily on the number of larger magnitude earthquakes on a given day. In conclusion, we furnished monitoring data on the activity rate of a Deep Seated Gravitational Slope Deformation in seismic context, we indicated two sectors of the investigated deformation that resulted more unstable and we proved that the combination of InSAR and GPS data is a useful monitoring system for earthquake activated, slow-moving slope instabilities.Published337-3482T. Deformazione crostale attivaJCR Journa

Geomorphological Hazard in Active Tectonics Area: Study Cases from Sibillini Mountains Thrust System (Central Apennines)

In many areas of the Umbria-Marche Apennines, evident traces of huge landslides have been recognized; these probably occurred in the Upper Pleistocene and are conditioned by the tectonic-structural setting of the involved Meso-Cenozoic formations, in a sector of the Sibillini Mountains (central Italy). The present work aimed to focus on a geomorphological hazard in the tectonic-structural setting of a complex area that is the basis of several gravitational occurrences in different types and mechanisms, but nonetheless with very considerable extension and total destabilized volume. An aerophoto-geological analysis and geomorphological survey allowed verification of how the main predisposing factor of these phenomena is connected with the presence in depth of an important tectonic-structural element: the plane of the Sibillini Mountains thrust, which brings the pre-evaporitic member of the Laga Formation in contact with the Cretaceous-Eocene limestone lithotypes (from the Maiolica to the Scaglia Rosata Formations) of the Umbria-Marche sedimentary sequence. Another important element for the mass movements activation is the presence of an important and vast water table and related aquifer, confined prevalently by the different structural elements and in particular by the thrust plane, which has acted and has continued to act, weakening the rocky masses and the overlaying terrains

Applicazione della scheda di pericolosità geoturistica all'ambiente carsico ipogeo: l'esempio delle Grotte di Frasassi (Marche centrali)

Ogni forma di frequentazione dell'ambiente sotterraneo può provocare un'alterazione all'ecosistema grotta. Grotte turistiche incontrollate ed anche speleologi disattenti arrecano danni consistenti ai sistemi ipogei: inquinamento e distruzione sono causati da ignoranza e sottovalutazione degli effetti conseguenti a determinate azioni. Analogamente i visitatori che frequentano grotte, adattate alla fruizione turistica con percorsi opportunamente attrezzati, sono soggetti a pericolosità che, pur nella maggioranza dei casi si risolvono con piccoli incidenti, talvolta tuttavia possono dar luogo a problematiche ben più importanti. Ne risulta quindi che la corretta conoscenza, valutazione e divulgazione dei livelli di pericolosità “oggettiva” e “soggettiva”, anche per gli ambienti sotterranei, basato sul censimento e sulla quantificazione di tali pericolosità, risulta di fondamentale importanza soprattutto in vista della loro gestione e programmazione futura