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Rainfall can trigger flow-like mass movements characterised by different percentages of solid and water (debris flows, hyperconcentrated flows, and flash floods). They exhibit different magnitude (volume), run-out distance and consequence, due to both distinct triggering mechanisms and kinematic features. Indeed, discriminating among these phenomena for appropriate risk analysis and zoning is a relevant issue also considering that the volume of the flow may sudden increase along the propagation path. The paper deals with September 2010 combined types of flows occurred at Atrani village (Amalfi coast, southern Italy), and originated by heavy rainstorm in the catchment located upslope to the urban centre. The events were reconstructed by using multi-source information. Field surveys, geological analysis, elaboration of videos recorded during the events and numerical modelling were combined. A 40 minutes lasting water flood abruptly combined to a relatively small-sized high-discharge hyperconcentrated flow, with the consequence of an abnormal flow that invaded the narrow main street of the urban area in few minutes. The peak discharge at the catchment outlet was increased by erosion and/or other rainfall-induced slope instabilities occurred in the whole catchment. As main conclusion, the multidisciplinary analysis has resulted effective to enhance the understanding of the complex flow-like mass movements.

Sea-level rise as a consequence of global warming increases the need to analyze coastal risks to conceive adaptation strategies aimed at coping with marine impacts at both short- and long-term scales. In this context, this study presents future scenarios of inundation risk evaluated along the main alluvial coastal plains of the Campania region (Italy). Due to their geomorphological and stratigraphical setting, the investigated areas are characterized by low topography and relevant but variable subsidence rates. Based on the upgrade of already published data and the new analysis of available datasets derived by multi-temporal interferometric processing of satellite Synthetic Aperture Radar (SAR) images, future scenarios of local sea level for the years 2065 and 2100 have been evaluated coupling global projections with local subsidence trends. Furthermore, aspects related with the distribution of natural and anthropic assets, as well as the local social vulnerability, have been taken into account to calculate the overall risk. The inundation risk maps here proposed can effectively address the request to improve the knowledge of policymakers and local administrators and to raise their awareness about the potential impacts of climate change in coastal areas.

This chapter illustrates the marine record of a spectrum of volcanic, hydrothermal, and sedimentary features that characterize the Latest Pleistocene–Holocene evolution of the Naples Bay offshore Campi Flegrei and Somma–Vesuvius. The work is based on review of previous literature integrated with interpretation of new high-resolution marine Digital Terrain Models (DTMs) derived from swath bathymetry surveys and high-resolution reflection seismic profiles calibrated with marine gravity core data. Seismic profiles from Pozzuoli Bay provide detailed images of the ring fault system and resurgent dome associated with the evolution of the Neapolitan Yellow Tuff (NYT) collapse caldera and document a series of uplift episodes associated with volcanic unrest as documented on land throughout the Holocene, with a notable subsidence phase occurring between ∼ 2.5 ka BP and 1538 CE (Monte Nuovo eruption). Offshore seismic images also revealed the occurrence of ascending hydrothermal fluids and volcanic/subvolcanic intrusions along the ring fault zone of the NYT caldera. Seismic data acquired along the SW submerged slope of Somma–Vesuvius display evidence of gravitational instability, associated with slump folding and faulting, of sand waves originated by pyroclastic flows that entered the seawater after destroying the Roman city of Herculaneum during the 79 CE eruption of Vesuvius. Between the Somma–Vesuvius and Pozzuoli Bay, seismic profiles calibrated with gravity core data revealed the occurrence of a hummocky seafloor region, known as Banco della Montagna (i.e., the Montagna bank). This volcanic bank was shaped by the dragging and rising up of volcaniclastic diapirs (mostly unconsolidated pumice) because of pore fluid overpressure at depth and associated active fluid venting at the seafloor.

Landslides and surface erosion are major processes controlling the progressive recession of many rocky cliffs along the Italian coastline. Nevertheless, many coastal settlements were built along cliffed sectors prone to rapid collapses. This represents a serious risk for tourists and living people, as well as for buildings, roads and railway networks. The densely urbanized coastline of the Campi Flegrei active volcanic district is one of the rocky coastal areas of South Italy mostly exposed to the recession. Here, coastal cliffs are made by volcaniclastic deposits and include remnants of ancient volcanic edifices formed in the last 15 ka. Due to petrographic, geotechnical and geostructural properties of volcaniclastic deposits, these cliffs have been affected by rapid recession since their origin. This research focuses on a cliff of the Campi Flegrei coastaline (Torrefumo, Monte di Procida) which, although currently protected from the sea waves by a seawall, is still retreating. We assessed the ongoing recession using a change detection analysis, based on accurate topographic data acquired with two terrestrial laser scanning surveys executed in 2013 and 2016. The quantitative comparison of 3D point clouds datasets allowed detecting 191 cliff failures. We verified that the frequency-magnitude distribution of the detached blocks followed an inverse power law, and most of the involved volumes were between 0.01 and 1 m(3). Retreat rates of different cliff sectors varied from 0.001 to 0.025 m/year. Our analysis also allowed us to recognize slope failure mechanisms and distinguish rock falls from grain-by-grain surficial erosion.

The coastal zone of the Campi Flegrei volcanic district is prone to a wide spectrum of natural hazards, including earthquakes, tsunamis, flash floods, ground deformation, landslides and coastal erosion. In this research we focus on flash flood phenomena occurred in the Pozzuoli catchment, by analyzing historical documents (e.g. newspapers, archive reports, web site news) and integrating the results with daily rain time series of the rain gauge station of Pozzuoli city. In order to understand the evolution of these phenomena, we analyze the 6 November 2011 event that hit the city of Pozzuoli. The study includes the description of meteorological conditions, rainfall properties, ground effects obtained by a web-based research and results obtained simulating flood propagation by means of FLO-2D code. Preliminary results of our research provide a contribution for the understanding of flash floods and flow processes in the study area as well as relevant information for hazard and risk assessment.

The utility of new imaging technologies to better understand hazardous geological environments cannot be overstated. The combined use of unmanned aerial vehicles (UAV) and digital photogrammetry (DP) represents a rapidly evolving technique that permits geoscientists to obtain detailed spatial data. This can aid in rapid mapping and analyses of dynamic processes that are modifying contemporary landscapes, particularly through the creation of a time series of digital data to help monitor the geomorphological evolution of volcanic structures. Our study comprises a short-term (in geological terms) monitoring program of the dynamic and diffuse Pisciarelli degassing structure caused by the interplay between intensive rainfall and hydrothermal activity. This area, an unstable fumarole field located several hundred meters east of the Solfatara Crater of the Campi Flegrei caldera (southern Italy), is characterized by consistent soil degassing, fluid emission from ephemeral vents, and hot mud pools. This degassing activity is episodically accompanied by seismic swarms and macroscopic morphology changes such as the appearance of vigorously degassing vents, collapsing landslides, and bubbling mud. In late-2019 and 2020, we performed repeated photogrammetric UAV surveys using the Structure from Motion (SfM) technique. This approach allowed us to create dense 3D point clouds and digital orthophotos spanning one year of surveys. The results highlight the benefits of photogrammetry data using UAV for the accurate remote monitoring and mapping of active volcanoes and craters in harsh and dangerous environments.

The high levels of geo-hydrological, seismic, and volcanic hazards in the Campania region prompted full data collection from C-band satellites ERS-1/2, ENVISAT, and RADARSAT within regional (TELLUS) and national (PST-A) projects. The quantitative analysis, interpretation, and classification of natural and human-induced slow-rate ground deformations across a span of two decades (1992–2010) was performed at regional scale (Campania, Italy) by using interferometric archive datasets, based on the Persistent Scatterer Interferometry approach. As radar satellite sensors have a side-looking view, the post-processing of the interferometric datasets allows for the evaluation of two spatial components (vertical and E-W horizontal ones) of ground deformation, while the N-S horizontal component cannot be detected. The ground deformation components have been analyzed across 89.5% of the Campania territory within a variety of environmental, topographical, and geological conditions. The main part (57%) of the regional territory was characterized during 1992–2010 by stable areas, where SAR signals do not have recorded significant horizontal and vertical components of ground deformation with an average annual rate greater than +1 mm/yr or lower than −1 mm/yr. Within the deforming areas, the coastal plains are characterized by widespread and continuous strong subsidence signals due to sediment compaction locally enhanced by human activity, while the inner plain sectors show mainly scattered spots with locally high subsidence in correspondence of urban areas, sinkholes, and groundwater withdrawals. The volcanic sectors show interplaying horizontal and vertical trends due to volcano-tectonic processes, while in the hilly and mountain inner sectors the ground deformation is mainly controlled by large-scale tectonic activity and by local landslide activity. The groundwater-related deformation is the dominant cause of human-caused ground deformation. The results confirm the importance of using Persistent Scatterer Interferometry data for a comprehensive understanding of rates and patterns of recent ground deformation at regional scale also within tectonically active areas as in Campania region.

In this study, we present the results of an analysis of Terrestrial Laser Scanning ( TLS) datasets, referred to multi-temporal (2013-2015) acquisition, aimed at evaluating volumetric changes and average retreat rates of the Coroglio tuff cliff, located in the western sector of Naples (Italy) in the Campi Flegrei caldera. The multi-temporal analysis was carried out in two steps: firstly, we developed a preliminary 3D Cloud-to-Cloud comparative analysis of point clouds obtained by TLS data processing, providing a view on geomorphological evolution; secondly, we obtained quantitative information by analyzing in GIS processing the differences between multi-temporal Digital Elevation Models. Finally, a morphometric analysis was carried out in order to evaluate retreat both retreat and failure rates. Four types of landslides (rock fall, debris fall, earth flow, and soil slip) have been accurately mapped in the different sectors of the cliff. The morphological analysis shows that several morphological variations have been recognized in different areas of the cliff with a maximum retreat of 8 m at the foot of the cliff due to the erosive action of the sea on poorly lithified deposits. We estimated that the average linear retreat rate related to the Coroglio cliff between 2013-2015, was equal to 0.07 m/yr; the linear retreat rate is higher (0.34 m/yr) at the base of the cliff, directly beaten by the sea waves. The results of the statistical analysis of the relationship between volume and area calculated for rock falls are consistent with the results of previous studies. Geo-structural analysis confirms that some discontinuity sets strongly control the failure kinematisms.

Geomorphic evolution of sea cliffs has significant impact on coastal settlements worldwide, so that evaluation of cliff instability processes, failure factors, and retreat rates involves a growing number of scientists for coastal risk and management purposes. Aerial photogrammetry and lidar are among the most used techniques for topographic characterization and geomorphic monitoring of coastal environments. A crucial role in the combined use of such techniques is the evaluation of different spatial accuracy and co-registration between derived terrain models, so that a robust error analysis is required. In this study, we present a change detection analysis of the Torrefumo coastal cliff, in the Campi Flegrei volcanic area (Southern Italy). Aerial images taken in 1956 and 1974, processed through digital photogrammetry, and an airborne lidar point cloud acquired in 2008 were used to produce Digital Elevation Models of the cliff. The analysis was based on the multi-temporal comparison of these models and included the calculation of volumetric changes and average retreat rates of the cliff face with reference to the 1956–1974 and 1974–2008 time intervals. The spatially variable elevation uncertainty of each Digital Elevation Model was evaluated with a probabilistic approach based on the fuzzy set theory. The results of this study showed significant eroded volumes during the period 1956–1974 and relatively smaller volumes in the 1974–2008 time span, with mean annual retreat rates of 1.2 m/year and 0.17 m/year, respectively. We infer that the significant decrease of erosion characterizing the second period was induced by the sheltering effect at the base of the cliff produced by the construction of a seawall in the early 80’s.

Climate change is affecting the frequency and severity of extreme meteorological and geo-hydrological events hitting the coastal zone of the Campi Flegrei volcanic district (southern Italy), which is prone to a wide spectrum of natural hazards, including volcanism, earthquakes, ground deformation, flash floods, landslides and coastal erosion. This study documents the trend of flash floods affecting the urban area of Pozzuoli, located along the coastline of the Campi Flegrei volcanic area during 1970-2014 time period. An archive research together with the collection of data published on news websites and social media allowed understanding of the triggering and evolution mechanisms of flash floods in the area, as well as the most recurrent damages. Rainfall data collected by the rain gauge located within the Pozzuoli watershed were also analyzed and rainfall properties estimated. Results of this study show an increased frequency of flash flood events occurred in the study area. The variation in flash flood frequency is likely not related to urbanization changes, as no increase of the urban area occurred after the year 2000. The observed increase in the flash flood events in recent years (2000-2014) can be reasonably ascribed to variations in the rainfall regime. Our research provide a contribution for the understanding of flash flood processes in the study area as well as relevant information for hazard and risk assessment.

Many coastlines around the world are subsiding, often due to tectonic causes. In tectonically active areas, the exploitation of natural resources has caused acceleration of subsidence rates. In these cases, it is difficult to separate the many different components of the subsidence process. We try to fill this gap, using both remote sensing data and geological evidence, in an area located in southern Italy (Sele River plain) and characterized by the presence of both human activities and natural processes. The coastal sector of the Sele plain shows a complex subsidence pattern, as testified by Persistent Scatterer Interferometry (PS InSAR) data related to a period of about two decades (1992–2010), that we put in correlation with stratigraphical data from both outcrops and boreholes (ca. 250). The Quaternary infill of the coastal sectors of the plain is not laterally isotropic and homogeneous because of the presence of layers of clastic sediments with different degrees of compaction. Dunal and beach sands, back-ridge (lagoonal and palustrine) silty clays, palaeosols and thick peaty layers are the main facies of this sedimentary prism. The back-ridge depressions hosted palustrine and marshy environments and were artificially drained in the last centuries. The main output of the PS- InSAR analysis is a map of vertical ground deformation (VGD), which has been a useful tool to understand the causes of the subsidence process if combined with geological data from field and boreholes. In fact, the overlay of the SAR interferometry VGD map with the geomorphological and stratigraphical features shows that the subsidence is higher in the northern sector of the plain, where the Quaternary alluvial-coastal deposits are thicker because of the structural asymmetry of the graben. The maximum subsidence rate, however, can be observed in the central part of the plain, in correspondence of the Sele, Tusciano and Picentino river mouths and in the coastal belt. This could be related to the thickness of loose sediments (>20 m) and to the presence of still compacting clay-rich sediments. In the southernmost sector the rates are the lowest recorded in the plain due to the minor thickness of Holocene deposits and to the presence of very thick sedimentary bodies of travertine. The understanding of subsidence patterns may represent a basic tool for future studies about the assessment of the coastal inundation hazard and related risk mitigation in the Sele River plain. Such a tool may reinforce the methodological approach to risk assessment in similar morphological settings.

A Nápolyi-öbölben felvett ultra nagy felbontású egycsatornás (IKB-Seistec™) reflexiós szeizmikus szelvények korábbi geológiai és geofizikai vizsgálatok eredményeivel együtt kivételes, eddig soha nem látott felbontású szeizmikus leképezését nyújtják a Flegrei-mezők és a Somma-Vezúv felszín alá süllyedt késő-pleisztocén–holocén rétegtani felépí - tésének. A szeizmikus szelvényeken látott geometria és gravitációs magvevővel nyert üledékek adatainak összevetéséből Campania partközeli kontinentális talapzatán számos olyan üledékes és vulkáni szerkezet, valamint hidrotermális jelenség került leképezésre, melyek a legutolsó glaciális maximum (kb. 18 000 év) óta keletkeztek. A Pozzuoli-öbölben mért Seistec szelvények jól mutatják a beomlott kaldera gyűrűs vetőjét, a kb. 15 ezer éves Nápolyi Sárga Tufa (NYT) lerakódáshoz vezető kitöréskor felújuló boltozatot, és alátámasztják a deformáció későnegyedidőszaki korára és stílusára vonatkozó hipotéziseket. A szeizmikus szelvényeken látható a NYT rétegeinek töréses szerkezete, valamint hidrotermális fluidum-feláramlások és vulkáni/szubvulkáni intrúziók a gyűrűs vetők mentén. A Somma-Vezúv rétegvulkán előterében a kontinentális talapzat felett mért szeizmikus szelvények leképezték a Vezúv i.sz. 79-es kitörésekor Herculaneum városát elpusztító piroklaszt-ár tengervízbe érésekor keletkező, gravitációsan összeomló homokhullámok szerkezetét is. A Somma-Vezúv és a Pozzuoli-öböl közti, buckás felszínű Banco della Montagna területén mért szelvények és fúrómagok vulkanoklasztos diapírok sorát tárták fel. Ezeket a konszolidálatlan horzsakőből álló testeket a fluidum - feláramlás és aktív kigázosodás hatására kialakult mélybeli túlnyomás hozta fel a tengerfenékre. Very high-resolution, single channel (IKB-Seistec™) reflection seizmic profiles acquired in the Bay of Naples, com - plemented with geological and geophysical data from the literature, provide unprecedented, superb seismic imaging of the latest Pleistocene–Holocene stratigraphic architecture of the submerged sectors Campi Flegrei and Somma-Vesuvius volcanic districts. Seismic profiles were calibrated by gravity core data and document a range of depositional systems, volcanic structures and hydrothermal features that evolved after the onset of the Last Glacial Maximum (~ 18 ka BP) over the continental shelf on the Campania coastal zone. Seistec profiles from the Pozzuoli Bay yield high-resolution images of the shallow structure of the collapse caldera-ring fault — resurgent dome system associated with the eruption of the Neapolitan Yellow Tuff (NYT) (ca 15 ka) and support a working hypothesis to assess the timing and the styles of deformation of the NYT resurgent structure throughout the latest Quaternary. Seismic images also revealed the nature of the fragile deformation of strata along the NYT ring fault system and the occurrence of hydrothermal fluids and volcanic/subvolcanic intrusions ascending along the ring fault zone. Seismic data acquired over the continental shelf off the Somma-Vesuvius stratovolcano, display evidence of gravit - ational instability of wavy bedforms representing the submarine prosecution of pyroclastic flows originated from the Vesuvius during the eruption that destroyed the Roman city of Herculaneum in 79 CE. At the Banco della Montagna, a hummocky seafloor knoll located between the Somma-Vesuvius and the Pozzuoli Bay, seismic profiles and gravity core data revealed the occurrence of a field of volcaniclastic diapirs formed by the dragging and rising up of unconsolidated pumice, as a consequence of fluid overpressure at depth associated with active degassing and fluid venting at the seafloor.

In this study we document a post-fire erosion response to a short-lived, intense rainstorm occurred on 6 September 2012 in the Sant'Angelo creek watershed, Sarno Mountains, Southern Italy. The rainstorm occurred one month after a wildfire that burned about 11 ha of the steep watershed (55 ha), almost entirely mantled by volcaniclastic deposits. The research was based on fieldwork and laboratory analysis addressed to the understanding of the geomorphic effects of the wildfire and their impact on erosional and depositional processes triggered by subsequent rainstorms. Field evidence indicates that a series of overland flows caused significant runoff and sediment yields along the hillslope and accumulation of hyperconcentrated flow deposits in a concrete channel occluded by a sealed culvert at the outlet of the watershed. The results of geomorphological and sedimentological analysis suggest that the occurrence of volcaniclastic covers mantling the slopes likely favored accelerated soil erosion, especially where vegetation and litter had been removed by the fire. Chemical analysis on sediment samples, revealed the occurrence of iron oxides that enhanced soil water repellency conditions over wide areas of the burned watershed compared to the unburned areas. Quantitative analysis of sediment budgets showed that the rainfall-induced erosion response at Sant'Angelo creek watershed resulted in a soil loss of 19.8–33.1 tons ha − 1 over burned areas. Post-fire erosion response following severe rainstorms needs to be considered in the spectrum of natural hazards associated with the geomorphological evolution of mountainous landscapes mantled by volcaniclastic deposits.

We apply the Permanent Scatterers Synthetic Aperture Radar Interferometry (PS-InSAR) technique to the Campania Region (Southern Italy), which includes the Southern Apennines chain and Plio-Quaternary structural depressions, with the aim to detect ground displacements at a regional scale. The study area, which extends for 13,600 km 2 , is characterized by intense urbanization, active volcanoes (Phlegraean Fields, Vesuvius and Ischia), seismogenic structures, landslides, hydrogeological instability. PS-InSAR technique allows us to identify a set of radar benchmarks (PS) where accurate displacement measurements can be carried out. About 1.7·10 6 PS are identified by processing Synthetic Aperture Radar (SAR) images acquired in ascending and descending orbits from 1992 to 2001 by the European Remote Sensing satellites (ERS). The PS-InSAR application at regional scale detected ground deformations ranging from + 28 to − 39 mm/yr. The calculated velocity values are consistent with the available GPS and levelling data from selected areas. We identify volcanic areas in which the deformation is mainly related to the depressurization of the local hydrothermal systems, and recognize deformations along seismogenic and aseismic NNW–SSE and NW–SE faults. The deformations localized along the Southern Apennines chain are mainly related to landslides while those occurring in the plains are due to subsidence processes induced by intensive drainage from wells, i.e. anthropic activity. The review of 9 years of SAR data shows that tectonic, volcanic/hydrothermal, gravity, and anthropic processes are responsible for the ground deformation of Campania. The proposed joint interpretation of deformation fields related to natural and anthopogenic factors provides a comprehensive view of the dynamics of the Earth’s surface.

We present a long-range terrestrial laser scanner application for the geostructural mapping of Coroglio cliff, a tuff rock face exposed along the coastal zone of Campi Flegrei, Napoli. The procedure includes several phases (geomorphological analysis, structural field survey, laser scanner data acquisition and data processing, 3-D model development and analysis, geostructural classification of discontinuity orientation data and 2-D vertical cartographic production). Field data were processed with specific software dedicated to geostructural and geometric analysis. Spatial data were managed with a geographical information system and have been used for the construction of 2-D and 3-D geometric models of the rock cliff surface and geostructural interpretation. The main product of this study is a vertical geostructural map of the Coroglio cliff at 1:500 scale that illustrates the spatial distribution and orientation of the major families of structural discontinuities detected along the exposed surface of the cliff. The cartographic product includes base information useful to identify the main rock failure mechanisms along the cliff and represents a first step for the zonation of areas susceptible to block failures and the planning of monitoring activities.

The paper presents a method for estimating and mapping – at detailed scale (1:5000) – the thickness of pyroclastic cover beds resting on calcareous bedrock. This method, tested in the study area of Mount Albino (Campania region, southern Italy), makes use mainly of information gathered from in situ investigations, managed and processed in a geographical information system environment via a geostatistical interpolation technique (i.e. ordinary kriging) and finally integrated and amended by adopting a heuristic approach. Given its easy applicability and affordable costs, the proposed method can be used in similar geological contexts where knowledge of the spatial distribution of pyroclastic cover beds is a requirement for understanding and predicting slope instability processes.

We present the results of a detailed bathymetric survey of Pozzuoli Bay (Gulf of Naples, Italy). This shallow marine area, along with the Campi Flegrei inland, is a highly active volcanic district in the coastal zone of SW Italy. The area has been active since at least 78 ka B.P., and is structurally dominated by a caldera collapse (∼8 km in diameter) associated with the eruption of the Neapolitan Yellow Tuff (NYT), a 30–50 km3 dense rock equivalent (DRE) ignimbrite dated ∼15 ka B.P. The main cartographic product consists of a 1:10,000 scale morpho-bathymetric map of Pozzuoli Bay, derived from 1 m cell-size, colour hill-shaded, digital terrain model of the seafloor. Multibeam bathymetry data reveal the precise extent of Roman underwater archaeological remains located in the N–NW infralittoral zone of the Bay. Morphometric analysis allowed for the development of thematic representations, including slope and aspect maps. A complete data set of active fluid vents seafloor locations were also recorded during the survey and reported in the final map. The multibeam bathymetric survey illustrated in this study provides an unprecedentedly detailed image of the seafloor morphology of Pozzuoli Bay and represents a contribution to the understanding of the dynamic evolution of the Campi Flegrei caldera, a high-risk volcanic area densely populated by almost one million people.

The Volturno Plain is one of the largest alluvial plains of peninsular Italy, which is one of the most susceptible plains to coastal hazards. This area is characterized by both natural and human-induced subsidence. This present study is based on the post-processing, analysis and mapping of the available Persistent Scatterer interferometry datasets. The latter were derived from the combination of both ascending and descending orbits of three different radar satellite systems during an observation period of almost two decades (June 1992–September 2010). The main output of this study is a map of vertical deformation, which provides new insights into the areal variability of the ground deformation processes (subsidence/uplift) of Volturno plain over the last few decades. The vertical displacement values obtained by the post-processing of the interferometric data show that the Volturno river plain is characterized by significant subsidence in the central axial sectors and in the river mouth area. Moderate uplift is detected in the eastern part of the plain, whereas other sectors of the study area are characterized by moderate subsidence and/or stability. On the basis of the analyzed subsoil stratigraphy, we inferred that the subsidence recorded in the Volturno plain is mainly a consequence of a natural process related to the compaction of the fluvial and palustrine deposits that form the alluvial plain. The anthropic influences (e.g., water exploitation, urbanization) are substantially considered to be an additional factor that may enhance subsidence only locally. The uplift mapped in the eastern sector of the plain is related to the tectonic activity. The study of the subsidence in the Volturno plain is a valuable tool for river flood analyses and the assessment of the coastal inundation hazards and related risk mitigation.

Campi Flegrei is an active volcanic district located along the Eastern Tyrrhenian continental margin, Italy, and is worldwide known for dramatic ground deformation phenomena (bradyseism) recorded over the last centuries. The purpose of this article is to present the annual rates of ground deformation fields (average velocity, average acceleration, and combined annual velocity/acceleration) at Campi Flegrei, during almost two decades (years 1993-2010). The research work was conducted based on a temporal analysis and advanced mapping of Persistent Scatterer Pair (PSP) data, obtained from interferometric processing of radar satellite European Remote Sensing-1/2 and Environmental Satellite (ENVISAT) scenes of the study area. Patterns and trends of annual PSP velocity have provided a reconstruction of the spatial and temporal variability of ground deformation in terms of uplift and/or subsidence along the satellite line of sight (LOS). The analysis of annual PSP velocity and acceleration has revealed an intense dynamics of the Campi Flegrei caldera collapse-resurgence system, testified by the high PSP velocity and acceleration values, as well as the significant changes in the rates of ground deformation through time. The main results of this research indicate that the largest ground deformation is localized within and around the structural border of the Campi Flegrei caldera and suggest a systematic recurrence of opposite trends (uplift vs. subsidence) in the ground deformation of the inner caldera region with respect to the surrounding areas throughout the analysed time period.

This study presents the results of a Terrestrial Laser Scanner (TLS) application aimed at characterizing the structural pattern of Punta Epitaffio tuffaceous coastal cliff, Pozzuoli Bay, Eastern Tyrrhenian margin. The study site is located in the Campi Flegrei, an active volcanic caldera, characterized by dense urbanization, near the town of Naples, Italy. The 3D digital model of the Punta Epitaffio cliff derived from TLS data, provided a base for the classification of rock discontinuities by geostatistical analysis. In particular, the work flow of geostructural data processing included: 1) statistical analysis of spatial orientation of the facets of the 3D mesh derived by the TLS survey; 2) extraction of the best-fit attitudes (dip and dip direction) of discontinuity sets for each sub-planar patch of the rock face; 3) cluster analysis of best-fit structural discontinuities; 4) definition of all the discontinuity sets and geo-structural classification of 3D model facets; 5) kinematic analysis for the definition of possible failure mechanisms. Kinematic analysis took into account primarily structurally-controlled failure mechanisms (planar sliding, wedge sliding, flexural toppling, and direct toppling). The method illustrated in this research can be extensively applied to identify unstable areas along tuffaceous coastal cliffs and define shape and volume of rocks potentially involved by failures.

This study presents a Terrestrial Laser Scanning (TLS) application to monitor the slope stability along tuffaceous cliffed coast of Pozzuoli Bay, at Coroglio test site, Naples, Italy. We tested TLS technique based on Time of Flight method in order to obtain a 3D model of the coastal cliff, along with a classification of the rock discontinuities on the basis of their spatial orientation. A high-resolution digital model of the study outcrop has been produced, with a cell dimension of 5 cm. The analysis of spatial orientation of planar-like surfaces derived from the digital 3D model shows an excellent correlation with the sets of fractures and faults actually measured in the outcrop by classic geo-structural analysis. The results obtained from the Coroglio test suggest that the use of TLS application is an effective method for the monitoring of instability and evolution of coastal cliffs in volcanic settings.

The paper deals with the assessment of rockfall risk to persons travelling in vehicles along the SS163 road, an important transportation corridor supporting a high vehicle traffic within the well-known tourist area of the Amalfi Coast (southern Italy). To this aim, the Rockfall Hazard Rating System (RHRS) and quantitative risk assessment (QRA) procedures, in this latter case for three rockfall risk scenarios, are applied. With reference to a large portion (33. 820 out of a total of 50. 365 km) of the SS163 road, the obtained QRA results highlight that, although the estimated individual risk to life satisfies the adopted tolerable risk criterion, the computed societal risk cannot be tolerated. Starting from this result, site-specific QRA analyses-carried out with reference to some road sections chosen on the basis of the RHRS results-allow the detection of the SS163 portions where the individual risk to life exceeds the tolerable risk threshold and, then, the recourse to mitigation measures could reveal necessary. In this regard, RHRS and QRA methods can be considered complementary tools in prioritizing the road sections where construction funds can be profitably spent in order to mitigate the rockfall risk with reference to both direct consequences (life loss) and indirect ones (traffic delay and diversions). © 2012 Springer Science+Business Media B.V.

In high risk, coastal, urban areas, cliff stability monitoring is an essential task for human activities. This paper presents the implementation of an integrated monitoring system at the Coroglio tuff cliff, located in the highly urbanized coastal area of Naples (Italy) on the border of the active volcanic caldera of Campi Flegrei. The system consists of standard geotechnical monitoring instruments (crackmeters and clinometers) coupled with a modern deformation monitoring technique based on Brillouin Optical Time-Domain Analysis (BOTDA) optical fiber network, integrated by a velocimetry sensor and a weather station. Remote sensing equipment like UAV digital photogrammetry (UAV-DP) and terrestrial laser scanning (TLS) have been also used for obtaining detailed multitemporal DTM of the cliff, as well as geostructural analysis and classification of the slope, supported by structural fieldwork. In the first phase of the study, we integrated the results of long-range TLS surveys with structural field mapping. The accurate and rapid detection of structural discontinuities of the rock played an important role for the understanding of the failure mechanism and the kinematic analysis of unstable blocks along the cliff. The preliminary results obtained during the first two year of monitoring activity (2014-2015) are presented. Micro-deformation of rocks measured by geotechnical sensors reveals a general sinusoidal trend, possibly linked to the bulk volume variation of the rocks, as a response to seasonal and daily temperature variations. This research provides a contribute to the understanding of the rates of geomorphic evolution of coastal tuff cliff and its relation with forcing factors (e.g. meteo-marine weathering, human actions, volcano-tectonic activity) in the perspective of early-warning actions and policies.