In order to assess the geodiversity of the Italian Peninsula, which covers approximately 300.000 km
2
, a semi-quantitative method based on the use of grids recording several indicators and indices ...was developed. The variety of geological, geomorphological, and pedological elements, characterizing the Italian territory, has been assessed with a two-step procedure. Firstly, the variety algorithm has been applied using grid cells with variable size, related to the spatial resolution of the input data, then the resulting variety values were averaged with a fixed cell size functional to the extent of the study area and the output scale of the geodiversity map. This procedure made it possible to preserve the spatial resolution of the input data (Digital Terrain Model, lithological and soil maps) providing as output a geodiversity map that faithfully reproduces the features of the Italian territory. In case of discrete data (rivers, lakes, glaciers, etc.), a procedure that assigns to each cell the maximum area or length values out of all its elements has been implemented. It made possible to preserve the hydrological elements that shape the landscape (e.g., the longest rivers, largest lakes, etc.) and represent important freshwater resource. An overview of the geographical distribution of geodiversity classes over the whole Italian territory has been elaborated. The resulting geodiversity map is a valuable tool for environmental planning, in particular for the identification of areas to be preserved, for the proper management of geo-resources and natural services.
In coastal alluvial plains, the variability of sedimentary inputs, tectonic and eustatism causes a complex subsurface geology which influences the position of fresh/saltwater interface. Furthermore, ...in these areas densely populated, the over-pumping of freshwater, coupled with the climate change events, promotes the landward migration of freshwater/saltwater boundary. This research illustrates the ability of geophysical tools to recognize the presence of salt/brackish water at Volturno Coastal Plain, Southern Italy. This area is characterized by a peculiar geological setting, due to the proximity at Somma–Vesuvio and Campi Flegrei volcanic areas, which profoundly influences the circulation of groundwater. The subsurface is mainly characterized by: (i) two denser layers located at − 10 m and − 20 m depth which in part prevents the vertical migration of groundwater, (ii) facies heteropy that facilitates the hydraulic connection between the different geological bodies, (iii) a discontinuous
Campanian Ignimbrite
deposits which favor the hydraulic connection between deeper and shallower aquifers. In this geological framework, 2D-ERT and 3D-ERT integrated with Downhole, Multichannel Analysis of Surface Waves and boreholes made possible to recognize the presence of two main zones with salt and brackish waters, respectively. The first zone, characterized by very low resistivity (≤ 1 Ωm) typical of salt water, stretches 1.5 km inland from the coast. The second zone, with a resistivity between 2 and 5 Ωm typical of brackish water, continues for other 3 km inland. This knowledge is useful for the engagement of all stakeholders (farmers, ranchers and policy makers) in the sustainable use of fresh water and for making water management plan operational tools.
The possible emplacement of pyroclastic fall and flow products from Campi Flegrei and Somma-Vesuvio represents a threat for the population living in Napoli city. For this area, the volcanic hazard ...was always partially investigated to define the hazard related to the Campi Flegrei or to the Somma-Vesuvio activity one at a time. A new volcanic hazard and risk assessment, at the municipality scale, as a vital tool for decision-making about territorial management and future planning, is presented here. In order to assess the hazard related to the explosive activity of both sources, we integrated the results of field studies and numerical simulations, to evaluate the future possibility for Napoli to be hit by the products of an explosive eruption. This is defined for the Somma Vesuvio central volcano through the sum of "field frequency" based on the thickness and distribution of past deposits (Lirer et al., 2001), and for the Campi Flegrei volcanic field by suitably processing simulated events based on numerical modelling (Alberico et al., 2002; Costa et al., 2009). Aiming at volcanic risk assessment, the hazard areas were joined with the exposure map, considered for our purposes as the economical value of artefacts exposed to hazard. We defined four risk classes, and argued that the medium and low-very low risk classes have the largest extent in Napoli municipality, whereas only few zones located in the eastern part of the city and in the westernmost coastal area show a high risk, owing to the correspondence of high economical value and high hazard.
Catastrophic tsunami events like those occurred in Papua New Guinea in 1998, Sumatra in 2004 and Japan in 2011, attracted the attention of the scientific community and promoted the development of ...different tools for assessing tsunami hazard. A preliminary step towards this goal is the knowledge of the events which might affect a specific coastal zone. In this context, we propose a method to identify the tsunami events possibly occurring in areas characterized by scarce data and a non-conservative environment. Accordingly, we propose different indices to summarize the knowledge on tsunami triggering mechanisms (earthquakes, landslides, volcanic eruptions), the characteristics of those mechanisms (magnitude of earthquakes, volume of landslide, Volcanic Explosivity Index) and tsunami features (water height, run-up, wave amplitude, propagation time). This knowledge, considered over a wider area than that of interest, allows for a paramount vision of possible hazardous events that could affect a particular coastal zone. Moreover, the tsunami simulation data and the analysis of potentially tsunamigenic slides which occurred on the Campania continental margins were also considered in the analysis. We focused our attention on Napoli megacity, because the high population density (about 1 million of people live on a territory of 117 km
2
), together with the presence of active volcanic areas (Ischia, Somma-Vesuvio and Campi Flegrei), make this city potentially exposed to tsunami risk. The main outcome of such an approach shows that in the near field a tsunami amplitude varying from a few centimetres (30–40 cm) to some metres (1–4 m) might be expected at the coastline if the tsunami event was triggered by volcanic activity, whereas no relevant tsunami event should be expected given the peculiar seismicity of the Neapolitan volcanic areas, with earthquakes rarely exceeding 4 Mw, if any possible cascade effects are overlooked. A morphometric analysis of high-resolution bathymetry collected between Ventotene Island and the Gulf of Salerno has shown that the submarine southern sectors of the Ischia Island and the Sorrento Peninsula are characterized by a high density of landslide scars, being thus a potential source area of landslide-generated tsunamis. However, despite the susceptibility of these areas to recurrent slope failures, only four submarine landslide scars were found to be potentially tsunamigenic with estimated tsunami amplitude of few metres at the coastline as predicted by coupling slide morphometry with tsunami amplitude equations. Concerning the tsunamis generated by earthquakes in the Western Mediterranean, only those triggered by high magnitude events (value ≥ 6–7 Mw) might affect the city of Napoli with an amplitude not exceeding 0.5 m, in about 30′.
The amount of coastal subsidence on the Sele River coastal plain has been examined and measured with local vertical land movement data. The vertical displacements, derived by satellite radar ...differential interferometry processing (Ps‐InSAR), show that the analysed coastal sector is characterised by a south‐eastward decrease of vertical subsidence rates. These results have been coupled with sea‐level rise (SLR) scenarios, in order to identify the most critical areas. In general, the subsidence mostly affects areas where alluvial deposits are thicker, the back‐dune areas and the Sele River mouth, all late Holocene in age. Five local SLR scenarios allow identifying zones in the plain potentially prone to inundation and the shoreline retreat for the years 2065 and 2100. For these dates, 2.2% and 7.06% of the investigated area will have a topography lower than the estimated future sea level. Moreover, results show that the extent of the areas potentially exposed to inundation and erosion increases moving from south to north.
The analysis of 90 surficial sediments from three docks of the Naples Harbour (
Levante,
Granili, and
Diaz) permits to compare the distribution modes of heavy metals with grain sizes, total organic ...carbon content (TOC) and distribution patterns of benthic foraminifera. Foraminiferal density and species richness decrease with the increasing toxic elements concentrations from the
Levante to the
Diaz dock. Median concentrations of Ni, Pb, Zn, and Hg (medians of 21.43
mg/kg, 270.24
mg/kg, 489.65
mg/kg, and 1.18
mg/kg, respectively) were reported for the
Diaz dock where foraminifera are absent, thus suggesting a possible impact of toxic elements on the benthic ecosystem balance. Compared to the unpolluted marine sediments of the
Granili dock, the
Levante area shows higher heavy metals levels and a quasi-oligotypic benthic assemblage. This is dominated by the tolerant species
Ammonia tepida that may be used as bio-indicator of pollution of anthropised marine sediments.
Benthic foraminiferal density and species distribution may be used as pollution indicators.
Anthropic pressure has caused severe variations of Mediterranean coastal areas currently hosting about 480 million people. The replacement of natural land covers with crops and urban environment ...coupled with the reduction of sediment supply to the coast, subsidence, Relative Sea Level Rise and the high frequency of storm events, have caused severe shoreline erosion. In this paper, we stress the key role of historical maps, topographic maps and free satellite images to forecast the rates of coastline changes and to recognize the main features of past landscapes as tools for risk reduction. This data was recorded into a Geographical Information System dedicated to coastal management that allows to compare different coastal zones and elaborate maps. The analysis was applied to the case study of Volturno Coastal Plain (VCP), extending from the town of Mondragone to Patria Lake (Campania Region, Southern Italy). Indeed, the intense territorial modification that occurred between the seventies and eighties, coupled with the exposure to coastal erosion, make the VCP a good test area. The spatial analysis algorithms allowed to outline the main features of past landscapes and how they changed from roman times to present while the coastal evolution (erosion, accretion) and possible future coastal trend was assessed with the Digital Shoreline Analysis System (DSAS) software. Starting from the Bourbon domain, the reclamation caused the first great territorial change (e.g. wetlands were transformed into agricultural lands, regimentation of surperficial water) but the negative effects of antrophic pressure, as the intense urbanization of the coastal belt, emerged in the seventies of the last century. The shoreline position was defined for 9 time intervals (from 1817 to 2012) as the ratio of the distance between two shorelines and the relative elapsed time. Moreover, for the 1957–1998 and 1998-2012 time windows, the shoreline trends were calculated with the weighted linear regression method. The first trend pointed out an intensive erosional phase (mean value: 5 m/yr) for a wide sector close to the Volturno River mouth, the eroded sediment nourished the beaches of other coastal sectors. This phase was related to the reduction of River sediment supply mainly due to the construction of the Ponte Annibale dam on the Volturno River. The second (1998-2012) showed an alternation of erosion and accretion sectors due to a sediment starved condition to deltaic zone and to a sequence of 52 sea protection works in the Gaeta Gulf. Furthermore, the regression values of more recent time interval, was assumed as a scenario to draw the probable shoreline position in 2022. The overlay of this shoreline on the Technical Maps of Campania Region at 1:5000 scale highlighted the urban area that could be exposed to damages.
In order to zone the territory of Campania Region (southern Italy) with regard to the hazard related to future explosive activity of Somma-Vesuvio, Campi Flegrei, and Ischia Island, we drew a ...multi-source hazard map for tephra and pyroclastic flows. This map, which merges the areas possibly endangered by the three volcanic sources, takes into account a large set of tephra fall and pyroclastic flow events that have occurred in the last 10 ka. In detail, for fall products at Campi Flegrei and Somma-Vesuvio we used the dispersal of past eruption products as deduced by field surveys and their recurrence over the whole area. For pyroclastic flows, the field data were integrated with VEI = 4 simulated events; about 100 simulations sourcing from different points of the area were performed, considering the different probability of vent opening. The spatial recurrence of products of both past eruptions and simulated events was used to assign a weight to the area endangered by the single volcanic sources. The sum of these weights in the areas exposed to the activity of two sources and/or to different kinds of products was used to draw a hazard map, which highlights the spatial trend and the extent of the single equivalent classes at a regional scale. A multi-source risk map was developed for the same areas as the graphic result of the product of volcanic hazard and exposure, assessed in detail from a dasymetric map. The resulting multi-source hazard and risk maps are essential tools for communication among scientists, local authorities, and the public, and may prove highly practical for long-term regional-scale mitigation planning.
We present the distribution pattern of living and surface sediment coccolithophores, the main phytoplankton calcifying group, from 22 stations set in a neritic environment (from 10 to 50m water ...depth), adjacent to the shelf area of the Volturno River mouth (Gulf of Gaeta — central part of the Tyrrhenian Sea). The survey conducted in June 2012 included five transects perpendicular to the coast, which enabled us to provide indications on the structure of calcareous phytoplankton associations in relation to coastal dynamics and the Volturno River runoff. The total number of coccospheres ranged from 15 to 64∗103∗l−1 coccolithophores. Emiliania huxleyi dominates the assemblages, followed by Rhabdosphaera xiphos, holococcolithophores and Syracosphaera pulchra. The coccolithophore community shows a typical vertical zonation, with K-strategist taxa in the upper 15m and the deep community developed down to 40m. The local water circulation significantly affects the spatial and vertical distribution of coccolithophores. The river discharge influences the distribution of coccolithophore taxa, resulting in a north–south gradient. In the northern sector, outside the influence of the Volturno River, the high values of R. xiphos suggest a negative correlation with river runoff.
The surface sediment assemblages reflect the overall composition of the living coccolithophore communities. The distribution of abundant reworked species, both in water and sediment, provides useful information about coastal dynamics and sediment transport in the study area.
•Living coccolithophores and sediment coccoliths of central Tyrrhenian Sea coast.•Placolith -bearing taxa dominate the living and sediment assemblages.•Sampling season and river discharge influence community diversity and distribution.•Rhabdosphaera xiphos is not associated with the Volturno river runoff.•Reworked coccoliths highlight the direction of the Volturno river runoff.
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