Land subsidence is a concern in many coastal plains worldwide, particularly in the low-lying areas already facing sea level rise due to climate change, and much still needs to be done, with respect ...to both mapping land subsidence and gaining a comprehensive understanding of the relevant cause-effect relationships. Land subsidence of the northern coastal plain encompassing the Friuli Venezia Giulia (FVG) region in Italy, remains, to the authors' knowledge, poorly investigated. This coastland includes low-lying agricultural and urban areas and highly valuable lagoon environments, archaeological and touristic sites, and industrial zones.
Here, we resolve land subsidence in the coastal plain between the Tagliamento River delta and the Isonzo River mouth over the period 1992–2010 using Envisat ASAR and ERS1/2 interferometric datasets. We identify a large variability of the land subsidence and a spatial gradient that ranges from less than 1mm/year in the high southwestern plain toward the littoral to more than 5mm/year close to the Tagliamento River delta. A comparison between the 2003–2010 and 1992–2000 sinking rates depicts quite similar behaviors of the process over the two time spans. The analysis indicates unclear correlations between ground movements and the typical driving mechanisms acting in the north Adriatic coastal plains, such as the variability of the morphological setting, the subsoil characteristics and the land use. We reason that multi-component mechanisms contribute to the observed image of the subsidence in the FVG coastland. Specifically, anthropogenic activities, e.g., groundwater exploitations, hydraulic reclamations and the development of newly built-up areas, are superposed to natural mechanisms related to the spatial variability of the subsoil characteristics, typical of transitional coastal environments.
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•The coastland subsides from 1 to 5 mm/yr and locally more than 10 mm/yr.•Land subsidence regional trend mainly depends on the geologic characteristics.•Cumulative 1992-2010 land subsidence exceeds 110 mm.•Uneven human-induced coastal subsidence is revealed at local scale.•Newly built-up areas subside more than older urbanization.
Groundwater resources in the Friuli Venezia Giulia (FVG) Region (northeast Italy) are an important natural wealth in terms of quantity, quality and ease of supply. This optimal condition, however, ...has long believed that it allowed an irrational and uncontrolled exploitation that inevitably produced tangible consequences on the water resources availability.The goal of the present research is the evaluation of the sustainable use of the groundwater in the Friuli Venezia Giulia Region aimed at providing guide-lines for its rational use. The study area belongs to the hydrogeological basin of the Friuli Plain and includes part of Veneto Region and Slovenia. The plain area is divided in two parts: the High Plain (HP) characterized by a phreatic aquifer and the Low Plain (LP) where eleven confined aquifer systems were identified. The two physiographic zones are separated by the spring belt. In order to evaluate the groundwater avaliability, a 3D model of the Low Friuli Plain aquifer systems was realized using Rockworks R14 software, starting from 603 lithostratigraphic wells data. Isobath and isopach maps were elaborated using kriging geostatistical method. Precipitation, evapotranspiration, runoff and infiltration were calculated to evaluate the inflow and outflow groundwater budget terms (109 rainfall and 46 thermometric stations, time series 1979-2008). To better define the river influences and the outflows at sea, a series of recent surveys on river discharges and surface withdrawals were considered. To obtain the water-budget in non-natural conditions, as the currents, were taken into account the groundwater withdrawals that were evaluated for each type of use and for each aquifer systems, starting from 2 geodatabases: one for the domestic uses (50101 estimated wells) and one for the industrial, agricultural, fish breeding, hygienic, geothermal and other minor uses (7594 wells). Well withdrawals amount were evaluated on annual base for recent periods and expressed as m3/s. The total current estimated groundwater withdrawals reach 62.4 m3/s, of which 41.1 m3/s from the confined aquifer systems in the LP area. More than 52% of the withdrawals are due to the domestic wells. For the water-budget, the studied territory was considered a “semi-closed box” in which groundwater sharings with the neighboring areas are not relevant and where the recharge is mainly due to the influent character of the river, infiltration, rainfall and irrigation practices. As result, the waterbudget for the confined LP is equal to +2.6 m3/s representing the accuracy, fairly acceptable for the scale of the research. Withdrawal entity, spring belt discharge, phreatic levels and confined aquifer’s pressure are closely interdependent and in dynamic equilibrium. The sustainability comes from the consistency and ratio between recharge and withdrawals. The confined aquifer withdrawals in the LP represent the 23.1% of the groundwater recharge coming from the HP and the 30.6% of the spring belt discharge. Seen that this last one can not further decrease, unless loss of important ecosystems, is likely to think that the present situation can be defined of limit equilibrium.
•Comparative analysis of several spatially distributed flow approximations.•Coupling of flow approximations with a flash flood simulation.•Analysis of the influence of spatial resolution on the ...behavior of spatial flow approximations.•Validation of the developed model with a flash flood event in the Fella Basin.
Within hydrological models, flow approximations are commonly used to reduce computation time. The validity of these approximations is strongly determined by flow height, flow velocity and the spatial resolution of the model. In this presentation, the validity and performance of the kinematic, diffusive and dynamic flow approximations are investigated for use in a catchment-based flood model. Particularly, the validity during flood events and for varying spatial resolutions is investigated. The OpenLISEM hydrological model is extended to implement both these flow approximations and channel flooding based on dynamic flow. The flow approximations are used to recreate measured discharge in three catchments, among which is the hydrograph of the 2003 flood event in the Fella river basin. Furthermore, spatial resolutions are varied for the flood simulation in order to investigate the influence of spatial resolution on these flow approximations. Results show that the kinematic, diffusive and dynamic flow approximation provide least to highest accuracy, respectively, in recreating measured discharge. Kinematic flow, which is commonly used in hydrological modelling, substantially over-estimates hydrological connectivity in the simulations with a spatial resolution of below 30 m. Since spatial resolutions of models have strongly increased over the past decades, usage of routed kinematic flow should be reconsidered. The combination of diffusive or dynamic overland flow and dynamic channel flooding provides high accuracy in recreating the 2003 Fella river flood event. Finally, in the case of flood events, spatial modelling of kinematic flow substantially over-estimates hydrological connectivity and flow concentration since pressure forces are removed, leading to significant errors.
•We develop a 3D material point method based on finite strain elastoplasticity.•The parameters possess a strong physical meaning, allowing a priori calibration.•We reproduce four full-scale, well ...documented, historical cascading events.•Complex processes naturally emerge from the simulations, granting accurate results.
Alpine mass movements can generate process cascades involving different materials including rock, ice, snow, and water. Numerical modelling is an essential tool for the quantification of natural hazards. Yet, state-of-the-art operational models are based on parameter back-calculation and thus reach their limits when facing unprecedented or complex events. Here, we advance our predictive capabilities for mass movements and process cascades on the basis of a three-dimensional numerical model, coupling fundamental conservation laws to finite strain elastoplasticity. In this framework, model parameters have a true physical meaning and can be evaluated from material testing, thus conferring to the model a strong predictive nature. Through its hybrid Eulerian–Lagrangian character, our approach naturally reproduces fractures and collisions, erosion/deposition phenomena, and multi-phase interactions, which finally grant accurate simulations of complex dynamics. Four benchmark simulations demonstrate the physical detail of the model and its applicability to real-world full-scale events, including various materials and ranging through five orders of magnitude in volume. In the future, our model can support risk-management strategies through predictions of the impact of potentially catastrophic cascading mass movements at vulnerable sites.
The foreland basin of the southern European Alps is characterized by large fan-shaped alluvial systems fed by the main montane valleys and these depositional systems present an extent of 300–3000km2, ...with a length of 30–70km. Most of them are megafans, characterized by evident longitudinal differentiation in which steep piedmont sector consists of amalgamated gravels, while the distal portion has a gradient <2‰ and is dominated by fine sediments. The major depositional phase occurred between 26 and 19kyrcalBP during the Last Glacial Maximum (LGM) marine lowstand, when the Alpine glaciers reached the plain and fed the related fluvioglacial systems. The easternmost megafans also partly extended on the Adriatic shelf whereas, west from Garda Lake, their downstream development was limited by the Po River plain. The thickness of LGM alluvial sedimentation ranges between 30 and 15m and pinches out about 25km off the present coast. Soon after ice decay, after 19–17kyrcalBP, sediment delivery from Alpine catchments to the plain dramatically decreased and in the central Alps large intramontane lakes formed, trapping almost all the bedload. Thus, the ratio between sediment and water discharge dramatically decreased and an erosive phase affected the LGM megafans and fans, leading the rivers to entrench for tens of meters. The funneling effect created by the fluvial incisions allowed the gravels to arrive tens of kilometers further downstream than in the LGM. In the Venetian–Friulian megafans a single valley formed in the piedmont sector, while 2–5 incised valleys developed in the distal sector. These latter valleys have been almost completely filled by a depositional lobe formed in the last 8kyr, partly triggered by Holocene sea-level rise. The Alpine tributaries of the river Po still flow along a single incised valley from their megafan apex to the junction with the Po and they have not yet been affected by sea-level influence.
In recent years, global e-commerce has grown exponentially due to the evolution of markets and companies’ selling strategies. Moreover, COVID-19 has accelerated this trend, increasing the demand for ...new logistic hubs, responding to the growing request for the online buying/selling of goods/ or services, while generating a remarkable land take process. The national database on LULC and municipal land use plans do not detect logistics, thus limiting the adoption of strategies and policies for contrasting the associated phenomenon of land taken. Photo-interpretation and manual validation techniques, in combination with ancillary geodata, could fill the gap through an in depth classification of selected land use categories for mapping logistic hubs in a simple, accessible and economic way. The method was tested in two northern Italian regions (Lombardy and Friuli-Venezia-Giulia). Results display radical differences between the two con-texts, emphasising the heterogeneous impacts generated by logistics on the landscape. Lombardy has a significant concentration of new hubs located in the municipalities surrounding the Milan metropolitan area, whereas, in Friuli-Venezia-Giulia, this type of land take is only a marginal problem when compared to other land use change. Findings confirm the need to define tailor-made land classification methodologies that support the definition of site-specific land take management policies.
In the last few years several studies have reassessed the attraction and the role of small game in the subsistence economy of hunter-gatherers across Europe and the Mediterranean region since the ...Middle Paleolithic. The exploitation of small mammals intensified during the Pleistocene-Holocene transition, when some unusual faunal assemblages were recorded in the Alpine arch and the Prealpine belt. In this region marmot became a relevant resource during the Late Glacial, albeit the relative foraging systems were mostly focused on the exploitation of medium and large size herbivores. In this report we present zooarchaeological data from Grotte di Pradis (northeastern Italy) which displays a faunal assemblage composed of at least 637 marmot individuals, representing about the 99% of the total remains. Taphonomic evidence suggests a standardized processing of marmot carcasses finalized to the deferred consumption and utilization of different resources. The intensive exploitation together with the acquisition through repetitive hunting events and the ecological and ethological factors proper of this animal, substantially affected its definition of prey type and its ranking in terms of energy return balance. Hence, in this particular context marmot might be regarded as a high-ranked resource, seasonally exploited within a well-established logistical mobility system which reflects a repetitive regional phenomenon peculiar of the alpine area throughout the Late Glacial.
•Pradis represents a specialized hunting camp for the exploitation of alpine marmot.•Bone surfaces show an intensive and standardized treatment of marmot carcasses.•Meat and grease were stored and transported away for a deferred consumption.•Hunting was planned to carry out a sort of resource management over the time.•At Pradis several factors “upgrade” this small game as a high-ranked prey type.
SUMMARY
Strong ground motion prediction is a fundamental topic in the field of engineering seismology, as it provides the input for seismic hazard studies as well as for vulnerability and risk ...assessment. The spectral modelling approach can provide a realistic representation of ground motion behaviour, possibly including its frequency variability, as the full ground motion spectrum is modelled analytically. In its parametric form, this approach requires a careful calibration of the model, starting from empirical observations and fitting the source, path and the site-specific response assuming a predefined physically constrained functional form. This study explores the use of spectral modelling for a study area in northeast Italy, at the border with Slovenia and Austria. It is based on the parametrization of seismic source and attenuation effects, and it also allows to estimate site effects, as a by-product. The main innovation with respect to standard spectral modelling is the inclusion of dedicated uncertainty estimators in the functional form. Parametric inversion of source and path attenuation is performed on a data set corresponding to 23 events recorded by 24 stations located within the target area. The modular inversion setup allows to properly include a priori constraints in the mathematical solution to reduce trade-off between variables. Spectral amplification at each site is defined with respect to the network average rock condition, and its frequency-dependent component is estimated from residual analysis after the inversion. Inverted source parameters are comparable with reference values for the region available from literature (with seismic moments between ${10}^{13}$ and ${10}^{15}$ N·m, and related stress drop values in the range $1.5 - 15.5\ {\rm{MPa}}$); the same is also true for average attenuation properties (e.g. apparent frequency-independent attenuation quality factor ${Q}_0$ of $1145$). For a selection of stations with available characterization based on different methods, a preliminary comparison of site-specific response functions shows that both the frequency value and amplitude of the main amplification peaks are well recovered. These encouraging results open to the possibility of subsequently using the calibrated model for forward modelling purposes.
•Analysis of the response of an Alpine catchment to rainfall and snowmelt events.•The selection of pre-event sample can affect hydrograph separation results.•Event water contribution to streamflow is ...higher during large/intense rain events and late snowmelt events.•Distinct runoff generation processes during dry and wet conditions.
Alpine catchments are important sources of fresh water but compared to lower altitude catchments our understanding of the hydrological functioning of these catchments during rainfall and snowmelt events is still limited. The objectives of this study were i) to identify the dominant runoff generation mechanisms in the 0.14-km2 Bridge Creek Catchment in the Italian Dolomites during nine rainfall–runoff events and six snowmelt–runoff events in spring, summer and autumn of 2010–2012; and ii) to assess the effect of the selection of the pre-event water sample on the isotope hydrograph separation results. The isotopic composition of the pre-event water was determined by either a stream water sample taken prior to the event or the average of 19 stream water samples taken during baseflow conditions. The hydrograph separation results for the two methods were very similar for the rainfall events but differed for the snowmelt events. Average event water contributions ranged between 4% and 19% or 2% and 20% of the total runoff during rainfall events, and between 7% and 25% or 9% and 38% during snowmelt events, depending on the method used to determine the isotopic composition of pre-event water. Event water contributions were important during large rainfall events, intense rainfall events and late in the snowmelt season, with maximum event water contributions up to 37% and 46%, depending on the method used for determining the pre-event water composition. The electrical conductivity of stream water tended to first decrease and reach a minimum before peak streamflow and then to increase above pre-event values. The results of this study suggest that during dry conditions, direct channel precipitation and overland flow from the permanently saturated part of the riparian zone dominated the runoff response, with limited contributions of riparian or hillslope groundwater. During wet or very wet conditions (large rainfall events or peak snowmelt), saturation overland flow increased due to the expansion of the saturated areas and riparian groundwater and hillslope subsurface flow to streamflow increased as well. On the one hand, this work contributes to a better understanding of runoff generation processes in mountain headwater catchments where rainfall and snowmelt events dominate the hydrological response. On the other hand, this study highlights the sensitivity of the two-component hydrograph separation technique to the selection of the pre-event water sample for snowmelt events. This calls for further studies in snow-dominated catchments to determine the consistency of the isotopic composition of stream water prior to individual snowmelt events and to assess whether the individual melt events during the melt season should be considered part of a single long snowmelt event.