Po River Research Articles

Drought‐Induced Vertical Displacements and Water Loss in the Po River Basin (Northern Italy) From GNSS Measurements

AbstractWe study vertical ground displacement time series from Global Navigation Satellite System (GNSS) stations to measure deformation associated with hydrological drought in the Po river basin. Focusing on interannual trend changes, rather than seasonal (annual) components, we found a clear spatially correlated deformation signal that is temporally (anti)correlated with changes in the Po river level and the SPEI‐12 drought index, with stations moving upward during periods of river/index level decrease and vice versa. In the 2021–2022 time span, which culminated in the most severe drought of the last two centuries, we estimate the amount and spatial distribution of water loss in the basin and its surroundings. Excluding the seasonal signals, between January 2021 and August 2022, the GNSS stations underwent uplift, up to 7 mm, which corresponds to ∼70 Gtons of water loss. Compared to Global Land Data Assimilation System and Gravity Recovery and Climate Experiment estimates, GNSS results show a similar temporal evolution of water content but a more heterogeneous distribution of values. We show that continuous GNSS networks provide an effective way to monitor multiannual trend changes in water storage even in small water basins and serve as a reliable indicator of drought severity.

Myth and reality in the work of Italian neorealists

The object of research is Italian neorealism of the 1940-1950s. The subject of research is the work of neorealist directors Roberto Rossellini, Cesare Zavattini, Giuseppe de Santis, Vittorio de Sica, Alberto Latuada. Features of neorealism are also inherent in the early work of directors Luchino Visconti («Obsession» 1943, «Earth Trembles» 1948), Federico Fellini («The Road» 1954, «Nights of Cabiria» 1957), Piero Paolo Pasolini («Accatone» 1961, «Mama Roma» 1962), Michelangelo Antonioni «People from the Po River» 1947). Neorealism develops under the influence of French poetic realism, as well as, under the influence of verism, especially, the work of L. Pirandello. The focus of the neorealists was a person in interaction with society, the environment. The purpose of this study is to consider the features of realism and neorealism, to consider the space created by directors. This study uses various research methods - phenomenological, intertextual, comparative, hermeneutic, content analysis in their combination and complementarity. The scientific novelty of this study lies in the opposition of mythological and real space in the films of Italian directors, as well as in the application of an integrated approach. The main conclusion of this study is the thesis that myth and reality in the work of Italian neorealists interact with each other. Despite the documentary approach to filming, neorealists create their own, special reality, turn to history and myth. The concept of "neorealism" is quite complex, many of its representatives called themselves realists. The focus of neorealism becomes a person in interaction with society, with the environment. As the principles of neorealism, one can single out chorality, that is, the interaction of people. A separate feature of neorealism is the appeal to fantasy. F. Fellini and M. Antonioni open a new chapter in the history of Italian cinema.

Remote sensing assessment of anthropogenic and climate variation effects on river channel morphology and vegetation: Impact of dry periods on a European piedmont river

AbstractRivers are subject to increasing human pressure, resulting in a loss of their natural characteristics, further enhanced by climate change. The present study focuses on a piedmont reach of the Italian Po River and combines Landsat satellite information with hydrological records to investigate changes in sandbars exposure and riparian vegetation coverage, considering the summer period of 1984–2022. Satellite data were handled via Google Earth Engine, looking at common indexes such as the Modified Normalized Difference Water Index, which was used to identify temporal variations in wetted channel area, and the Normalized Difference Vegetation Index, considered as a proxy of vegetation coverage variations. Changes in the river hydrology were analysed by looking at the annual minimum water levels, the discharge duration curve, the stage–discharge relationship and the yearly annual water volume. Results suggest that a process of oversimplification is affecting this reach of the Po River, showing how climate change can affect piedmont European watercourses. Indeed, after an initial period where bars tended to be barer and somehow stable over time, in the most recent decade a different trend appeared, with vegetation able to colonize the exposed sandbars more. Using the Po River as an exemplary case study, this work suggests that prolonged dry periods, which are more common in recent decades, might impact large and medium rivers located in temperate climates, favouring the development of vegetation on exposed sandbars, eventually resulting in a less dynamic active channel.

Pediatric Lyme Disease in Northern Italy: An 18-Year Single-Center Case Series.

Tracing the profile of pediatric Lyme borreliosis (LB) in Europe is difficult due to the interregional variation in its incidence and lack in notifications. Moreover, the identification of LB can be challenging. This study is an 18-year case series of 130 children and adolescents aged under 18 years referred to the Pediatric Infectious Diseases Unit at L. Sacco Hospital, Milan, with suspicion of LB, between January 2005 and July 2023. The routine serological workup consisted of a two-step process: an initial screening test followed by Western blot (WB). Forty-four (34%) patients were diagnosed with LB. The median age was six years, and 45% were females. Of the children with erythema migrans (EM), 33 (57%) were confirmed as having true EM, and, of these, 4 (12%) were atypical. Ten (23%) patients had early disseminated/late diseases, including facial nerve palsy (n = 3), early neuroborreliosis (n = 1), arthritis (n = 3), relapsing fever (n = 2), and borrelial lymphocytoma (n = 1). No asymptomatic infections were documented. Over seventy percent of confirmed LB cases (n = 31/44) recalled a history of tick bites; in this latter group, 19 (61%) were from the area of the Po River valley in Lombardy. Almost half of the children evaluated for LB complained of non-specific symptoms (fatigue, musculoskeletal pain, skin lesions/rash, and persistent headache), but these symptoms were observed in only two patients with confirmed LB. Most LB cases in our study were associated with EM; two-tier testing specificity was high, but we found frequent non-adherence to international recommendations with regard to the timing of serology, application of the two-step algorithm, and antibiotic over-prescription. Most children were initially assessed for a tick bite or a skin lesion suggestive of EM by a family pediatrician, highlighting the importance of improving awareness and knowledge around LB management at the primary healthcare level. Finally, the strengthening of LB surveillance at the national and European levels is necessary.

Anthropogenic vs. natural habitats: Higher microbial biodiversity pays the trade-off of lower connectivity

Climate change and anthropogenic disturbances are known to influence soil biodiversity. The objectives of this study were to compare the community composition, species coexistence patterns, and ecological assembly processes of soil microbial communities in a paired setting featuring a natural and an anthropogenic ecosystem facing each other at identical climatic, pedological, and vegetational conditions. A transect gradient from forest to seashore allowed for sampling across different habitats within both sites. The field survey was carried out at two adjacent strips of land within the Po River delta lagoon system (Veneto, Italy) one of which is protected within a natural preserve and the other has been converted for decades into a tourist resort. The anthropogenic pressure interestingly led to an increase in the α-diversity of soil microbes but was accompanied by a reduction in β-diversity. The community assembly mechanisms of microbial communities differentiate in natural and anthropic ecosystems: for bacteria, in natural ecosystems deterministic variables and homogeneous selection play a main role (51.92%), while stochastic dispersal limitation (52.15%) is critical in anthropized ecosystems; for fungi, stochastic dispersal limitation increases from 38.1% to 66.09% passing from natural to anthropized ecosystems. We are on calcareous sandy soils and in more natural ecosystems a variation of topsoil pH favors the deterministic selection of bacterial communities, while a divergence of K availability favors stochastic selection. In more anthropized ecosystems, the deterministic variable selection is influenced by the values of SOC. Microbial networks in the natural system exhibited higher numbers of nodes and network edges, as well as higher averages of path length, weighted degree, clustering coefficient, and density than its equivalent sites in the more anthropically impacted environment. The latter on the other hand presented a stronger modularity. Although the influence of stochastic processes increases in anthropized habitats, niche-based selection also proves to impose constraints on communities. Overall, the functionality of the relationships between groups of microorganisms co-existing in communities appeared more relevant to the concept of functional biodiversity in comparison to the plain number of their different taxa. Fewer but functionally more organized lineages displayed traits underscoring a better use of the resources than higher absolute numbers of taxa when those are not equally interconnected in their habitat exploitation. However, considering that network complexity can have important implications for microbial stability and ecosystem multifunctionality, the extinction of complex ecological interactions in anthropogenic habitats may impair important ecosystem services that soils provide us.

Lead isotopes of prehistoric copper tools define metallurgical phases in Late Neolithic and Eneolithic Italy.

The diffuse presence of small copper ore deposits in the Alpine area, mostly exploited since Late Medieval times, led most scholars to assume that these deposits may actually be active much earlier and that many of the circulating prehistoric metal objects found in the area were produced with local copper sources. This assumption was recently validated for the Recent Bronze Age through the use of lead isotope tracers, and well supported by the archaeometallurgical evidences found in the South-Eastern Alps. However, the scarcity of available lead isotope data for pre-Bronze Age metals precluded to date the reconstruction of the metal flow through the Late Neolithic and Eneolithic (or Copper Age). Based on 49 new analyses of important archaeological objects from the Alpine region, the Po River Valley and Central Italy, mostly axes dated from the Late Neolithic to the Late Eneolithic, here we show that the diffusion of copper in Northern Italy (approximately 4500-2200 BC) includes three major periods of metal use and/or production, each related to specific ore sources. The South Alpine copper was massively used only starting from the middle of the 3rd millennium BC, in connection or slightly earlier than the Beaker event.

Removal of clozapine from polluted waters via C₃N₄ based materials

New photocatalysts with a g-C₃N₄-ZnO heterojunction were prepared following different synthetic routes, fully characterized, and evaluated for the abatement of the antipsychotic drug clozapine. Experiments were performed with clozapine standard and clozapine based commercial tablet solutions in a sun simulator and the evaluation of clozapine removal was assessed in different aqueous media: Milli-Q and natural water (Po River) to evaluate the role of natural occurring components on the drug removal efficiency. The photocatalyst prepared via hydrothermal method (CA_1) exhibited the highest efficiency, allowing to achieve the complete abatement of clozapine within 30 min, in Milli-Q water. Its photocatalytic performance decreased in river water, where the total drug degradation was obtained after1h, and is notably inhibited on Leponex tablets (80% removal after 1 h of irradiation). Clozapine degradation proceeds through the formation of nineteen (19) transformation products, all less hazardous that the parent compound, as proved by the acute and chronic toxicity valued by ECOSAR. Mechanistic studies evidenced that OH⦁ radicals are the key reactive species involved in the pollutant removal, while other species such as superoxide radical anion (O₂•⁻) and especially singlet oxygen (O₂¹) played a marginal role in the degradation process.

Development of a qPCR Duplex Assay for simultaneous detection of Fascioloides magna and Galba truncatula in eDNA samples: Monitoring beyond boundaries

Parasites constitute a significant economic burden and highly impact environmental, public, and animal health. The emergence of many parasitic diseases is environmentally mediated and they share the same biogeography with humans and both domestic and wild animals. American liver fluke, Fascioloides magna – a trematode parasite of domestic and wild ungulates – is an example of the anthropogenic introduction of an “invasive alien species” in Italy and Europe. Multiple introductions to Europe have led to the biogeographical expansion of the parasite across the Danube region mainly provided by the presence of suitable habitats for all hosts involved in the parasite's life cycle, human-assisted transport, and drastic environmental events such as flooding. In Italy, it was introduced and established in La Mandria Regional Park (LMRP) near Turin in 1865 along with imported wapitis (Cervus elaphus canadensis) from North America (Bassi, 1875), but with no reported expansion to the surrounding areas. LMRP isolated F. magna focus, poses an important threat of possible expansion since the enclosed area is vulnerable to occasional bidirectional passage of roe deer. Additionally, tributary rivers to the Po river system, traversing the enclosed area, could further bolster the possibility of such spread. In this study, we developed a duplex qPCR assay for F. magna and its principal intermediate host Galba truncatula optimized for testing eDNA samples to meet the needs for surveillance of the parasite. Moreover, we validated the developed assay in natura by testing samples derived from filtered water and sediments collected inside and outside LMRP's fenced-off area. Our findings for the first time demonstrate the presence of F. magna's eDNA outside the park's internal fenced-off area.

Evolution of Freshwater Runoff in the Western Adriatic Sea over the Last Century

The evaluation of the hydrography and biogeochemistry of the Adriatic Sea over the last century was summarized in this review to point out any changes in river runoff and provide an overview of the cause and effect of these trends on marine ecosystems. Although several rivers flow into the Adriatic, the most affected area is the northern Adriatic, where the Po River loads into the basin half of the total freshwater input, carrying river runoff and causing algal blooms and hypoxia phenomena. These fresh waters of the northern Adriatic flow predominantly along the entire western side, reaching the southernmost part of the basin up to the Mediterranean Sea. Here, and in the whole basin, variations in river runoff and nutrient concentration have been observed through the years. Starting from 1960 until the end of the century, an increase in nutrient discharge and phytoplankton activity was reported, with negative repercussions on local fisheries, species richness, and recreational activities within the basin. However, a recent decrease in river inflow has been observed along the coastal belt, which can trigger negative consequences for the food web of the marine ecosystem. These trends, more broadly, corroborate the vulnerability of the Adriatic Sea and stress the importance of implementing strategies for the defense of the relevant ecosystems within its confines.

Multi‐source detrital contributions in the Po alluvial basin (northern Italy) since the Middle Pleistocene. Insights into sediment accumulation in intermediate sinks

AbstractIntegrated stratigraphic‐compositional studies on alluvial successions provide a valuable tool to investigate the provenance of detritus in multi‐source systems. The Po Plain is an intermediate sink of the Po‐Adriatic source‐to‐sink system, fed by rivers draining two orogens. The Alps are characterized by extensive outcrops of plutonic‐metamorphic and ultramafic rocks to the north‐west and of Mesozoic carbonates to the east (Southern Alps). The Northern Apennines, to the south, are dominated by sedimentary successions. The Po River flows from the Western Alps to the Adriatic Sea, interacting with a dense network of transverse tributaries that drain the two orogens. Stratigraphic, sedimentological and compositional analyses of two 101 and 77.5 m‐long cores, recovered from the Central Po Plain, reveal the stacking of three petrofacies, which reflects distinct provenance and configurations of the fluvial network. A South‐Alpine sedimentary input between MIS 12 and MIS 10 is testified by petrofacies 1, characterized by carbonate‐ and volcanic‐rich detritus from rocks exposed in the Southern Alps. A northward shift of the Po River of more than 30 km is marked by a quartz‐feldspar and metamorphic‐rich detritus (petrofacies 2), similar to modern Po River sands. This dramatic reorganization of the fluvial network likely occurred around MIS 9–MIS 8 and is possibly structurally controlled. A further northward shift of the Po River and the onset of Apennine sedimentation in the Late Holocene is revealed by petrofacies 3, rich in sedimentary lithics from the Apennine successions. The results of this study document how compositional analysis, if framed in a robust stratigraphic picture, may provide clues on the evolution of multi‐source alluvial systems.

Structural Rehabilitation Work On The Viaduct Over The River Po On The A7 Motorway

The work consisted of the static and seismic retrofitting of the bridge over Po River, on northbound carriageway of highway A7, managed by Milano Serravalle Milano Tangenziali S.p.A. under concession of Italian ministry of transportation. The bridge, designed in the 1960s, is made of reinforced concrete, 800 m long, and consists of 11 identical spans, each with a length of about 69 m. The deck width is 18.4 m, of which 14 m is available for traffic.Over the years, the structure has undergone various strengthening and restoration works, of which the most important took place in 1992, when an integrative slab was built over the existing deck and an external cable pre-stressing system was installed for both the caissons and the buffer beams.The continuous inspections of the structure detected deterioration in various parts of the structure, as well as defects in the realization of the pre-stressing system, which has significantly lost its effectiveness.This article will describe the results of the in-depth investigations carried out on the viaduct, the design of the static and seismic interventions of retrofitting, to restore the structure to a level of complete adequacy to current regulations, and the methods of carrying out the works.

Advanced Hydrodynamic Modelling of Flow at a River Bridge: Insights from 3D Computational Fluid Dynamics

Failure of river bridges is often due to hydraulic reasons, such as the development of severe scouring around piers and abutments. In many cases, the presence of bridge structures produces complex flow fields, which are difficult to predict using standard hydraulic models. This entails difficulties in estimating the hydrodynamic actions on the structure and the potential scour on the riverbed. A three-dimensional Computational Fluid Dynamics (3D CFD) model is used to analyze the flow field and the bed shear stresses at an existing bridge. The Volume of Fluid (VoF) method allows resolving the deformable free-surface, and the Detached Eddy Simulation (DES) approach allows resolving the dynamics of the energetically important turbulent eddies in the flow. The analysis deals with modeling the flow around a realistic, full-scale, multi-pier bridge in the Po River. Simulations considered different hydrodynamic regimes, i.e., the free-surface flow regime and the hypothetical pressure-flow regime which would occur when water levels are higher than the low chord of the bridge deck. The numerical application highlights the potential of the DES technique for analyzing the hydrodynamics of flow at bridges in natural river channels. Besides the turbulent flow fields and the description of the vortical structures, relevant results include the time-varying spatial distribution of the hydrodynamic forces acting on the different parts of the bridge and the time-varying distribution of the shear stress on the bed. This aspect is of particular interest because i) the estimation of drag forces on the structure components may be oversimplified using canonical, averaged formulas, and ii) the fluctuations in time of the bed shear stresses play a key role in determining the removal of sediments from the bed and the scour hole close to the bridge piers.

The stone artifacts of the National Archaeological Museum of Adria (Rovigo, Italy): a noteworthy example of heterogeneity

This paper reports on the results of the analyses of 56 stone samples from Roman and pre-Roman artifacts from the ancient town of Atria, currently preserved at the National Archaeological Museum of Adria. The city is located in the eastern Veneto lowlands, close to the Po River delta, and far from the main rock outcrops of the region. The objective of this research is to determine the provenance of the stones used in ancient Atria and their trade networks. The analytical techniques adopted include polarized-light optical microscopy (PLM), X-ray fluorescence (XRF), and quantitative phase analysis by X-ray powder diffraction (QPA-XRPD). The results reveal a widespread use of imported stones from the central-western territories of Veneto, primarily comprising trachyte from the Euganean Hills and the soft limestone Vicenza Stone from the Berici Hills/eastern Lessini Mounts. Rosso Ammonitico, Maiolica (Biancone) and Scaglia Rossa limestones are also documented. From neighbouring regions, the imported stone types include Aurisina limestone from the Trieste Karst and Istrian Stone. Sandstone was uniquely recognized in G. Popillius’s milestone. Moreover, advanced geochemical and mineralogical analyses performed on the Euganean trachytes allow tracking accurately the quarry sites, revealing an extensive exploitation of the main historical quarries of M. Oliveto, Monselice and M. Merlo, although some provenances from outcrops less systematically exploited were also detected. Notably, the use of rhyolite for manufacturing a pre-Roman gravestone provides new insights regarding the exploitation of Euganean stone resources before the Roman era.

A diatom-based approach to refine nutrient concentrations compatible with the “good” status of Northern Italy rivers

The identification of ecologically sound thresholds represents an important step toward improving the ecological status of rivers through appropriate measures to contain nutrient loads. The aim of the present study was to estimate phosphorus and nitrogen concentrations compatible with the achievement of the “good” ecological status of rivers from data collected in the Po River District, the largest hydrographic system in Italy. For this purpose, relationships between the diatom index used in Italy for the national assessment of the stream ecological status, the ICMi (Intercalibration Common Metric index), and total phosphorus and nitrate concentrations were analyzed using monitoring data collected between 2009 and 2019. The Po River Basin encompasses five distinct river types, from Alpine to Mediterranean to Lowlands, characterized by different anthropogenic pressures and water quality. Through regression analysis between the ICMi and nutrient concentrations, we estimated ranges of the latter values corresponding to a “good” ecological status for each river type. The resulting thresholds are far more stringent than the limits set by the Italian legislation for water quality classification. This is particularly true for total phosphorus, whose threshold value should be roughly halved for all river types. For nitrates, the results are more differentiated according to river type: the estimated thresholds are much more stringent than those currently in use for siliceous Alpine and Mediterranean rivers. Moreover, the availability of such a large database allowed also to assess the influence of one nutrient over the other on the diatom community and to highlight some critical issues in the formulation of ICMi for Mediterranean rivers.

INTEGRATING OPTICAL AND RADAR IMAGERY TO ENHANCE RIVER DROUGHT MONITORING

Abstract. Drought events are growingly affecting European and Italian territories, hampering local environments and biodiversity, such as the ones relying on rivers for their subsistence. Monitoring of rivers is becoming an important issue to face drought crisis and may be exploited with different tools. Among the most commons, satellite imagery is exploited to map water coverage, basing on optical or radar sources. This work proposes a combination of the two sensors to overcome possible limitations of the single dataset exploitation, reaching a reliable result. The methodology is applied to a stretch of Po River in Lombardy region (Italy). Through Google Earth Engine platform, optical satellite Sentinel-2 and radar satellite Sentinel-1 data are processed. The combination of the radar data and of the optical spectral indices is carried out through a pixel-based supervised classification, with a Random Forest classifier. Maps of water coverage are obtained, numerical outcomes of water surface evaluation are recorded and validated by the mean of reference hydrometric data. A multitemporal analysis is then reported, aiming to prove the efficiency of the procedure. All iterations show reliable accuracies and correlation among water surface estimation and water table measurements in two sections of interest. In perspective, the proposed methodology will be implemented in tools for supporting drought monitoring to be integrated in environmental public administration policies.

A physical/statistical data-fusion for the dynamical downscaling of GRACE data at daily and 1 km resolution

GRACE (Gravity Recovery And Climate Experiment) is one of the most important satellite instrument for terrestrial hydrology and water cycle analysis. It is the unique source of information for the Total Water Storage Change (TWSC) that includes the mostly unknown groundwater storage change. Its use for many socio-economic applications is however drastically reduced by its spatial (≃200 km) and temporal (≃ monthly) resolutions. A statistical/physical dynamical downscaling is proposed here to obtain High Resolution (HR) 1 km and daily TWSC estimates, using auxiliary information from other satellite and modeling data (i.e. precipitation, evaporation and river network direction from topography). This scheme utilizes the Water Budget (WB) closure, an hydrological model and a set of statistical tools. The quality of the results is demonstrated over the Po river basin, a very challenging basin for GRACE observations due to its relatively small size and complex contrasting surface types. It is shown that terrestrial runoff and river discharge are well disentangled in the obtained HR TWSC fields. The new TWSC data can also show the impact of weather events such as strong precipitations. This study demonstrates how the optimal combination of multiple Earth data can help us better describe the terrestrial water cycle at higher space/time resolutions.

Comparison of plastic pollution between waters and sediments in four Po River tributaries (Northern Italy)

The monitoring of plastic contamination in freshwaters is still pioneering in comparison with marine environments, and few studies analyzed the distribution of these pollutants in both aqueous and bottom compartments of continental waters. Therefore, the aim of this study was the comparison of plastic pollution in both waters and sediments of four Po River tributaries (Ticino, Adda, Oglio and Mincio Rivers), which outflow from the main Italian sub-alpine Lakes, in order to establish the strengths and weaknesses of both matrices. The main results pointed out a heterogeneous plastic contamination, with the lowest values in Ticino (0.9 ± 0.5 plastics/m3 in waters and 6.8 ± 4.5 plastics/kg dry weight - d.w. - in sediments) and the highest in Mincio (62.9 ± 53.9 plastics/m3 in waters and 26.5 ± 13.3 plastics/kg d.w in sediments), highlighting a plastic amount in sediments four times higher than waters. Plastic pollution, mainly due to microplastics, was associated principally to a domestic input in both waters and sediments of Ticino and Adda Rivers, as well as in sediments of Oglio, while an industrial pollution was found in waters and sediments of Mincio and Oglio waters. Our data clearly highlighted as the monitoring of both matrices provide complementary information for a holistic risk assessment of these emerging contaminants in freshwaters: the aqueous matrix provides an instantaneous picture of contamination, while sediments the history of pollution.

The Long-Term Detection of Suspended Particulate Matter Concentration and Water Colour in Gravel and Sand Pit Lakes through Landsat and Sentinel-2 Imagery

Over the past half century, the demand for sand and gravel has led to extensive quarrying activities, creating many pit lakes (PLs) which now dot floodplains and urbanized regions globally. Despite the potential importance of these environments, systematic data on their location, morphology and water quality remain limited. In this study, we present an extensive assessment of the physical and optical properties in a large sample of PLs located in the Po River basin (Italy) from 1990 to 2021, utilizing a combined approach of remote sensing (Landsat constellation and Sentinel-2) and traditional limnological techniques. Specifically, we focused on the concentration of Suspended Particulate Matter (SPM) and the dominant wavelength (λdom, i.e., water colour). This study aims to contribute to the analysis of PLs at a basin scale as an opportunity for environmental rehabilitation and river floodplain management. ACOLITE v.2022, a neural network particularly suitable for the analysis of turbid waters and small inland water bodies, was used to atmospherically correct satellite images and to obtain SPM concentration maps and the λdom. The results show a very strong correlation between SPM concentrations obtained in situ and those obtained from satellite images, both for data derived from Landsat (R2 = 0.85) and Sentinel-2 images (R2 = 0.82). A strong correlation also emerged from the comparison of spectral signatures obtained in situ via WISP-3 and those derived from ACOLITE, especially in the visible spectrum (443–705 nm, SA = 10.8°). In general, it appeared that PLs with the highest mean SPM concentrations and the highest mean λdom are located along the main Po River, and more generally near rivers. The results also show that active PLs exhibit a poor water quality status, especially those of small sizes (<5 ha) and directly connected to a river. Seasonal comparison shows the same trend for both SPM concentration and λdom: higher values in winter gradually decreasing until spring–summer, then increasing again. Finally, it emerged that the end of quarrying activity led to a reduction in SPM concentration from a minimum of 43% to a maximum of 72%. In this context, the combined use of Landsat and Sentinel-2 imagery allowed for the evaluation of the temporal evolution of the physical and optical properties of the PLs in a vast area such as the Po River basin (74,000 km2). In particular, the Sentinel-2 images consistently proved to be a reliable resource for capturing episodic and recurring quarrying events and portraying the ever-changing dynamics of these ecosystems.

Photocatalytic Degradation of Emerging Contaminants with N-Doped TiO2 Using Simulated Sunlight in Real Water Matrices

In the present work, the photodegradation performances of N-doped TiO2 photocatalysts with enhanced absorption of visible light were exploited for the abatement of some representative contaminants of emerging concern (CECs). Pristine TiO2 and N-TiO2 were synthesized using hydrothermal (HT) and sol–gel (SG) routes, they were characterized using XRD and UV-Vis spectroscopy, and their band gaps were determined via analysis in diffuse reflectance. Their photodegradation efficiency was tested on a mixture of recalcitrant organic pollutants, namely, benzotriazole, diclofenac, sulfamethoxazole, and bisphenol A, using a solar simulator lamp with two different cut-off filters (λ > 340 nm and λ > 400 nm). The evaluation of the photocatalytic performances was initially carried out in spiked ultrapure water and subsequently in aqueous matrices of increasing complexity such as Po River water and water coming from an aquaculture plant. The exclusive utilization of visible light (λ > 400 nm) highlighted the advantage of introducing the dopant into the TiO2 photocatalyst since this modification allows for the material to be responsive to visible light, which is not sufficient in the case of pristine TiO2 and the higher efficiency of materials obtained via the sol–gel route. Thanks to the doping, improved performance was obtained in both ultrapure water and real water matrices, indicating the potential of the doped material for future applications in the field.

High-Resolution Real-Time Coastline Detection Using GNSS RTK, Optical, and Thermal SfM Photogrammetric Data in the Po River Delta, Italy

High-resolution coastline detection and monitoring are challenging on a global scale, especially in flat areas where natural events, sea level rise, and anthropic activities constantly modify the coastal environment. While the coastline related to the 0-level contour line can be extracted from accurate Digital Terrain Models (DTMs), the detection of the real-time, instantaneous coastline, especially at low tide, is a challenge that warrants further study and evaluation. In order to investigate an efficient combination of methods that allows to contribute to the knowledge in this field, this work uses topographic total station measurements, Global Navigation Satellite System Real-Time Kinematic (GNSS RTK) technique, and the Structure from Motion (SfM) approach (using a low-cost drone equipped with optical and thermal cameras). All the data were acquired at the beginning of 2022 and refer to the areas of Boccasette and Barricata, in the Po River Delta (Northeastern of Italy). The real-time coastline obtained from the GNSS data was validated using the topographic total station measurements; the correspondent polylines obtained from the photogrammetric data (using both automatic extraction and manual restitutions by visual inspection of orhophotos) were compared with the GNSS data to evaluate the performances of the different techniques. The results provided good agreement between the real-time coastlines obtained from different approaches. However, using the optical images, the accuracy was strictly connected with the radiometric changes in the photos and using thermal images, both manual and automatic polylines provided differences in the order of 1–2 m. Multi-temporal comparison of the 0-level coastline with those obtained from a LiDAR survey performed in 2018 provided the detection of the erosion and accretion areas in the period 2018–2022. The investigation on the two case studies showed a better accuracy of the GNSS RTK method in the real-time coastline detection. It can be considered as reliable ground-truth reference for the evaluation of the photogrammetric coastlines. While GNSS RTK proved to be more productive and efficient, optical and thermal SfM provided better results in terms of morphological completeness of the data.