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Dissertations / Theses on the topic 'Lagoon of Venice'
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1
Cucco, Andrea <1975>. "Transport and dispersion processes in a micro tidal lagoon: the Venice lagoon study case." Doctoral thesis, Università Ca' Foscari Venezia, 2005. http://hdl.handle.net/10579/180.
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Ferrarin, Christian <1975>. "A sediment transport model for the lagoon of Venice." Doctoral thesis, Università Ca' Foscari Venezia, 2007. http://hdl.handle.net/10579/636.
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Sammarco, Paolo. "Theory of subharmonic resonance of storm gates for Venice lagoon." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/43467.
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Tran, Hoang Huu. "Experiments on subharmonic resonance of the Venice lagoon storm gates." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/42582.
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Villatoro, Lacouture Monique Marie. "Sand transport in Chioggia Inlet, Venice Lagoon and resulting morphodynamic evolution." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/195035/.
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The magnitudes and pathways of sand transport in Chioggia Inlet, southern Venice Lagoon, and the resulting morphological evolution have been investigated. Bathymetric analysis has established that there is a net export of sediment from the southern Lagoon Basin, and that significant morphodynamic changes in the barrier-inlet system have taken place. The total loss of sediment from the lagoon was evaluated as 125,770 m3/a, 10% of which is estimated to be sand. In addition, the presence of an ebb-tidal delta, extending from the mouth of Chioggia Inlet, as well as two subaqueous spits, were identified. The ebb-tidal delta annual growth was estimated as 50,000 m3/a, suggesting the existence of an additional source of sand for the delta, in addition to the Lagoon. The pathways and provenance of sand in transport were determined through seabed sampling and mineralogical analysis. Three predominant sources were identified: sand eroded from the tidal flats in the Southern Basin; a northelrly littoral drift of quartz-rich sand supplied by the Adige and Brenta rivers, to the south of the Chioggia Inlet; and a southerly littoral drift of carbonate-rich renourishment sand from Pellestrina, to the north of the Inlet. The nature and magnitude of transport through the inlet was investigated through direct measurements and modelling. It was found that the export of sand through the inlet is bed grain size dependant, ebb dominant and mostly in the bottom 1 m of the water column. The shape of the profile of concentration is well reproduced by the Rouse parameter, and thresholds for motion are between those derived by Van Rijn (1993) and by Amos et al. (2010b) for the Venetian inlets. Modelling results suggest that present export rates are 40% lower than those evaluated from longterm bathymetry changes. Volumetric and modelling estimates of drift along the shores adjacent to the Inlet indicate that the main contribution to the inlet features is littoral drift, with a longshore transport rate of 118,000 m3/a, from the south, and 91,000 m3/a, from the north. A conceptual sand budget for Chioggia Inlet was proposed. Littoral drift was found to be dominant over transport through the Inlet; thus, it is suggested that although the overall budget of sand in Chioggia Inlet is still negative, a small import of sand is starting to take place. Furthermore, the contribution of Chioggia Inlet to the net export of sand from the lagoon, based on present net budget estimates was calculated as 15%.
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Tubaro, Marco <1989>. "Application of an environmental exposure model for POPs in Venice lagoon." Master's Degree Thesis, Università Ca' Foscari Venezia, 2015. http://hdl.handle.net/10579/6139.
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Risk managers and decision makers are in need of flexible tools that inform environmental and human exposures in realistic, complex scenarios. In this thesis a new modelling tool for the integrated assessment of exposure to chemicals, called MERLIN-Expo, is applied to a case study on POPs exposure in Venice Lagoon. This tool provides a library of exposure models which can be flexibly combined to explore complex scenarios, coupling on the same platform multimedia and physiologically-based pharmacokinetic (PBPK) models for estimating human intake and internal exposure. The models can be used to dynamically simulate fate and exposure for organic and inorganic contaminants. MERLIN-Expo is applied to a case study in the Lagoon of Venice, aimed at estimating environmental exposure to different congeners of PCBs, considering bioaccumulation in aquatic species. Past PCBs concentration trends, reconstructed from dated sediment cores, are used as inputs to model the time-dependent bioaccumulation in selected aquatic organisms. Modelling results are compared to available monitoring data on chemical concentrations in edible aquatic species in Venice area to validate and assess the applicability of the tool.
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Callegher, Gianmarco <1995>. "A geostatistical approach for extreme precipitations simulations in the Venice lagoon." Master's Degree Thesis, Università Ca' Foscari Venezia, 2020. http://hdl.handle.net/10579/18137.
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In this work, extreme precipitations in the Venice lagoon will be simulated combining Extreme Value Theory (EVT), Generalized Additive Models (GAM) and geostatistics. Extreme events are identified as exceedances of a high threshold defined as a fixed quantile and fitted through quantile regression based on the Asymmetric Laplace Distribution (ALD). Then the Generalized Pareto Distribution (GPD) is used to model the excesses. Spatio-temporal variation of the parameters of both distributions is captured via the flexible framework of GAM. Obtained marginal models are coupled under a copula-based technique, forming a Gaussian process for high-resolution simulations of extreme events in space and time. The random field is assumed to have zero mean and its covariance is described using a separable parametric correlation function.
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Norris, Rebecca M. "Carpaccio’s “Hunting on the Lagoon” and “Two Venetian Ladies”: A Vignette of Fifteenth-Century Venetian Life." Kent State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=kent1185214455.
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Cappuci, Sergio. "The stability and evolution of an intertidal flat in Venice Lagoon, Italy." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250074.
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Helsby, Rachel. "Sand transport in northern Venice Lagoon through the tidal inlet of Lido." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/66264/.
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The provenance and transport of sand has been investigated around Lido Inlet, the largest of three tidal inlets in Venice Lagoon, Italy. Morphological analysis has established the presence of an ebb-tidal delta extending from the mouth of Lido Inlet as well as other features typical of tidal inlets. The stability of the inlet, as well as the canals of Treporti and Burano, was determined through the application of the tidal prism/cross-sectional areas relationship theorized by O’Brien (1969). Whilst Lido Inlet and Treporti Canal have both remained in equilibrium in terms of this relationship, Treporti Canal has suffered erosion due to a fluctuating tidal prism. Lido Inlet is slightly flood dominant although grain trend analysis of bottom sediment reveals net export of sand. Treporti Canal is ebb dominant and is the source of this sand, but it is becoming increasingly flood dominant as average current speeds have reduced and ebb currents are weakening at a faster pace than flood currents. This is proposed as a reason to why the northern lagoon is accreting (0.44 cm yr−1), contrary to trends in the southern (-0.37 cm yr −1) and central lagoon (-0.23 cm yr−1). A sediment budget formulated for the whole lagoon has revealed that whilst the overall rate of erosion is reducing, the area subject to erosion is increasing and the rate of accretion is decreasing, resulting in no net change in the net sediment loss rate between 1930-1970 to 1970-2000 (-0.05 cm yr−1). Mineralogical analysis on bottom samples, beach and riverine samples confirmed that longshore transport is from north to south along the northern lagoon; carbonate grains are dominant in the north with proportions gradually replaced by quartz to the south. Lido Inlet proved to have similar mineralogy to the River Piave with a higher calcite/dolomite ratio than inner lagoon samples suggesting a less mature sediment and thus import of sediment. Conversion of ADCP backscatter into bedload transport rate, suspended sand, and suspended fines concentrations has shown that no sand is transported at velocities below ∼0.4 m s−1. 55% of sediment transported during an ebb flow was sand in suspension (peak: 527,000 kg hr−1), 37% was fines in suspension (peak: 283,000 kg hr−1), and the remaining 8% of sediment was transported as bedload (peak 68,700 kg hr−1).
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Vale, Manfredi <1972>. "Hydrology and water quality of a subbasin discharging in the Venice lagoon." Doctoral thesis, Università Ca' Foscari Venezia, 2006. http://hdl.handle.net/10579/169.
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Fiandra, Marco <1993>. "DAPSI(W)R(M) problem-structuring framework applied to the Venice Lagoon." Master's Degree Thesis, Università Ca' Foscari Venezia, 2020. http://hdl.handle.net/10579/16538.
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Attraverso l’utilizzo del framework ambientale DAPSI(W)R(M) (Elliott et al., 2017), sono state definite qualitativamente le molteplici connessioni tra attività antropiche e degrado ambientale all’interno della Laguna di Venezia. Tale modello si pone come obiettivo di organizzare secondo un rigoroso schema causa-effetto le informazioni disponibili, in modo da raggiungere più facilmente una moltitudine di portatori di interesse, organismi di gestione ambientale, la comunità scientifica ed il pubblico. DAPSI(W)R(M) è quindi caratterizzato dalla spiccata multidisciplinarità, analizzando i diversi aspetti della gestione ambientale (ricerca, monitoraggi, politiche..) per valutarne e quindi indirizzarne l’operato.
Si compone di 5 elementi collegati tra loro. A partire dai Drivers (D), ovvero i bisogni umani, vengono inserite, discusse e confrontate svariate Attività (A) umane che hanno luogo all’interno della conterminazione lagunare, con un focus specifico sui settori ad alto “impatto ambientale”. Tali settori producono di conseguenza una moltitudine di Pressioni (P) sull’ambiente naturale, che modificano sinergicamente o meno lo stato del territorio (S), modificando negativamente i servizi ecosistemici, e quindi il welfare locale (I(W)). A concludere il processo, vengono prodotte una serie di risposte in forma di misure(R(M)), che mirano a migliorare il territorio agendo su una o più componenti, sottolineando la ciclicità del framework.
A causa dell’importante diversità e quindi complessità del territorio considerato, il lavoro vuole primariamente introdurre il framework DAPSI(W)R(M) come metodologia d’approccio alla gestione dell’ambiente costiero lagunare, più che definire esaustivamente ogni singolo elemento. Nonostante non sia un approccio di dettaglio, è stata effettuata la descrizione e analisi più esaustiva possibile, raccogliendo quanto più materiale informativo possibile. Tale metodologia di lavoro potrebbe divenire fondamentale in futuro, per definire le linee guida per la gestione di sistemi ambientali complessi, tenendo in considerazione tutti gli aspetti sociali, economici e ambientali in un quadro unico di riferimento.
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Scudiero, Elia. "Multiscale Soil Salinity Assessment at the Southern Margin of the Venice Lagoon, Italy." Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3422637.
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Saltwater intrusion affects many coastlands around the world contaminating fresh-groundwater and decreasing soil quality. In order to manage saline soils one should understand the spatiotemporal dynamics of salinity in the soil profile and its spatial variability at field scale. In the last decades, soil and pore-water salinity have been assessed using geophysical techniques, most commonly with the use of apparent electrical conductivity (ECa) measurements. At point-scale, pore-water salinity can be estimated once its relationship with ECa, soil properties, and water content is understood. Moreover, most sensors for water content estimation normally provide biased readings in saline conditions and in soil with high clay and organic carbon contents. At field-scale proximal-sensing can be used to characterize large portions of land from a relatively small number of soil samples. Sometimes, characterizing salinity is however not sufficient to understand crop yield spatial variability, which can be also influenced by other soil properties. Understanding the influence of salinity and other soil properties on crop productivity can be useful in the identification of areas that can be managed site-specifically.
The general aim of this dissertation is to evaluate some sensor-based methodologies for monitoring and characterizing salinity and other related soil properties both at point- and field-scale. In particular, at point-scale the dissertation will deal with the issues regarding the use of capacitive-resistive technology for water content and pore-water salinity estimation. At field-scale some methodologies will be proposed in order to characterize the spatial variability of salinity and other soil properties influencing maize (Zea mais L.) yield using soil proximal-sensing. All the material presented in this manuscript regard the soils of an area affected by saltwater intrusion located at the southern edge of the Venice Lagoon (Italy).
The dissertation is structured in five chapters. The first one includes a review on commonly used methodologies for point- and field-scale salinity assessment. An overview on the environmental issues concerning the coastland at the southern margin of the Venice Lagoon is also presented. The second chapter deals with the calibration of a low-cost capacitance-resistance probe for simultaneous monitoring of soil water content and salinity. In the third chapter an ECa-directed soil sampling scheme optimization procedure is proposed. The forth chapter analyzes maize yield as a function of soil chemical and physical properties and investigates on the use of soil-proximal sensing correlated to soil spatial variability for site-specific management units. The final chapter presents the general conclusions of the work.L’intrusione salina interessa molte zone costiere del mondo con effetti negativi sulla qualità dell’acqua di falda e del suolo. Per gestire i problemi di salinità è necessario capirne le dinamiche temporali a livello di profilo di suolo e la variabilità spaziale a scala di campo. Tecniche geofisiche, in particolare l’utilizzo della conducibilità elettrica apparente (ECa), sono state utilizzate negli ultimi decenni per stimare la salinità del suolo e della soluzione circolante. A scala puntuale la bontà delle misure di salinità della soluzione circolante è legata alla giusta interpretazione del rapporto che la lega ad ECa, alle caratteristiche del suolo e al contenuto idrico. Inoltre, i sensori che misurano l’umidità del suolo spesso forniscono misure falsate in suoli salini e con alto contenuto di argilla e/o sostanza organica. A scala di campo il proximal-sensing può essere utile per caratterizzare vaste porzioni di territorio a partire da un numero relativamente ridotto di campioni di suolo. Spesso la caratterizzazione della salinità non è sufficiente per capire la variabilità spaziale delle rese colturali, che può essere influenzata da altre caratteristiche del suolo. Capendo come la salinità e altre proprietà del suolo influenzano la produttività agraria può essere utile per identificare delle aree in cui apportare interventi agronomici sito-specifici. L’obiettivo generale di questo lavoro è valutare delle metodologie per monitorare e caratterizzare la salinità del suolo ed altri parametri chimico-fisici del suolo ad essa legati, con l’ausilio di sensori, sia a scala puntuale che di campo. In particolare a scala puntuale si affrontano le problematiche relative all’utilizzo di sensoristica capacitivo-resistiva per stimare il contenuto volumetrico e la salinità della soluzione circolante. Mentre a scala di campo si propongono delle metodologie per caratterizzare la variabilità spaziale della salinità del suolo e di altre proprietà che influenzano la resa di Zea mais L. con l’utilizzo di tecniche di proximal-sensing del suolo. Questa tesi riguarda i suoli di un’area di studio interessata da intrusione salina, al margine meridionale della Laguna di Venezia. La tesi è strutturata in cinque capitoli. Il primo include una review sulla metodologia comunemente usata per caratterizzare la salinità del suolo con metodi geofisici sia a scala puntuale che di campo. È inoltre presentata una panoramica introduttiva sulle problematiche ambientali relative alla zona a sud della Laguna di Venezia. Il secondo capitolo si concentra sulla calibrazione di una sonda (low-cost) capacitivo-resistiva da utilizzare per stime in continuo di contenuto idrico volumetrico e salinità della soluzione circolante. Il terzo capitolo propone una metodologia per ottimizzare schemi di campionamento del suolo sulla base della variabilità spaziale di misure geofisiche. Il quarto capitolo analizza la variabilità spaziale della resa colturale in funzione delle proprietà chimico-fisiche del suolo e propone l’utilizzo di dati di proximal-sensing del suolo ad esse correlati per identificare delle aree di gestione omogenee. Infine, l’ultimo capitolo riporta le conclusioni generali e delle note conclusive sui lavori presentati nella tesi.
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Marcosanti, Agnese <1982>. "Experimental study of the transitional behaviour of the silty soils from the Venice Lagoon." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/4167/1/marcosanti_agnese_tesi.pdf.
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Marcosanti, Agnese <1982>. "Experimental study of the transitional behaviour of the silty soils from the Venice Lagoon." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/4167/.
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Scapin, Luca <1989>. "Habitat use of fish in seagrass meadows of the Venice lagoon: implications for seagrass restoration and for conservation of the lagoon seascape." Doctoral thesis, Università Ca' Foscari Venezia, 2017. http://hdl.handle.net/10579/12910.
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Seagrass meadows play a primary role in supporting ecosystem services in coastal lagoons. Still, their importance as habitat for fish in transitional waters is poorly understood. Moreover, the persistent loss of seagrass beds during the last decades requires conservationists to provide scientifically sound plans to enhance their preservation. The objectives of this work are i) to investigate the influence of environmental factors, including habitat characteristics, on seagrass fish assemblages in the Venice lagoon (northern Adriatic Sea, Italy); ii) to evaluate the suitability of fish fauna as indicator of the effectiveness of seagrass restoration. Ultimately, this work aims at presenting approaches for planning seagrass conservation efforts and assessing their outcomes.
This work features three main sections. Firstly, the role of different floristic composition and habitat structure of seagrass beds was linked to distribution of pipefishes and seahorses (Syngnathidae), highlighting the importance of enhancing conservation of Zostera marina meadows in shallow coastal lagoon waters. Secondly, the role of seagrass fish and other nekton fauna as indicator of the success of conservation actions was investigated. A seagrass restoration scheme that recently started in the Venice lagoon allowed to test a model-based method, to predict reference conditions for nekton fauna in Z. marina and Z. noltei transplantation sites, and provide an assessment of the progress of restoration towards designed goals. Thirdly, the potential role of habitat mosaic structure in influencing seagrass fish in the Venice lagoon was evaluated. The study highlighted the importance of conservation of seagrass habitat quality at multiple spatial scales for the preservation of the associated fish assemblages, and the need for including seascape ecology in seagrass restoration projects.
On the whole, this thesis provides some new insights into the critical role of seagrass conservation for the maintenance of biodiversity, and suggestions for more successful management strategies in coastal lagoons.
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Dalmonte, Camilla. "Use of isotopes for studying nitrogen processes in a wetland within the Venice Lagoon watershed." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6680/.
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The present study is based on the use of isotopes for evaluating the efficiency of nutrients removal of a wetland, in particular nitrogen and nitrates, also between the different habitats present in the wetland. Nutrients like nitrogen and phosphorus, normally distributed as fertilizers, are among the principal causes of diffuse pollution. This is particularly important in the Adriatic Sea, which is frequently subjected to eutrophication phenomena. So it is very crucial requalification of wetland, in which there are naturally depurative processes such as denitrification and plant uptake, which allow the reduction of pollutant loads that flow in water bodies.
In this study nutrient reduction is analyzed in the wetland of the Comuna drain, which waters flow in the Venice lagoon. Chemical and isotopical analyses were performed on samples of water, vegetation, soil and sediments taken in the wetlands of the Comuna drain in four different periods of the year and on data of nitrogen and phosphorus concentration obtained by the LASA of the University of Padova. Values of total nitrogen and nitrates were obtained in order to evaluate the reduction within the different systems of the wetland. Instead, the isotopic values of nitrogen and carbon were used to evaluate which process influence more nitrogen reduction and to understand the origin of the nutrient, if it is from fertilizers, waste water or sewage.
To conclude, the most important process in the wetland of the Comuna drain is plant uptake, in facts the bigger percentage of nitrogen reduction was in the period of vegetative growth. So it is important the study of isotopes in plant tissues and water residence time, whose increase would allow a greater reduction of nutrients.
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Soldatini, Cecilia <1975>. "Anthropogenic influences on the behaviour and ecology of birds in Venice and the surrounding lagoon." Doctoral thesis, Università Ca' Foscari Venezia, 2005. http://hdl.handle.net/10579/732.
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Munaretto, Stefania <1975>. "Governing water and environment in times of climate change: the case of the Venice lagoon." Doctoral thesis, Università Ca' Foscari Venezia, 2011. http://hdl.handle.net/10579/1057.
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Climate change is an additional challenge that coastal regions have to face nowadays. To address old and new problems, institutional reforms are increasingly required.
This research focuses on a case study, namely the Venice lagoon. The objective is to explore institutional arrangements for water and environmental management that would improve effectiveness in the governance of the Venice lagoon under conditions of climate change.
For this purpose, a qualitative analysis of scientific literature, archive data and interviews is conducted in three separated studies. In addition to that, knowledge about the functioning of the formal and informal institutional system at work in the studied area was gained during the past six years working in the field of the safeguarding of Venice and was helpful to perform the analysis and interpreting the findings.
The first study reflects on the ability of the non-structural and structural measures for flood protection in Venice to anticipate expected sea-level rise induced by climate change. Then, the second study looks into the institutions for water and environmental management to assess whether they support adaptive capacity of society to climate change. This analysis is done in comparison with another coastal region, the Dutch Wadden Sea with the aim of searching for lessons to be learnt. Finally, the level of implementation of the adaptive co-management as normative framework for effective governance and its implication in terms of policy learning are explored in the third study.
The findings of this research suggest that decades of studies funded by the Special Law for Venice generated technical and scientific knowledge and allowed building infrastructure that could make Venice one of the foremost regions adapting to climate change and an example for other coastal regions to learn. This provided that the governance structure allows for timely completion of all infrastructures as well as adequate management and maintenance by supplying adequate funding and reforming institutions. Reforming the current Special Law for Venice offers an opportunity to develop a novel governance regime with all relevant parties. Taking a climate change perspective in developing the new regime would then ensure long term protection from climate related risks. Recommendations include a possible path and a number of institutions to improve effectiveness in the governance of the Venice lagoon.La ricerca esplora strumenti di governo ambientale per migliorare l’efficacia della governance della laguna di Venezia in presenza di cambiamenti climatici. La ricerca inizialmente riflette sulla capacità di difesa dall’innalzamento del livello del mare delle misure di protezione dalle acque alte. Poi, valuta la capacità di adattamento al cambiamento climatico delle politiche per il governo dell’ambiente lagunare e lo fa comparando Venezia e il Wadden Sea in Olanda. Infine, valuta l’attuazione dell’adaptive co-management a Venezia quale strumento di efficace governance ambientale. L’analisi evidenzia come l’alto livello di conoscenze tecniche e scientifiche e le infrastrutture in corso di realizzazione collochino Venezia tra le zone costiere che meglio possono adattarsi al cambiamento climatico. Deve però essere assicurato un regolare flusso di risorse e strumenti di governo per il completamento delle infrastrutture, la gestione e la manutenzione delle opere di salvaguardia e della città. La riforma della Legge Speciale per Venezia offre l’opportunità di disegnare una nuova governance lagunare capace di rispondere a queste esigenze. Le raccomandazioni di questa ricerca offrono un possibile percorso per avviare la riforma e alcune ipotesi di strumenti per una più efficace governance della laguna di Venezia.
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Sigovini, Marco <1980>. "Multiscale dynamics of zoobenthic communities and relationships with environmental factors in the Lagoon of Venice." Doctoral thesis, Università Ca' Foscari Venezia, 2011. http://hdl.handle.net/10579/1092.
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The thesis focuses on the macrozoobenthic community in the Lagoon of Venice. Main aspects investigated include: spatial and interannual variability of the community structure; the role of environmental factors in structuring benthic communities; spatial scales of variability of the community, also in relationship to variability scales of environmental factors. A three-year data set was analyzed. High interannual variability and spatial heterogeneity was verified. Multivariate structure and univariate descriptors were considerably related to environmental factors. A gradient from sea landwards in species richness and community composition was evidenced and related to the composite ecocline, mainly to seawater renewal and salinity. More complex spatial patterns were recognized. Univariate descriptors and multivariate structures follow different scales of variability. The results have implications for quality assessment of transitional ecosystems.La tesi analizza la comunità macrozoobentonica della Laguna di Venezia. Sono stati principalmente indagati: la variabilità spaziale e interannuale della struttura della comunità; il ruolo dei fattori ambientali; le scale spaziali di variabilità della comunità, in relazione alla scala di variabilità dei fattori ambientali. Il data set analizzato è relativo a tre anni. E' stata verificata un'elevata variabilità interannuale ed eterogeneità spaziale. Descrittori di struttura multivariata e univariate sono risultati notevolmente correlati ai fattori ambientali. E' stato evidenziato un gradiente da mare verso terra in merito al numero di specie e alla composizione della comunità, in relazione ad un ecocline composito, e principalmente a ricambio idrico e salinità. Sono emersi pattern spaziali più complessi. Descrittori univariati e strutture multivariate seguono diverse scale di variabilità. I risultati hanno implicazioni per la valutazione della qualità degli ecosistemi di transizione.
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Bellafiore, Debora <1981>. "Study of the circulation processes in the northern Adriatic sea - coastal area and Venice lagoon inlets." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/2104/1/bellafiore_debora_tesi.pdf.
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This work is a detailed study of hydrodynamic processes in a defined area, the littoral in front of the Venice Lagoon and its inlets, which are complex morphological areas of interconnection. A finite element hydrodynamic model of the Venice Lagoon and the Adriatic Sea has been developed in order to study the coastal current patterns and the exchanges at the inlets of the Venice Lagoon. This is the first work in this area that tries to model the interaction dynamics, running together a model for the lagoon and the Adriatic Sea. First the barotropic processes near the inlets of the Venice Lagoon have been studied. Data from more than ten tide gauges displaced in the Adriatic Sea have been used in the calibration of the simulated water levels. To validate the model results, empirical flux data measured by ADCP probes installed inside the inlets of Lido and Malamocco have been used and the exchanges through the three inlets of the Venice Lagoon have been analyzed. The comparison between modelled and measured fluxes at the inlets outlined the efficiency of the model to reproduce both tide and wind induced water exchanges between the sea and the lagoon. As a second step, also small scale processes around the inlets that connect the Venice lagoon with the Northern Adriatic Sea have been investigated by
means of 3D simulations. Maps of vorticity have been produced, considering the influence of tidal flows and wind stress in the area. A sensitivity analysis has been carried out to define the importance of the advection and of the
baroclinic pressure gradients in the development of vortical processes seen along the littoral close to the inlets. Finally a comparison with real data measurements, surface velocity data from HF Radar near the Venice inlets,
has been performed, which allows for a better understanding of the processes and their seasonal dynamics. The results outline the predominance of wind and tidal forcing in the coastal area. Wind forcing acts mainly on the mean coastal current inducing its detachment offshore during Sirocco events and an increase of littoral currents during Bora events. The Bora action is more homogeneous on the whole
coastal area whereas the Sirocco strengthens its impact in the South, near Chioggia inlet. Tidal forcing at the inlets is mainly barotropic. The sensitivity analysis shows how advection is the main physical process responsible for the persistent vortical structures present along the littoral between the Venice Lagoon inlets. The comparison with measurements from HF Radar not only permitted a validation the model results, but also a description of different patterns in specific periods of the year. The success of the 2D and the 3D simulations on the reproduction both of
the SSE, inside and outside the Venice Lagoon, of the tidal flow, through the lagoon inlets, and of the small scale phenomena, occurring along the littoral, indicates that the finite element approach is the most suitable tool for the
investigation of coastal processes. For the first time, as shown by the flux modeling, the physical processes that drive the interaction between the two basins were reproduced.
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Bellafiore, Debora <1981>. "Study of the circulation processes in the northern Adriatic sea - coastal area and Venice lagoon inlets." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/2104/.
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This work is a detailed study of hydrodynamic processes in a defined area, the littoral in front of the Venice Lagoon and its inlets, which are complex morphological areas of interconnection. A finite element hydrodynamic model of the Venice Lagoon and the Adriatic Sea has been developed in order to study the coastal current patterns and the exchanges at the inlets of the Venice Lagoon. This is the first work in this area that tries to model the interaction dynamics, running together a model for the lagoon and the Adriatic Sea. First the barotropic processes near the inlets of the Venice Lagoon have been studied. Data from more than ten tide gauges displaced in the Adriatic Sea have been used in the calibration of the simulated water levels. To validate the model results, empirical flux data measured by ADCP probes installed inside the inlets of Lido and Malamocco have been used and the exchanges through the three inlets of the Venice Lagoon have been analyzed. The comparison between modelled and measured fluxes at the inlets outlined the efficiency of the model to reproduce both tide and wind induced water exchanges between the sea and the lagoon. As a second step, also small scale processes around the inlets that connect the Venice lagoon with the Northern Adriatic Sea have been investigated by
means of 3D simulations. Maps of vorticity have been produced, considering the influence of tidal flows and wind stress in the area. A sensitivity analysis has been carried out to define the importance of the advection and of the
baroclinic pressure gradients in the development of vortical processes seen along the littoral close to the inlets. Finally a comparison with real data measurements, surface velocity data from HF Radar near the Venice inlets,
has been performed, which allows for a better understanding of the processes and their seasonal dynamics. The results outline the predominance of wind and tidal forcing in the coastal area. Wind forcing acts mainly on the mean coastal current inducing its detachment offshore during Sirocco events and an increase of littoral currents during Bora events. The Bora action is more homogeneous on the whole
coastal area whereas the Sirocco strengthens its impact in the South, near Chioggia inlet. Tidal forcing at the inlets is mainly barotropic. The sensitivity analysis shows how advection is the main physical process responsible for the persistent vortical structures present along the littoral between the Venice Lagoon inlets. The comparison with measurements from HF Radar not only permitted a validation the model results, but also a description of different patterns in specific periods of the year. The success of the 2D and the 3D simulations on the reproduction both of
the SSE, inside and outside the Venice Lagoon, of the tidal flow, through the lagoon inlets, and of the small scale phenomena, occurring along the littoral, indicates that the finite element approach is the most suitable tool for the
investigation of coastal processes. For the first time, as shown by the flux modeling, the physical processes that drive the interaction between the two basins were reproduced.
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Simeoni, Christian <1994>. "A Machine Learning-based approach for the assessment of water quality variation in the Venice Lagoon." Master's Degree Thesis, Università Ca' Foscari Venezia, 2020. http://hdl.handle.net/10579/16759.
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Water quality (WQ) is one of the most critical issues in lakes, estuaries, marine and costal water management, affecting not only the socio-economic systems, but also the sustainability of natural processes. As a consequence of the complex interplay between climate and human-induced pressures, changes in marine WQ are observed (e.g. higher turbidity with resulting reduced water clarity, acidification) with cascading effects on the environmental status of natural ecosystems and their capacity to flow services for human wellbeing. To evaluate such effects, a continuous monitoring of WQ parameters is advisable. With advances in space science and the increasing use of computer applications, near real time remotely sensed observations in combination with novel machine learning (ML) methods have become useful tools for monitoring and management of WQ, overcoming limitations posed by traditional in-situ measurements.
In the frame of this thesis, a ML-based approach integrating monitoring and satellite data was developed, in order to allow for a multi-scenario analysis and modelling of spatio-temporal dynamics of key WQ parameters (e.g. Chl, turbidity) in the Venice lagoon, also in consideration of changing climate and land-use conditions (e.g. increase of precipitation and temperature, urban sprawl). Resulting output of the application of the methodology at the case study level represents a valuable support for the implementation of relevant EU acquis (e.g. Water Framework and Marine Strategy Framework Directives) in the investigated area, supporting decision makers and managers in the identification of key drivers of deterioration of natural ecosystems and the design of appropriate evidence-based management measures.
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YANG, ZHICHENG. "ANALYZING GEOMORPHOLOGICAL AND ECOLOGICAL CHANGES IN VENICE LAGOON SALT MARSHES THROUGH REMOTE SENSING AND FIELD OBSERVATIONS." Doctoral thesis, Università degli studi di Padova, 2022. http://hdl.handle.net/11577/3447676.
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Le barene sono ecosistemi di grande importanza che forniscono servizi ecosistemici vitali, ma allo stesso tempo sono tra gli ambienti più fragili al mondo. La vegetazione alofila svolge un ruolo fondamentale nel sostenere la sopravvivenza delle barene attraverso complessi feedback eco-morfodinamici. L'analisi del ruolo della vegetazione nei processi bio-geomorfologici sulle barene è un passaggio fondamentale per comprendere e prevedere la loro evoluzione morfodinamica.
A tal fine, utilizzando sia dati di campo che dati telerilevati, abbiamo analizzato i cambiamenti nella distribuzione della vegetazione alofila sia nel piano verticale che orizzontale, tra il 2000 e il 2019, per la barena di San Felice (nella Laguna di Venezia, Italia).
I risultati principali dello studio suggeriscono che: i) la relazione tra vegetazione e quota, precedentemente riportata da altri autori (ad es., specie alofite diverse popolano specifici intervalli di quota, cioè nicchie ecologiche, che mostrano una sequenza di specie a quote crescenti) è risultata affidabile e coerente a scala di barena e, soprattutto, per un periodo di 20 anni. Si suggerisce che questo sia un segno della resilienza della vegetazione ai cambiamenti delle forzanti; ii) sebbene diversi siti sulla superficie di barena abbiano aumentato la loro quota assoluta con tassi diversi, le quote delle barene rispetto all'attuale livello medio relativo del mare (LMRM) sono diminuite nel tempo, indicando la possibile sommersione della barena. Ciò suggerisce la necessità di considerare le quote locali delle barene riferite al LMRM per monitorare l’evoluzione della superficie di barena e la risposta ai cambiamenti delle forzanti ambientale; iii) le specie alofile hanno modificato la quota alla quale popolano la barena con andamenti sito e specie specifici in risposta all'aumento del LMRM; iv) l’algoritmo di Random Forest Soft Classification sviluppato per la classificazione della vegetazione, si è dimostrato accurato, consentendo di analizzare la dinamica della vegetazione nello spazio e nel tempo. Spartina e Salicornia hanno maggiori probabilità di essere sostituite da suolo nudo, mentre Limonium e Sarcocornia tendono a invadere le aree prive di vegetazione, e le transizioni tra specie diverse o tra zone vegetate e non vegetate sono ampiamente osservate sulla barena, indicando che i modelli eco-geomorfici sono altamente dinamici e sito specifici; v) il nuovo algoritmo Random Forest Regression per l'analisi dei dati Lidar è affidabile per costruire DEM derivati dal lidar sulle barene con elevata precisione, rappresentando uno strumento importante per monitorare i processi eco-geomorfologici di barena, fornendo inoltre mezzi per informare e testare modelli eco-geomorfologici; vi) L'accoppiamento tra il DEM derivato dal lidar e le mappe della vegetazione telerilevate suggerisce che la relazione vegetazione-elevazione è coerente anche a scala di barena. vii) Infine, le analisi evidenziano che la vegetazione di barena può bilanciare rapidamente la perdita di biomassa superficiale causata die back della Spartina attraverso i feedback eco-morfodinamici.
Tutti questi risultati sono di grande importanza per ulteriori analisi eco-morfodinamiche, soprattutto nel caso di barene popolate da molteplici specie di vegetazione alofila. Inoltre, suggeriamo anche che l'applicazione di diversi tipi di dati telerilevati sia uno strumento utile per analizzare i processi eco-morfodinamici sulle barene.Salt marshes are important ecosystems, providing vital ecosystem services, but at the same time they are among the most fragile landscapes in the world. Halophytic vegetation is of critical importance in supporting marsh survival through complex eco-morphodynamic feedbacks. Analyzing the role of halophytic vegetation in biogeomorphic processes on salt marshes is a key step to understand and predict their morphodynamic evolution. Towards this goal, using both field data and remote sensing observations, we have analyzed changes in marsh vegetation distribution both in the vertical and horizontal frames, between 2000 and 2019, for the San Felice salt marsh (in the Venice Lagoon, Italy). Our main results suggest that: i) the previously reported vegetation-elevation relationship (e.g., halophytic vegetation species encroach specific elevation ranges, i. e., ecological niches, displaying a species sequence with increasing elevations) is found to be reliable and consistent at the whole marsh scale and, most importantly, over a period of 20 years. This is suggested to be a signature of vegetation resilience to changes in the forcings. ii) Although all marsh sites increased their absolute elevations with site-specific rates, marsh elevations relative to the current relative mean sea level (RMSL) decreased in time, indicating the possible drowning of the marsh. This indicates the need to consider local marsh elevations referenced to RMSL when monitoring marsh surface evolution and response to changes in the environmental forcings. iii) Halophytic vegetation species modified the elevation at which they populate the marsh platform with site- and species-specific trends in response to the increase in RMSL. iv) The proposed Random Forest Soft Classification algorithm developed for vegetation classification is accurate and allows one to analyze vegetation dynamics in space and time. We note that Spartina and Salicornia are more likely to be replaced by bare soil, whereas Limonium and Sarcocornia tend to encroach unvegetated areas, and the transitions among different species or between vegetated and unvegetated spots are widely observed over the marsh, indicating that eco-geomorphic patterns are highly dynamic and site-specific. v) The newly developed Random Forest Regression algorithm for the analysis of Lidar data is reliable to construct lidar-derived DEMs over the marsh with high accuracy. This represents an important tool to monitor marsh eco-geomorphic patterns, furthermore providing means to inform and test eco-geomorphic models. vi) The coupling of the corrected lidar-derived DEM and remotely sensed vegetation maps suggests that the vegetation-elevation relationship is also consistent at the whole marsh scale. vii) Finally, we also realized that marsh vegetation can quickly balance the loss in the above-ground biomass (AGB) caused by a dieback event of Spartina through the eco-morphodynamic feedbacks. Our results are of critical importance for further eco-morphodynamic analyses, especially in the case of marshes encroached by multiple halophytic vegetation species. In addition, we also suggest that the application of different types of remote sensing data is a useful tool to analyze eco-morphodynamic processes over the marsh.
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Sciama, Lidia Dina. "Relations between centre and periphery in the City of Venice : a study of Venetian life in a lagoon island." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338944.
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Lovato, Tomas <1979>. "Modelling the hydrodynamic circulation and the biogeochemical cycles in the lagoon of Venice and along the North Adriatic coast." Doctoral thesis, Università Ca' Foscari Venezia, 2009. http://hdl.handle.net/10579/583.
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Tagliafierro, Nicola <1990>. "The artificial creeks in Sant'Erasmo island (Venice lagoon): present status and suggestion for management based on two indicator species." Master's Degree Thesis, Università Ca' Foscari Venezia, 2016. http://hdl.handle.net/10579/9256.
Full textAbstract:
Estuaries and coastal lagoons show high levels of habitat heterogeneity and support a large fish production (Elliott & Hemingway, 2002). Hosting a wide variety of biodiversity, the Venice lagoon is the biggest lagoon in the Mediterranean basin, and Sant'Erasmo island is one of the largest of the lagoon.
The salt marshes represent one of the main habitats for many fish species of the Venice lagoon, characterized by seagrass meadows, bare sand areas, intertidal flats, sandy and muddy subtidal beds, and tidal marshes.
The ecological importance of these marginal habitats is mainly due to the high level of trophic resources available and to the refuge function from predation deriving from a complex morphological structure
Land claim, erosion, pollution, aquaculture and relative sea level rise determined the alteration or the complete destruction of these habitats.
An important role is played by the artificial creeks, present in many islands of the lagoon, once used for aquaculture and transport means. Nowadays, even though the use has changed in many cases, these artificial sites gained an ecological value as alternative refuge habitats to natural salt marsh creeks.
The Aphanius fasciatus, as an autochthonous species, belongs to the ecosystem of the lagoon of Venice, in particular to the shallow waters and subsequently, also to the artifical creeks of some islands of the lagoon. Considering that many studies have been carried out on the Aphanius, and knowing the chemical and physical characteristics of its habitat, one of the objectives of this work is to determine what is the cause of absence or presence of the Aphanius in Sant'Erasmo creeks (Venice lagoon).
As the salt marshes, the artificial creeks offer favorable conditions and protection from predators for the Aphanius, but recently this species in Sant'Erasmo island, started to decrease.
Despite both species can survive in a wide range of salinty conditions, the Aphanius shows a more aggressive behavior at higher salinity conditions compared to the Gambusia, thus we expect to find a higher concentration of Aphanius in sea water conditions (Alcaraz, Carles, et al. 2008).
Defining the Gambusia (Porte, C., Barceló, D., & Albaigés, J., 1992) and the Aphanius (Messaoudi, Imed, et al 2009) as indicator species and knowing their habitat, then it will be possible to indicate which watercourses have faced a change by observing their presence or absence.
Aiming to confirm the previous studies on the habitats and ecological niches of the two species, this study will allow us to identify which creeks are suitable both for the aphanius and gambusia populations, and therefore, suitable for other species with the same ecological preferences.
The intrinsic objective of the work, is to give more importance to the potential role of biological reservoir of the artificial creeks of Sant'Erasmo, which could possibly host part of the salt marshes population in view of sea level rise. Therefore, the artificial creeks are supposed to be mostly brackish water.
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Radomyski, Artur <1986>. "Integration of ecological and human PBPK exposure models and their application in exposure assessment to POPs in Venice lagoon." Doctoral thesis, Università Ca' Foscari Venezia, 2017. http://hdl.handle.net/10579/12922.
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The proposed PhD project focuses on an integration of ecological and human exposure models, and it is aimed at demonstrating the feasibility of linkage between environmental fate models, bioaccumulation models and human PBPK model on a common platform, integrating uncertainty, variability and sensitivity analysis to allow complete exposure analysis.
The project main objective is the integration of multimedia models (MM) simulating the fate of chemicals in environmental media, and of physiologically based pharmacokinetic (PBPK) models simulating the fate of chemicals in human body using MERLIN-Expo in order to determine internal effective chemical concentrations. The project was developed within ‘4FUN’ EU-funded initiative aimed at the development of a unique tool called MERLIN-Expo designed to aid exposure assessment by serving as a platform enabling integration of human and ecological exposure models.
The PhD project was developed for the transitional ecosystem of the Lagoon of Venice, affected by catchment densely populated area, industrial settlings, oil refining plants, wastewaters and waste incineration plants. The pollution sources have been affecting different environmental compartments, through the release of range of environmental contaminants to the lagoon including organic (e.g. PCBs, dioxin-like PCBs, PCDD/Fs, PAHs) and inorganic (e.g. Cd, Pb, As, Cr, Zn, Ni) chemicals.
Specific objectives of the project involve:
1. Reviewing and selecting the bioaccumulation modelling approaches for aquatic organisms;
2. Implementation of the selected bioaccumulation modelling approach in MERLIN-Expo;
3. Parameterisation of environmental and human PBPK models in order to adapt the models to a site-specific exposure scenario (Venice lagoon case-study), considering peculiar pollutants and environmental media. This step involves data evaluation for ensuring that they support the model of choice, and can be parameterized probabilistically;
4. Verification of model outputs by comparing the model outcomes with actual monitoring data;
5. Application of probabilistic approach in addressing uncertainty and variability of exposure assessment to chemicals;
6. Application of sensitivity analysis in order to identify parameters having the most influence on observed results.
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Tommasini, Laura. "Analysis of wind-wave induced erosion in the Venice Lagoon in the last four centuries: field observations and modelling." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3425751.
Full textAbstract:
Tidal systems are subjected to a variety of internal and external drivers whose interplay and feedbacks affect the shape and the morphological evolution of typical tidal landforms such as channel networks, salt marshes and tidal flats. Several studies have been carried out describing the various processes that drive the evolution of tidal landforms (e.g., the hydrodynamic circulation, the consequences of tidal currents and wind waves on sediment dynamics, vertical and horizontal dynamics of salt marshes, sea level rise and human interferences). Understanding the positive feedbacks existing between salt-marsh erosion, tidal-flat widening and deepening and more energetic wave generation by means of observational evidence and numerical models is a critical step to predict the response of tidal landforms to future environmental changes. With this aim we first improved current our knowledge on the ancient configurations of the Venice lagoon through the bathymetric reconstruction of the oldest map, dating back to 1611, providing a realistic representation of its morphological features. This furthermore allowed us to gain new insights on the hydrodynamic changes occurred in the last four centuries. We then compared different existing model approaches, in order to unravel the implications of different assumptions and formulations used to model wave dynamics in shallow tidal basins. Subsequently, we analysed the effects of wave action on marsh boundaries and how the wave field has changed in the last four centuries with the aim of further emphasizing the feedbacks existing between the overall erosion of the Venice Lagoon and the increase in wave power density. Finally, we analysed the bottom shear stress distribution obtained for different configurations of the Venice Lagoon, in order to support the possibility of describing wind-wave induced bottom erosion as a marked Poisson process.
The main results from this work highlighted that: I) the most important mophodynamic changes in the Venice Lagoon have started in the last century and were mainly triggered by human interferences; II) the assumptions adopted in different modelling framework strongly influence the computation of the bottom shear stress induced by waves, in particular when very shallow water depths are considered; III) the salt-marsh erosion rate is linearly related to the mean wave power density; IV) the erosive trend of the Venice Lagoon during the last four centuries can be explained also by the increase in wave power density and by the analysis of bottom shear stress distribution; V) wind-wave induced erosion processes over tidal flats can be described as marked Poisson processes for all the past and current lagoon configurations, thus leading important consequences for the prediction of future scenarios and implications for the long-term morphodynamic modelling of tidal environments.I sistemi mareali sono soggetti ad innumerevoli forzanti interne ed esterne, le cui interazioni e feedbacks influenzano l’evoluzione morfologica delle principali strutture morfologiche che caratterizzano gli ambienti a marea:i canali, le barene e i bassifondi. Sono stati svolti innumerevoli studi che descrivono i diversi processi che determinano l’evoluzione degli ambienti lagunari (e.g., l’idrodinamica dei canali a marea, le conseguenze delle correnti di marea e delle onde da vento sulla dinamica dei sedimenti, i meccanismi di evoluzione laterale e orizzontale delle barene, l’incremento del livello del medio mare, gli interventi antropici). Capire i meccanismi di feedback positivi esistenti tra l’erosione delle barene, l’allargamento e approfondimento dei bassifondi e la generazione di moto ondoso più energetico con l’aiuto di dati di campo e di modelli numerici risulta un passo fondamentale per prevedere la risposta delle strutture morfologiche degli ambienti a marea ai futuri cambiamenti ambientali. Al fine di raggiungere questo obiettivo, abbiamo, in primo luogo, ampliato la nostra conoscenza delle configurazioni storiche della Laguna di Venezia attraverso la ricostruzione batimetrica della più antica mappa, risalente al 1611, che forniva una rappresentazione realistica delle strutture morfologiche lagunari. Questo ha consentito di conseguenza di approfondire l’analisi dei cambiamenti idrodinamici che si sono verificati negli ultimi quattro secoli. Abbiamo in seguito confrontato diversi approcci adottati in modelli esistenti, al fine di investigare e comprendere le implicazioni delle diverse assunzioni e formulazioni utilizzate per modellare la dinamica delle onde da vento in bacini a marea poco profondi. Di seguito, abbiamo analizzato gli effetti dell’azione delle onde da vento sui bordi delle barene e il cambiamento del campo di moto ondoso negli ultimi quattro secoli, allo scopo di enfatizzare ulteriormente i feedbacks esistenti tra l’erosione generale della Laguna di Venezia e l’aumento della potenza delle onde. Infine, abbiamo analizzato gli sforzi di attrito al fondo ottenuti per diverse configurazioni della Laguna di Venezia, in modo da supportare la possibilità di descrivere l’erosione del fondo indotta da onde da vento come un processo di Poisson marcato. I principali risultati di questo lavoro hanno evidenziato che: I) i più gravosi cambiamenti morfodinamici nella Laguna di Venezia sono iniziati nell’ultimo secolo e sono stati innescati principalmente dagli interventi antropici; II) le assunzioni adottate in diversi approcci modellistici fortemente influenzano il calcolo dello sforzo di attrito al fondo dovuto alle onde da vento, in particolare quando si considerano profondità molto ridotte; III) il tasso di erosione delle barene è linearmente correlato alla potenza generata dalle onde da vento; IV) la tendenza erosiva della Laguna di Venezia negli ultimi quattro secoli può essere spiegata dall’aumento della potenza media e dall’analisi della distribuzione dello sforzo di attrito al fondo; V) i processi erosivi dovuti alle onde da vento in sistemi lagunari possono essere descritti come processi di Poisson marcato in tutte le configurazioni passate e per quella attuale, questo produce importanti conseguenze per quanto riguarda la previsione di scenari futuri e implicazioni per la modellazione morfodinamica a lungo termine degli ambienti a marea.
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Cultrera, Matteo. "HYDROGEOLOGICAL SURVEYS AND ANALYTICAL APPLICATIONS OF THE VENETIAN AQUIFER SYSTEM. IMPLEMENTATIONS OF SAFETY MEASURES FOR THE VENICE LAGOON AREA." Doctoral thesis, Università degli studi di Padova, 2010. http://hdl.handle.net/11577/3422386.
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In the study area (Venetian hinterland, Porto Marghera) there is an average of a few hundred artesian wells (80-350 m in depth) drilled between 1910-1970 and later abandoned. These wells represent a means through which the artesian waters rise; therefore a dispersion process takes place between the groundwaters in the Shallow Aquifer System (0-80 m) and those in the deep artesian aquifers (Artesian Aquifer System, 80-350 m below ground level), in which the hydraulic head has steadily risen for the last 40 years. In this instance the shallow aquifers (about 0-30 m) could be subjected to a recharge through the abandoned wells. This recharge effect adds itself to a hydro-geological system greatly influenced by anthropic activities, such as: safety measures by means of a drainage system made up of many pumping stations which guard both the phreatic level in wide-spread areas and the hydraulic head; diaphragm walls in the whole area of Porto Marghera both near the lagoon border and the inland. The diaphragm wall goes down to 15-20 m in depth.
These diaphragm walls should remove the superfluous groundwaters that – by passing through highly polluted lands – must necessarily be dealt with and treated in suitable plants.
The spontaneous rise of the groundwaters through abandoned wells due to the increase of the hydraulic head in the deep aquifers has not been studied in depth from a scientific point of view.
The analytical and numerical models available in scientific literature mainly deal with the definition of a system made up of abandoned deep wells, through which fluids may run because of the injection of fluid waste or carbon dioxide through injection wells.
Starting from the analytical solutions suggested by different authors new ones have been achieved which may be more effectively adapted to the unusual problems occurred in defining the vertical flow through abandoned wells.
The use of these solutions requires the analysis of a series of hydrogeological parameters. The most important is the geometrical reconstruction of the aquifers involved. An updated hydro-geological model of the whole study area is necessary. As there is no data on explorations at such depths, an updated hydrostratigraphic reconstruction has been developed of the only core drilling on which there is a lot of information: the Ve-1 drilled at 951 m in 1971. The reference hydrostratigraphic sequence required an analysis of the earliest scientific publications on Ve-1 on a sedimen-tological, palynological and magnetostratigraphic level.
The data from the stratigraphies of some wells built through full drilling has been used in a new software package completed in this paper (modalstrata). Modalstrata allows the establishment of a mean stratigraphy from a series of reference verticals in a certain area. In the areas in which there is not much stratigraphic data, the geophysical method of passive seismic was used which allows the identification of lateral continuity in the main reflectors.
This hydrostratigraphic model is confirmed by the comparison of a first hydrostratigraphic series developed for Ve-1.
Therefore the updated hydrostratigraphic model of the study area allowed the definition of the geometries included in the analytical solutions in order to identify the leakage rates in the spe-cific instance a sufficient number of hydrogeological parameters are known.
The GIS environment manages a great amount of data and information. The use of GIS means also allows the development of further geostatistical assessments.Nell’area di studio (hinterland veneziano, Porto Marghera) si segnala la presenza di alcune centinaia di pozzi artesiani (80-350 m di profondità) realizzati nel periodo 1910-1970, successiva-mente dismessi. Tali pozzi rappresentano un possibile passaggio di risalita delle acque artesiane; processo, può innescarsi pertanto un di miscelazione tra le acque sotterranee del Sistema Acquifero Superficiale (0-80 m) con quelle contenute negli acquiferi artesiani profondi (Sistema Acquifero Artesiano, 80-350 m dal piano campagna) dove il potenziale piezometrico è in continua crescita da almeno 40 anni. In tal caso gli acquiferi prossimi al piano campagna (ca 0-30 m) potrebbero essere soggetti alla ricarica attraverso questi pozzi abbandonati. Tale effetto di ricarica va ad aggiungersi ad un sistema idrogeologico fortemente condizionato dalle attività antropiche, quali: il drenaggio prodotto dal sistema di bonifiche costituito da numerose idrovore che mantengono su vaste aree il livello freatico e piezometrico al di sotto del piano campagna; la conterminazione dell’intera area di Porto Marghera, sia in corrispondenza della gronda lagunare, sia nelle aree interne (retromargina-mento). Il marginamento si spinge fino a 15-20 m di profondità. Tale conterminazione prevede l’allontanamento delle acque sotterranee in surplus, che - attraversando terreni caratterizzati da un forte livello di contaminazione - devono necessariamente essere allontanate e trattate per un opportuno stoccaggio. La risalita spontanea di flussi di acque sotterranee attraverso pozzi abbandonati a causa di un incremento del potenziale piezometrico negli acquiferi profondi, dal punto di vista scientifico è un argomento poco investigato. I modelli analitici e numerici disponibili nella letteratura scientifica sono rivolti soprattutto alla definizione di un sistema composto da pozzi profondi dismessi, attraverso si possono avere flussi causati dall’iniezione di rifiuti fluidi o anidride carbonica attraverso da pozzi di re-immissione. L’applicazione di tali soluzioni richiede la conoscenza di una serie di parametri idrogeologici. Il più importante di questi è la ricostruzione geometrica degli acquiferi coinvolti. Un modello idrogeologico aggiornato dell’intera area di studio risulta essere necessario. Poiché mancano dati di indagini dirette alle profondità di interesse, è stata effettuata una aggiornata ricostruzione idrostrati-grafica dell’unico carotaggio continuo del quale si hanno numerose informazioni: il Ve-1 realizzato a 951 m nel 1971. La successione idrostratigrafica di riferimento ottenuta ha richiesto l’analisi delle più recenti pubblicazioni scientifiche relative al Ve-1 in ambito sedimentologico, palinologico, magnetostratigrafico. I dati provenienti dalle stratigrafie derivate da alcuni pozzi realizzati a distruzione di nucleo sono stati utilizzati all’interno di un nuovo pacchetto software, sviluppato all’interno del presente studio (modalstrata). Modalstrata consente di ottenere una stratigrafia media da una serie di verticali d’indagine in una determinata area. Nelle aree dove la distribuzione di dati stratigrafici è carente, è stato utilizzato il metodo geofisico della sismica passiva che ha consentito di individuare la conti-nuità laterale di alcuni riflettori principali. Il modello idrostratigrafico così ottenuto è stato validato attraverso il confronto con la successione idrostratigrafica precedentemente definita per il Ve-1. This hydrostratigraphic model is confirmed by the comparison of a first hydrostratigraphic series developed for Ve-1. Il modello idrostratigrafico aggiornato dell’area di studio ha così consentito la definizione delle geometrie da inserire all’interno delle soluzioni analitiche per la definizione delle portate di leakage ad un caso specifico, del quale si dispone di un sufficiente numero di parametri idrogeologici. Un ambiente GIS gestisce un elevato numero di dati ed informazioni. Il ricorso all’uso di applicativi GIS, permette anche lo sviluppo di ulteriori valutazioni geostatistiche e decisionali.
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Wang, Cheng. "Contribution of airborne hyperspectral remote sensing and lidar altimetry to the classification of vegetation species of the Venice lagoon area." Université Louis Pasteur (Strasbourg) (1971-2008), 2005. http://www.theses.fr/2005STR1A002.
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Ce travail a deux objectifs: i) évaluer le potentiel d'images hyperspectrales de télédétection pour la classification précise des espèces végétales d'un système écologique complexe comme la zone intertidale de marais salants de la lagune de Venise. Ii) évaluer en combinaison avec des mesures altimétriques Lidar la réalité d'une relation entre espèces végétales et hauteur du terrain par rapport au niveau moyen de marée. La recherche porte sur le développement d'une procédure pour le traitement et l'analyse depuis les données brutes de télédétection et mesures de vérité terrain jusqu'à la relation entre espèces et morphologie. Les principales contributions sont: i) évaluation de deux méthodes pour la sélection des bandes les plus significatives des données hyperspectrales et étude sommaire de l'impact de l'atmosphère sur la sélection. Ii) algorithme de classification pour l'estimation de la fraction intra pixel de mélanges d'espèces et la classification en zones intertidales. Iii) analyse des erreurs associées au données Lidar brutes et méthode d'extraction de l'information (morphologie). Iv) analyse combinée et synergie des données Lidar et images hyperspectrales pour la mise en évidence d'une relation robuste entre espèces végétales et morphologie du terrainThe objective of the work are twofold: i) investigate the potential of remotely sensed hyperspectral image data for accurate classification of vegetation species in complex ecological systems such as the salt-marshes in the Venice lagoon; ii) in conjunction with airborne Lidar altimetric measures, evaluate the reliability over the whole Venice salt-marsh area of a relationship between vegetation species and ground elevation with respect to mean tide level. This research thus develops an approach and complete procedure for data processing and analysis from the collection of raw remotely sensed data and field measurements to the relationship established at the end of this thesis. Significant advances in this study focused on a remote sensing perspective include: i) assessment of two methods for the selection of most informative spectral bands out of the ones acquired with hyperspectral images and exploration of the atmospheric influence on the band selection results. Ii) classification algorithm for the estimation of sub-pixel fractional abundance of vegetation species and vegetation mapping in salt-marsh areas. Iii) error analysis of raw Lidar data and information (geomorphic properties) extraction. Iv) synergistic analysis of Lidar data and hyperspectral data to search for a reliable relationship between vegetation species and associated geomorphic properties
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Sambo, Beatrice <1995>. "Building the resilience of coastal systems to extreme events: the case of the Metropolitan City of Venice and its lagoon." Master's Degree Thesis, Università Ca' Foscari Venezia, 2020. http://hdl.handle.net/10579/16973.
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The significant increases in magnitude and frequency of climate related extreme events are placing considerable economic, logistical, and at times social strains upon coastal systems. Within the BRIDGE project, a scenario-informed multicriteria methodology was designed to integrate qualitative (i.e. local stakeholders’ preferences) and quantitative information (i.e. climate change projections) in a unique framework supporting the enhancement of coastal systems resilience to extreme events. Different group of local stakeholders (e.g. local authorities, civil protection agencies, SMEs, NGOs) were involved to identify critical functions (i.e. coastal systems and processes that are likely to be affected by extreme events) and propose risk management initiatives/measures that can be strategic to enhance overall system resilience under the future climate scenarios, and that they wish to consider for prioritization. Most representative scenarios describing main climatic threats (e.g. storm surges, floods, heatwaves, drought) that could affect coastal areas of interests were selected and represented based on projections of Regional Climate Models for medium term period (e.g. 2021–2050). Multicriteria Decision Analysis (MCDA) was finally used to compare the initiatives and to select the optimal ones across different scenarios, using the set of critical functions and local stakeholders’ perspectives as the basis for the ranking. The methodology was tested in the Metropolitan City of Venice to assess the resilience of proposed risk management projects against the impacts of climate change scenarios envisioned for the area.
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Bernardi, Ilaria. "indagine sperimentale sull'attenuazione del moto ondoso da parte di vegetazione sommersa o parzialmente emersa." Doctoral thesis, Università degli studi di Padova, 2009. http://hdl.handle.net/11577/3426517.
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Salt marsh vegetation of the Lagoon of Venice has an important role on the energy wave dissipation and it can be considered a natural factor to protect internal areas from erosion. In this research a study of the mechanisms of wave damping by vegetation and modeling wave attenuation by vegetation was carried out. Laboratory experiments were conducted to measure wave attenuation resulting from synthetic vegetation (Spartina maritima), under a range of wave conditions and plant stem densities typical of salt marsh. The laboratory data were analyzed using linear wave theory and compared to the model of Mendez and Losada (2004), to quantify vegetation drag coefficient and to find relations between wave damping and vegetation characteristics.
Generally, in the formulation of the drag coefficient CD, bottom friction is neglected and only the resistance of vegetation is taken into account: it is a “bulk” drag coefficient, which does not distinguish between the vegetation effect and the effect of bottom friction. In the present work bottom friction is, instead, explicitly considered in order to quantify the drag coefficient due only to the resistance induced by vegetation, and to quantify a specific bottom friction coefficient due to the presence of vegetation. Here a theoretical approach is presented and validated by experimental data.
This work can find a possible application when describing wave propagation within shallow basins characterized by the presence of vegetation, such as the Lagoon of Venice.La presenza di vegetazione sul suolo delle barene della Laguna di Venezia svolge un importante effetto dissipativo sul moto ondoso che si propaga all’interno della laguna e può essere considerato un fattore naturale di protezione dai fenomeni di erosione. In questa tesi è stato effettuato uno studio sui meccanismi di dissipazione dell’energia del moto ondoso in presenza di una superficie vegetata, e sulla modellazione matematica degli effetti della vegetazione sul moto ondoso, attraverso un’indagine sperimentale condotta in laboratorio, con un tipo di vegetazione artificiale (Spartina maritima) e in condizioni idrodinamiche simili a quelle presenti in una zona di barena. I risultati sperimentali ottenuti sono stati analizzati assumendo valida la teoria lineare dell’onda, e confrontati con le soluzioni teoriche proposte da Mendez e Losada, allo scopo di quantificare il coefficiente di resistenza della vegetazione artificiale e determinare delle relazioni fra la dissipazione di energia del moto ondoso e le caratteristiche della vegetazione. Generalmente, nelle formulazioni dei coefficienti di resistenza CD presenti in letteratura, la resistenza prodotta dall’attrito del fondo viene considerata trascurabile rispetto a quella prodotta dalla vegetazione: vengono considerati dei CD globali, che inglobano al loro interno tutti gli effetti (vegetazione più attrito), senza alcuna distinzione fra di essi. In questo lavoro, invece, si è cercato di considerare separatamente i due effetti, allo scopo di determinare un coefficiente Kv responsabile dell’effetto della sola vegetazione, e un coefficiente Kf responsabile dell’effetto del solo attrito di fondo, in presenza di vegetazione. Per affrontare il problema viene presentato un approccio teorico, che è validato dai dati sperimentali. Questo lavoro può trovare delle possibili applicazioni nella descrizione della propagazione del moto ondoso all’interno di bacini caratterizzati da bassi fondali e presenza di vegetazione, come è il caso della Laguna di Venezia.
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Diao, Toba <1977>. "Metal contamination of sediments in the lagoon of Venice: Studio of their geochemical speciation by sequential extraction in order to assess their mobility and their bioavailability." Master's Degree Thesis, Università Ca' Foscari Venezia, 2017. http://hdl.handle.net/10579/9411.
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Main industrial activities of Porto Marghera include different basic chemical products, oil refining and storage, shipbuilding, metal extraction and metallurgy, as well as energy production and distribution, wastewater treatment, hazardous waste incineration and petrochemical plants thermal power plants, steel, aluminum and fertilizer production sites. These industrial activities led to severe chemical contamination of soil, groundwater, sediment and inner tidal canal, to the point of the regional authorities to classify one third of the Venice lagoon as not suitable for shell fish harvesting (DGR3366/2004 ). The primary aim of this study is, therefore, to determine the concentration of heavy metals in superficial sediments of lagoon Venice and to assess their potential ecological risks. For this goal it was considered the study of height metal element ,Al, Bi Co, Cu, Mo, Mn , Rb using sequential extraction procedure of four fraction of the sediment minerals. Mollusks, crustaceans and other marine invertebrates are known to accumulate high levels of heavy metals in their tissues and yet survive in polluted environments. The second aim of this study is understand the relationship between metal fractionation and bioaccumulations of metal in clams (Ruditapes philippinarum). The manila clam , a filter-feeding organism living in the seafloor sediment, represents the major aquaculture species within the Venice lagoon, and due to its widespread distribution across the entire lagoon, it is considered an excellent “sentinel” species for bio-monitoring Venice lagoon areas and metal mobility on sediments. The Inductively Coupled Plasma Optical Emission and mass spectrometry was used for making an analytical procedure i.e. a quantitative analysis of multielements.
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Adu, Godbless Benhene <1992>. "Occurrence of Rare Earth Elements (REEs) and trace elements in in feathers of fledglings of Ichthyaetus melanocephalus (Mediterranean gull) and Chroicocephalus ridibundus (Black-headed gull) from the Venice Lagoon (Italy)." Master's Degree Thesis, Università Ca' Foscari Venezia, 2019. http://hdl.handle.net/10579/16160.
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Rare earth Elements (REEs) are emerging global pollutants due to their distinctive physical and chemical features that render them vital in a multitude of manufacturing apps. However, few researchers have been able to draw on any systematic study into REE’s presence and build up in the environment. So far, no previous study has investigated REE’s in the feathers of gulls using a non-invasive biomonitoring tool.
The concentrations of 16 REEs and trace elements (Hg,Pb,Cd, Rb and Se) were analysed in the feathers of the Mediterranean gull (MG) (Ichthyaetus melanocephalus) and Black-headed gull (BHG) (Chroicocephalus ridibundus). The concentrations were ascertained by an Inductively Coupled Plasma-Mass Spectrometer subsequent to a microwave digestion of feathers.
MG accumulated higher REEs and trace elements than BHG. All the 16 REEs were detected in each feather sample with a strong correlation to each element; only in the case of Ce, there were data below the Limit of Quantification (LoQ). Light rare earth elements (LREE) were found to be higher in concentration as compared to heavy rare earth elements (HREE). In the case of the trace elements, extreme concentrations of Cd and Rb were found in some bird species indicating a greater exposure. Most of the other trace elements (Hg, Pb and Se) were found below the LoQ.
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Buscemi, Federico. "Analysis of a mesoscale cyclone in the Adriatic Sea." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/24953/.
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In the evening of November 12, 2019, an exceptional high tide - the second most intense since sea level data are recorded - hit the city of Venice and the entire lagoon, flooding and damaging a large part of the historical center. The causes of this event are due to a small mesoscale cyclonic structure characterized by a warm core, grown in the central Adriatic, which, moving towards the Northwest, strengthened and passed over the Venice lagoon. The passage of the cyclone was anticipated by intense Bora, which turned into Sirocco first and Libeccio afterward, causing the sudden rise of the sea level in the lagoon. This work investigates the factors that determined the development of the cyclone, as well as the characteristics of its particular structure. For this purpose, simulations were carried out with the WRF-ARW model, with initial and boundary conditions supplied by the global GFS model. Three simulations with different starting times were performed, each initialized with a different analysis of the GFS model. The results were compared on the basis of the prediction of the minimum sea level pressure value and of the trajectory of the cyclone. The simulation whose results are closest to the data observed by the meteorological stations is identified, and the factors that have contributed the most to the development of the cyclone are searched for. The interaction between a strong potential vorticity anomaly at 300 hPa and the advection of warm, humid air in the lower layers was the main factor responsible for the cyclone development. The pre-existence of positive cyclonic vorticity, resulting from the convergence of the Sirocco and Bora winds in the northern Adriatic, also made the environment favorable to the cyclone development. Therefore it appears as the cyclone developed by a baroclinic instability process typical of extra-tropical cyclones, but with much smaller dimensions and characteristics.
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Barbaro, Jvan. "Hydro-morphodynamics of tidal embayments and climate change." Doctoral thesis, Università degli studi di Padova, 2014. http://hdl.handle.net/11577/3424614.
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This thesis is motivated by the desire to understand better and to model some important aspects of tidal estuary. Three different subjects are studied: cross-section modelling; wind characterization in Venice Lagoon (Italy); drainage channel initiation.
It has been developed a physical based analytical model to study the estuary cross-section for hydrodynamics and sediment transport. The main focus is to study the effects of different boundary conditions.
At the bed, three condition are applied: the classical no-slip condition with constant eddy viscosity; a partial-slip condition with constant eddy viscosity; a no-slip condition with parabolic eddy viscosity profile. Solutions are investigated using scaling and perturbations methods. Whereas the partial-slip condition does not consistently improve the no-slip condition, the use of parabolic eddy viscosity is a really impressive progress: it allows a better understanding and representation of the physical dynamics of the environment.
Regarding wind in the Venice lagoon, it has been analysed an 11-years database of wind data taken in the lagoon and in the nearby sea. Wind statistics are studied by rose plots and nine probability density functions. This work results in a characterization of the annual, seasonal, monthly and hourly statistics of the wind in the lagoon.
The last argument of research concerns the modelling of drainage channel initiation in sheet flow condition. The analysis is specialized to model the periodic spacing of parallel drainage channels; this type of networks are present in many different environments and with a wide range of length-scales. The model is analytical and physical based; solutions are searched by scaling and perturbation methods. The results point out that the main parameters are the water depth, the concentration of sediment, the critical velocity for sediment resuspension. Spacing of drainage channels are found for a wide range of parameters.L'interesse di questa tesi è quello di meglio comprendere alcuni aspetti importanti degli ambienti a marea. In questo contesto, sono stati analizzati tre argomenti: modellazione delle sezioni trasversali di un estuario, caratterizzazione del vento nella laguna di Venezia e la formazione di canali di drenaggio. Si è costruito un modello analitico per lo studio dell'idrodinamica e il trasporto dei sedimenti focalizzando l'attenzione alle sezioni trasversali. Lo scopo principale è stato quello di analizzare gli effetti dell'applicazione di differenti condizioni al contorno. Al fondo sono state applicate tre differenti condizioni: quella classica di non scivolamento con viscosità di vortice costante, la condizione di parziale scivolamento con viscosità costante e la condizione di non scivolamento con profilo parabolico di viscosità. Le soluzioni sono state cercate attraverso l'utilizzo dell'analisi dimensionale e lo sviluppo perturbativo. La condizione di parziale scivolamento non ha comportato un miglioramento significativo rispetto al non scivolamento. Invece, la condizione di viscosità con profilo parabolico è risultata una miglioria significativa: permette una migliore comprensione e rappresentazione della fisica del sistema. Per quanto riguarda il vento in laguna di Venezia, si è studiato un database di 11 anni di dati di vento in laguna e nel mare vicino. Si sono utilizzati grafici di vento a settori e si sono calcolate le distribuzioni di probabilità. Attraverso questo lavoro, si sono caratterizzati gli andamenti annuali, stagionali, mensili e orari. L'ultimo argomento riguarda lo studio della formazione di canali di drenaggio in consizioni di flusso laminare. L'analisi riguarda lo studio della spaziatura dei canali a distribuzione parallela e periodica che caratterizzano diversi ambienti per un range ampio di parametri. Il modello è analitico e basato sulla fisica del sistema; le soluzioni sono ricercate attraverso l'analisi dimensionale e i metodi perturbativi. I risultati evidenziano che i parametri principali sono il battente d'acqua, la concentrazione, e la velocità critica per la risospensione. Si sono trovati i valori di spaziatura dei canali per un ampio spettro di variazione dei parametri.
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Tolomio, Massimo. "Evaluation of long-term water management strategies for saving water and reducing nitrogen and phosphorus losses from agricultural fields: controlled drainage and surface flow constructed wetland case studies in Venice Lagoon drainage basin." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3421846.
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In in contesto di carenza idrica e di inquinamento delle acque superficiali causato dalle attività agricole, devono essere identificate nuove pratiche di gestione delle risorse idriche che rispondano a queste problematiche e possano essere utilizzate in diversi ambienti.
Il bacino idrografico della Laguna di Venezia (nell'Italia nord-orientale) è un'area sensibile all'inquinamento delle acque superficiali. La prevalenza di terreni pianeggianti e la presenza di una falda freatica superficiale, tuttavia, suggeriscono condizioni idonee per la realizzazione di due pratiche di gestione idrica per la riduzione dei carichi di N e P provenienti dalle aree agricole: il drenaggio controllato (controlled drainage: CD) e le wetland artificiali a flusso superficiale (surface flow constructed wetlands: SFCWs). Il monitoraggio di lungo periodo delle performance di queste pratiche è necessario per fornire risultati di validità generale, che non siano condizionati dalla variabilità meteorologica annuale.
Questo lavoro valuta le performance di un sistema di CD e di SFCW in un esperimento di lungo periodo. Il CD è stato monitorato durante i periodi 1995-2002 e 2006-2013, in termini di bilancio idrico e di resa delle colture, e dal 2007 al 2013 anche per le perdite di N e P. La SFCW è stata monitorata dal 2007 al 2013 per la riduzione dei carichi di N e P.
Il CD ha permesso di ridurre i deflussi idrici del 69% e ha determinato un aumento complessivo della resa di granella di mais del 26,3%, e della resa di mais da insilato del 4,0%. Le perdite di NO3-N e PO4-P nelle acque superficiali sono state ridotte rispettivamente del 92% e del 65%.
La SFCW ha mostrato tassi di rimozione annui apparenti dell'83% e del 79% rispettivamente per NO3-N e N totale, e del 48% e del 67% rispettivamente per PO4-P e P totale.
Sia il CD che la SFCW si sono rivelati efficaci nel ridurre i carichi inquinanti di N e P, ed il CD ha anche contribuito ad aumentare la resa delle colture attraverso il risparmio idrico. Per questi motivi, l'applicazione di queste due pratiche di gestione idrica è da prendersi in considerazione in questo ambiente.In the context of increasing water scarcity and surface water pollution caused by agricultural activities, new water management practices that tackle these issues and that could be used in different environments should be identified. The Venice Lagoon drainage basin (in north-eastern Italy) is a sensitive area to surface water pollution. The prevalence of flat lands and the presence of shallow phreatic groundwaters, however, create suitable conditions for the implementation of two water management practices that can reduce N and P loads coming from agricultural fields: controlled drainage (CD) and surface flow constructed wetlands (SFCWs). Long-term monitoring of the performances of these practices is required to provide sound results that are not contingent on annual weather variability. This work evaluates the performances of a CD and SFCW system in a long-term experiment. CD was monitored during the periods 1995-2002 and 2006-2013 for water balance and crop yield, and from 2007 to 2013 for N and P losses. The SFCW was monitored from 2007 to 2013 for N and P removal loads. CD permitted to reduce water outflows of 69%, and provided an overall increase in maize grain yield of 26.3% and in silage maize yield of 4.0%. NO3-N and PO4-P losses to surface waters were reduced by 92% and 65%, respectively. The SFCW showed annual apparent removal rates of 83% and 79% respectively for NO3-N and total N, and of 48% and 67% respectively for PO4-P and total P. Both CD and SFCW proved effective in reducing N and P loads, and CD helped increasing crop yield through water saving. For these reasons, the application of these two water management practices is advisable in this environment.
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Roner, Marcella. "READING THE SIGNATURES OF CHANGING ENVIRONMENTAL FORCINGS IN SALT-MARSH BIOGEOMORPHIC SYSTEMS." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3424455.
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The question on whether actual tidal morphologies are in equilibrium with current environmental conditions or retain signatures of past climatic changes or human interventions is a classical and fascinating one, furthermore being of intellectual as well as practical interest. Understanding the dynamic response of tidal landscapes to past conditions is critical to predict their response to future environmental changes, such as rate of relative sea-level rise and sediment supply. This is an open and fundamentally important point, particularly in times of natural and anthropogenic changes, during which tidal environments are most exposed to possibly irreversible transformations with far-reaching socio-economic and ecological implications worldwide.
The proposed work aims at analyzing the signatures of changing environmental forcings imprinted in the landscape and in the sedimentary record of the Venice Lagoon to refine our knowledge of tidal landforms dynamics. The thesis is developed following a biogeomorphic approach to the study of salt-marsh landscapes. Marsh biomorphological evolution, in response to changes in the environmental forcings, is analyzed investigating the relative role and mutual interactions and adjustments between physical and biological processes shaping the salt-marsh landscape.
This thesis was carried out through a series of extensive temporal and spatial high-resolution morphological, sedimentological, geochronological and elemental analyses, aimed at exploring the main features of sub-surface marsh samples and lagoonal sediment cores.
The study of sub-surface marsh samples highlights the mutual role of inorganic and organic accretion on salt marshes, which is mainly driven by the inorganic component near the channels, while the organic component largely contributes in the inner-marsh portion. The analyses carried out on sediment cores refine the knowledge of the latest Holocene sedimentary succession of the Venice Lagoon, and furnish a chronostratigraphical model for the evolution over the last two millennia. In particular, for a salt-marsh succession, the analyses highlight the occurrence of a delayed marsh-dynamic response to changing sediment delivery rates.La questione inerente l’equilibrio delle morfologie tidali con le attuali condizioni ambientali, o se esse conservino tutt’ora i segni dei cambiamenti climatici o degli interventi antropici passati, è un argomento classico ed affascinante nel campo delle Geoscienze, oltre ad essere di interesse sia intellettuale che pratico. Comprendere i meccanismi che governano la risposta di un ambiente a marea a variazioni passate delle forzanti ambientali è fondamentale per prevedere la loro risposta a cambiamenti ambientali futuri, quali il tasso di innalzamento del livello del mare relativo e l’apporto di sedimenti. Si tratta di un tema tutt’oggi sospeso e di fondamentale importanza, soprattutto in tempi di cambiamenti sia naturali che umanamente indotti, durante i quali gli ambienti tidali sono maggiormente esposti a trasformazioni potenzialmente irreversibili, con implicazioni di vasta portata socio-economica ed ecologica in tutto il mondo. Il presente lavoro si propone di analizzare le firme del cambiamento delle forzanti ambientali impresse nella morfologia e nel record sedimentario della Laguna di Venezia, con lo scopo di affinare la conoscenza delle dinamiche tidali. La tesi volge allo studio di sistemi di barena attraverso un approccio biogeomorfologico. L’evoluzione geomorfologica delle barene, in risposta ai cambiamenti delle forzanti ambientali, è analizzata investigando il ruolo relativo, le interazioni reciproche e le regolazioni esistenti tra i processi fisici e biologici che modellano gli ambienti di barena. Il lavoro è realizzato attraverso una serie di analisi morfologiche, sedimentologiche, geocronologiche ed elementali, eseguite ad alta risoluzione spazio-temporale, volte ad esplorare le principali caratteristiche sia di campioni sub-superficiali di barena, sia di carote di sedimenti lagunari. Lo studio dei campioni sub-superficiali evidenzia il ruolo reciproco delle componenti organica ed inorganica nell’accrezione delle barene, la quale è principalmente guidata dalla componente inorganica in prossimità dei canali, mentre la componente organica contribuisce in gran parte nelle porzioni più interne delle barene. L’analisi effettuata sulle carote lagunari implementa la conoscenza della successione sedimentaria tardo-Olocenica della Laguna di Venezia, e fornisce un modello di evoluzione cronostratigrafica degli ultimi due millenni. In particolare, le analisi effettuate su una successione sedimentaria di barena, evidenziano la presenza di una risposta dinamica ritardata dell’ambiente a cambiamenti nei tassi di apporto sedimentario.
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Brivio, Lara. "Morphodynamic evolution of meandering channels in tidal landscapes: sedimentology and stratal architecture." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3427220.
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Meandering channels constitute one of the fundamental components of tidal systems, as related tidal point bars are ubiquitous features in lagoonal or estuarine sedimentary successions. Nevertheless, a limited number of studies analyzed their morphodynamic evolution, together with their planimetric shape and morphometric characteristics. Their internal architecture and sedimentary facies distribution are relatively unexplored, and commonly investigated using facies models developed for fluvial meander bends.
Focusing on differences, more than on similarities, between tidal and fluvial meanders, the present work aims at investigating the stratal architecture and sedimentary facies distribution of selected tidal point bars in the Venice Lagoon (Adriatic Sea, Italy). Three main issue were investigate by the present work: i) the role of low order tributaries in controlling the evolution of tidal meander bend; ii) the influence of salt marsh aggradation in shaping geometries of tidal point bars, iii) sedimentary process and morphodynamics changes acting on subtidal point bars. The morphodynamic evolution of tidal channels, and related sedimentary products, were analyzed using a multidisciplinary approach, which comprises the comparison of historical photos, the interpretation of high-resolution sub-bottom profiles, core logging analysis and 3D modelling.
The main results stemmed out form the study sites highlight that: I) lateral tributaries can strongly influence the evolution of bends modifying local mechanisms of sediment and flow distribution; II); the migration of tidal point bars occurs under aggradational conditions both in intertidal and subtidal setting; III) subtidal bars evolve under the strong interaction between wave and tidal currents.I canali meandriformi costituiscono una delle principali componenti dei sistemi tidali e, come le relative point bar, sono una caratteri ricorrenti all'interno delle successioni sedimentarie lagunari. Tuttavia, un numero limitato di studi hanno analizzato l’evoluzione morfodinamica e le caratteristiche morfometriche di canali meandriformi tidali. La loro architettura interna e la distribuzione delle facies sedimentarie sono relativamente inesplorate, e comunemente investigate utilizzando i modelli di facies sviluppati per i meandri fluviali. Concentrandosi sulle differenze, più che sulle similitudini, tra i meandri tidali e fluviali, questo lavoro si propone di investigare le architetture stratali e la distribuzione delle facies sedimentarie delle point bar selezionate nella della Laguna di Venezia (Mare Adriatico, Italia). In questo lavoro vengono affrontate tre problematiche principali: i) il ruolo dei tributari di ordine inferiore nell'evoluzione dei meandri tidali; ii) l’influenza dell'aggradazione delle barene nella modellazione delle geometrie delle point bar tidali; iii) i processi sedimentari e le variazioni morfodinamiche agenti sulle point bar subtidali. L’evoluzione morfodinamica dei canali tidali, e i relativi prodotti sedimentari, sono stati analizzati utilizzando un approccio multidisciplinare, che comprende la comparazione di foto storiche, l’interpretazione di profili sub-bottom ad alta risoluzione, log di carote e modellazione 3D. I risultati principali ottenuti dai tre siti in esame evidenziano che: I) gli affluenti laterali possono influenzare fortemente l’evoluzione dei meandri, modificando i meccanismi locali di distribuzione dei flussi e dei sedimenti; II) la migrazione delle point bar tidali avviene in contesti aggradazionali, sia in ambienti intertidali che subtidali; III) le barre subtidali evolvono sotto l’influenza della forte interazione tra correnti da onde e di marea.
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Cosma, Marta. "Stratal patterns and sedimentary facies in tidal point bars." Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3422690.
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Tidal channels play a key role in the evolution of coastal environments and commonly dominate tidal landscapes. These channels commonly show a clear meandering pattern which shapes the architectural geometries of sedimentary successions accumulated in tidal coastal realms. Nevertheless, a limited number of studies analysed the morphodynamic evolution of tidal meanders and the related point bar sedimentary bodies, whose internal architecture and sedimentary facies distribution remain still poorly explored, as highlighted by their scarce documentation in the rock record. The capability of reading the signature of tidal processes in sedimentary successions represents a powerful tool for paleo-environmental reconstructions. Detecting tidal channel deposits will contribute to studies on Holocene deposits and ancient rocks, with implications spanning from adaptation of natural systems to anthropic pressure to subsurface exploration for georesources. The present work aims at improving our understanding of the relationship between the evolution of tidal meander bends and the related sedimentary products, through the investigation of different research issues (RI), including: i) the influence of vertical aggradation and substrate compaction in shaping geometries of tidal point bars (RI1); ii) the reconstruction of three-dimensional architecture of tidal point bars, through a numerical modelling approach, developed under different aggradational conditions and planform transformation styles (RI2); iii) the relationship between mechanisms of bar growth and internal facies arrangements (RI3); and iv) the analysis of piracy-controlled geometries of point bar bodies (RI4). These research issues have been carried out in different tidal settings, including microtidal (Venice Lagoon, Italy – RI1, 2, and 4) and macrotidal (Bay of Mont Saint Michel, France – RI3) environments; both in modern (RI1, 2, 3, and 4) and ancient record (Eocene deposits of the Tremp-Graus Basin, Spain – RI4). A multidisciplinary approach has been adopted for modern examples, with different methodologies encompassing remote sensing techniques (i.e. historical aerial photos and LiDAR topographic time-series analysis), geomorphological field observations, sedimentary core analysis, and 3D forward stratigraphic modelling. The analysis of the ancient case study examples relies on classical outcrop sedimentology approach, which included line-drawing of photomosaics, bed-by-bed logging, and collection of paleo-flow measurements.
The main results from this work highlighted that:
I) geometries of tidal point bars can vary following aggradational conditions of surrounding overbank areas, along with changes in local accommodation space and channel discharge. These are, in turn, influenced by differential substrate compaction and channel network evolution;
II) 3D geometries of point bars developed by slowly migrating tidal channels under aggradational conditions, differ from tabular bodies envisaged by traditional point bar models. Indeed, their geometries are shaped by the planform and vertical shift of channel bends;
III) tidal meanders can expand alternating accretionary stages along seaward and landward side of point bars. In this contest, large amounts of mud-rich deposits are stored in their axial zone, where rhythmic tidal deposition is better recorded;
IV) occurrence of densely-drained tidal networks prevents channel bends to freely meander and causes interaction with adjacent channels triggering piracies. These piracies cause premature deactivation of sinuous channels and hinder the development of laterally extensive point bar bodies.
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Vianello, Rita. "Le savoir des mytiliculteurs de la lagune de Venise et du littoral breton : étude d'anthropologie comparative." Thesis, Brest, 2013. http://www.theses.fr/2013BRES0025/document.
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D’un point de vue géographique, la lagune de Venise n’a que peu en commun avec les baies principales de la Bretagne septentrionale, si ce n’est son ouverture sur la mer. Les deux réalités étudiées ont pourtant en commun leur soumission à l’action des marées qui a poussé les populations littorales à développer des savoirs et des techniques de pêche traditionnelles d’une très grande richesse et qu’ils ont su faire évoluer au cours du temps pour mieux les adapter aux caractéristiques du milieu.Les différentes formes de récolte et de pêche, l’élevage des moules en particulier, ont entraîné une domestication et une anthropisation de ces zones. En Bretagne, tout comme à Venise, la valorisation de la moule en tant que ressource alimentaire et économique est assez tardive.Que ce soit dans les sources bibliographiques ou durant l’enquête réalisée sur le terrain, notre recherche nous a permis de repérer des allusions fréquentes à la toxicité présumée de ce mollusque, à Venise appelé « peòcio » c’est-à-dire « pou » et considéré non comestible. Quels mécanismes ont métamorphosé la moule en un aliment aujourd’hui apprécié et recherché ? Et comment des zones, autrefois très pauvres se sont transformées, en des lieux renommés pour la production de moules ? C’est pour répondre à ces questions que nous avons entrepris la reconstruction de l’histoire de la mytilicultureFrom a geographic perspective, the Venice Lagoon has almost nothing in common with the main northern bays of “Bretagne”; simply, both open on the sea. Therefore, the two studied realities have to share their submission to the action of tides that have pushed the coastal communities to develop fishing knowledge and techniques. They were able to evolve over time to better suit the characteristics of the environment. The different forms of harvesting and fishing, mussel farming in particular, led to domestication and human impacts in these areas. In “Bretagne”, as in Venice, is rather late the development of mussels as food and as economic resource.Whether in the literature sources or during the survey in the field, our research has led us to identify frequent allusions to the alleged toxicity of this mollusk in Venice called “peòcio” that mean “cootie” and considered inedible. What mechanisms have metamorphosed mussels into a regarded and sought food today? And how formerly very poor areas are transformed into places renowned for the production of mussels? It is to answer these questions that we undertook the reconstruction of the history of the mussel
Da un punto di vista geografico la laguna di Venezia ha poco in comune con la Bretagna settentrionale se non il suo sbocco sul mare. Di conseguenza le due realtà condividono la dipendenza dall’azione delle maree, le quali hanno spinto le popolazioni litoranee a sviluppare dei saperi e delle particolari tecniche di pesca adattate alle caratteristiche dell’ambiente.Nel corso della nostra ricerca abbiamo incontrato delle frequenti allusioni alla presunta tossicità del mitilo, a Venezia chiamato “peòcio”, cioè pidocchio. Infatti a Venezia, come in Bretagna, la valorizzazione dei mitili quale risorsa alimentare ed economica è un fenomeno tardivo. Quali meccanismi hanno trasformato i mitili in un alimento che è oggi apprezzato e ricercato? E in che modo delle zone un tempo molto povere si sono trasformate in località rinomate per la produzione di questi molluschi? Per rispondere a queste domande abbiamo ricostruito la storia della mitilicoltura
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O'Connell, Giuliana Cattelan. "Venice, the lagoon and the Adriatic Sea : a historic struggle for survival /." 2005. http://www.consuls.org/record=b2743480.
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Thesis (M.S.) -- Central Connecticut State University, 2005.Thesis advisor: Timothy Rickard. "... in partial fulfillment of the requirements for the degree of Master of Science in International Studies." Includes bibliographical references (leaves 123-137). Also available via the World Wide Web.
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Sommerfreund, Julie K. "Evaluation of contaminant fate in the Venice Lagoon using a multi-segment fugacity/aquivalence model and a probabilistic uncertainty analysis." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=452794&T=F.
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