Venice Lagoon (Italy), the largest wetland in the Mediterranean basin, is extremely vulnerable to... more Venice Lagoon (Italy), the largest wetland in the Mediterranean basin, is extremely vulnerable to variations in relative sea level (RSL) which is locally defined by an average rising rate of about 2.5 mm per year, resulting from both sea-level change and vertical land movements. The environmental pressures stemming from projected higher RSL rising rates will have a profound impact on Venetian coastal ecosystems with a significant loss of wetlands partly due to a drastic reduction of salt marsh habitats. To understand how changes in marine influence could create such ecological upheaval in the near future, and fully remodel these coastal salt marshes, we reconstructed 5650 years of RSL rise history and land subsidence impacts on ecosystem dynamics during the Holocene transgression of Venice Lagoon. We show that the evolution of ecosystems mainly mirrors the gradual intrusion of salt water that progressively reshaped the coastal vegetation by turning the area into salt lagoon habitats. Before marine influence became dominant, the area was mainly fed by substantial freshwater supplies allowing the development of a diversified alluvial vegetation. Environmental pressures increased markedly about 6800-6600 years ago when seawater began to significantly influence the area, affecting marsh-swamp ecosystems. These marine inputs promoted the spread of halophytic and salt-tolerant vegetation types which laid the foundations for what would become the current salt marsh habitats. Venice Lagoon serves as a stark reminder of how rising sea levels, accompanied by increased saltwater intrusion into freshwater habitats and adjacent lands, can drastically alter and reshape pre-existing ecosystems. The lagoon's long-term ecological record indicates that contemporary fluctuations in RSL pose a substantial ecological threat, potentially culminating in a major upheaval of aquatic habitats in the near future.
ABSTRACT The aim of the investigation was to define the mechanisms of sediment transport in the s... more ABSTRACT The aim of the investigation was to define the mechanisms of sediment transport in the swash zone of microtidal coarse-clastic beaches in the very short term by evaluating the displacement rates of marked pebbles under low-energy wave conditions. Tests were performed at two sites (Marina di Pisa, Ligurian Sea, and Portonovo, central Adriatic Sea) to check the consistency of the data over a range of different grain sizes. Two recovery campaigns were carried out at both sites, one 6 h and the other 24 h after the injection. During the experiments wave action was at a minimum (wave heights never exceeded 0.3 m). The results show that 20% of pebbles ranging in diameter from 30–90 mm moved significantly (more than 0.5 m) already 6 h after the injection, with some tracers being lost (3%). After 24 h, 40% of the pebbles were significantly displaced and 10% were lost. The preferential downslope movement of tracers, which suggests that coarse sediment movement under low-energy conditions is mainly controlled by gravity processes enhanced by steep beachface slopes, represents the novelty of the results reported here. It would appear that swash processes on low-energy beaches cause a significant rate of pebble displacement through the destabilization induced by wave uprush and backwash. Despite the microtidal range, the position of the mean water level plays a major role in changing the beach level at which swash processes can actually trigger pebble movement. The results of this study show that considerable, and mostly seaward-directed, coarse sediment transport takes place even during short fair-weather periods.
The storm response of three Italian mixed beaches is investigated. Two sites are located on the e... more The storm response of three Italian mixed beaches is investigated. Two sites are located on the eastern side of the country (Portonovo and Sirolo) and one on the western side (Marina di Pisa). Portonovo and Sirolo are two mixed sand and gravel beaches (MSG) where the storms approach from two main directions (SE and NE). Marina di Pisa is a composite mixed beach subject to storms driven by SW. Gravel nourishments were undertaken in recent years on the three sites. Beach evolution was monitored measuring the same network of topographic profiles at a monthly to seasonal frequency. Beach orientation and the presence of protecting structures are the main reasons for the displacement and the accumulation of significant amount of sediments. In Marina di Pisa storm wave tend to pile material towards the upper part of the beach with no rotation of the shoreline. Sirolo and Portonovo act like pocket beaches with shoreline rotation that occurs after each storm in a clockwise or counter-clockwi...
The fluvial harbour of Aquileia (Italy), one of the most important Roman trading centres in the M... more The fluvial harbour of Aquileia (Italy), one of the most important Roman trading centres in the Mediterranean, was abandoned after the city's destruction in 452 AD. The deserted harbour evolved into a swamp surrounded by a floodplain that has recorded the anthropogenic, environmental and climatic pressures that have occurred during the last 1500 years in the northern Adriatic. Focusing on the period since 500 AD, we here reconstruct the area's long-term ecosystem dynamics. We show that ecosystem dynamics mainly mirror the climate phases of the pre-industrial era. After the Roman era, anthropogenic activities (agriculture, pasture and fire activity) declined in scope and amplitude and are chronologically limited (from the late 7th to the early 13th centuries AD), acting as a background pressure on ecosystems. The main non-human impacts recorded by ecosystems correspond to the Late Antique Little Ice Age and the Pre-industrial Little Ice Age. The temperatures reconstructed for the Medieval Climate Anomaly are close to those recorded for the 20th century AD but they differ from the 21st century AD. Aquileia shows that ancient harbours are key areas to understand how climate and human societies have shaped northern Adriatic environments since the post-Roman period.
The erosion issue is a constant threat along most of the littoral areas around the Mediterranean ... more The erosion issue is a constant threat along most of the littoral areas around the Mediterranean Sea. The Northern Adriatic Sea makes no exception, in particular the Emilia-Romagna region is subject to erosion processes that jeopardize human activities and natural ecosystems along large stretches of the coast. The factors responsible for the erosion processes are multiple and often depend on the characteristics of the site: the Bellocchio area can be considered as a case study for the landward retreat of a barrier system, caused by the decrease of sediment supply from the River Reno. A series of aerial ortho-photographs was analyzed to define the evolution of the sector of coast comprised between the village of Porto Garibaldi to the north and the River Reno’s mouth to the south. The photographs, spanning from 1942 to 2010, showed a severe landward migration of the whole system, in particular the area north of the river’s mouth, where a large spit was progressively eroded and eventu...
in this paper the authors describe the structure of a wireless sensor node designed to measure he... more in this paper the authors describe the structure of a wireless sensor node designed to measure height variations in coastal sand dunes. The paper focuses on the project and development of a sensing device able to measure the changes of height of sand dunes, based on an array of photoresistors (LDRs), designed to withstand the critical atmospheric conditions of coastal environments. Together with the sensing device, also a power control logic has been studied and developed, to reduce the power consumption leading to an ideal life time of the node of around two years. The sensor node is also provided with wireless communication capabilities based on the ZigBee communication protocol and is integrated in a network infrastructure for remote data collection. The proposed sensor node, together with a minimal network architecture, has been developed and tested directly on the beach to prove its effectiveness. In this paper, the overall structure of the node is described, along with its ope...
In this study we aimed to gain insights into dune formation and evolution from select coastal tra... more In this study we aimed to gain insights into dune formation and evolution from select coastal tracts of Northern Tuscany by inspecting their internal sedimentary architecture with Ground-Penetrating Radar (GPR) analysis. Erosion, equilibrium and accretion characterize the selected coastal tracts, and this analysis remarks on some GPR features consistently associated with specific coastal evolution states. A standard sequence of data processing made it possible to trace several radar surfaces and reflectors in the GPR profile, eventually interpreted in terms of depositional processes and erosive events. The stable or currently accreting coastal sectors show radar features compatible with a general beach progradation process, punctuated by berm formation in the general context of a positive sedimentary budget. Additionally, the radar facies distribution locally supports a mechanism of dune nucleation on an abandoned berm. Conversely, the GPR profile of the coastal sector today affecte...
In the present study we describe a straightforward and highly replicable methodology to assess th... more In the present study we describe a straightforward and highly replicable methodology to assess the anthropogenic sediment budget within a coastal system (the Northern Tuscany littoral cell, Italy), specifically selected in a partially natural and partially highly urbanized coastal area, characterized by erosion and accretion processes. The anthropogenic sediment budget has been here calculated as an algebraic sum of sediment inputs, outputs and transfer (m3) within a 40 year time interval (1980–2020). Sediment management strongly influences the sediment budget and, even if its evaluation is crucial to assess the efficiency of a coastal management policy, it is often difficult to quantify the anthropogenic contribution to sedimentary processes. Different types of intervention are carried out by a variety of competent authorities over time (Municipalities, Marinas, Port Authorities), and the correct accountability of sediment budget is no longer known, or possible, for the scientific ...
A multidisciplinary approach to coastal process research has been increasingly encouraged in the ... more A multidisciplinary approach to coastal process research has been increasingly encouraged in the last decade, and it is now widely accepted for a thorough, in-depth analysis of any issue related to such an environment. In this study, we emphasized the need for the integration of different time-scales, not just disciplines. Many geological datasets provided by several sources contribute to the knowledge of coastal processes. We retrieved the available datasets about morphodynamic, geomorphological, and geological aspects of the northern Tuscany (Italy) littoral cell, and we merged all of them with QGIS (Quantum Geographic Information System) applications to provide an assessment of the current situation starting from a geological perspective. Data processing resulted in maps and stratigraphic sections that confirmed that sediment supply is the main factor driving the evolution of the littoral cell. Such a perspective is also useful for the development of reliable coastal evolution fu...
A better knowledge of the relationship between sediment characteristics and sediment transport is... more A better knowledge of the relationship between sediment characteristics and sediment transport is crucial to establish the suitability of fill material for gravel nourishments. In this paper pebble transport is investigated by means of RFID passive tracing technology. Tracers were injected in a small portion of a mixed sand and gravel beach separating sphere from disc shaped pebbles. Tracer recovery was undertaken 6 and 24 h after the injection and wave characteristics were measured during the whole experiment duration. After 6 h the marked pebbles already covered significant displacements with a prevalent longshore component which became evident after 24 h. According to statistical analyses (T-tests and box plots) no significant difference among the displacement of different shapes resulted. The swash zone proved to be the most dynamic area of the beach where all the pebble displacements took place. Because of their higher dynamic, spheres are preferred to discs for nourishment pur...
Venice Lagoon (Italy), the largest wetland in the Mediterranean basin, is extremely vulnerable to... more Venice Lagoon (Italy), the largest wetland in the Mediterranean basin, is extremely vulnerable to variations in relative sea level (RSL) which is locally defined by an average rising rate of about 2.5 mm per year, resulting from both sea-level change and vertical land movements. The environmental pressures stemming from projected higher RSL rising rates will have a profound impact on Venetian coastal ecosystems with a significant loss of wetlands partly due to a drastic reduction of salt marsh habitats. To understand how changes in marine influence could create such ecological upheaval in the near future, and fully remodel these coastal salt marshes, we reconstructed 5650 years of RSL rise history and land subsidence impacts on ecosystem dynamics during the Holocene transgression of Venice Lagoon. We show that the evolution of ecosystems mainly mirrors the gradual intrusion of salt water that progressively reshaped the coastal vegetation by turning the area into salt lagoon habitats. Before marine influence became dominant, the area was mainly fed by substantial freshwater supplies allowing the development of a diversified alluvial vegetation. Environmental pressures increased markedly about 6800-6600 years ago when seawater began to significantly influence the area, affecting marsh-swamp ecosystems. These marine inputs promoted the spread of halophytic and salt-tolerant vegetation types which laid the foundations for what would become the current salt marsh habitats. Venice Lagoon serves as a stark reminder of how rising sea levels, accompanied by increased saltwater intrusion into freshwater habitats and adjacent lands, can drastically alter and reshape pre-existing ecosystems. The lagoon's long-term ecological record indicates that contemporary fluctuations in RSL pose a substantial ecological threat, potentially culminating in a major upheaval of aquatic habitats in the near future.
ABSTRACT The aim of the investigation was to define the mechanisms of sediment transport in the s... more ABSTRACT The aim of the investigation was to define the mechanisms of sediment transport in the swash zone of microtidal coarse-clastic beaches in the very short term by evaluating the displacement rates of marked pebbles under low-energy wave conditions. Tests were performed at two sites (Marina di Pisa, Ligurian Sea, and Portonovo, central Adriatic Sea) to check the consistency of the data over a range of different grain sizes. Two recovery campaigns were carried out at both sites, one 6 h and the other 24 h after the injection. During the experiments wave action was at a minimum (wave heights never exceeded 0.3 m). The results show that 20% of pebbles ranging in diameter from 30–90 mm moved significantly (more than 0.5 m) already 6 h after the injection, with some tracers being lost (3%). After 24 h, 40% of the pebbles were significantly displaced and 10% were lost. The preferential downslope movement of tracers, which suggests that coarse sediment movement under low-energy conditions is mainly controlled by gravity processes enhanced by steep beachface slopes, represents the novelty of the results reported here. It would appear that swash processes on low-energy beaches cause a significant rate of pebble displacement through the destabilization induced by wave uprush and backwash. Despite the microtidal range, the position of the mean water level plays a major role in changing the beach level at which swash processes can actually trigger pebble movement. The results of this study show that considerable, and mostly seaward-directed, coarse sediment transport takes place even during short fair-weather periods.
The storm response of three Italian mixed beaches is investigated. Two sites are located on the e... more The storm response of three Italian mixed beaches is investigated. Two sites are located on the eastern side of the country (Portonovo and Sirolo) and one on the western side (Marina di Pisa). Portonovo and Sirolo are two mixed sand and gravel beaches (MSG) where the storms approach from two main directions (SE and NE). Marina di Pisa is a composite mixed beach subject to storms driven by SW. Gravel nourishments were undertaken in recent years on the three sites. Beach evolution was monitored measuring the same network of topographic profiles at a monthly to seasonal frequency. Beach orientation and the presence of protecting structures are the main reasons for the displacement and the accumulation of significant amount of sediments. In Marina di Pisa storm wave tend to pile material towards the upper part of the beach with no rotation of the shoreline. Sirolo and Portonovo act like pocket beaches with shoreline rotation that occurs after each storm in a clockwise or counter-clockwi...
The fluvial harbour of Aquileia (Italy), one of the most important Roman trading centres in the M... more The fluvial harbour of Aquileia (Italy), one of the most important Roman trading centres in the Mediterranean, was abandoned after the city's destruction in 452 AD. The deserted harbour evolved into a swamp surrounded by a floodplain that has recorded the anthropogenic, environmental and climatic pressures that have occurred during the last 1500 years in the northern Adriatic. Focusing on the period since 500 AD, we here reconstruct the area's long-term ecosystem dynamics. We show that ecosystem dynamics mainly mirror the climate phases of the pre-industrial era. After the Roman era, anthropogenic activities (agriculture, pasture and fire activity) declined in scope and amplitude and are chronologically limited (from the late 7th to the early 13th centuries AD), acting as a background pressure on ecosystems. The main non-human impacts recorded by ecosystems correspond to the Late Antique Little Ice Age and the Pre-industrial Little Ice Age. The temperatures reconstructed for the Medieval Climate Anomaly are close to those recorded for the 20th century AD but they differ from the 21st century AD. Aquileia shows that ancient harbours are key areas to understand how climate and human societies have shaped northern Adriatic environments since the post-Roman period.
The erosion issue is a constant threat along most of the littoral areas around the Mediterranean ... more The erosion issue is a constant threat along most of the littoral areas around the Mediterranean Sea. The Northern Adriatic Sea makes no exception, in particular the Emilia-Romagna region is subject to erosion processes that jeopardize human activities and natural ecosystems along large stretches of the coast. The factors responsible for the erosion processes are multiple and often depend on the characteristics of the site: the Bellocchio area can be considered as a case study for the landward retreat of a barrier system, caused by the decrease of sediment supply from the River Reno. A series of aerial ortho-photographs was analyzed to define the evolution of the sector of coast comprised between the village of Porto Garibaldi to the north and the River Reno’s mouth to the south. The photographs, spanning from 1942 to 2010, showed a severe landward migration of the whole system, in particular the area north of the river’s mouth, where a large spit was progressively eroded and eventu...
in this paper the authors describe the structure of a wireless sensor node designed to measure he... more in this paper the authors describe the structure of a wireless sensor node designed to measure height variations in coastal sand dunes. The paper focuses on the project and development of a sensing device able to measure the changes of height of sand dunes, based on an array of photoresistors (LDRs), designed to withstand the critical atmospheric conditions of coastal environments. Together with the sensing device, also a power control logic has been studied and developed, to reduce the power consumption leading to an ideal life time of the node of around two years. The sensor node is also provided with wireless communication capabilities based on the ZigBee communication protocol and is integrated in a network infrastructure for remote data collection. The proposed sensor node, together with a minimal network architecture, has been developed and tested directly on the beach to prove its effectiveness. In this paper, the overall structure of the node is described, along with its ope...
In this study we aimed to gain insights into dune formation and evolution from select coastal tra... more In this study we aimed to gain insights into dune formation and evolution from select coastal tracts of Northern Tuscany by inspecting their internal sedimentary architecture with Ground-Penetrating Radar (GPR) analysis. Erosion, equilibrium and accretion characterize the selected coastal tracts, and this analysis remarks on some GPR features consistently associated with specific coastal evolution states. A standard sequence of data processing made it possible to trace several radar surfaces and reflectors in the GPR profile, eventually interpreted in terms of depositional processes and erosive events. The stable or currently accreting coastal sectors show radar features compatible with a general beach progradation process, punctuated by berm formation in the general context of a positive sedimentary budget. Additionally, the radar facies distribution locally supports a mechanism of dune nucleation on an abandoned berm. Conversely, the GPR profile of the coastal sector today affecte...
In the present study we describe a straightforward and highly replicable methodology to assess th... more In the present study we describe a straightforward and highly replicable methodology to assess the anthropogenic sediment budget within a coastal system (the Northern Tuscany littoral cell, Italy), specifically selected in a partially natural and partially highly urbanized coastal area, characterized by erosion and accretion processes. The anthropogenic sediment budget has been here calculated as an algebraic sum of sediment inputs, outputs and transfer (m3) within a 40 year time interval (1980–2020). Sediment management strongly influences the sediment budget and, even if its evaluation is crucial to assess the efficiency of a coastal management policy, it is often difficult to quantify the anthropogenic contribution to sedimentary processes. Different types of intervention are carried out by a variety of competent authorities over time (Municipalities, Marinas, Port Authorities), and the correct accountability of sediment budget is no longer known, or possible, for the scientific ...
A multidisciplinary approach to coastal process research has been increasingly encouraged in the ... more A multidisciplinary approach to coastal process research has been increasingly encouraged in the last decade, and it is now widely accepted for a thorough, in-depth analysis of any issue related to such an environment. In this study, we emphasized the need for the integration of different time-scales, not just disciplines. Many geological datasets provided by several sources contribute to the knowledge of coastal processes. We retrieved the available datasets about morphodynamic, geomorphological, and geological aspects of the northern Tuscany (Italy) littoral cell, and we merged all of them with QGIS (Quantum Geographic Information System) applications to provide an assessment of the current situation starting from a geological perspective. Data processing resulted in maps and stratigraphic sections that confirmed that sediment supply is the main factor driving the evolution of the littoral cell. Such a perspective is also useful for the development of reliable coastal evolution fu...
A better knowledge of the relationship between sediment characteristics and sediment transport is... more A better knowledge of the relationship between sediment characteristics and sediment transport is crucial to establish the suitability of fill material for gravel nourishments. In this paper pebble transport is investigated by means of RFID passive tracing technology. Tracers were injected in a small portion of a mixed sand and gravel beach separating sphere from disc shaped pebbles. Tracer recovery was undertaken 6 and 24 h after the injection and wave characteristics were measured during the whole experiment duration. After 6 h the marked pebbles already covered significant displacements with a prevalent longshore component which became evident after 24 h. According to statistical analyses (T-tests and box plots) no significant difference among the displacement of different shapes resulted. The swash zone proved to be the most dynamic area of the beach where all the pebble displacements took place. Because of their higher dynamic, spheres are preferred to discs for nourishment pur...
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