Papers by Giovanni Cecconi
ciesm.org
Different strains of cyanobacteria were isolated from salt-marsh of Venice Lagoon. One of them wa... more Different strains of cyanobacteria were isolated from salt-marsh of Venice Lagoon. One of them was used in the laboratory to colonize artificial substrates to induce a better colonization of eroded sediments. Different materials for cyanobacteria colonization were ...
Different strains of cyanobacteria were isolated from salt-marsh of Venice Lagoon. One of them wa... more Different strains of cyanobacteria were isolated from salt-marsh of Venice Lagoon. One of them was used in the laboratory to colonize artificial substrates to induce a better colonization of eroded sediments. Different materials for cyanobacteria colonization were used from silica, zeolite to sediments. Different tests were made to improve cyanobacteria survival and exo-polysaccharide production under diverse conditions to consolidate sediments.
Comparing and combining space and terrestrial geodetic techniques to monitor crustal deformation
It is of particular importance to define and establish appropriate observational strategies chara... more It is of particular importance to define and establish appropriate observational strategies characterized by the ability to measure, with high accuracy, spatially and time continuous deformations of the land surface. An ensemble of space, airborne and terrestrial techniques can be adopted by taking advantage of the complementary strengths of the different observations. We present a network encompassing northeastern Italy, which
The importance of dredge islands for breeding waterbirds. A three-year study in the Venice Lagoon (Italy)
Ecological Engineering, May 1, 2013
ABSTRACT Since 1989, intertidal dredge islands have been constructed in the Venice Lagoon using s... more ABSTRACT Since 1989, intertidal dredge islands have been constructed in the Venice Lagoon using sediments originating from regular dredging of lagoon channels and inlets. Between 2005 and 2007, 75 dredge islands were surveyed in each year and the number of breeding pairs of seabirds and shorebirds estimated. The results showed that, of the 13 species that nested at least once, eight represented more than 1% of their total Italian population, sometimes even higher than 10%. Our results indicated that the majority of birds prefer site dimensions of between 10 and 30 ha, even if some species use small or very small (<1 ha) sites particularly heavily. Most of the other environmental variables we measured concurred in explaining species’ occurrence and abundance. Redshank and Shelduck selected sites with high vegetation coverage, whereas sites with lower vegetation were preferred by Kentish Plover and Little Tern. More pairs than expected were observed at sites between 25 and 30 ha. These sites have a considerable wealth of habitat types, becoming suitable for species with contrasting nesting habitat requirements. Density of breeding pairs ranged between one and four pairs/10 ha; these values compare well with those observed in natural habitats existing in the Venice Lagoon, and support the opinion that dredge islands are a good alternative to natural sites. Along coastal sites where human pressure on beaches is particularly heavy, man-made habitats such as dredge islands may become a valuable alternative breeding site for those seabirds and waders of conservation concern. The results presented allow an assessment of the importance of dredge islands for breeding waterbirds over a short to medium period. They may also be used to estimate the expected richness and abundance of breeding birds that will use intertidal man-made sites, when these are built in a temperate coastal marsh.
Ecological Engineering, Nov 1, 2000
On a intertidal flat in the lagoon of Venice (Italy), the effects of a fence on sediment elevatio... more On a intertidal flat in the lagoon of Venice (Italy), the effects of a fence on sediment elevation and vegetation establishment were studied throughout the years 1994-1997. With the use of a sedimentation erosion table (SET) we measured 5.7 cm of accumulated sediment in the protected tidal flat after 28 months (2.5 cm/year), compared with − 0.7 cm (−0.3 cm/year) in a nearby, unprotected tidal flat. After a storm which damaged part of the fence, there was a similar loss in elevation in both tidal flats; following repair, only the protected tidal flat gained elevation. After 1 and 3 years, vegetation coverage (mainly due to Salicornia 6eneta, Sarcocornia fruticosa and Atriplex portulacoides) was higher along the edge of the salt marsh of the protected tidal flat compared to the control salt marsh, but differences were not significant.
Estuarine Coastal and Shelf Science, Nov 1, 1999
Over the past century, Venice Lagoon (Italy) has experienced a high rate of wetland loss. To gain... more Over the past century, Venice Lagoon (Italy) has experienced a high rate of wetland loss. To gain an understanding of the factors leading to this loss, from March 1993 until May 1996 the soil accretionary dynamics of these wetlands were studied. Vertical accretion, short term sedimentation, soil vertical elevation change and horizontal shoreline change were measured at several sites with varying sediment availability and wave energy. Short term sedimentation averaged 3-7 g dry m 2 day 1 per site with a maximum of 76 g m 2 day 1. The highest values were measured during strong pulsing events, such as storms and river floods, that mobilized and transported suspended sediments. Accretion ranged from 2-23 mm yr 1 and soil elevation change ranged from 32 to 13•8 mm yr 1. The sites with highest accretion were near a river mouth and in an area where strong wave energy resuspended bottom sediments that were deposited on the marsh surface. A marsh created with dredged spoil had a high rate of elevation loss, probably due mainly to compaction. Shoreline retreat and expansion of tidal channels also occurred at several sites due to high wave energy and a greater tidal prism. The current rate of elevation gain at some sites was not sufficient to offset relative sea-level rise. The results suggest that reduction of wave energy and increasing sediment availability are needed to offset wetland loss in different areas of the lagoon. Using the data collected as part of this project, we developed a wetland elevation model designed to predict the effect of increasing rates of eustatic sea-level rise on wetland sustainability. The advantage of this model, in conjunction with measured short-term rates of soil elevation change, to determine sustainability is that the model integrates the effects of long term processes (e.g. compaction and decomposition) and takes into account feedback mechanisms that affect elevation. Specifically, changes in elevation can result in changes in allogenic sediment deposition, decomposition and autogenic primary production. Model results revealed that, given the Intergovernmental Panel on Climate Change (IPCC) ' best estimate ' eustatic sea-level rise scenario of 48 cm in the next 100 years, only one site could maintain its elevation relative to sea level over the next century. Under the IPCC ' current conditions' scenario of 15 cm in the next 100 years, four of seven sites remained stable. This work demonstrates that more accurate predictions of the future of coastal wetlands with rising sea level will be obtained with a combination of short-term measurements of accretion and soil elevation change and long-term modelling.
Resolving land subsidence within the Venice Lagoon by persistent scatterer SAR interferometry
Physics And Chemistry Of The Earth, Parts A/b/c, 2012
Land subsidence is a severe geologic hazard threatening the lowlying transitional coastal areas w... more Land subsidence is a severe geologic hazard threatening the lowlying transitional coastal areas worldwide. Monitoring land subsidence has been significantly improved over the last decade by space borne earth observation techniques based on Synthetic Aperture Radar (SAR) interferometry. Within the INLET Project, funded by Magistrato alle Acque di Venezia – Venice Water Authority (VWA) and Consorzio Venezia Nuova (CVN), we
Geomorphology, Nov 1, 2007
This article was published in an Elsevier journal. The attached copy is furnished to the author f... more This article was published in an Elsevier journal. The attached copy is furnished to the author for non-commercial research and education use, including for instruction at the author's institution, sharing with colleagues and providing to institution administration. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright
Use of dredge islands by a declining European shorebird, the Kentish Plover Charadrius alexandrinus
Wetlands Ecology and Management, Nov 6, 2012
Colonization of newly created habitats is a challenge for waterbird populations in a changing wor... more Colonization of newly created habitats is a challenge for waterbird populations in a changing world. Knowing which habitat characteristics are required by waterbird populations is a research challenge for rational management of the new ecosystems and their aquatic bird populations. Since 1989 intertidal dredge islands have been built in the lagoon of Venice using sediments coming from regular dredging of lagoon channels and inlets. Kentish Plover, a species declining in Europe, readily uses these new sites as soon as they become available. Between 2005 and 2007, 75 dredge islands were surveyed each year and the number of breeding pairs of Kentish Plover estimated. Each year about one-third of available dredge islands was used by Kentish Plover. Between 34 (in 2005) and 131 (in 2007) breeding pairs were found, and possible differences in vegetation and morphological characteristics between occupied and unoccupied sites were investigated. Only age, mean elevation above sea level and extension of bare ground were statistically different; Kentish Plover preferred younger sites, with higher elevation and with larger areas of bare ground. The largest groups of breeding pairs, up to thirty pairs, were found on islands which also supported colonies of Little Terns. In the study period dredged islands supported about 60 % of the total breeding population of the lagoon of Venice and 4–6 % of the estimated Italian population. Along coastal sites where human pressure on beaches is particularly heavy, man made habitats such as dredge islands may become a valuable alternative breeding site for this and other species of conservation concern. Management works aimed at promoting the occurrence of this species at selected dredge islands have been made in the lagoon of Venice.
210Pb and 137Cs as chronometers for salt marsh accretion in the Venice Lagoon – links to flooding frequency and climate change
Journal of Environmental Radioactivity, Oct 1, 2007
Five salt marsh sediment cores from different parts of the Venice Lagoon were studied to determin... more Five salt marsh sediment cores from different parts of the Venice Lagoon were studied to determine their depositional history and its relationship with the environmental changes occurred during the past approximately 100 years. X-radiographs of the cores show no disturbance related to particle mixing. Accretion rates were calculated using a constant flux model applied to excess (210)Pb distributions in the cores. The record of (137)Cs fluxes to the sites, determined from (137)Cs profiles and the (210)Pb chronologies, shows inputs from the global fallout of (137)Cs in the late 1950s to early 1960s and the Chernobyl accident in 1986. Average accretion rates in the cores are comparable to the long-term average rate of mean sea level rise in the Venice Lagoon ( approximately 0.25 cm y(-1)) except for a core collected in a marsh presumably affected by inputs from the Dese River. Short-term variations in accretion rate are correlated with the cumulative frequency of flooding, as determined by records of Acqua Alta, in four of the five cores, suggesting that variations in the phenomena causing flooding (such as wind patterns, storm frequency and NAO) are short-term driving forces for variations in marsh accretion rate.
Vertical Crustal Movements and Sea-level Changes in the Northern Adriatic
The Department of Physics of the University of Bologna (UNIBO), the Consorzio Venezia Nuova, sole... more The Department of Physics of the University of Bologna (UNIBO), the Consorzio Venezia Nuova, sole agent of the Magistrato alle Acque di Venezia for the managemente of the Venice lagoon environment (MAV), the Italian National Agency for Environmental Protection and Technical Services (APAT), have recently started joint projects to determine and study vertical crustal movements and sea-level fluctuations in the northern Adriatic area where the natural subsidence has been enhanced by anthropogenic components during last century. The combination of the permanent GPS stations belonging to UNIBO and of those of the MAV and APAT constitutes a basic network for the study of land subsidence in the northern Adriatic. We have studied and applied a combined observational strategy for monitoring and reliably identifying both seasonal and log-term crustal movements, namely height variations/changes. The strategy adopted is based on a multidisciplinary approach that combines the information provided by GPS, InSAR and terrestrial and space gravimetry. The results of these different techniques are compared and combined in a study on land subsidence in the southeastern Po Plain and the northern Adriatic coast, in Italy. The sea-level time series of the Marina di Ravenna, Venice and Trieste tide gauge stations are compared to the Topex/Poseidon satellite altimetry sea-level elevation and to the GPS height and InSAR long-term trends at the same stations
The Venice Lagoon, Italy, is a unique worldwide environment which is presently vulnerable due to ... more The Venice Lagoon, Italy, is a unique worldwide environment which is presently vulnerable due to loss in surface elevation as a result of land subsidence referred to the mean sea level. Land displacements in the Venice coastland have been determined over time by traditional monitoring techniques (i.e., spirit leveling and GPS). Recently, SAR-based analyses have been used to complement the ground-based methods. Interferometric analysis on persistent point targets has been proved to be very effective in detecting land displacement in the coastal environment. ERS SAR and ENVISAT ASAR images spanning the time period 1992-2005 and 2003-2006, respectively, have been processed at regional and local scale and on "natural" as well as "artificial" reflectors.
Land subsidence is a severe geologic hazard threading the lowlying coastal areas worldwide. Monit... more Land subsidence is a severe geologic hazard threading the lowlying coastal areas worldwide. Monitoring land subsidence has been significantly improved over the last few years by space borne earth observation techniques based on SAR (Synthetic Aperture Radar) Interferometry. Within the INLET Project, funded by Magistrato alle Acque di Venezia-Venice Water Authority (VWA) and Consorzio Venezia Nuova (CVN), we have used the Interferometric Point Target Analysis (IPTA) to characterize the ground displacements within the Venice Lagoon. IPTA measures the movement of backscattering objects (point targets, PT) at the ground surface which persistently reflect radar signal emitted by the SAR antenna. For this study 80 ERS-1/2 and 44 ENVISAT scenes recorded from 1992 to 2005 and from 2003 to 2007, respectively, have been processed by IPTA. High reliable land subsidence data have been detected for thousands of PT located on the lagoon margins, along the littorals, in major and small islands, and on single anthropogenic structures scattered within the lagoon. On the average, land subsidence ranges from less than 1 mm/year to 5 mm/year, with some PT that exhibit values also larger than 10 mm/year depending on both the local geologic conditions and anthropogenic activities. A network of few tens of artificial square trihedral corner reflectors (TCR) has been established before summer 2007 to monitor land subsidence in the inner lagoon areas where natural reflectors completely lack (e.g., on the salt marshes). The first interferometric results on the TCR appear very promising.
Aquatic Ecosystem Health & Management, Oct 1, 2000
The present study was conducted in the Lago dei Teneri area of the Venice Lagoon in Italy. This a... more The present study was conducted in the Lago dei Teneri area of the Venice Lagoon in Italy. This area has long received massive pollutant input from the industrial area of Porto Marghera. It is adjacent to the Canale dei Petroli, an important industrial waterway. Because of its location, this area represents an ideal site for applying a new remedial solution: the capping of contaminated sediment with clean sand to support the benthic recolonization of the sediment. Capping was selected for this anoxic and most contaminated portion of the area as the most cost-effective way to provide a clean benthic habitat. to isolate the contamination and prevent contaminate release. An extensive sediment monitoring program was in place before, during and after the capping operations. Monitoring activities included hydrodynamics, measurement of cap thickness, in situ sediment profi le imaging, benthos colonization, analysis of contaminants, and toxicity tests with Microtox and amphipods. To evaluate the efficiency of the capping. the results were analyzed with an integrated approach, which includes the Habitat Evaluation System. This approach allowed the quantifi cation of the environmental benefits with respect to remediation of the Venice lagoon.
Le macroalghe degli affioramenti rocciosi (tegnùe) del litorale veneto
Introduction: The morphological reconstruction projects carried out by the Venice Water Authority... more Introduction: The morphological reconstruction projects carried out by the Venice Water Authority (Magistrato alle Acque di Venezia), through its concessionary Consorzio Venezia Nuova, began about 20 years ago and concern the reconstruction of mudflats and salt marshes using sediments from maintenance dredging of lagoon canals. Up to now, interventions have been realised in eighty sites distributed in the whole basin of the Venice lagoon.
International Journal of Design & Nature and Ecodynamics, 2010
Confined Ontic Open Systems is a new ecodynamic model based on Prigogine's thermodynamics, Ulanow... more Confined Ontic Open Systems is a new ecodynamic model based on Prigogine's thermodynamics, Ulanowicz's ontic openness and Coherence Domains with defined boundaries and constraints. The model has a wide range of applications, including ecosystems (e.g. invasive species, the lagoon of Venice), ecological economics, urban organization, the supra-molecular structure of water and global biosphere's models. The model is explained in terms of evolutionary thermodynamics and Jørgensen's ecosystems theory, namely "order out of chaos" and eco-exergy. Particular attention is devoted to the emergence of novelties and to the role of water.
210Pb and 137Cs as chronometers for salt marsh accretion in the Venice Lagoon – links to flooding frequency and climate change
Journal of Environmental Radioactivity, 2007
Five salt marsh sediment cores from different parts of the Venice Lagoon were studied to determin... more Five salt marsh sediment cores from different parts of the Venice Lagoon were studied to determine their depositional history and its relationship with the environmental changes occurred during the past approximately 100 years. X-radiographs of the cores show no disturbance related to particle mixing. Accretion rates were calculated using a constant flux model applied to excess (210)Pb distributions in the cores. The record of (137)Cs fluxes to the sites, determined from (137)Cs profiles and the (210)Pb chronologies, shows inputs from the global fallout of (137)Cs in the late 1950s to early 1960s and the Chernobyl accident in 1986. Average accretion rates in the cores are comparable to the long-term average rate of mean sea level rise in the Venice Lagoon ( approximately 0.25 cm y(-1)) except for a core collected in a marsh presumably affected by inputs from the Dese River. Short-term variations in accretion rate are correlated with the cumulative frequency of flooding, as determined by records of Acqua Alta, in four of the five cores, suggesting that variations in the phenomena causing flooding (such as wind patterns, storm frequency and NAO) are short-term driving forces for variations in marsh accretion rate.
Relative sea level rise and Venice lagoon wetlands
Journal of Coastal Conservation, Dec 1, 1998
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Papers by Giovanni Cecconi