An Economic Assessment of the Impacts of the MOSE Barriers on Venice Port Activities

Due to its hydro-geological features, the lagoon of Venice is especially vulnerable to climate change. In particular, it is strongly affected by gradual global warming that brings about the so-called ‘acqua alta’ (high water) phenomenon with greater frequency and intensity. In order to protect the city of Venice from the more and more frequent phenomenon of flooding, some protective measures have been adopted. Among them, the system of mobile barriers commonly known as MOSE: however, by separating the lagoon from the Adriatic Sea, it interferes with ship traffic and has negative impacts on port activities. Against this background, the aim of the present work is to provide an estimate of the direct costs of ship traffic interruption due to the functioning of the MOSE, i.e. the additional costs resulting from longer waiting time for ships passing through the Venice lagoon. The estimate uses inputs from the application of a specific hydrodynamic model and the elaboration of ship traffic data during the period 2000-2002. Results indicate that the additional costs would range between 347,943 and 1,288,067 €/year, depending on the hypothesis assumed.Climate Change, ‘Acqua Alta’, MOSE, Ship Traffic, Direct Costs

Changes in Venice Lagoon dynamics due to construction of mobile barriers

The MoSE project (construction of mobile barrier to safeguard the Lagoon of Venice) entails changes to the structure of the lagoon\u27s inlets. This could have consequences for the areas near the inlets and for the dynamics of the lagoon ecosystem as a whole. In order to predict the effects of the proposed alterations on the hydrodynamics of the lagoon, a well-tested hydrodynamic-dispersion model was applied. Simulations were carried out considering both idealised and realistic tide and wind scenarios. The results show that with the new structures the Lido sub-basin tends to increase its extension due the southward movement of the watershed, at the expense of the Chioggia sub-basin, whereas the Malamocco sub-basin changes its relative position, but not its extension. The residence time shows variations in agreement with this trend, decreasing in the southern part of the Lido sub-basin and increasing in the inner part of the Chioggia sub-basin. The variations in residence time and return fl ow factor indicate that they are caused by changes in both instantaneous current velocities and sea-lagoon interaction. In fact the new breakwaters in front of the Malamocco and Chioggia inlets modify the length and direction of the out fl ow jet (up to 1 ms− 1 ) and the patterns of the currents around the inlets and the nearby coast. The new arti fi cial island in the Lido inlet changes the current pattern and increases the current velocity on the southern side of the channel propagating this effect up to the Venice city. The risks and benefits individuated from our conclusion are that the Lido sub-basin can improve its renewal time, but the more intense current speeds can be a risk for the conservation of habitats and infrastructures. Finally the micro-circulation between the breakwater and the coast in Chioggia and Malamocco inlets can be a trap for pollutants or suspended sediment

Modeling the inter-annual variability of salinity in the lagoon of Venice in relation to the water framework directive typologies

The Water Framework Directive (2000/60/EC) requires member states to classify and enhance the ecological quality of water bodies in accordance with their type. To estimate the effect on type of the natural variability of lagoons, we applied a two-dimensional hydrodynamic model to the lagoon of Venice. The model calculated the mean annual spatial distributions of two variables: salinity and residence time. The standard deviation of salinity was also included, in order to estimate the variation of salinity values around the mean, which is associated with the instability of the mean salinity value. A highly detailed numerical grid was calibrated and high-frequency tributary discharge data were used. The simulations, under realistic forcing conditions, are based on the years 2003 and 2005. The former was characterized by low precipitation, around 30% less than the typical value. A comparison of model results and measurements shows the high reliability of the model in reproducing the spatial distribution and temporal evolution of salinity. We found strong inter-annual variation in salinity, standard deviation of salinity and residence time. The effect on the typing process is that the most representative types shift from one category to another. On the basis of the spatial patterns of the variables and their superposition, we identi fi ed types that described the bulk of the lagoon. This numerical tool offers support for lagoon management on various levels, in terms of both WFD requirements and other applications, by: (1) providing unbiased and objective zoning indications for the basin; (2) evaluating the response of water quality elements; (3) establishing the reference status of a water body; and (4) establishing a hierarchical division of a lagoon that can be used to select an appropriate number of sampling stations for monitoring

Development of a novel tool to predict different water quality scenarios within a Marine Protected Area (MPA) in the Maltese Islands : the 2D SHYFEM-BFM model

Effective operational marine conservation and management is thwarted by a lack of financial and human resources. A coupled 2D hydrodynamic (SHYFEM) and ecological (BFM) model was developed in the current study as a Decision Support System (DSS) to spearhead good governance of a Marine Protected Area (MPA) in Dwejra (Maltese Islands) in the Central Mediterranean. Two scenarios were considered – one with the current levels of nutrient runoff from land and one in which such levels are increased as a result of a greater human activity within the area. Although the developed numerical modeling platform needs to be refined and to be run for a longer time -frame, its output suggests that it is a promising tool to assist in the operational management of an MPA.peer-reviewe

Hydraulic zonation of the lagoons of Marano and Grado, Italy. A modelling approach

The hydraulic regime-based zonation scheme of the Lagoons of Marano and Grado (Italy) has been derived by means of numerical models. A finite element modelling system has been used to describe the water circulation taking in account different forces such as tide, wind and rivers. The model has been validated by comparing the simulation results against measured water levels, salinity and water temperature data collected in several stations inside the lagoons. The analysis of water circulation, salinity and spatial distribution of passive tracers released at the inlets, led to a physically-based division of the lagoons system into six subbasins. The derived classification scheme is of crucial value for understanding the renewal capacity and pollutants distribution patterns in the lagoon

Tide-surge-wave modelling and forecasting in the Mediterranean Sea with focus on the Italian coast

Abstract A tide-surge-wave modelling system, called Kassandra, was developed for the Mediterranean Sea. It consists of a 3-D finite element hydrodynamic model (SHYFEM), including a tidal model and a third generation finite element spectral wave model (WWMII) coupled to the hydrodynamic model. The numerical grid of the hydrodynamic and wave models covers the whole Mediterranean with variable resolution. The comparison with coastal tide gauge stations along the Italian peninsula results in a root sum square error for the main tidal components equal to 1.44 cm. The operational implementation of the Kassandra storm surge system through the use of a high resolution meteorological model chain (GFS, BOLAM, MOLOCH) allows accurate forecast of total water level and wave characteristics. The root mean square error for the first day of forecast is 5 cm for the total water level and 22 cm for the significant wave height. Simulation results indicate that the use of a 3-D approach with a depth-varying loading factor and the inclusion of the non-linear interaction between tides and surge improve significantly the model performance in the Italian coast

Can we predict the dispersal path of a jellyfish bloom?

Jellyfish blooms occurring in coastal waters can be a source of risk for public health, fishery and all the related economical activities. The prediction of the environmental conditions that promote jellyfish outbreaks as well as the fate of the bloom are of high interest especially when dealing with CZM.peer-reviewe

Morphology of the Veneto Coast

A considerable amount of the North Adriatic coast is currently eroding despite the development of a wide range of measures to protect shorelines from eroding and flooding. The management of Northern Adriatic coast need a multidisciplinary, updating and modular approach. We must understand how natural and man-induced dynamics act on littoral areas. This motivated to initiate a specific research program concerning these issues started in 2003 by a cooperation among CNR-ISMAR, the Autorità di Bacino dei fiumi dell’Alto Adriatico and APAT, Servizio Laguna di Venezia. This paper shows first results of such program in progress

Connectivity between coastal lagoons and sea: asymmetrical effects on assemblages' and populations' structure

Connectivity among marine populations plays a fundamental role in the dynamic of metapopulations and communities. Moreover, genetic connectivity is important for the evolutionary history and adaptive capability of species while demographic connectivity is essential to maintain ecological processes. In coastal lagoons, isolation degree or confinement is considered the main factor structuring biological assemblages. These environments also function as nursery areas for many marine species that colonize the lagoons as larvae or juveniles, returning to the sea for reproduction. It is therefore essential to know the connectivity between lagoons and sea for the management of biodiversity and the exploitation of coastal living resources. This work anases the role that connectivity between coastal lagoons and sea plays in the assemblages and subpopulations structure of the first. To this purpose, a finite element hydrodynamic model was used coupled with a lagrangian module to simulate the potential exchange of organisms between Mar Menor lagoon (Western Mediterranean) and the adjacent sea. Connectivity parameters from 40 stations, located inside and outside the Mar Menor, have been estimated. The outcomes of the eight simulations carried out were compared with field data, including ichthyoplankton species composition and genetic fluxes in 6 species with different life stories. The results suggest that pelagic larval phases are longer than expected or the species can extend PLD within certain limits if the conditions for the settlement are not adequate. Repetition can improve the chance of self-recruitment, coupling larval duration, competency period and finding the adequate location for settlement. The results also show that connectivity between all lagoon and Mediterranean stations is very low and is independent of geographical distance. There is a strong asymmetry in the probability of receiving particles, being lower the probability of colonization of the lagoon stations from the sea than vice versa. Despite its low values, connectivity can explain up to 65% of the similarities in species composition of the ichthyoplankton and between 30 and 96% of the variance in genetic differentiation of the studied species. The low value of connectivity and colonization rates is enough, however, to maintain the genetic fluxes between populations and, at the same time, restricted connectivity can play an important role in maintaining high diversity and heterogeneous assemblage structure