Ship-Induced Depression Wakes and Shoreline Erosion

Shoreline retreat as an effect of ship wakes was studied in a navigation channel of the industrial port of Venice, Italy: the Malamocco -Marghera Channel. The investigation revealed unprecedented erosion rates, up to 4 m y , that determined a total loss of about 1.2 million of m of soil in the period 1970 -2015. This interaction between navigation and the channel margins must be considered in order to understand the past evolution of the central Venice Lagoon and for a sustainable management of the port traffic in the future sea -level rise scenario

Quantification of Submarine Groundwater Discharge and Optimal Radium Sampling Distribution in the Lesina Lagoon, Italy

Performing a mass balance of radium isotopes is a commonly employed method for quantifying the flux of groundwater into the sea. However, the spatial variability of 224Ra can compromise the results of mass balances in environmental studies. We address this uncertainty by optimizing the distribution of Ra samples within a surface survey of 224Ra activity in the Lesina Lagoon, Italy. After checking for spatial dependence, location-allocation modeling (LAM) was utilized to determine optimal distribution of samples for thinning the sampling design. Trend surface analysis (TSA) was employed to interpolate the Ra activity throughout the lagoon. No significant change was found when using all 41 samples or only 25 randomly distributed samples. Results from the TSA showed a linear trend and bi-modal distribution in surface 224Ra. This information was utilized to perform mass balances in two separate basins (east and west). SGD was found to be significantly higher in the western basin (4.8 vs. 0.7 cm d− 1). Additionally, mass balances were performed using the average 224Ra activity from the trend surface analysis calculated with 41 and 25 samples respectively and total lagoon SGD was found to be 10.4–10.5 m3 s− 1. Results show that SGD is significant in the Lesina Lagoon