A bubble Barrier that removes litter from rivers is being applied in the Ave estuary (Portugal) in the framework of the MAELSTROM Project. In order to identify the location where the technology could possibly best be applied and to assess the impact of the litter removal on marine life, MAELSTROM makes use of numerical models. Facing the limited field data and absence of available models, we carried out field campaigns, set-up a hydrological model for the Ave river basin and set-up a hydrodynamic model for the estuarine region. The field studies included a bathymetric survey, short-term (12.5 hours) and long-term (several weeks) campaigns. Aiming to understand the temporal and spatial variation of the flow velocity in the estuary, and particularly in the area where the Bubble Barrier system is planned to be implemented, we have analysed observations from a boat sailing across the estuary (short-term), we have analysed observations at selected locations (long-term) and we have set-up a 3-dimensional (3D) hydrodynamic model to give insight in the flow velocity distribution. Only during the short-term campaigns the river discharge is known, which was relatively low during these campaigns. Since the river discharge is an important condition for the hydrodynamic model, we have only obtained maximal flow velocity maps for low river discharge. For higher river discharge we show a maximal flow velocity observed during a long-term campaign and we estimate maximal flow velocity based on an extreme river discharge.

Both the short-term and long-term campaigns were performed during summer and winter conditions, meaning respectively a low and high river discharge. The short-term campaigns were carried out from a boat during spring tide, anticipating that normally at highest tidal range the highest flow velocities occur. Flow velocity was measured using an Acoustic Doppler Current Profiler (ADCP).

Both the short-term and long-term campaigns were performed during summer and winter conditions, meaning respectively a low and high river discharge. For the long-term campaigns, instruments were deployed for several weeks: CTD and ADCP.

A bubble Barrier that removes litter from rivers is being applied in the Ave estuary (Portugal) in the framework of the MAELSTROM Project. In order to identify the location where the technology could possibly best be applied and to assess the impact of the litter removal on marine life, MAELSTROM makes use of numerical models. Facing the limited field data and absence of available models, we carried out field campaigns, set-up a hydrological model for the Ave river basin and set-up a hydrodynamic model for the estuarine region. The hydrodynamic numerical model for the Ave estuary was implemented using D-Flow Flexible Mesh (D-Flow FM), which is the hydrodynamic module of the Delft3D Flexible Mesh Suite developed by Deltares (for more information see the project deliverable D2.2 Numerical modelling and field campaigns to support litter removal at the demo sites).

An automated cable-robot on a platform that removes litter from the sea bed is being applied in demo sites near Venice (Italy) in the framework of the MAELSTROM Project. In order to identify the location where the technology could possibly best be applied and to assess the impact of the litter removal on marine life, MAELSTROM makes use of numerical models. The applied numerical tool consists of a three-dimensional hydrodynamic model that reproduces the water current evolution in the domain of the case study area. While the focus of the project is the Venice lagoon and the Gulf of Venice, the study covers the whole Adriatic Sea, including the sources of marine litter coming from the whole of the Adriatic coastline. The distribution of the marine litter in the Adriatic Sea was assessed by performing the numerical simulations, considering both the land based marine litter sources (rivers and cities), as well as marine sources (aquaculture) using the hydrodynamic model SHYFEM (for more information see the project deliverable D2.2 Numerical modelling and field campaigns to support litter removal at the demo sites).

A bubble Barrier that removes litter from rivers is being applied in the Ave estuary (Portugal) in the framework of the MAELSTROM Project. In order to identify the location where the technology could possibly best be applied and to assess the impact of the litter removal on marine life, MAELSTROM makes use of numerical models. Facing the limited field data and absence of available models, we carried out field campaigns, set-up a hydrological model for the Ave river basin and set-up a hydrodynamic model for the estuarine region. The hydrodynamic numerical model for the Ave estuary was implemented using D-Flow Flexible Mesh (D-Flow FM), which is the hydrodynamic module of the Delft3D Flexible Mesh Suite developed by Deltares (for more information see the project deliverable D2.2 Numerical modelling and field campaigns to support litter removal at the demo sites).