Bankbusters: A nature-based solutions engineered tidal marsh, beneficially re-using soft dredged sediments
Productive ecosystems such as river deltas are subject to many anthropogenic and natural pressures resulting in increased flood risk, tidal amplification and strong erosion. Estuarine tidal marshes provide various ecosystem services like natural flood protection, lessening the impacts on embankments. However, they are under pressure. This is leading to severe habitat deterioration, especially in lowly elevated tidal marshes that flood frequently. Increasing erosion can turn these habitats into non-vegetated mudflats, with an unfavourable steep transition to highly elevated marshes.
Moreover, socio-economic development activities in an estuarine habitat widely require dredging maintenance and flood management. Currently, dredging maintenance involves partial reuse of coarser dredged material, while large quantities of fine dredged sediment are disposed without being reused, due to economic, logistical, legislative and/or environmental constraints.
In the VLAIO ICON project Bankbusters a public private consortium consisting of Ghent University, the University of Antwerp, DEME, iFlux and Jan De Nul is committed to tackling the above-mentioned issues.
The Ghent University Hydraulics Laboratory has vast numerical and experimental experience in the study of tidal forcing and sediment transport in channelized water bodies, whereas the Ghent University Industrial Research Fund consortium BLUEGent has an extensive track record in innovation in aquaculture and Blue Life Sciences. Together with the Bankbusters consortium partners, they aim to strengthen the knowledge with regard to ecosystem processes, boundary conditions and concepts for the beneficial reuse of dredged material, in order to facilitate the restoration of eroded tidal areas and wetlands and to enhance local ecosystem services.
The innovative aspect is in the integration of biological and technological aspects for the protection of eroded natural tidal river banks. The accumulated knowledge is thereby used for the realization of Dredged Ecological Compartments (DRECOs - conceptual building blocks). In these DRECOs, new techniques and procedures are applied for the treatment, installation and dewatering of soft dredged material.
These DRECOs form a basis for the application of Nature-based Solutions (NbS), reuse and stabilization of soft sediment and creation of sustainable erosion protection of river banks. In addition, suitable measuring instruments and an approach for the monitoring of erosion protection are being developed.
Since the research area of this project has a highly dynamic, high-risk, complex and ecological nature, tests will first be carried out on a laboratory scale. Afterwards, a pilot project will be set up in the Scheldt basin to further elaborate the ecological, technical and economic feasibility.
The project results will support different routes to valorisation for the private partners regarding specific bottlenecks and uncertainties in the ecological, technical and economic feasibility of reuse of soft sediments and underground monitoring. Furthermore, the project results will strengthen the unique expertise of the research partners with regard to habitat development and hydro- and morphodynamic processes.
