State-of-the-art review, impacts of human measures, and updated sediment balance
Human interventions such as channelization, dredging, construction of transverse structures and long-term sediment extraction have strongly altered the sediment regime of the Rhine. These measures have increased transport capacity while reducing sediment input, leading to persistent bed incision, exposure of fixed layers, ecological degradation, and challenges for navigation and groundwater levels.
To address these issues and to support the development of the ICPR’s future Sediment Management Plan (starting 2027), the CHR is launching the RhineSed2028 project. This project focuses on updating essential knowledge on sediment dynamics in the Rhine basin through three interconnected steps:
- A literature and data review with a state-of-the-art update
- An assessment of anthropogenic activities: effects of local measures
- An update of the Rhine sediment balance for the period 2010–2025.
The first step, a state‑of‑the‑art review, will compile current literature, projects, activities, and scientific insights across the Rhine basin. This overview will assess sediment transport, composition, bathymetry, nourishments, and fixed layers, forming the basis for all subsequent work. In addition, this step will include a cause–effect analysis, reflect on current scientific discourse and apply a systems approach to sediment processes across the entire catchment. The goal is to identify knowledge gaps and develop a shared, transboundary understanding of the current sediment situation among all Rhine countries.
In the second step, the project will evaluate the effects of anthropogenic measures on the morphology of the Rhine’s main stem. Existing case studies and monitoring results will be analysed to understand how interventions such as nourishments, dredging, dumping, side-channel reconnections, and other river engineering measures influence sediment continuity and bed development. This step will be conducted in collaboration between the Bfg (Germany) and Rijkswaterstaat (Netherlands).
In the third step, RhineSed2028 will update the Rhine sediment balance by quantifying sediment fluxes and morphological changes between 2010 and 2025. This updated balance will build directly on earlier CHR work and will help identify zones of erosion, deposition, and system-wide trends.
A dedicated synthesis towards the end of 2027 will integrate the results of all three steps, providing a coherent understanding of present-day sediment processes and their drivers. This synthesis will serve as an important scientific building block for future sediment‑related planning and cooperation in the Rhine basin.