Morphodynamics in the Common Meuse

Outcome

Improve our understanding of the morphodynamics in the Common Meuse in order to find appropriate interventions for habitat restoration.

Motivation and Practical Challenge

Macrofauna in gravel bed rivers live in a morphologically dynamic environment that is challenging, especially when human influence worsens the living conditions. The Common Meuse is one of the most natural rivers in the Netherlands, but also heavily engineered to maintain the border, water quality and flood safety. Standards for aquatic biodiversity set for the European ‘Natura 2000’ protected natural areas are not met. The hypothesised cause is the lack of available suitable habitat, due to strong armouring of the river bed, bank protection, colmation and hydropeaking. The aim of this research is to find morphodynamic management strategies that help improve the aquatic biodiversity. This enhances both the ecological and the recreational value of the river reach.

Research Challenge

What are the limiting factors for macrofauna?
What is the spatial and temporal variation in composition of bed sediment and what factors determine (re)mobilisation and colmatering of silt, sand and gravel?
What management measures are effective in removing limiting factors for macrofauna by intervening in morphodynamics?

Innovative Components

The posed research questions are complex and range over different spatial and temporal scales. We therefore plan an approach that combines lab and field work to understand smaller scale processes with modelling to integrate the morphodynamics and ecology towards bigger scales. We collaborate with ecologists within the R2M program (Joshua Climo, RU) to eventually understand both the ecological needs and the morphodynamic possibilities.

Relevant for whom and where?

The results of this research can be used by Rijkswaterstaat Zuid-Nederland, to improve morphodynamic management. Changes may contribute to increase in habitat availability and with that biodiversity. This means enhanced ecological and recreational value.

Status for day-to-day practice

The research is still in an early phase, but the expectation is that the main challenge lies in going from ideal measures and an ideal living environment for macrofauna to a realistic interventions plan that compromises with the other goals that RWS sets for the river reach.

Next steps

Field experiments where potentially improving measurements can be tested (on a smaller scale), like a gravel suppletion with a related measurement campaign focused on the hyporheic zone.

Last modified: 27/02/2024