Sediment Dynamics

Fine, cohesive sediment or mud is encountered in all open waters, e.g. rivers, canals, lakes, reservoirs, estuaries, coasts. It makes our soils fertile. It forms an essential part of healthy ecosystems. Mud attains it special properties from a subtle interplay between molecular forces between clay particles, the chemistry of the pore water and the amount and quality of organic materials. As a result, the water content of mud in the water column and in/on the sedimentary bed is high, sometimes over 90%. Therefore, mud can behave as a Newtonian fluid or as a stiff soil, and everything in between.

The civil engineer is confronted with many mud-related questions, such as siltation in harbor basins and fairways, effects of sediment-induced turbidity on primary production, stability of salt marshes and wetlands, erosion of muddy coasts, such as mangrove-mud coasts, and recently the beneficial use of fine sediments in ecosystem building (Markerwadden) and dyke stabilization (Mudmotor). Much of our work addresses nature’s response to human interventions.

Our group develops the scientific knowledge to address these questions properly. A major part of our research has a multi-disciplinary approach, e.g. physics, soil mechanics, ecology, biology and chemistry. We work in the laboratory and in the field, using sophisticated and simple instruments. We deploy and develop a range of numerical models, amongst which our workhorse Delft3D. We use satellite images and other remote sensing techniques. And we work with many partners in The Netherlands, and abroad.

Mud has many appearances and occurrences – here landing of fluid mud on Cassino Beach, Brazil

Not so long ago this was a dense mangrove forest, now subject to non-stoppable erosion