Hochschule Karlsruhe Hochschule Karlsruhe - University of Applied Sciences
Hochschule Karlsruhe Hochschule Karlsruhe - University of Applied Sciences
Projekt Töging, Beispiel für eine kolmatierte Gewässersohle

Colmation in hydraulic laboratories

Colmation – Unravelling physical interactions of surface and subsurface processes


The long history of research on fine sediment infiltration and accumulation into gravel riverbeds and more recently, research that relates these processes to the phenomena called colmation has shown the importance to understand the basic physics behind colmation processes; especially given their immense impact on river ecology. There is a consensus that surface and subsurface processes including hydraulic, sedimentary and biogeochemical processes trigger the spatio-temporal behaviour of colmation processes.

However, substantial knowledge gaps exist regarding the interactions and the dynamics of the involved processes. Hence, a general physical description of the interacting surface and subsurface processes and their effect on sediment infiltration and accumulation is still unaccounted for.


The focus of the research project is on laboratory flume experiments to separate and investigate distinct processes involved in colmation. The key aspects of the proposed work include investigations into the role of turbulences at the water-sediment interface on infiltration rates and how they influence and interact with the interstitial flow fields in the pores.


In addition, the hydraulic forces acting on already infiltrated particles will be examined to derive thresholds for the initiation of interstitial sediment transport processes. Finally, functional relationships between the increasing pore filling, its effect on the interstitial flow field to different infiltration rates are explored.


For the flume experiments, an innovative setup and measurement concept is used to gather spatio-temporal information about the infiltration and accumulation processes and the interstitial flow field. Particle Image Velocimetry (PIV) is used for the multidimensional acquisition of flow fields, Gamma Ray Absorption (GRA) for detectin infiltration masses, as well as 3D printers for the production of simplified streambeds. The measurement concept results in the detailed and so far unique data set.

Hochschule Karlsruhe University of Applied Sciences

Project Management

Prof. Dr.-Ing. Markus Noack

Phone: +49 (0)721 925-2619 markus.noackspam prevention@h-ka.de

Stuttgart University

Institute of Water and Environmental Systems Modeling (IWS) Chair of Hydraulic Engineering and Water Quantity Management

Prof. Dr.-Ing. Silke Wieprecht

Phone: +49 (0)711 685-64461
silke.wieprechtspam prevention@iws.uni-stuttgart.de


Ongoing project 04/2021- 03/2024

Project funding

The project "Colmation – Unravelling physical interactions of surface and subsurface processes" is funded by the Deutsche Forschungsgemeinschaft e.V. (DFG).