"How to determine the erosion risk of contaminated cohesive sediments best? Putting in situ and laboratory practices to the test"In contrast to non-cohesive sediments, the dynamics of cohesive sediments is not yet fully understood mainly because of multiple physico-chemical factors and variable biological influence. Hence, site-specific investigations are required to develop water management strategies as well as modelling approaches to predict the dynamic behavior of cohesive material. The Institute for Modelling Hydraulic and Environmental Systems (IWS, University of Stuttgart) has a long record in developing measuring strategies and techniques to deal with the complex interactions between biological and sedimentary characteristics regarding the erosion behavior of cohesive material. Specifically, the detection of critical shear stresses for incipient motion of cohesive particles has been realized for both one laboratory device (SETEG) and an in situ device. This paper presents results from two measuring campaigns in different rivers analyzing correlations between sedimentary and biological attr
ibutes and indicating the chances and drawbacks of both measuring techniques.