ABSTRACT
To plan and evaluate river restoration projects with wood, the analysis of the interactions between flow, wood, and sediment is crucial. The knowledge of the required amount and position of wood to sufficiently alter flow and morphology is still missing. Flume experiments were conducted according to Froude similitude with a model scale factor of 5. The first test setup included a single log placed on a movable bed with a uniform grain size diameter. For this setup, the effect of log diameter, log orientation to the flow, and log length on flow variability was studied for various approach flow conditions. The results demonstrate that even a single log increases flow variability, herein defined by flow velocity and turbulent kinetic energy. Due to increased shear and turbulence downstream of the log, scour is induced downstream of the log and can be described as a function of the log diameter.
