Abstract:
This paper deals with flow field and sediment flux measurements at alpine desanding facilities. 3D flow
velocities and turbidity were recorded and water samples were taken at three alpine desanding
facilities. The samples were evaluated regarding suspended sediment concentration (SSC) and
particle size distribution (PSD) in the laboratory. SSC was correlated with turbidity and reliable
correlations were found for two facilities. The applied instrumentation and methods proved to be
appropriate to assess flow field and sediment fluxes. The results show that the flow field is
inhomogeneous in large parts of the basins and that the presence of tranquilizing racks has a
strong influence on the flow. PSD revealed a refinement of the mean particle size in streamwise
direction. The mass-related trapping efficiency of the desanding facilities was estimated based on
calculated sediment fluxes and compared to two different trapping efficiency definitions. The
results are briefly compared with a current design guideline.