Author(s): Nils Ruther; Sonja Huber; Stephan Spiller; Jochen Aberle
Keywords: Photogrammetry; Bed load; Experiment; Armor layer; CEDREN
Abstract: In this study the software tool BASEGRAIN is used to derive the grain size distribution from pictures of different armor layers. The armor layer pictures were taken from two different hydraulic flume studies and from a real river bed, respectively. Armor layers in a 1 m wide hydraulic flume were developed with a discharge of 240 and 270 l/s. The initially well mixed sediments had a d50 of 5. 2 mm. Additional data from a flume study carried out with a similar initial grain-size distribution was available from the literature. The subaquatic pictures taken from armor layers in a real river were taken in the river Surna in Norway. Surna is a hydropower regulated river which experiences a constant discharge around 40 m3/s most of the year. The results gained by BASEGRAIN are compared with the ones from the classical line-by-number method, and showed good agreement.