1. Preliminary evidence on laboratory experiments to detect the impact of transient flow on bedload transport.
- Author
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Przyborowski, Łukasz, Nones, Michael, Mrokowska, Magdalena, Książek, Leszek, Phan, Cong Ngoc, Strużyński, Andrzej, Wyrębek, Maciej, Mitka, Bartosz, and Wojak, Szymon
- Subjects
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BED load , *SHEARING force , *SEDIMENT transport , *DIGITAL photogrammetry , *UNSTEADY flow , *FLUMES , *EROSION - Abstract
Trapezoidal-shaped hydrographs are typical of anthropized rivers, as this form is generally associated with the release of water from hydropower dams. To investigate how such unnatural waves can affect bedload rate, preliminary flume experiments were performed in Krakow, Poland, looking at bedload transport rate, bed shear stress and bed morphology. In addition, close-range bed surface photogrammetry was used to investigate bed changes due to the passage of the flood wave. Three scenarios, having the same water volume but different wave magnitudes, were tested. The lowest wave showed almost no sediment transport and no visible changes in bed morphology, while higher waves changed the bed morphology, creating erosion and accumulation zones. The highest wave was characterized by an 8-shaped hysteresis of the bedload rate with a peak during the wave maximum. The lag time between the maximum bedload rate and the wave plateau was longer than expected due to zero-slope conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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