Author(s): Stefan Haun; Clemens Dorfmann; Gabriele Harb; Nils Reidar B. Olsen
Linked Author(s): Clemens Dorfmann, Stefan Haun, Nils Reidar B. Olsen, Gabriele Harb
Keywords: No Keywords
Abstract: The Bodendorf reservoir is located in the province of Styria in Austria. The high sedimentation rate of about 4% per year decreased the reservoir volume from 900. 000 m3 to300. 000 m3 in only 12 operation years. To reduce the high amount of deposited sediments, a first reservoir flushing was carried out in 1994. Since the first flushing a more or less frequently reservoir flushing was established. Through the Interreg IIIb project ALPRESERV a detailed study of the flushing event in 2004 was conducted. The recorded bathymetry data, water levels, discharge rates and the measured grain size distributions at the bed were used as boundary condition for a flushing simulation. The used numerical model solves the Reynolds-averaged NavierStokes equations in three-dimensions. The turbulence is simulated by the standard k-εmodel and the pressure is computed accordingly to the SIMPLE method. The program uses an adaptive and unstructured grid which moves during the computation with changes in the bed and water levels. The suspended sediment transport is calculated by solving the convection-diffusion equation and the bed-load transport by the empirical formulas from Meyer-Peter Muller and van Rijn. Bed forms are taken into account in the study by an empirical formula from van Rijn. The presented results of the simulation show agreement in the amount of flushed out sediments. A comparison of the measured and simulated cross sections after the flushing is given in this study. This comparison also shows the sensitivity of the results in relation to different bed-load transport formulas.
Year: 2012