Journal cover Journal topic
Natural Hazards and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Nat. Hazards Earth Syst. Sci., 18, 647-668, 2018
https://doi.org/10.5194/nhess-18-647-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
02 Mar 2018
Sediment traps with guiding channel and hybrid check dams improve controlled sediment retention
Sebastian Schwindt1,2, Mário J. Franca1,3, Alessandro Reffo4, and Anton J. Schleiss1 1Laboratory of Hydraulic Constructions (LCH), École polytechnique fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
2Department of Land, Air and Water Resources, UC Davis, Davis, 95616, California, USA
3Water Science and Engineering Department, IHE Delft Institute for Water Education, Delft, 2611, the Netherlands
4Ingenieure Patscheider & Partner GmbH, Bolzano, 39100, Italy
Abstract. Sediment traps with partially open check dams are crucial elements for flood protection in alpine regions. The trapping of sediment is necessary when intense sediment transport occurs during floods that may endanger urban areas at downstream river reaches. In turn, the unwanted permanent trapping of sediment during small, non-hazardous floods can result in the ecological and morphological degradation of downstream reaches. This study experimentally analyses a novel concept for permeable sediment traps. For ensuring the sediment transfer up to small floods, a guiding channel implemented in the deposition area of a sediment trap was systematically studied. The bankfull discharge of the guiding channel corresponds to a dominant morphological discharge. At the downstream end of the guiding channel, a permeable barrier (check dam) triggers sediment retention and deposition. The permeable barrier consists of a bar screen for mechanical deposition control, superposed to a flow constriction for the hydraulic control. The barrier obstructs hazardous sediment transport for discharges that are higher than the bankfull discharge of the guiding channel without the risk of unwanted sediment flushing (massive self-cleaning).
Citation: Schwindt, S., Franca, M. J., Reffo, A., and Schleiss, A. J.: Sediment traps with guiding channel and hybrid check dams improve controlled sediment retention, Nat. Hazards Earth Syst. Sci., 18, 647-668, https://doi.org/10.5194/nhess-18-647-2018, 2018.
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Short summary
Mountain rivers can mobilize important amounts of sediment that endanger downstream dwellers and infrastructure during floods. Sediment traps are built immediately upstream of urban areas to retain hazardous sediment. However, many sediment traps retain too much sediment, which is then missing in downstream river sections, leading to a poor eco-morphological state. This study proposes an experimental research-based solution to improve sediment traps using a guiding channel.
Mountain rivers can mobilize important amounts of sediment that endanger downstream dwellers and...
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