Sediment traps with guiding channel and hybrid check dams improve controlled sediment retention
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...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-03-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | https://www.nat-hazards-earth-syst-sci.net/18/647/2018/nhess-18-647-2018.pdf |
| Summary: | 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). |
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| ISSN: | 1561-8633 1684-9981 |