Instream River Training

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Schematic representation of a pendulum ramp with low and mean water discharge
Structural diversity in the vicinity of an impact bank of the Ellikerbach / Canton of Zurich protected by steering bridges
"Energy body" by Viktor Schauberger (Source: Austrian Patent Office 1933)

The Instream River Training (engl., Dt. Literally Flussbau in the current line ) is a form of flow assembly , in which the flow as the cause of bank and bed erosions by inducing one or more secondary flows is modified. In this case, overflowing bodies of water are used even at low water flow.

aims

Depending on the area of ​​application, the flow modification pursues at least one of the following goals:

  • Water stabilization while largely dispensing with massive measures (e.g. block rate)
  • Sustainable bed load management
  • Initialization of momentum

Construction methods

When instream River training are steering groynes and suspended ramps used. Both construction methods are made from natural materials. Shaped blocks are used in particular, which are often combined with biological engineering building materials. There are sizing guidelines for pendulum ramps.

Iowa Vanes are a design that also specifically induces secondary currents . In contrast to steering gates and pendulum ramps, however, they are made of non-natural materials such as sheet piling and concrete bodies with pile foundations and only overflowed when the discharge is medium to high. Iowa Vanes are therefore not a construction method for Instream River training .

history

The instream River training was first already in the 1920s by the Austrian forester and naturalist Viktor Schauberger implemented (1885 to 1958), who wrote in 1930:

"You can create certain improvements through smaller installations where these are unavoidable for the protection of cultural assets, but it would be wrong to regulate the river from its banks, so only to combat the effects, not the causes. "

Viktor Schauberger was best known for his wooden washer systems , for which he used a half-oval cross-section on which he fastened wooden ribs in the outer curves. Due to the secondary currents induced in this way, the swept wood was always transported in the middle of the channel, even in curves, and blockages and damage to the system were avoided. Among other things, Schauberger built "energy bodies" into flowing waters to regulate the transport of bed load.

It was only about 50 years later that the idea of ​​flow modification by inducing secondary flows was pursued again. Jacob Odgaard developed the above-mentioned Iowa Vanes on the basis of the linear hydrofoil theory , which, however, despite their good effectiveness in terms of bank protection and bed load management, could never really prevail, at least in Europe, which is probably due to the non-natural design.

Independent of the research carried out by Odgaard, Otmar Grober from the Bruck an der Mur building district management developed the steering platform and pendulum ramp construction methods from practice since the early 1990s . Compared to the Iowa Vanes , they can be classified as being much closer to nature and also suitable for large currents.

Water ecological effect

Steering platforms and pendulum ramps have been examined in detail as part of monitoring since 2005. It turned out that their surroundings are characterized by a great diversity of currents, which is associated with substrate sorting and pronounced depth variance. This also applies if they were implemented primarily for stabilization. Even on the ramp, despite the good stabilizing effect, there is a pronounced dynamic. Supplementary fishery biology studies show a significant increase in the number of individuals and species.

literature

  • Mende, M .; Gassmann, E .: Pendulum ramps - functionality and experience. Engineering biology, issue 3/2009, 19th year. Pp. 29-36, 2009
  • Mende, M .; Sindelar, C .: Instream River Training: Steering platforms and pendulum ramps. Contribution to the 15th joint symposium of the hydraulic engineering institutes TU Munich, TU Graz and ETH Zurich from 1-3. July 2010 in Wallgau, Upper Bavaria, pp. 35–44, 2010
  • Pinter, K .; Unfer, G .; Wiesner, C .: Survey of fish stocks on the Mur in the St. Michael area. University of Natural Resources and Life Sciences Vienna, Institute for Hydrobiology and Water Management, Vienna, June 2009
  • Odgaard, AJ: River Training and Sediment Management with Submerged Vanes. American Society of Civil Engineers, ASCE Press, ISBN 978-0-7844-0981-7 , 171 pages, 2009
  • Austrian Patent Office (1933): Patent No. 134543 - Viktor Schauberger in Vienna - water flow in pipes and channels. Registered on August 12, 1931, patent period commenced on April 15, 1933. Vienna: Österreichische Staatsdruckerei
  • Schauberger, V .: Temperature and Water Movement. Wasserwirtschaft, Issue 20, p. 428, 1930
  • Sindelar, C .; Knoblauch, H .: Model experiment for the dimensioning of a pendulum ramp on the Grosse Tulln. In: Ingnenieurbiologie, Heft 3/2009, Volume 19, pp. 37–42, 2009
  • Sindelar, C .: Design of a Meandering Ramp, dissertation at the Institute for Hydraulic Engineering and Water Management at TU Graz, 242 pages, 2011.

Individual evidence

  1. ↑ a b c Mende & Sindelar 2010
  2. ↑ Mende & Gassmann 2009
  3. ↑ Sindelar 2011
  4. ↑ a b Odgaard 2009
  5. ↑ Schauberger 1930
  6. ↑ Austrian Patent Office 1933
  7. ↑ Sindelar & Knoblauch 2009
  8. ↑ Pinter et al. 2009

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