Expansion of the Rhine
The widening of the Rhine (also known as the Rhine widening ) is a proposed measure for the revitalization and renaturation of the Alpine Rhine and, at the same time, for strengthening flood security by increasing the discharge capacity.
With the development concept Alpenrhein (EKA), which was adopted by the four governments of the neighboring countries (Austria, Switzerland, Lichtenstein and Germany) in 2005 within the framework of the International Government Commission Alpenrhein , numerous expansions along the Alpine Rhine are already being considered and the basis for planning and development. Executions.
Arguments
Per widening of the Rhine
- Higher transport capacity for water,
- Surge reduction and flood peak reduction ,
- Prevention of further deepening and flooding of the Rhine, especially due to the reduced bed load transport capacity , especially in the long deepening stretches above Buchs ( bed load management ),
- Improvement and creation of new habitats for plants and animals as well as greater biodiversity and use for (gentle) fishing by restoring the passability for fish in the Alpine Rhine itself and in the tributaries as well as new habitats for birds ,
- Creation of a new local recreation area for the residents of the Alpine Rhine Valley , attractiveness also for tourism ,
- Increasing the quality of the groundwater ,
- Reducing water turbidity in the river.
Against the widening of the Rhine
- Destruction of existing agricultural structures and areas,
- Land consumption at the expense of agriculture ,
- possible fog formation ,
- Costs cannot currently be estimated
- Risk of flooding due to blockages ,
- Long-term damage to the existing building structure due to an increase in the groundwater level .
Rhesi
With the flood protection project Rhesi ("Rhine - Recreation and Security"), the first major stage in the implementation of the Alpine Rhine development concept is to be realized. By eliminating the current deficits, especially the flood hazard in the section below the mouth of the Ill , the prerequisites for sustainable regional development are to be created. Over the next few years, the capacity of the floodplains is to be expanded to at least 4,300 m³ / s (HQ 300) by giving the Rhine more space within the existing external dams, among other things.
However, for many experts and residents of the Rhine Valley, these measures are not sufficient and further-reaching measures for revitalization etc. should also be taken above the mouth of the Ill near Feldkirch .
Model test
In a 4700 m² hall in Dornbirn near the University of Applied Sciences , a relevant five-kilometer-long section of the Alpine Rhine was recreated as a physical model on a 1:50 scale by the International Rhine Regulation in order to carry out hydraulic model tests for the Rhesi flood protection project. The test facility was put into operation in March 2019, opened on June 15, 2019, invites you to guided tours and is expected to run until summer 2022.
In a first test setup (spring 2019 to autumn 2020) a five-kilometer northern section of the Rhine from Widnau to Höchst - the narrowest point for floods - is modeled, in the second setup a section from Oberriet to Koblach (winter 2020) about 20 km upstream until summer 2022) - the widest range.
The behavior was observed in nature through measurements. The test system is set to analog behavior and can then be used to simulate processes after design interventions in different waterways. It is characteristic that in the model on a spatial scale of 1:50 processes show up much faster over time and floods can be simulated in a targeted manner.
These findings should flow into the further planning and help optimize the project economically and technically.
The model test was designed by the ETH Zurich , which carried out such tests for the Rhine as early as 1938. The technical questions to be clarified:
-
Behavior of the Alpine Rhine with changes in cross-section
- Where do landings occur (gravel banks)?
- Where do depressions (pools) arise and how deep do they reach into the bottom?
-
Embankment protection and bank protection
- How deep must the bank be protected from erosion with armourstones?
- How can or must a secure bank be designed?
-
Bridge structures
- How can deep spots (pits) in bridge piers be secured?
- How large is the amount of driftwood at the bridges in the event of a flood?
- Comparison between reality and model
| Alpine Rhine | Model system | Unit of measurement | |
|---|---|---|---|
| Section length | 5000 | 100 | meter |
| Section width | 450 to 550 | 7 to 11 | meter |
| Mean water flow | 150,000 to 200,000 | 8 to 11 | Liter / second |
| Flood (HQ 100 ) | 3,100,000 | Liter / second | |
| Flood (HQ 300 ) | 4,300,000 | around 240 | Liter / second |
| Rhine gravel on average | 25 to 30 | around 1 | millimeter |
| Rhine gravel largest grain | around 120 | 2.4 | millimeter |
| Bed load (HQ 300 ) | 21,000,000 to 100,000,000 | 148 to 800 | liter |
| in the period of | 7th | 1 | Day (s) |
- HQ 100 = 3100 m 3 / s 100-year flood - dam design so far
- HQ 300 = 4300 m 3 / s 300-year flood - planned design
A 300-year flood currently has a damage potential of 11 billion euros. According to the IRR, the desired redesign should have a duration of 50 to 100 years.
Approval of the population
The approval in Liechtenstein, Austria and Switzerland for these further measures differs.
According to a survey by the Liechtenstein Institute and the WWF , the majority of the residents of the Alpine Rhine are in favor of widening the Rhine and extensive revitalization. The quality of the survey is being questioned by politicians and the majority of politicians in Liechtenstein do not see the widening of the Rhine as realistic, but for various reasons.
Examples
Other very successful revitalization projects are used by the proponents of the expansion of the Alpine Rhine, such as B.
or existing ecologically valuable areas such as the Mastrilser Auen near Landquart or such as the Rhine widening Chur-Felsberg, to prevent the Alpine Rhine from deepening further by reducing the flow velocity.
See also
- Flood section in the Alpine Rhine article
- Flood section in the article Bodensee
- Alpine floods in 2005
Web links
Organizations and projects
- International Rhine Regulation (IRR)
- Rhesi
- Environment platform Lebendiger Alpenrhein
- Future of the Alpine Rhine
- private initiative Rheinraus
- Workshop fair future
items
- Concepts and reports on the future of the Alpine Rhine ,
- Alpine Rhine development concept , short report December 2005
- The Rhine: higher, slower, wider? , LIEWO, July 3, 2016
- Alpine Rhine: start widening now , bau: zeit, p. 8 ff.
- Development concept for the Alpine Rhine , December 2005
- Environment: Experts are working on the model test Rhesi orf.at, October 16, 2019 - with a video of the test
Video
- Rhesi. The film
- Rhesi - relaxation and security
- Nature and relaxation: this is what the Alpine Rhine could look like! ,
- Widening on the Alpine Rhine: this is what the future looks like! (Liechtenstein version)
- Rhesi is being recreated in Dornbirner Halle , youtube.
- Schweiz Aktuell (SRF) visits the Rhesi model test hall , youtube.
Individual evidence
- ↑ Development concept «Future of the Alpine Rhine» and press release Land Vorarlberg , August 2002 and The Alpine Rhine needs more space ( page can no longer be accessed , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , Federal Office for the Environment (FOEN), Switzerland, November 25, 2015.
- ↑ What is Rhesi ?, project description. International Rhine Regulation (IRR), accessed on December 25, 2013 .
- ↑ Signed in 2005 by the governments of Vorarlberg, Liechtenstein, Graubünden and St. Gallen.
- ↑ Hydraulic model tests , fact sheet of the International Rhine Regulation, St. Margrethen, June 2019, pp. 2, 6.
- ↑ a b Hydraulic model tests , fact sheet of the International Rhine Regulation, St. Margrethen, June 2019, p. 2.
- ↑ Hydraulic model tests , fact sheet of the International Rhine Regulation, St. Margrethen, June 2019, p. 6.
- ↑ Flood protection project Rhesi 2017-03 International Rhine Regulation , March 17, 2017, accessed October 17, 2019. - Video (2:34)
- ↑ Widening the Rhine, the sound makes the music , LIEWO, July 3, 2016
- ↑ Media presentation of the results of the “Alpenrhein” survey and Liechtenstein voters clearly in favor of widening the Rhine .
- ↑ Liechtenstein Fatherland : Politics and the people are drifting apart. December 28, 2016, p. 3.
