CHR launches project RheinBlick2027 (2024-2027)

8 08 2024
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Rheinblick2027 stakeholder seminar
Attendees at the Rheinblick stakeholder seminar (on site) at the ICPR premises in Koblenz spring 2024

For a long time, the International Commission for the Hydrology of the Rhine Basin (CHR) has been engaged with the investigation of the impacts of climate change on discharge of the Rhine River and its major tributaries.

In 2010, the large CHR RheinBlick2050 study was finished and published in the CHR publication I-23 (CHR, 2010). This study covered the "future" time period of 2021-2050, also including information on the period 2071-2100, labeled as "2050" and "2100", respectively. This resulted in the original name "RheinBlick2050". However, meanwhile new data sources emerge with each IPCC report, occurring approximately every 6 to 8 years. Furthermore, the previous "future" period (2021-2050) transitions into the "present". This necessitated a) regular updates for "RheinBlick" and b) the implementation of a versioning system. Consequently, a new naming convention was developed for climate change assessments by CHR, utilizing the acronym "RheinBlick" extended by the publication year.

Now, the CHR launches September 2024 the next RheinBlick project, named "RheinBlick2027". It has the objective to investigate the effects of climate change on the Rhine River discharge based on the latest state of the art. An international working group with experts from several research institutions and technical water agencies will conduct the analyses thus ensuring an improved shared understanding of the system. Also new scientific questions and the water cycle as a whole will be tackled in the project. With each iteration of the RheinBlick project and report, the core products - comprising coordinated change signals regarding high, mean, and low flow indicators for key gauging stations across the international Rhine basin - will be updated. Numerous stakeholders within the basin, including users and the Rhine Commissions ICPR and CCNR, seek insights into these future Rhine discharge projections.

 

Stakeholder seminar spring 2024 and statements on CHRs RheinBlick plans

In early April 2024, the CHR organised a stakeholder seminar on its plans for the Rheinblick2027 study at the secretariat of the International Commission for the Protection of the Rhine (ICPR) in Koblenz Germany. Delegates from various organisations associated within the Rhine basin were present (on site and online) to show their interest and importance in this study. Prior to the seminar, the various organisations present were asked to prepare a statement about the necessity and importance of such a project like Rheinblick2027 which are summarised below:

BfG (Bundesanstalt für Gewässerkunde), Germany:International catchments can only be assessed through coordinated international cooperation such as CHR and RheinBlick studies. International research networks such as RheinBlick are important sources of knowledge for BfG. The BfG carries out nationwide research and has a broad spatial coverage. The interrelationships are of great importance. 

CCNR (The Central Commission for the Navigation of the Rhine):Inland waterway transport can only adapt if reliable scientific findings on climate change effects are available which is done in Rheinblick2027. CCNR needs science to develop policy and adaptation measures.”

Deltares: “The IPCC report 6 is published and analysed with Dutch models. The knowledge preferably has to be integrated on Rhine river scale.

EDF Hydro Est, France: EDF Hydro Est is interested into future Rhine discharge projections from Rheinblick studies for a. Forecast of production of renewable energy, b. Flood management, c. Planning maintenance, d. Operating the fish passes and e. Operating the locks.”

FOEN (Federal Office for the Environment), Switzerland:The HCLIM results have shown that there are differences between the Swiss Hydro-CH2018 scenarios and the scenarios of the other countries, particularly for low water parameters. Switzerland has a great interest in analyzing these differences in greater depth and explaining them if possible. This work should be carried in an international Rhine View 2027 project.”

HCLIM (working group Climate) ICPR: “We want science to deliver consolidated data and information on climate change effects in the Rhine catchment as a basis for the ICPR strategy!”

KNMI (The Royal Netherlands Meteorological Institute): “The KNMI is part of an international cooperation on hydrological models, e.g. input of HYRAS datasets. Rheinblick will be helpful and therefore appreciated.” ….

LANUV NRW (Landesamt für Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen): General importance of the topic “Climate change impacts on discharge in the Rhine river basin” for the basis and consequences for our work (e.g. planning, dimensioning, permissions, maintenance…). Projects like KLIWAS are of great importance to show the outcomes and impact on actors in the Rhine basin. Every 10 years the design values should be checked together, e.g. the LARSIM-model with waterboards, the DWD, BfG, etc.”

Rijkswaterstaat, Netherlands: “….As Rijkswaterstaat, we see the value of Rheinblick2027, as the climate is changing ever faster, and hence we must be aware of the update of changes in the before mentioned disciplines (ecology , economy , infrastructure , transport , energy production or water management). Most probably, the challenges that we are going to face regarding effective and efficient river management will not become easier to solve. It is therefore that Rijkswaterstaat fully endorses RheinBlick2027, and is committed to actively contribute to the study in any way necessary to ensure its success.”

RIWA-Rijn (Dutch Association of River water companies): Securing a drinking water resource for millions. Drinking water resource for 5 million people in the Netherlands (and the number is growing). Highly dependent on sufficient supply of fresh Rhine water to counteract salt intrusion. Lower discharges lead to higher concentrations of (persistent) substances. High (calamitous) river discharges may lead to higher risks of undesired emissions Low (and high) water levels may lead to more shipping accidents and potential water pollution (And the Rhine does not stop at Lobith!)

The permits for drinking water last for about 30-40 years.”

University of Strasbourg: “The low flows analysis is important in order to come up with early warnings on low flows. The confluences play a crucial role in this. Brave predictions are also important for stakeholders, this is valid for surface water and groundwater as well. The communication should be better. Try to close the gap between the scientific work and politics.”

WMO (World Meteorological Organization):WMO supports the project RheinBlick that studies at the impact of climate change on the hydrology of Rhine river basin, which is one of the best monitored basins in the world. This will also help to advocate at a global level the need for better hydrological monitoring, and forecasting, and present to the world an example case study and tools for use. WMO sees the potential for joint development of such products on a continuous basis under the framework of HydroSOS (Hydrological status and outlook system).”

 

 

Content of Rheinblick2027

In the fall of 2023, a task team (consisting of CHR members) prepared an initial project plan/proposal for Rheinblick2027. This plan was as well presented and discussed at the stakeholder seminar in early 2024 in Koblenz Germany. The plan distinguishes between 2 parts, namely main items (like previous RheinBlick from 2010) and exploration of some new special items.

 

Main items:

  1. Literature review on impacts of climate change on the hydrology of the Rhine river, closing the gap between Rheinblick2010 and today (including new IPCC6 information).
  2. Data collection and structuring of meteorological and hydrological observational data (such as HYRAS, MeteoSuisse, ASGI and II products) from the contributing working groups.
  3. Modelling: simulation allowing compatible validation and projection runs using available climate projections ensembles (such as CMIP5/6-CORDEX) and hydrological Rhine models (such as Prevah, Larsim, Wflow).
  4. Communication and data products: stakeholder involvement, organizing workshops, collected observed data, generated new raw data, i.e. model output, improved models and reports containing aggregated data (hydrometeorological and hydrological change indicators).

 

Special new items (for exploration):

The joint evaluation and potential improvement of hydrological models (validation runs) and the consistent set of discharge projections (main items above) is the primary duty of RheinBlick2027. However, there are several additional items that already are or presumably will become relevant for water managers in the Rhine Basin with respect to climate change. These will be addressed in RheinBlick2027 as case studies or based on literature in order to prepare future RheinBlick projects, consisting of:

  1. Stress test scenario’s: severe droughts (5 dry years), local extreme events, no snow accumulation, etc.
  2. Flashfloods
  3. Groundwater: validate "ground water recharge" of the conceptual models with dedicated groundwater data
  4. Extreme value statistics: compare Weather generators (CH, NL, DE), Hydrodynamic scenarios (overbank flow, dike breach), etc.
  5. Sea level rise: intercomparison of existing sea level rise scenarios from the all Rhine countries, external saltwater intrusion path during low flows, etc.
  6. Meuse: extend the RheinBlick model projection runs in the best possible way to the Meuse catchment using available models WFLOW and LARSIM-ME.

 

What next?

As of September 2024, a duo is contracted by the CHR as project coordinators for the project. This duo is from Switzerland and affiliated with the University of Zurich and the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL). The project coordinators will further shape the current project plan, in coordination with the task team and input gathered during stakeholder seminar spring 2024, and take charge of the project until 2027 under the guidance of the CHR. The project's official kick-off event is scheduled for fall 2024. The CHR will communicate about this soon, in coordination with its project coordinators.

 

Finally, the CHR likes to express its ambition to conduct RheinBlick studies periodically every few years in the future. In doing so, CHR sees itself as scientific commission in which scientists form research institutes from the riparian states of the Rhine work together to a result. And thus, we can periodically provide our stakeholders and interested parties with future insights into Rhine discharges in view of climate change. The stakeholder seminar spring 2024 did reveal that all present stakeholders fully appreciate and support the development of RheinBlick studies as a fundament for future decision making.