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-Hasenhündl.JPG/jcr:content/20260312_Gruppenbild%20(c)%20Hasenh%C3%BCndl.JPG "A group of around 50 people can be seen standing on an embankment descending to the Danube Canal. Measuring instruments are lying on the embankment; event tents and the participants’ cars can be seen in the background. In the far background, an iron bridge over the Danube Canal and part of the hydraulic engineering laboratory can be seen.")
© BAW/Hasenhündl zoom gallery -
-Hasenhündl.JPG/jcr:content/20260312_Vergleichsmessung%202(c)%20Hasenh%C3%BCndl.JPG "An aerial drone shot providing an overview of the section of the Danube Canal across which three cables are stretched, to which measurement boats are attached. Looking towards the right bank, measurement teams, tents and the participants’ cars can be seen. In the background, a railway bridge spans the Danube Canal, and parts of the Hydraulic Engineering Laboratory are visible.")
© BAW/Hasenhündl zoom gallery
On 12 and 13 March 2026, a comprehensive ADCP intercomparison took place at the Institute for Hydraulic Engineering and Hydrometry in Vienna Nussdorf. The aim of this event was to evaluate and further improve the quality of discharge determinations. A total of XY instruments and XY experts participated, including staff from the hydrographic services of all Austrian provinces, representatives from universities and hydropower companies, as well as international guests.
Purpose and Importance of Intercomparisons
Modern ADCP instruments (Acoustic Doppler Current Profilers) used to measure flow velocity and, in a next step, for discharge determination, cannot be calibrated in a laboratory in the same way as traditional mechanical current meters. To ensure the quality of the collected data, intercomparisons, also known internationally as regattas, have become an established approach. During these intercomparisons, multiple ADCP discharge determinations are carried out in the same section of a river, and the results are then evaluated collectively.
This method makes it possible to assess instrument performance, compare different measurement techniques, and examine various approaches to data processing. It also promotes professional exchange and strengthens cooperation between the participating institutions.
Event Programme
During the two‑day event:
- several measurements were carried out with each instrument under comparable conditions
- different measurement approaches and methodological considerations were discussed
- data sets were analysed jointly and checked for plausibility
- expert presentations and discussion sessions on current hydrometric topics were held
The detailed analysis of all collected data will take some additional time. However, it will provide valuable insights into differences between instruments, measurement procedures, and data processing methods. These findings will make an important contribution to ensuring the long‑term quality of discharge data in Austria.
Acknowledgement
The Federal Agency for Water Management would like to express its sincere thanks to Silke Kainz and Steffen Büchen for leading the organisation of the event, as well as to the entire team of the Institute for Hydraulic Engineering and Hydrometry for their dedicated support. We would also like to thank our partner institutions for their contributions, including the Institute of Hydraulic Engineering and River Research at BOKU, viadonau, and the Hydrographic Service of Lower Austria.
Further Information
More detailed information on quality assurance of modern discharge determination methods can be found in the following publication:
https://link.springer.com/article/10.1007/s00506-025-01127-x
