The Danube Water Balance project, supported by the Interreg Danube Region Project was launched in January 2024, under the consortium leadership of the General Directorate of Water Management (OVF), which aims to develop a harmonized water balance modelling system for the Danube River Basin.
The expected results of the project covers four areas:
- Improved data management methodology for current and future water balance calculations, which includes the set-up of a joint data base, the collection and validation of input data, and the development of tools to support the visualization and interpretation of results; furthermore elaborating a new data management strategy, that provides a solid foundation for future activities related to water balance and water management modelling data.
- The development of a state-of-the-art, open-source water balance model enables the quantification of water balance components for the entire catchment area and the selected areas of interest.
- In order to test and validate jointly the new calculation method, more detailed analyses will be prepared for four selected, transboundary sub-basins (Morava, Tisza, Upper Sava, and Drina River), under several climate scenarios.
- Involvement of relevant stakeholders in the application of the model: the project places great emphasis on involving sectoral stakeholders and capacity building. In addition to the basic technical modelling steps, we will organize training courses to foster the development of a community of experts consisting of modelling specialists, water management and other professionals in water-related sectors.
On 5 June 2025, the OVF in cooperation with the Hungarian Hydrological Society held the first national stakeholder forum, where the project results to date were introduced to the participants.
On behalf of the International Department of OVF, Norbert Csatári presented the general characteristics of the project (partnership, work package structure), followed by experts from the Budapest University of Technology and Economics (BME), who presented the preliminary technical results.
Máté György (BME) presented the process of data specification and data collection carried out with partner countries, which will form the basis for data management strategy to be developed later. Local data and local expert knowledge can help to avoid misparameterisation and to ensure mutual acceptance of the model. One of the main challenges is the collection of water management data types.
This was followed by a presentation by Tamás Ács and Dr. Zsolt Kozma, who introduced the operation and calibration results of the CWatM model developed by the Austrian IIASA institute, which forms the basis of the water balance model for the entire Danube River basin and the Tisza River sub-basin.
At the end of the program, Ágnes Tahy and Máté Chappon (OVF) presented the potential uses of the water balance model results in water management. At the end of the event, participants were able to specify areas in which they would like to use the model by filling an online questionnaire, which will provide important feedback to the development team for programming the model’s operation.
In the second half of this year and early next year, OVF plans to organize further stakeholder forums, which will be announced on the OVF’s website as well as on the project’s website and social media platforms.
Figure 1: Sub-basins affected by the project
Figure 2: Total runoff from surface, interflow and groundwater: monthly average