Climate change impacts in the Danube River Basin (DRB) are causing significant water balance issues, affecting the environment, economy, and society. Current joint water management is hindered by fragmented data and varying national methods. The Danube Water Balance project aims to address these challenges by creating a unified data management system and water balance model for the basin. Project Objectives: • Data Management Improvement: Develop a comprehensive data repository and tools for data collection, validation, and visualization. These resources will be open access, benefiting water experts, related professionals, and decision-makers. • Water Balance Model: Create a state-of-the-art, open-source model for the DRB to quantify water balance components. This model will be calibrated with measured data and will support sustainable water management. • Water Balance Scenarios: Develop scenarios for four key transboundary sub-basins: Morava, Tisa, Upper Sava, and Drina. This will test and refine the Danube River Basin Water Balance model and data repository. • Stakeholder Engagement: Enhance stakeholder understanding and capacity through training and the establishment of an expert hub, including water managers and professionals. This will improve collaboration on transboundary water issues. The project’s novelty lies in its development of a unified water balance methodology for the DRB, incorporating climate scenarios and extensive partnerships. This will enhance river basin management and foster cooperation among the 14 countries sharing the DRB, marking the first collective effort to improve understanding and management of the basin’s water balance.

Keywords
water management; Danube River Basin; water quantity, mathematical modelling