Eini et al. (2026) Rising heavy precipitation extremes in Central European river basins under a high emission scenario

Identification

• Journal: Scientific Reports
• Year: 2026
• Date: 2026-04-01
• Authors: Mohammad Reza Eini, Haniyeh Salmani, Pouya Ghezelayagh, Mehdi Nodeh, Mikołaj Piniewski
• DOI: 10.1038/s41598-026-45624-9

Research Groups

• Department of Computational Landscape Ecology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
• Department of Hydrology, Meteorology, and Water Management, Institute of Environmental Engineering, Warsaw University of Life Sciences – SGGW, Warsaw, Poland
• University of Alcalá, Madrid, Spain
• Economic and Institutional Analysis Group, IMDEA Water, Madrid, Spain
• Centre for Climate Research, Warsaw University of Life Sciences – SGGW, Warsaw, Poland
• Leibniz Universität Hannover, Hannover, Germany

Short Summary

This study assesses historical trends and future projections of extreme precipitation events in Central Europe’s Vistula and Oder transboundary river basins using ETCCDI climate indices. Findings demonstrate a consistent and statistically significant increase in extreme precipitation events under the high-emission RCP8.5 scenario, notably in heavy rainfall days and their contribution to total precipitation, particularly in southern mountainous areas.

Objective

• To analyze historical trends and future projections of extreme precipitation utilizing ETCCDI indices and bias-corrected EURO-CORDEX RCP8.5 datasets applied to the Vistula and Oder transboundary river basins in Central Europe.

Study Configuration

• Spatial Scale: Union of the Vistula and Oder (Odra) transboundary river basins and Poland, covering 349,766 km². Daily precipitation data with a resolution of 12.5 km.
• Temporal Scale:
  • Historical baseline: 1990–2019 (for trend analysis).
  • Future projections: 2006–2100 (under RCP8.5 scenario).
  • Spatial projection periods: 2021–2040, 2041–2060, 2061–2080, 2081–2100.

Methodology and Data

• Models used: Ensemble of six bias-corrected GCM-RCM (General Circulation Model-Regional Climate Model) from the EURO-CORDEX archive, under the RCP8.5 scenario. Bias correction was performed using the quantile-mapping method.
• Data sources:
  • Historical gridded 2 km daily climate dataset (G2DC-PL+) for 1951–2019, based on observed stations and geostatistical interpolation (kriging).
  • Daily precipitation data from EURO-CORDEX regional climate models (12.5 km resolution).
  • Ten intensity-based precipitation indices recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI).
  • Statistical methods: Non-parametric Mann–Kendall (MK) test for trend detection and Sen’s slope estimation for trend magnitude, with a pre-whitening procedure to address serial correlation.

Main Results

• Historical Trends (1990–2019): Statistically significant increasing trends were detected for the frequency of heavy rainfall days (R10mm) and the average intensity on wet days (SDII). Other indices (R20mm, R25mm, R95pTOT) showed increasing tendencies, but key intensity metrics (Rx1day, Rx5day), total precipitation (PRCPTOT), and the most extreme contribution (R99pTOT) did not show statistically significant trends. Duration indices (CDD, CWD) showed no significant historical trends.
• Future Projections (2006–2100, RCP8.5):
  • Highly statistically significant increasing trends were projected for nearly all indices related to precipitation amount (PRCPTOT), intensity (SDII, Rx1day, Rx5day), frequency of heavy events (R10mm, R20mm, R25mm), and the contribution of extremes to total precipitation (R95pTOT, R99pTOT).
  • Total annual precipitation (PRCPTOT) is projected to rise by 100–150 mm by the end of the century.
  • Maximum 1-day precipitation (Rx1day) is projected to increase by approximately 5–10 mm by 2100.
  • Maximum 5-day precipitation (Rx5day) is projected to increase by approximately 10–20 mm by 2100.
  • The proportion of total rainfall from very wet (R95pTOT) and extremely wet (R99pTOT) days is projected to rise significantly.
  • Duration indices (CDD, CWD) showed less clear and more uncertain future trends, with no strong consensus signal across the model ensemble.
• Spatial Distribution: Southern mountainous regions (Carpathians and Sudetes) consistently exhibited the highest extreme precipitation values historically and are projected to experience the most pronounced absolute increases. However, significant relative increases are projected broadly across the entire study area, including the central lowlands.

Contributions

• Provides a comprehensive and consistent assessment of historical trends and future projections of extreme precipitation in the Vistula and Oder river basins, a critical transboundary region in Central Europe.
• Utilizes recently bias-corrected EURO-CORDEX RCP8.5 datasets and standardized ETCCDI indices, enhancing the robustness and comparability of the findings.
• Offers a robust scientific basis for informing proactive adaptation measures, such as updating hydraulic design standards, strengthening flood risk management strategies, and improving water resource planning in the region.
• Reinforces the growing body of evidence that climate change will intensify the hydrological cycle and wet extremes in Central Europe, underscoring the urgency for policymakers and planners to integrate these projections into risk assessments.

Funding

Open Access funding enabled and organized by Projekt DEAL.

Citation

@article{Eini2026Rising,
  author = {Eini, Mohammad Reza and Salmani, Haniyeh and Ghezelayagh, Pouya and Nodeh, Mehdi and Piniewski, Mikołaj},
  title = {Rising heavy precipitation extremes in Central European river basins under a high emission scenario},
  journal = {Scientific Reports},
  year = {2026},
  doi = {10.1038/s41598-026-45624-9},
  url = {https://doi.org/10.1038/s41598-026-45624-9}
}