Ali et al. (2025) Hydrological analysis of the Oder droughts for the period 1950‒2022 in the context of the 2022 river disaster

Identification

• Journal: Scientific Review Engineering and Environmental Sciences (SREES)
• Year: 2025
• Date: 2025-12-31
• Authors: Muhammad Umar Ali, Mateusz Grygoruk
• DOI: 10.22630/srees.10421

Research Groups

• Warsaw University of Life Sciences – SGGW, Centre for Climate Research, Poland

Short Summary

This study analyzed Oder River drought patterns from 1950-2022, finding no significant long-term trends in annual low flows but a clear increase in summer drought frequency and duration, especially downstream, with the severe 2022 drought significantly contributing to the ecological disaster.

Objective

• To conduct a comprehensive hydrological analysis of the Oder River, focusing on the catastrophic events of 2022.
• To reveal the trends and specifics of droughts along the Oder in its upper, middle, and lower courses, providing background for the analysis of the 2022 drought.
• To analyze and reveal drought criteria expressed by the average value of the annual lowest discharges (SNQ) at three gauging stations: Chałupki (upper), Połęcko (middle), and Gozdowice (lower).
• To calculate and analyze the durations of droughts at the three listed gauging stations.
• To calculate trends of droughts, with a special focus on their changing lengths and discharge deficits.
• To analyze the 2022 drought as a possible trigger for the extensive Prymnesium parvum bloom and related exposure of aquatic ecosystems to the toxic enzyme prymnesine.

Study Configuration

• Spatial Scale: Oder River basin (118,938 km²), covering parts of Poland (86%), Germany (9%), and the Czech Republic (5%). Specific analysis at three gauging stations: Chałupki (upper course), Połęcko (middle course), and Gozdowice (lower course).
• Temporal Scale: 1950–2022 (73 years), using daily discharge data.

Methodology and Data

• Models used: Mann–Kendall test (non-parametric method for trend analysis).
• Data sources: Daily river discharge data retrieved from the Institute of Meteorology and Water Management – National Research Institute (IMGW-PIB).

Main Results

• No statistically significant long-term trends were observed in the lowest annual discharges at any of the three gauging stations (Chałupki p=0.9922, Połęcko p=0.8975, Gozdowice p=0.9563).
• Significant increasing trends in lowest monthly discharges were found at Chałupki in January (p=0.019), February (p=0.001), and October (p=0.032).
• Significant decreasing trends in lowest monthly discharges were observed at Połęcko in April (p=0.032), May (p=0.001), June (p=0.0002), July (p=0.003), and August (p=0.003).
• Significant decreasing trends in lowest monthly discharges were found at Gozdowice in May (p=0.007), June (p=0.002), July (p=0.015), and August (p=0.008).
• The average duration of droughts increased downstream: Chałupki (22 days), Połęcko (29 days), Gozdowice (36 days).
• The total number of drought days also increased downstream: Chałupki (1,586 days, 6.03% of the period), Połęcko (2,076 days, 7.9%), Gozdowice (2,584 days, 9.8%).
• The majority of droughts across all stations occurred in August and September.
• Chałupki showed statistically significant decreasing trends in both the number of drought days (p=0.0093) and the duration of the longest annual drought (p=0.0021).
• The 2022 drought (March 1 to September 30) was particularly severe in the lower course, with Gozdowice experiencing 204 drought days and a negative discharge deficit of 1,898 million cubic meters (Mm³), indicating insufficient water resources to balance the drought. This period coincided with the Oder disaster.

Contributions

• Provides a comprehensive, long-term (1950-2022) hydrological analysis of drought patterns in the Oder River, specifically linking them to the 2022 ecological disaster.
• Identifies distinct spatial and seasonal trends in drought characteristics, showing increasing summer drought frequency and duration in the middle and lower reaches despite overall stable annual low flows.
• Quantifies the severity of the 2022 drought, particularly the significant discharge deficit in the lower Oder, highlighting its role as a key trigger for the mass fish mortality.
• Contrasts the Oder's long-term low-flow stability with other European rivers, suggesting unique regional factors or management practices.
• Emphasizes the critical need for enhanced adaptive water management, transboundary cooperation, and catchment-scale solutions for water retention and ecological restoration to build resilience against future extreme droughts.

Funding

• The research was developed as a master’s thesis by Muhammad Umar Ali, supervised by Mateusz Grygoruk, at the Faculty of Civil and Environmental Engineering of the Warsaw University of Life Sciences – SGGW.

Citation

@article{Ali2025Hydrological,
  author = {Ali, Muhammad Umar and Grygoruk, Mateusz},
  title = {Hydrological analysis of the Oder droughts for the period 1950‒2022 in the context of the 2022 river disaster},
  journal = {Scientific Review Engineering and Environmental Sciences (SREES)},
  year = {2025},
  doi = {10.22630/srees.10421},
  url = {https://doi.org/10.22630/srees.10421}
}