Abraham et al. (2025) Meteorological to hydrological drought propagation: The influence of future climate change at grid scale

Identification

• Journal: Theoretical and Applied Climatology
• Year: 2025
• Date: 2025-12-20
• Authors: Tesfalem Abraham, Zaher Mundher Yaseen‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬, Gebre Gelete, Andreas Hartmann
• DOI: 10.1007/s00704-025-05963-5

Research Groups

• Department of Water Resources and Irrigation Engineering, Institute of Technology, Hawassa University, Ethiopia
• Environmental and Atmospheric Sciences Research Group, Scientific Research Center, Al-Ayen University, Iraq
• Civil and Environmental Engineering Department, King Fahd University of Petroleum & Minerals, Saudi Arabia
• College of Agricultural and Environmental Science, Arsi University, Ethiopia
• Faculty of Civil and Environmental Engineering, Near East University, Turkey
• Institute of Groundwater Management, Technical University of Dresden, Germany

Short Summary

This study investigates the propagation of meteorological to hydrological drought and its characteristics under future climate change at a high-resolution grid scale (0.1°) in the Gidabo catchment, Ethiopia, finding a general decrease in drought propagation and increased resilience in certain regions under the RCP8.5 scenario.

Objective

• How will gridded drought propagation and propagation ratio change with a changing climate?
• How will climate change affect gridded drought characteristics?
• Which grid cells in the study area demonstrate resilience to hydrological drought development?

Study Configuration

• Spatial Scale: Gidabo catchment, Ethiopia (3,390 km²), gridded at 0.1° resolution (approximately 11 km x 11 km at the equator).
• Temporal Scale:
  • Historical period: 1981–2005
  • Future periods (under RCP8.5 scenario):
    • Near-Future (NF): 2025–2049
    • Mid-Future (MF): 2050–2074
    • Far-Future (FF): 2075–2099
  • Model calibration: 1996–2002
  • Model validation: 2003–2007

Methodology and Data

• Models used:
  • Gridded HBV hydrological model
  • Regional Climate Models (RCMs) from the CORDEX Africa project (RCA4CNRM, RCA4CSIRO, RCA4GFDL, RCA4MIROC5, RCA4_NorESM)
• Data sources:
  • Precipitation: Multi-Source Weighted-Ensemble Precipitation (MSWEP) at 0.1° (historical); CORDEX Africa RCMs at 0.44° (future, regridded to 0.1°).
  • Potential Evapotranspiration (PET): Global Land Evaporation Amsterdam Model (GLEAM V4.2) at 0.1° (historical); computed using Hargreaves equation with RCM temperature and radiation data (future).
  • HBV parameters: Global gridded HBV parameters at 0.1° (10 ensemble parameterizations).
  • Temperature: ERA5 reanalysis at 0.25° (for bias correction); CORDEX Africa RCMs at 0.44° (future, regridded to 0.1°).
  • Observed streamflow: Ministry of Water Irrigation and Energy of Ethiopia (MOWIE) at Measso gauging station.
  • Drought indices: Standardized Precipitation Index (SPI), Standardized Streamflow Index (SSI).
  • Bias correction: Quantile Mapping (QM) technique (Gamma distribution for precipitation, Gaussian for temperature).

Main Results

• The gridded HBV model showed efficient performance, achieving median Kling-Gupta Efficiency (KGE) values of 0.55 for monthly calibration and 0.77 for monthly validation.
• The highest Pearson correlation (median 0.83) for drought propagation was observed between the 1-month Standardized Streamflow Index (SSI-1) and the 3-month Standardized Precipitation Index (SPI-3).
• Spatially, the strongest drought propagation occurred in the northeastern part of the catchment, while the central and southwestern regions exhibited the lowest propagation.
• Under the RCP8.5 climate change scenario, the historical median drought propagation value of 0.83 decreased to 0.80 in the Near Future (NF) and 0.81 in the Far Future (FF) periods.
• The median percentage change in drought propagation across grid cells showed reductions of -1.4% (NF), -0.69% (MF), and -3.07% (FF), with the largest reduction in the FF period, suggesting increased resilience at the catchment scale.
• Higher drought propagation ratios (PR) were found in the northeastern grid cells, while lower PR values in the central and southwestern regions indicated greater resilience to hydrological drought development.
• Among drought characteristics, peak drought showed percentage reductions in most grid cells during the NF and MF periods, but a slight percentage increase in the FF period. Drought duration increased by a median of 10.91% in the NF, then decreased by -14.5% (MF) and -6.20% (FF). Drought severity increased by a median of 13.8% in the NF, then decreased by -21.87% (MF) and -10.77% (FF).

Contributions

• This is the first study to investigate meteorological to hydrological drought propagation and quantify the gridded drought propagation ratio at a finer grid-scale (0.1° ≈ 11 km) under climate change in the East African region (Gidabo catchment, Ethiopia).
• It provides a novel methodology for high-resolution drought assessment in data-scarce regions by adapting globally available gridded input data and parameters.
• The research advances the understanding of drought propagation dynamics at a grid-scale, enabling the prioritization and implementation of targeted mitigation strategies.
• It integrates gridded drought quantification with gridded climate models for detailed impact analysis, identifying drought-resilient and vulnerable areas.

Funding

No funding was received for conducting this study.

Citation

@article{Abraham2025Meteorological,
  author = {Abraham, Tesfalem and Yaseen‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬, Zaher Mundher and Gelete, Gebre and Hartmann, Andreas},
  title = {Meteorological to hydrological drought propagation: The influence of future climate change at grid scale},
  journal = {Theoretical and Applied Climatology},
  year = {2025},
  doi = {10.1007/s00704-025-05963-5},
  url = {https://doi.org/10.1007/s00704-025-05963-5}
}