Abraham et al. (2026) Meteorological to Hydrological Drought Propagation: the Role of Catchment Properties in Contrasting Climatic Regions

Identification

• Journal: Water Resources Management
• Year: 2026
• Date: 2026-01-01
• Authors: Tesfalem Abraham, Yan Liu, Zaher Mundher Yaseen, Andreas Hartmann
• DOI: 10.1007/s11269-025-04485-z

Research Groups

• Department of Water Resources and Irrigation Engineering, Institute of Technology, Hawassa University, Hawassa, Ethiopia
• Environmental and Atmospheric Sciences Research Group, Scientific Research Center, Al-Ayen University, Thi-Qar, Nasiriyah, Iraq
• Agrosphere (IBG 3), Forschungszentrum Jülich, Jülich, Germany
• Civil and Environmental Engineering Department, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia
• Institute of Groundwater Management, Technical University of Dresden, Dresden, Germany

Short Summary

This study investigated meteorological to hydrological drought propagation across 49 gauged and ungauged catchments in the Ethiopian Rift Valley Lakes Basin, revealing that the 3-month accumulated Standardized Precipitation Index (SPI-3) best correlates with the 1-month accumulated Standardized Streamflow Index (SSI-1), and that catchment properties significantly influence propagation differently across humid, semi-arid, and arid climatic zones.

Objective

• Determine the optimal meteorological to hydrological drought propagation period for both gauged and ungauged catchments in the Ethiopian Rift Valley Lakes Basin (RVLB).
• Investigate how drought propagation is influenced in different climate groups (Humid, Semi-Arid, Arid).
• Analyze the role of catchment properties in influencing drought propagation within different climate groups.

Study Configuration

• Spatial Scale: 49 gauged and ungauged catchments within the Ethiopian Rift Valley Lakes Basin (RVLB), covering an area of 53,035 square kilometers.
• Temporal Scale: Drought analysis conducted for the period 1995–2007. Drought indices calculated for various accumulation periods (1, 3, 6, 9, 12, 18, and 24 months for SPI; 1 month for SSI).

Methodology and Data

• Models used:
  • Hydrologiska Byråns Vattenbalans (HBV) model (modified version by Zhang and Lindström, 2007) for streamflow prediction in ungauged catchments.
  • Random Forest (RF) classification model for identifying the importance of catchment properties in predicting drought propagation periods.
• Data sources:
  • Precipitation: Multi-Source Weighted-Ensemble Precipitation (MSWEP) version 2 (0.1° spatial resolution, 3-hourly temporal resolution).
  • Streamflow: Observed data from the Ministry of Water, Irrigation, and Energy of Ethiopia (MOWIE) for 14 gauged catchments; regionalized streamflow data for 35 ungauged catchments (derived using the HBV model).
  • Potential Evapotranspiration: Global Land Evaporation Amsterdam Model (GLEAM V3) (0.25° spatial resolution, daily temporal resolution).
  • Catchment Properties: Drainage area, drainage density, mean catchment slope, mean elevation, catchment index, Aridity Index, permeability, and porosity (derived from physical and climatic information, and global datasets).

Main Results

• The optimal drought propagation period (T_PROP) was identified as SPI-3 (3-month accumulation period for SPI), showing the highest correlation with SSI-1 across 39 of the 49 catchments.
• The median Pearson correlation coefficient between SSI-1 and SPI-3 across all 49 catchments was 0.81.
• Drought propagation strength varied significantly across climate zones:
  • Semi-Arid catchments exhibited the highest propagation (median correlation: 0.81).
  • Arid catchments followed closely (median correlation: 0.80).
  • Humid catchments showed the lowest propagation (median correlation: 0.61).
• A Random Forest model identified Area, Elevation, Catchment Index, and Porosity as the most important catchment properties influencing drought propagation periods, with Porosity having the highest influence.
• The role of catchment properties within climate groups:
  • In Humid regions, lower porosity values were associated with higher propagation, while other physical properties showed minimal influence.
  • In Semi-Arid regions, catchments with lower values for all important physical properties (Area, Elevation, Catchment Index, Porosity) exhibited higher propagation.
  • In Arid regions, catchments with smaller areas, lower elevations, and reduced porosity demonstrated higher drought propagation.

Contributions

• First study to investigate meteorological to hydrological drought propagation in the data-scarce Ethiopian Rift Valley Lakes Basin, incorporating both gauged and ungauged catchments.
• Unique characterization of the combined influence of climate grouping (based on aridity index) and catchment properties on drought propagation.
• Quantified hydrological drought development processes in ungauged regions, providing crucial information for prioritizing drought mitigation and adaptation strategies in data-scarce areas.
• Utilized a robust regionalization approach for streamflow prediction in ungauged catchments and a Random Forest model to identify key catchment property predictors.

Funding

The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.

Citation

@article{Abraham2026Meteorological,
  author = {Abraham, Tesfalem and Liu, Yan and Yaseen, Zaher Mundher and Hartmann, Andreas},
  title = {Meteorological to Hydrological Drought Propagation: the Role of Catchment Properties in Contrasting Climatic Regions},
  journal = {Water Resources Management},
  year = {2026},
  doi = {10.1007/s11269-025-04485-z},
  url = {https://doi.org/10.1007/s11269-025-04485-z}
}