Ewnetu et al. (2025) Spatial and Temporal Evaluation of Gridded Precipitation Products over the Mountainous Lake Tana Basin, Ethiopia

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Water
• Year: 2025
• Date: 2025-12-13
• Authors: Solomon S. Ewnetu, Mekete Dessie Wosenie, Mulugeta A. Belete, Ann van Griensven, Kristine Walraevens, Amaury Frankl, Enyew Adgo, Niko E. C. Verhoest
• DOI: 10.3390/w17243536

Research Groups

Not explicitly mentioned in the provided text.

Short Summary

This study evaluated the reliability of six satellite and reanalysis rainfall estimates (SREs) against gauge observations in the complex terrain of the Ethiopian highlands from 2005 to 2019, finding that SRE accuracy improves with temporal aggregation, and MSWEP, CHIRPS, and IMERG offer the most balanced performance despite a general tendency to misrepresent rainfall intensity.

Objective

• To evaluate the reliability of six satellite and reanalysis rainfall estimates (CHIRPS v2, ERA5, ERA5-Land, IMERG v07, MSWEP v2.8, and TRMM 3B42) against gauge observations in regions with complex terrain and variable precipitation.

Study Configuration

• Spatial Scale: Ethiopian highlands (regional scale).
• Temporal Scale: 15 years (2005 to 2019), evaluated at daily to seasonal timescales.

Methodology and Data

• Models used: CHIRPS v2, ERA5, ERA5-Land, IMERG v07, MSWEP v2.8, TRMM 3B42.
• Data sources: Satellite and reanalysis rainfall estimates (SREs), gauge observations.

Main Results

• The accuracy of SREs improves with temporal aggregation, with the monthly scale offering the highest reliability for water resource management.
• SREs tend to overestimate light daily rainfall and underestimate heavy daily rainfall, requiring bias adjustment for flood and extreme event analysis.
• MSWEP, CHIRPS, and IMERG provided balanced and consistent performance across all metrics, rainfall intensities, and terrain zones.
• ERA5 and ERA5-Land consistently overestimated average rainfall.
• All SREs accurately identified dry days, but their performance declined with increasing rainfall intensity.
• No significant performance variation was observed across different altitudes.

Contributions

• Provides valuable insights into the selection of appropriate rainfall products for climate and hydrological studies in data-scarce areas, specifically within the Ethiopian highlands.
• Offers a comprehensive evaluation of multiple SREs using statistical, categorical, and distributional metrics, incorporating terrain-based classification and rainfall intensity categories to assess performance under complex conditions.

Funding

Not explicitly mentioned in the provided text.

Citation

@article{Ewnetu2025Spatial,
  author = {Ewnetu, Solomon S. and Wosenie, Mekete Dessie and Belete, Mulugeta A. and Griensven, Ann van and Walraevens, Kristine and Frankl, Amaury and Adgo, Enyew and Verhoest, Niko E. C.},
  title = {Spatial and Temporal Evaluation of Gridded Precipitation Products over the Mountainous Lake Tana Basin, Ethiopia},
  journal = {Water},
  year = {2025},
  doi = {10.3390/w17243536},
  url = {https://doi.org/10.3390/w17243536}
}