Shazil et al. (2025) Assessing the Accuracy of Gridded Precipitation Products in the Campania Region, Italy

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

Identification

• Journal: Water
• Year: 2025
• Date: 2025-09-01
• Authors: Muhammad Shareef Shazil, Muhammad Adeel Aleem, Sheharyar Ahmad, Abdullah Abdullah, Roberto Greco
• DOI: 10.3390/w17172585

Research Groups

Not available from the provided text.

Short Summary

This study compares four reanalysis and satellite precipitation products (ERA5-Land, CHIRPS, PERSIANN, and TerraClimate) against ground data from 2003 to 2022, finding ERA5-Land to be the most accurate in reproducing observed precipitation and identifying wet months.

Objective

• To evaluate the performance of four reanalysis and satellite precipitation products (ERA5-Land, CHIRPS, PERSIANN, and TerraClimate) against ground data.
• To analyze spatial precipitation patterns and long-term precipitation trends using these gridded products.

Study Configuration

• Spatial Scale: Regional/Continental (implied by gridded products and spatial analysis of "northern regions").
• Temporal Scale:
  • Product comparison with ground data: 2003–2022 (20 years).
  • Trend analysis: 1983–2022 (40 years).

Methodology and Data

• Models used: Statistical comparison using Mean Bias Error (MBE), correlation coefficient (R2), Nash–Sutcliffe efficiency (NSE), categorical metrics, and Sen’s slope analysis for trend detection.
• Data sources:
  • Reanalysis/Satellite precipitation products: ERA5-Land, CHIRPS, PERSIANN, TerraClimate.
  • Ground data: Local observations (referred to as "ground data").

Main Results

• ERA5-Land demonstrated the best overall performance in reproducing ground data, with a mean bias error (MBE) of 1.91 mm, a correlation coefficient (R2) of 0.93, and a Nash–Sutcliffe efficiency (NSE) of 0.93.
• CHIRPS, PERSIANN, and TerraClimate significantly underestimated precipitation compared to ground data.
• ERA5-Land also showed superior performance in identifying wet months based on categorical metrics.
• Spatial analysis generally showed agreement in precipitation patterns among datasets, except for PERSIANN, which notably overestimated precipitation in northern regions.
• Sen’s slope analysis revealed no significant annual precipitation trend over the 1983–2022 period.
• In autumn, PERSIANN indicated a significant increasing trend of +1.81 mm/year, which was also observed by ERA5-Land (+2.68 mm/year) and CHIRPS (+1.34 mm/year), though without statistical significance for the latter two.

Contributions

• Provides a comprehensive, quantitative comparison of four widely used gridded precipitation products against ground observations over a two-decade period.
• Identifies ERA5-Land as the most accurate product among those evaluated for the study's context, offering valuable guidance for hydrological modeling and water resource management.
• Highlights specific biases and spatial discrepancies of other products (e.g., PERSIANN's overestimation in northern regions).
• Investigates long-term (40-year) precipitation trends, revealing seasonal changes despite no significant annual trend.
• Emphasizes the critical need for advancements in satellite algorithms and better integration with ground observations to enhance precipitation data accuracy.

Funding

Not available from the provided text.

Citation

@article{Shazil2025Assessing,
  author = {Shazil, Muhammad Shareef and Aleem, Muhammad Adeel and Ahmad, Sheharyar and Abdullah, Abdullah and Greco, Roberto},
  title = {Assessing the Accuracy of Gridded Precipitation Products in the Campania Region, Italy},
  journal = {Water},
  year = {2025},
  doi = {10.3390/w17172585},
  url = {https://doi.org/10.3390/w17172585}
}