Pérez-De-Gregorio et al. (2026) How Frequent Is an Extraordinary Episode of Precipitation? Spatially Integrated Frequency in the Júcar–Turia System (Spain)

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

Identification

• Journal: Atmosphere
• Year: 2026
• Date: 2026-01-31
• Authors: Pol Pérez-De-Gregorio, Robert Monjo
• DOI: 10.3390/atmos17020157

## Research Groups -

Short Summary

This study evaluates a novel explicitly spatial approach for estimating return periods of extraordinary precipitation in the Júcar and Turia basins. It finds that this spatially integrated method is more accurate for basin-scale risk assessment, indicating a 3 to 10 times higher probability of extreme events compared to traditional point-based analyses.

Objective

• To evaluate the feasibility and added value of an explicitly spatial approach for estimating return periods of extraordinary precipitation in the Júcar and Turia basins, as an alternative to traditional point-based or micro-catchment analyses.

Study Configuration

• Spatial Scale: Júcar and Turia river basins (western Mediterranean, Valencia coast). Analysis stabilizes with approximately 15–20 stations to sample relevant spatial heterogeneity.
• Temporal Scale: 10-minute rainfall data; long-term annual maxima time series.

Methodology and Data

• Models used: Fractal–intermittency n-index for temporal structure; Gumbel, Generalized Extreme Value (GEV), Weibull, Gamma, and Pareto distributions for tail behavior modeling.
• Data sources: Observational rainfall data from 98 meteorological stations within the Júcar and Turia basins.

Main Results

• The fractal–intermittency n-index for extreme rainfall is consistently found to be approximately 0.3–0.4.
• Return periods systematically decrease as more stations are spatially aggregated, stabilizing once about 15–20 stations are included, indicating sufficient sampling of spatial heterogeneity.
• The probability of exceeding extraordinary rainfall thresholds is between 3 and 10 times higher when using the areal (spatial) approach compared to a point-based approach.
• This implies that the recurrence of a catastrophic event would be once every few decades rather than once every few centuries.
• Spatially integrated return-period estimation is operational, physically consistent, and better suited for basin-scale risk assessment than purely point-based methods.

Contributions

• Introduces and validates an explicitly spatial approach for estimating return periods of extraordinary precipitation, moving beyond traditional point-based or micro-catchment analyses.
• Demonstrates that a spatially integrated method provides a more realistic and significantly higher probability of extreme rainfall events at the basin scale.
• Offers a relevant baseline for interpreting recent catastrophic events in the context of ongoing climatic warming in the Mediterranean region.

## Funding -

Citation

@article{PérezDeGregorio2026How,
  author = {Pérez-De-Gregorio, Pol and Monjo, Robert},
  title = {How Frequent Is an Extraordinary Episode of Precipitation? Spatially Integrated Frequency in the Júcar–Turia System (Spain)},
  journal = {Atmosphere},
  year = {2026},
  doi = {10.3390/atmos17020157},
  url = {https://doi.org/10.3390/atmos17020157}
}