Correa et al. (2026) Capturing the extremes: a quasi-comonotonicity-based algorithm for disaggregating daily to hourly rainfall

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

Identification

• Journal: Hydrology and earth system sciences
• Year: 2026
• Date: 2026-07-17
• Authors: Carlos Correa, Alfonso Hernanz, Iván San-Felipe, Esteban Rodríguez‐Guisado
• DOI: 10.5194/hess-30-4457-2026

Research Groups

• Department of Hydrology, University of Barcelona
• National Institute of Meteorology (INM), Spain
• Center for Water Research, University of Valencia

Short Summary

This study presents a novel algorithm, Q-CODA, that disaggregates daily precipitation data into hourly time scale with improved representation of rainfall extremes and temporal coherence. The approach outperforms state-of-the-art methods in 5-fold cross-validation over 91 Spanish meteorological stations.

Objective

• Develop an accurate and robust method for sub-daily rainfall disaggregation that captures extreme events and maintains temporal coherence.

Study Configuration

• Spatial Scale: 91 meteorological stations across Spain, with a focus on representing regional variability.
• Temporal Scale: Daily precipitation data from 1996 to 2024, with hourly time scale resolution.

Methodology and Data

• Models used: Quasi-Comonotonicity-based Disaggregation Algorithm (Q-CODA), Fréchet–Hoeffding upper bound copula, K-Nearest Neighbours (KNN) approach.
• Data sources: Observed precipitation data from 91 meteorological stations in Spain.

Main Results

• Q-CODA significantly improves the representation of rainfall extremes (90th to 99.9th percentiles) compared to state-of-the-art methods, with mean absolute error and Nash–Sutcliffe efficiency improved by up to 25% and 15%, respectively.
• The approach maintains temporal coherence and event structure, as evidenced by autocorrelation and rainfall event duration statistics.

Contributions

• Q-CODA offers a data-driven framework for accurate sub-daily rainfall disaggregation, addressing the limitations of existing methods in capturing extreme events and maintaining temporal coherence.
• This study contributes to the development of robust hydrological models and infrastructure design, with significant implications for hydrometeorological applications.

Funding

• Project: "Hydro-Meteo" (PID2020-113234GB-I00), funded by the Spanish Ministry of Science and Innovation.
• Program: "Agencia Estatal de Investigación" (AEI).
• Reference code: PID2020-113234GB-I00.

Citation

@article{Correa2026Capturing,
  author = {Correa, Carlos and Hernanz, Alfonso and San-Felipe, Iván and Rodríguez‐Guisado, Esteban},
  title = {Capturing the extremes: a quasi-comonotonicity-based algorithm for disaggregating daily to hourly rainfall},
  journal = {Hydrology and earth system sciences},
  year = {2026},
  doi = {10.5194/hess-30-4457-2026},
  url = {https://doi.org/10.5194/hess-30-4457-2026}
}