PERFORMANCE COMPARISON OF CROSS-VALIDATION TECHNIQUES IN FITTING GENERALIZED EXTREME VALUE (GEV) MODELS TO MONTHLY LOW-FLOW EXTREMES

Authors

Keywords:

Low-flow hydrological extremes; cross-validation; generalized extreme value (GEV); Porto Velho, Brazil.

Abstract

This study compares the performance of the K-Fold (K=10) and Leave-One-Out (LOOCV) cross-validation techniques in assessing the goodness-of-fit of Extreme Value Distributions (EVDs) for low-flow hydrological extremes. The analysis employed the Generalized Extreme Value (GEV) distribution and its subfamilies (Gumbel, Weibull, and Fréchet), using daily streamflow data from the Porto Velho gauging station, located in the municipality of Porto Velho, Rondônia state, within the Brazilian Amazon, over the period 1970–2024. A dynamic monthly 10th percentile was adopted as the threshold to define low-flow extremes. Both LOOCV and Stratified K-Fold procedures were applied, with model adequacy evaluated based on the Kolmogorov–Smirnov (KS) statistic. Results indicate that the The LOOCV method consistently exhibits more stable KS statistics across all months and distributions. This pattern indicates a more uniform model performance, with lower sensitivity to specific months or to the presence of extreme events. In contrast, the K-Fold method shows lower KS values but with pronounced fluctuations observed in certain months. These peaks are notably associated with periods of higher exceedance frequencies or the occurrence of minimum extreme streamflows. This behavior reflects the K-Fold method’s sensitivity to hydrological extremes: when extreme events are concentrated within specific folds, the KS statistic tends to decrease.

Author Biography

Oliveira, Laboratory of Climatology and Water Resources, Federal University of Uberlândia

Graduated in Geography from the Federal University of Uberlândia (Bachelor’s and Teaching Degree), with a Master’s and PhD in Geology, with an emphasis on Data Processing in Geology and Environmental Analysis, from the Institute of Geosciences of the University of Brasília. Currently an Associate Professor at the Institute of Geography of the Federal University of Uberlândia, where he is a member of the research group at the Laboratory of Climatology and Water Resources. His research focuses on Statistics and Mathematical Modeling of Environmental Data, Geoprocessing, Hydrology, Hydrogeology, and Hydrochemistry.

Downloads

Published

2026-03-12

Issue

Vol. 22 No. 2025 (2025): Water Management Journal in Latin America - REGA - ISSN 2359-1919

Section

Novel Articles

License

Copyright (c) 2025 Revista de Gestão de Água da América Latina (Water Management Journal in Latin America)

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

When sending the manuscript, notice that:

To be responsible for the other authors, when applicable, as co-responsible for the technical and scientific content of the article according to Article 5 of Brazilian Law N. 9610, regarding Copyright.

All statements published in the manuscript are the sole responsibility of the authors. However, all published material becomes the property of REGA, which reserves the copyright. Therefore, no material published in REGA may be reproduced without the written permission of REGA. All authors of articles submitted to REGA must sign a Copyright Transfer Agreement, which will take effect from the date of acceptance of the article. This term will be requested by REGA prior to the publication of the article. The author responsible for the article will receive, free of charge, the electronic record of the publication (in PDF format).

All articles published open access will be immediately and permanently free for everyone to read, download, copy and distribute. Permitted reuse is defined by your choice of one of the following user licenses:

Creative Commons Attribution (CC BY): lets others distribute and copy the article, to create extracts, abstracts, and other revised versions, adaptations or derivative works of or from an article (such as a translation), to include in a collective work (such as an anthology), to text or data mine the article, even for commercial purposes, as long as they credit the author(s), do not represent the author as endorsing their adaptation of the article, and do not modify the article in such a way as to damage the author’s honor or reputation.

Author Rights
For open access publishing this journal uses an exclusive licensing agreement. Authors will retain copyright alongside scholarly usage rights and REGA will be granted publishing and distribution rights.

Author Self-Archiving Policy
This journal permits and encourages authors to post items submitted to the journal on personal websites and institutional or funder repositories after publication. The final published PDF version should be used and bibliographic details that credit the publication in this journal should be included.