What is a drought-to-flood transition? Pitfalls and recommendations for defining consecutive hydrological extreme events

Anderson, Bailey J.; Muñoz-Castro, Eduardo; Tallaksen, Lena M.; Matano, Alessia; Götte, Jonas; Armitage, Rachael; Magee, Eugene; Brunner, Manuela I.

doi:10.5194/hess-29-6069-2025

Articles | Volume 29, issue 21

https://doi.org/10.5194/hess-29-6069-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/hess-29-6069-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 29, issue 21

Research article

|

07 Nov 2025

Research article |

| 07 Nov 2025

What is a drought-to-flood transition? Pitfalls and recommendations for defining consecutive hydrological extreme events

Bailey J. Anderson, Eduardo Muñoz-Castro, Lena M. Tallaksen, Alessia Matano, Jonas Götte, Rachael Armitage, Eugene Magee, and Manuela I. Brunner

Supplement

https://doi.org/10.5194/hess-29-6069-2025-supplement

Data sets

dataRetrieval: Retrieval Functions for USGS and EPA Hydro-logic and Water Quality Data L. DeCicco et al. https://doi.org/10.5066/P9X4L3GE

U.S. Geological Survey GAGES-II time series data J. A. Falcone https://doi.org/10.5066/F7HQ3XS4

CAMELS-AUS v1: Hydrometeorological time series and landscape attributes for 222 catchments in Australia K. Fowler et al. https://doi.org/10.1594/PANGAEA.921850

Catchment attributes and hydro-meteorological time series for large-sample studies across hydrologic Switzerland (CAMELS-CH) M. Höge et al. https://doi.org/10.5281/zenodo.7784633

Hourly discharge database HydroCH M. Kauzlaric et al. https://doi.org/10.5281/zenodo.7691294

The CAMELS-CL dataset C. Alvarez-Garreton et al. https://doi.org/10.1594/PANGAEA.894885

EStreams: An Integrated Dataset and Catalogue of Streamflow, Hydro-Climatic Variables and Landscape Descriptors for Europe T. V. M. do Nascimento et al. https://doi.org/10.5281/zenodo.13255133

Model code and software

rnrfa: An R package to Retrieve, Filter and Visualize Data from the UK National River Flow Archive C. Vitolo et al. https://doi.org/10.32614/RJ-2016-036

Short summary

When floods happen during or shortly after droughts, the impacts of each of the events can be magnified. In hydrological research, defining these events represents a challenging and important task in the process of understanding where and why they occur. We have used real-word examples to address some of these challenges and show different approaches influence outcomes. We make suggestions on when to use which approach and outline some pitfalls of which researchers should be aware.