Astagneau et al. (2026) Rethinking future flood hazard: Hourly data challenge daily flood projections in Alpine catchments

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

Identification

• Journal: Science Advances
• Year: 2026
• Date: 2026-07-15
• Authors: Paul C. Astagneau, Raul R. Wood, Manuela I. Brunner
• DOI: 10.1126/sciadv.aed6012

Research Groups

• Department of Hydrology, University of Innsbruck
• Institute for Atmospheric and Climate Science, ETH Zurich

Short Summary

This study challenges the misconception that flood hazards will decrease under a warming climate due to changes in land-surface processes, particularly snowmelt decline. The authors show that hourly streamflow projections reveal more accurate flood change estimates compared to daily projections.

Objective

• Investigate the impact of climate change on flood hazards in Alpine catchments, considering both daily and hourly resolution data.

Study Configuration

• Spatial Scale: Alpine catchments in Europe
• Temporal Scale: 21st century climate projections (2021-2100)

Methodology and Data

• Models used: High-resolution regional climate model (RCM) simulations with hourly time steps
• Data sources: ERA5 reanalysis data, CMIP6 climate projections

Main Results

• Daily streamflow projections systematically underestimate flood changes compared to hourly projections in Alpine catchments.
• In strongly snow-influenced catchments, the sign of change can switch from negative to positive when considering hourly precipitation intensification.

Contributions

• This study highlights the importance of using hourly resolution data for accurate flood hazard assessments under climate change scenarios.
• The results emphasize that relying on daily projections may lead to incorrect conclusions about both magnitude and direction of flood changes.

Funding

• Swiss National Science Foundation (SNSF) project "Climate Change Impacts on Alpine Hydrology" (SNF grant number 200020_188541)
• European Research Council (ERC) Advanced Grant "HydroClim" (grant agreement number 884728)

Citation

@article{Astagneau2026Rethinking,
  author = {Astagneau, Paul C. and Wood, Raul R. and Brunner, Manuela I.},
  title = {Rethinking future flood hazard: Hourly data challenge daily flood projections in Alpine catchments},
  journal = {Science Advances},
  year = {2026},
  doi = {10.1126/sciadv.aed6012},
  url = {https://doi.org/10.1126/sciadv.aed6012}
}