Hu et al. (2026) Drivers of flash flood frequency and intensity in the United States: a quantitative analysis of hydrometeorological interactions

Identification

• Journal: Natural hazards and earth system sciences
• Year: 2026
• Date: 2026-08-07
• Authors: Ying Hu, Huan Wu, Yiwen Mei, Zhijun Huang, Aihui Wang, Chaoqun Li, Bing Sui
• DOI: 10.5194/nhess-26-3667-2026

Research Groups

• Hubei Meteorological Service Center, Wuhan, China
• Southern Marine Science and Engineering Laboratory (Zhuhai), and School of Atmospheric Sciences, Sun Yat-sen University, Guangdong, China
• State Key Laboratory of Climate System Prediction and Risk Management/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing, Jiangsu 210044, China
• Carbon-Water Observation and Research Station in Karst Regions of Northern Guangdong, School of Geography and Planning, Sun Yat-sen University, Guangzhou, China
• Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
• Hunan Research Institute of Meteorological Sciences, Hunan Meteorological Bureau, Changsha, China

Short Summary

This study investigates the drivers of flash flood frequency and intensity in the United States using a quantitative analysis of hydrometeorological interactions. The results reveal that land cover changes have remained stable over the past four decades, while precipitation emerges as the primary driver of streamflow changes.

Objective

• Investigate the trends in flash flood intensity and frequency over the past 30 years (1990–2020) across the contiguous United States (CONUS)
• Quantify the impact of climate variables and land cover changes on flash floods

Study Configuration

• Spatial Scale: Continental scale, with a focus on small to medium-sized catchments (drainage area < 3000 km2)
• Temporal Scale: 30 years (1990–2020)

Methodology and Data

• Models used:
  • DRIVE hydrological model
  • TS-DUH model (Time-Space varying Distributed Unit Hydrograph)
• Data sources:
  • USGS river-watching network data
  • NLDAS-2 precipitation product
  • MERRA-2 atmospheric forcing data

Main Results

• Significant upward trends in heavy precipitation frequency were observed at approximately 67% of the stations, with a corresponding increase in flash flood frequency (POTF) in only 23% of catchments.
• The results reveal that land cover changes have remained stable over the past four decades, while precipitation emerges as the primary driver of streamflow changes.

Contributions

• This study provides a comprehensive understanding of the drivers of flash flood frequency and intensity in the United States.
• The results highlight the importance of considering hydrometeorological interactions when assessing flash flood risk.

Funding

• This research was supported by the National Natural Science Foundation of China (Grant No. 41875045)

Citation

@article{Hu2026Drivers,
  author = {Hu, Ying and Wu, Huan and Mei, Yiwen and Huang, Zhijun and Wang, Aihui and Li, Chaoqun and Sui, Bing},
  title = {Drivers of flash flood frequency and intensity in the United States: a quantitative analysis of hydrometeorological interactions},
  journal = {Natural hazards and earth system sciences},
  year = {2026},
  doi = {10.5194/nhess-26-3667-2026},
  url = {https://doi.org/10.5194/nhess-26-3667-2026}
}