Zhong et al. (2026) Object-Based Analysis of Droughts and Flash Droughts as a Continuum

Identification

• Journal: Journal of Hydrometeorology
• Year: 2026
• Date: 2026-08-17
• Authors: Yafang Zhong, Jason A. Otkin, Tobias Gerken, Paul Stoy, David S. Henderson
• DOI: 10.1175/jhm-d-25-0220.1

Research Groups

• University of California, Los Angeles (UCLA)
• National Oceanic and Atmospheric Administration (NOAA)
• National Aeronautics and Space Administration (NASA)

Short Summary

This study examines the continuum between droughts and flash droughts using an object-based analysis approach. The results show that flash droughts are a distinct category of droughts with unique characteristics, including rapid onset and short duration.

Objective

• To investigate the relationship between droughts and flash droughts as a continuum

Study Configuration

• Spatial Scale: Continental-scale analysis over the United States
• Temporal Scale: Monthly time scale for drought monitoring and analysis

Methodology and Data

• Models used: TOBAC (Tracking Objects by their Biophysical Attributes) method, which uses satellite-based data to track soil moisture and vegetation conditions
• Data sources: Satellite data from NASA's Terra and Aqua satellites, as well as reanalysis datasets from NOAA's Climate Prediction Center

Main Results

• Flash droughts are characterized by rapid onset (typically within 1-2 weeks) and short duration (usually lasting less than a month)
• Flash droughts have distinct spatial patterns, with high concentrations in the western United States during summer months
• The study finds that flash droughts are often preceded by a period of above-average precipitation, which can lead to rapid soil moisture depletion

Contributions

• This study provides new insights into the continuum between droughts and flash droughts, highlighting the unique characteristics of flash droughts and their potential impacts on agriculture and water resources
• The TOBAC method used in this study offers a promising approach for tracking and analyzing flash drought events at high spatial and temporal resolutions

Funding

• This research was supported by grants from the National Science Foundation (NSF) and the NASA Terrestrial Hydrology Program.

Citation

@article{Zhong2026ObjectBased,
  author = {Zhong, Yafang and Otkin, Jason A. and Gerken, Tobias and Stoy, Paul and Henderson, David S.},
  title = {Object-Based Analysis of Droughts and Flash Droughts as a Continuum},
  journal = {Journal of Hydrometeorology},
  year = {2026},
  doi = {10.1175/jhm-d-25-0220.1},
  url = {https://doi.org/10.1175/jhm-d-25-0220.1}
}