Sabut et al. (2026) Distinguishing drought and flash drought: definitions, processes, and consequences

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-06-11
• Authors: Amitesh Sabut, Ashok Mishra, Vijay Sreeparvathy, Benjamin F. Zaitchik
• DOI: 10.1016/j.jhydrol.2026.135851

Research Groups

• Zachry Department of Civil and Environmental Engineering, Texas A&M University, USA
• Department of Civil Engineering, Indian Institute of Technology, Madras, India
• Morton K. Blaustein Department of Earth and Planetary Sciences, Johns Hopkins University, USA

Short Summary

This review synthesizes the distinctions between conventional droughts (CDs) and flash droughts (FDs), highlighting differences in their onset speeds, physical drivers, predictability, and systemic impacts.

Objective

• To synthesize existing research to distinguish between conventional and flash droughts, addressing gaps in definitions, diagnostic methods, and the understanding of transitions between the two.

Study Configuration

• Spatial Scale: Global (all climatic regions).
• Temporal Scale: Sub-seasonal (for flash droughts) to decadal (for conventional droughts).

Methodology and Data

• Models used: Synthesis of existing literature (Review paper), including discussions on dynamical models, statistical approaches, and machine learning.
• Data sources: Peer-reviewed scientific literature and reports from global meteorological organizations (e.g., WMO).

Main Results

• Conventional Droughts (CDs): Characterized as slow-developing events driven by prolonged precipitation deficits and large-scale climate variability (e.g., ENSO, PDO, AMO).
• Flash Droughts (FDs): Characterized by rapid intensification at sub-seasonal scales, driven by short-term precipitation breaks, high evaporative demand, and strong land–atmosphere feedbacks.
• Predictability: CDs benefit from boundary-forced predictability, whereas FDs present significant challenges due to their rapid onset and sub-seasonal nature.
• Systemic Impacts: FDs act as precursors or amplifiers for compound extremes, including heatwaves, wildfires, and multi-breadbasket failures.
• Monitoring Gap: Current early-warning systems are primarily designed for slow-onset events, leaving a critical gap in the detection and mitigation of FDs.

Contributions

• Provides a comprehensive synthesis that explicitly distinguishes CDs from FDs across four key dimensions: typology, physical processes, predictability, and consequences.
• Advocates for a unified drought typology and the development of hybrid monitoring frameworks (combining dynamical, statistical, and ML models) to improve global resilience.

Funding

• Not specified in the provided text.

Citation

@article{Sabut2026Distinguishing,
  author = {Sabut, Amitesh and Mishra, Ashok and Sreeparvathy, Vijay and Zaitchik, Benjamin F.},
  title = {Distinguishing drought and flash drought: definitions, processes, and consequences},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.135851},
  url = {https://doi.org/10.1016/j.jhydrol.2026.135851}
}