Memory-Based Drought Decomposition for Regionalized Drought Assessment
This project aims to improve how we measure and understand droughts, especially across the Southeastern U.S., by taking into account changing weather patterns over time. Current drought measures assume conditions stay the same, even with seasonal variations, and that assumption can miss important shifts.
A key part of the project is memory-based drought decomposition. In simple terms, rivers and climate systems can “remember” past conditions: conditions from previous months or years may influence a dry period today, while recurring seasonal and multi-year patterns can sometimes look like a permanent change. The research team will separate, or decompose, these records into shorter-term recurring patterns, longer-term changes, and irregular variability.
This project will distinguish normal ups and downs from more persistent shifts in drought behavior. By combining this information with established drought measures based on precipitation, temperature, and streamflow, researchers will examine how well different approaches work under different environmental conditions. The goal of the project is to determine which approaches are most appropriate for various regions.
By tailoring drought assessments to local conditions, researchers aim to provide more accurate information and support communities such as farmers, tribal nations, and water managers. In the long term, this work will help people and industries make smarter decisions and build resilience against drought across the U.S.
This research is part of the Fiscal Year 2026 NIDIS Coping with Drought research competition. For more information, please contact Britt Parker (britt.parker@noaa.gov).
Research Snapshot
Krzysztof Raczynski, Mississippi State University
John Cartwright, Jamie Dyer, Prakash Jha, and Narcisa Pricope, Mississippi State University
What to expect from this research
The research team will compare traditional drought measures with approaches that can account for changing conditions over time. They seek to identify where commonly used drought indicators perform well, where they may need to be adjusted, and which approaches are most useful for different parts of the Southeastern United States.
- The team will examine both meteorological drought (related to precipitation and atmospheric conditions) and hydrologic drought (related to streamflow and water availability). The research will also investigate how different types of drought are connected, and how long it might take for atmospheric dryness to affect rivers and water resources.
- The researchers will identify areas with similar drought behavior and develop regional recommendations describing the drought measures and approaches most appropriate to those areas.
- The researchers will evaluate how drought is changing over time, including changes in drought frequency, severity, timing, persistence, and the risk of increasing dryness or aridification.
- The methods will first be tested in selected parts of the Southeast, including environments such as the Appalachian Piedmont and Mississippi Delta, before researchers apply it across the broader study region.
- Researchers will share results through a publicly accessible interactive drought atlas and data hub. Users will be able to explore regional drought characteristics, changing conditions, recommended drought measures, and supporting project data and information.
