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Connecting Atmospheric Evaporative Demand to Fuel Flammability and Wildland Fire Potential

NIDIS Supported Research
NIDIS-Supported Research
Main Summary

It has been noted that during recent fire seasons anomalously high evaporative demand, as shown though the Evaporative Demand Drought Index (EDDI), has often preceded large wildfires. This project aims to quantify the relationship between EDDI and large wildfires and expand the study area outside of the previous work that focused on California and Nevada. In addition to wildfires, the project will examine prescribed fires and assess how well EDDI performs in relation to optimal climate and weather burning conditions. 

The second part of this project is aimed to explore how EDDI might relate to plant physiological stress and fuel flammability, which is the real driver of fire potential. Cases in which sudden increases in highly flammable fuel conditions during a short-term period of anomalous high temperature and low atmospheric moisture have been noted over the past few years. It has been hypothesized that anomalous summer warm and dry atmospheric conditions impacted the plant water cycle by allowing for a critical threshold in plant water potential to be reached that changed the fuel flammability characteristics and subsequently allowed for more intense burning. Current operationally used models and measures do not adequately capture plant flammability potential, yet fuel flammability is a fundamental physical basis for wildfire.

For more information, please contact Britt Parker (

Research Snapshot

Research Timeline
September 2021–August 2023
Principal Investigator(s)

Tim Brown, Andrés Andrade, and Dan McEvoy, Desert Research Institute

Project Funding

What to expect from this research

  • Produce an assessment of how well EDDI works as an early warning indicator for large wildfires.
  • Develop a statistical model that relates an atmospheric indicator such as EDDI and/or metrics of normalized difference vegetation index (NDVI) vegetation health to plant water potential and flammability.
  • Translate the results to a management decision support tool for testing with Predictive Services.

Publications Resulting from This Research:

Key Regions

Research Scope