Above: The percent of maximum soil moisture available to plants in the top 16 inches in Oklahoma, September 11, 2016.
David M. Engle, along with other scientists at Oklahoma State University, are making a case that soil moisture should be used as one of the components in determining grassland fire danger ratings.
To assess the herbaceous fuel dynamics in grasslands, they conducted 3 studies:
1) A study that used a database of large wildfires in Oklahoma to examine the relationship of fire occurrence and fire size with soil moisture;
2) An intensive field-based study to quantify and subsequently model herbaceous fuel load and moisture content in grassland patches that differed in time since fire and, therefore, proportion of live and dead herbaceous fuel load, and;
3) Modeling the influence of herbaceous fuel dynamics and weather conditions on fire behavior in tallgrass prairie.
Their final report can be read HERE.