Forestry management relies on combating the challenges posed by fire. Knowledge of fire risk helps in the planning for and reacting to forest fires. One method used is the mapping of the Keetch-Byram Drought Index (KBDI). Though it was not specifically designed to be a fire risk assessment tool it is used to highlight areas with a high potential of fire due to climactic factors. A statistical analysis is performed to determine the relevance of the use of this drought index to measure fire potential. Analysis is performed by testing the relationship of KBDI to the number of fires and area burned in the Mississippi Forestry Commission?s south east fire district. These analyses showed a weak relationship between total fires and KBDI. In many cases there was no relationship. This calls into question the use of KBDI to determine fire potential.

Forestry management relies on combating the challenges posed by fire. Knowledge of fire risk helps in the planning for and reacting to forest fires. One method used is the mapping of the Keetch-Byram Drought Index (KBDI). Though it was not specifically designed to be a fire risk assessment tool it is used to highlight areas with a high potential of fire due to climactic factors. A statistical analysis is performed to determine the relevance of the use of this drought index to measure fire potential. Analysis is performed by testing the relationship of KBDI to the number of fires and area burned in the Mississippi Forestry Commission's south east fire district. These analyses showed a weak relationship between total fires and KBDI. In many cases there was no relationship. This calls into question the use of KBDI to determine fire potential.

A continental-scale study of historic wildfire data within and across ecoregion provinces was conducted and geographical gradients in seasonal measures of wildfire size and frequency were observed. In the conterminous United States, western ecoregion provinces show north-south gradients in duration of season (short-to-long) and peak of season (early-to-late). Across the continent a gradient of unimodal to bimodal seasonal distributions of wildfire size and frequency was shown: western ecoregions have a single summer fire season and eastern regions have spring and late-summer fire seasons separated by an intervening dip in wildfire activity. From the ecoregion provinces with the highest wildfire frequency, average size, and area burned values, eight federal land units (four from the western and four from the eastern conterminous United States) were selected for a study of geographical variation in interactions between wildfire variables and the Keetch-Byram Drought Index (KBDI). Daily KBDI values for each location were provided by the North American Land Data Assimilation System (NLDAS). Confidence intervals around the mean for both days on which wildfires ignited and for days on which no new wildfires ignited were generated for each location using a bootstrap resampling method. A greater difference existed between non-fire and fire-start KBDI values in the western locations, indicating a stronger association between KBDI and wildfire potential. At eastern locations, the difference between mean non-fire and fire-start KBDI was lower than the minimum western mean difference for three of the four locations. The exception, the Great Dismal Swamp National Wildlife Refuge, showed the second highest difference between non-fire and fire-start KBDI values of all eight federal land units. These results indicate that across the southeastern United States, the soil moisture (and, by extension, fuel moisture) cycle from field capacity (saturation) to drought (wilting point) and back to field capacity does not follow the regular seasonal pattern shown in the western states, and neither do geographical characteristics of wildfires.