Keetch–Byram drought index

The Keetch–Byram drought index (KBDI), created by John Keetch and George Byram in 1968 for the United States Department of Agriculture's Forest Service, was devised based on mathematical models for predicting the likelihood of wildfire based on soil moisture and other conditions related to drought.

KBDI is a soil/duff drought index that ranges from 0 (no drought) to 800 (extreme drought) and is based on the soil capacity in 8 inches (200 mm) of water. The depth of soil required to hold 8 inches of moisture varies. A prolonged drought (high KBDI) influences fire intensity largely because fuels have a lower moisture content.

The KBDI is a measure of meteorological drought and reflects water gain or loss within the soil. It does not measure fuel moisture levels in the 1–10-hour fuel classes, which must be measured by other means for an accurate assessment of fuel moisture regardless of the drought index readings.

See also

• National Fire Danger Rating System
• Palmer drought index

References

• Keetch, John J.; Byram, George M. "A Drought Index for Forest Fire Control". srs.fs.usda.gov. USDA Forest Service Southern Research Station. Retrieved August 11, 2016. (Date: 1968) Res. Paper SE-38. 32 pp. Asheville, NC: U.S. Department of Agriculture, Forest Service CS1 maint: Uses authors parameter (link)
• 1988 revision of the paper, "A drought index for forest fire control.". http://www.srs.fs.fed.us/pubs/rp/rp_se273.pdf