The Keetch-Byram Drought Index (KBDI) is generally used to determine potential wildfire hazards across the southeastern United States and is calculated daily by the Florida Department of Agriculture and Consumer Services, Division of Forestry. KBDI is a continuous reference scale for estimating the dryness of the soil and duff layers. Forest managers have identified several uses for the KBDI in wildfire management. This 5-page fact sheet explains the nuts and bolds of the KBDI and how forecast the index on agroclimate.org. Written by Clyde W. Fraisse, Norman E. Breuer, and David Zierden and published by the UF Department of Agricultural and Biological Engineering, February 2011.
http://edis.ifas.ufl.edu/ae471