Keetch-Byram Drought Index (KBDI)

The KBDI is a daily value representative of the water balance where yesterday’s drought index is balanced with today’s drought factor (precipitation and soil moisture). The drought index ranges from 0 to 800; an index of 0 represents no moisture depletion and an index of 800 represents absolutely dry conditions.

Index KBDI Indicators
0-200 Soil and large class fuel moistures are high. Moist fuels will not readily ignite or burn.
200-400 Lower litter and duff layers are drying and beginning to contribute to fire intensity. Heavier fuels will still not readily ignite and burn.
400-600 Lower litter and duff layers actively contribute to fire intensity and will burn actively. Expect the complete consumption of all but the largest fuels. Drying of the soil will lower live fuel moistures, allowing live fuels to become available to burn.
600-800 Often associated with severe drought and increased wildfire occurrence. Expect intense, deep burning fires, with significant spotting problems. Live fuels will burn actively at these levels and expect fires to be difficult to contain and control.