Measured Soil Moisture is a Better Predictor of Large Growing-Season Wildfires than the Keetch–Byram Drought Index

Abstract (from https://dl.sciencesocieties.org/publications/sssaj/abstracts/81/3/490): In situ soil moisture measurements have the potential to improve wildfire danger assessments, which often rely on the Keetch–Byram Drought Index (KBDI) as a soil moisture surrogate. However, the relative merits of measured soil moisture and KBDI as indicators of wildfire danger are unknown. Therefore, our objectives were to (i) identify relationships between drought indices (KBDI or fraction of available water capacity, FAW) and wildfire size for 34,939 growing and dormant-season wildfires, (ii) compare relationships between each drought index and wildfire probability for 501 large (≥ 405 ha) growing-season and dormant-season wildfires, and (iii) [...]