Microwave Retrievals of Soil Moisture Improve Grassland Wildfire Predictions
A. J. Rigden, Robert S. Powell, A. M. Trevino, Kaighin A. McColl, Peter Huybers
Abstract
Abstract Statistical analyses of wildfires demonstrate that vapor pressure deficit (VPD) allows for skillful predictions, likely because it reflects fuel moisture content. Soil moisture provides a potentially complimentary measure of water availability but has been less explored because of sparse measurements. Using measurements from the Soil Moisture Active Passive satellite, the predictive skill afforded by using VPD and soil moisture together is explored across the Western United States. Receiver operating characteristic curves estimated from 1,907 fires indicate that inclusion of soil moisture in addition to VPD observations permits for more skillful prediction ( p < 0.05 ). When VPD already signals high risk, the addition of soil moisture reduces the false positive rate grasslands (from 75% to 62%), shrublands (76% to 67%), and forests (74% to 68%) for a true positive rate of 75%. These results show potential to improve daily fire risk models with the addition of remotely sensed soil moisture.