Using Earth Observations to Measure Hydrological Conditions Before, During, and After Wildfires in the Feather River Watershed

Abstract

The Feather River Watershed is home to the 2018 Camp Fire (California's deadliest wildfire), the 2020 North Complex Fire, and the 2021 Dixie Fire (California's largest single wildfire by area). Overall, these three fires combined to burn over 1.4 million acres of land - more than 60% of the Feather River Watershed's 2.3-million-acre area. Such exceptional wildfire activity is a reason for further studies. Our research proposes analyzing satellite data from the Feather River Watershed to measure the hydrological effects of such widespread wildfires over a period of four years. This study aims to study these wildfires using monthly observations of the major hydrological conditions [i.e., precipitation, soil moisture, vegetation index, and evapotranspiration (ET)] between 2015 and 2022. A 1-km remotely sensed dataset was used to study the spatial and temporal variability in soil moisture. Additionally, visible and infrared imagery were used to outline and analyze wildfire burn scars. Results of the study show that surface soil moisture maxima increase after wildfires due to a decrease in vegetation index and ET.