Assessment of biomass burned (BB) from wildfires provides important information on emitted quantities of trace gases and aerosols which can have negative consequences to both human and environmental health. During the 2018 wildfire season, the NSF sponsored the BB-FLUX project (?Biomass Burning Flux Measurements of Trace Gases and Aerosols?; 7/17-9/23/18, PI: R. Volkamer) to deploy two novel airborne sensors, the University of Colorado Solar Occultation Flux (CU SOF) and direct sun differential optical absorption spectroscopy (DS-DOAS) to characterize wildfire emissions during active burning of several wildfires. Emission characterization also requires ecosystem constraints on total fuel and area burned, which cannot be directly measured by the CU-SOF nor DS-DOAS. BBFLUX measurements were supplemented with airborne laser altimetry (lidar) and optical hyperspectral (HS) airborne measurements of post-burn wildfire areas to provide estimates of total area burned and available fuel. The National Ecological Observatory Network (NEON) provided access to airborne lidar and HS sensors on the Airborne Observation Platform (AOP) through their Assignable Asset (AA) program.

To meet project objectives, four post-burn wildfire areas were collected with the NEON AOP which included 1) the Keithly Fire (ID), the Miriam Fire (WA), the Tepee fire (OR) and the Watson Creek Fire (OR). All NEON AOP collections were conducted during September of 2018. The collected areas varied in the types of ecosystems burned, fire duration, total area burned and fire severity. All sites were processed through the standard processing pipeline used to derive NEON data products and verified for quality. The NEON products provided the basis for estimating total area burned and total fuel burned. Algorithms were developed for quantifying total above ground biomass as a proxy for available fuel. Models were built using field data from local NEON sites as calibration and validation data to predict the relationship between derived tree parameters and total above ground biomass. Sentinel 2A satellite data was also used to help inform burned area estimated nearer in time to BBFLUX acquisitions during active burning. A partnership with USFS was also formed. Field collections of biomass pertaining to burned and unburned areas was collected by the USFS at the Keithly and Tepee fire to estimate biomass burned (BB) during the fires. The Keithly and Tepee fires were selected for the additional analysis and collection of field data because pre-fire lidar was publically available which allowed estimation of pre-burn total biomass.

The partnership of the NEON AOP and BB-FLUX represents a novel synergy between previously disparate observation systems that introduces an inter-disciplinary approach for relating wildfire emission characteristics to the affected ecosystem. This work will be transformative through advancing techniques to forecast the impacts of wildfires by including ecosystem dependent variables. The general advancement of improved AGB and area burned estimates using lidar and HS measurements will have broad implications for ecological sciences, forestry, agriculture and environmental management. High accuracy AGB estimates is of interest for quantifying carbon stores and understanding the carbon cycle due to the carbon sequestration capabilities of living forests. This project will also provide a public dataset of high resolution airborne remote sensing of a wildfire area, enabling research of wildfire / ecosystem interactions.

Last Modified: 09/27/2020
Modified by: Tristan Goulden