Measuring Fire Scars with JPSS Satellites to Provide Preliminary Burn Intensity Estimates to NWS for Debris Flow Hazard Assessment

Abstract:

Major environmental disasters in the Western United States can result from wildfires followed by heavy rain. When heavy rain events happen within months, weeks, or days, of a wildland fire, especially in areas of steep terrain, the resulting flash floods and debris flows can threaten lives and cause millions of dollars of damage downstream of the fire scar area. NOAA’s National Weather Service Weather Forecast Offices (NWS-WFO) use a variety of inputs to assess the risk of post-fire debris flows, support emergency management and response partners, and when necessary, issue Flash Flood Warnings. Post-wildfire risk assessments of burned areas, done by Burned Area Emergency Response (BAER) Teams, generally start with satellite-derived burn intensity estimates. Typically, inputs from 30m-resolution Landsat imagery are used in the form of a BARC (Burned Area Reflectance Classification) map. However, BARC maps are not always available or can arrive too late to be of use for short-term forecasting and warning operations at NWS-WFOs. The goal of this project is to cut latencies by providing provisional coarser resolution (375m) satellite-derived inputs from the VIIRS sensor on the JPSS program’s NOAA-20 and Suomi-NPP satellites. The resulting Burn Intensity Delta Greenness Estimation (BRIDGE) maps are designed to support NWS-WFO flash flood and debris flow forecasting and impact-based decision support services to emergency management partners. The BRIDGE map is intended to “bridge” the gap between having no data at all and having access to a BARC map or final BAER Team risk assessment.