Underreporting of wildland fires in the US Fire Reporting System NFIRS: California

Abstract

The absence of a comprehensive and accurate database on fire occurrence means that some proportion of wildfires is not reported. This paper examines wildfires reported in the National Fire Incident Reporting System (NFIRS) database and compares it with the satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) fire detection data and the CAL FIRE Fire and Resource Assessment Program (FRAP) geodatabase to understand underreporting of wildland fires in the NFIRS system. The paper discusses a series of large wildland fires and uses a Generalised Linear Model to identify the conditions where large wildfires go unreported. This paper shows that the NFIRS database, which is the primary fire database in the US, significantly underreports wildland fires. Evidence from California suggests that 32% of fires within local jurisdictions detected via MODIS satellite were identified in the NFIRS database; thus, there could be a significant number of fires going unreported nationwide. Examining eight large fires in California, only 16% of the structures damaged or destroyed, as reported in CAL FIRE, were reported in NFIRS. Areas with underreporting tend to have a higher level of poverty, higher population density, higher level of people without vehicles, lower income and a higher level of single parents with children under 18, as well as a higher level of people under the age of 18.