Summary of approach and findings
Butry and Thomas examined MODIS-detected fires within areas of local jurisdiction in California from 2003 to 2014 and found that only 32% of them were present in NFIRS.
However, their analysis did not use geocoded NFIRS data, and they were only able to attempt to match NFIRS fires with MODIS-detected fires by county and date. In addition, the criteria they used to select NFIRS incidents may have omitted some fires that may have been detected by MODIS.
It should be noted that NFIRS is not a census of all fire department-responded incidents, and it is not based on a statistically derived sample. Among other issues that prevent the NFIRS from being a complete source for fire department incident data are reporting deadlines, data access and budgetary considerations. For fire incidents, as with other NFIRS fire department-responded incidents, the NFIRS raw totals do not reflect the whole of the U.S. fire problem; NFIRS contains incident data derived from voluntary reporting of fire incidents in the U.S.
The state of California is divided into distinct areas where either the local fire department, CAL FIRE or the agencies of the federal government have primary responsibility for wildfire incident management. The authors first identified MODIS-detected fires that occurred within local direct protection areas. They then retrieved a subset of California NFIRS incidents by selecting incidents where any of the following criteria was present:
Incident Type = 141: Forest, woods or wildland fire
Incident Type in 100 series (Fire) or 561 (Unauthorized burning), 631 (Authorized controlled burning), or 632 (Prescribed fire), and
- Actions Taken includes 13: Establish fire lines (wildfire), or
- Actions Taken includes 14: Contain fire (wildland), or
- Actions Taken includes 15: Confine fire (wildland), or
- Actions Taken includes 16: Control fire (wildland).
Incident Type in 100 series (Fire), and
- Area of Fire Origin = 95: Wildland, woods, or
- Suppression Factor includes 775: Urban-wildland Interface Area.
Wildland Fire Module: Was used for incidents where Incident Type was not 632 (Prescribed fire)
Finally, they found those NFIRS fires that occurred in the same county (using the county of the reporting fire department) and on the same day as any MODIS-detected fire in local direct protection areas (Figure 1).
Butry and Thomas found that 32% of the MODIS-detected fires in areas of local responsibility occurred in the same county and on the same day as an NFIRS-reported fire that met the criteria defined in the study to describe wildfires.