The Fire and Resource Assessment Program (FRAP) compiles fire perimeters and has established an on-going fire perimeter data capture process. CAL FIRE, the United States Forest Service Region 5, the Bureau of Land Management, and the National Park Service jointly develop the fire perimeter GIS layer for public and private lands throughout California at the end of the calendar year. Upon release, the data is current as of the last calendar year.

The fire perimeter database represents the most complete digital record of fire perimeters in California. However it is still incomplete in many respects. Fire perimeter database users must exercise caution to avoid inaccurate or erroneous conclusions. For more information on potential errors and their source please review the methodology section of these pages.

The fire perimeters database is an ESRI ArcGIS file geodatabase with three data layers (feature classes):

  • A layer depicting wildfire perimeters from contributing agencies current as of the previous fire year;
  • A layer depicting prescribed fires supplied from contributing agencies current as of the previous fire year;
  • A layer representing non-prescribed fire fuel reduction projects that were initially included in the database. Fuels reduction projects that are non prescribed fire are no longer included.

 

There are many uses for fire perimeter data. For example, it is used on incidents to locate recently burned areas that may affect fire behavior (see map left).

Other uses include:

  • Improving fire prevention, suppression, and initial attack success.
  • Reduce and track hazards and risks in urban interface areas.
  • Provide information for fire ecology studies for example studying fire effects on vegetation over time.

 

Download the Fire Perimeter GIS data here

Download a statewide map of Fire Perimeters here

 

History

Initially CAL FIRE and the USDA Forest Service jointly developed a fire perimeter GIS layer for public and private lands throughout California. The data covered the period 1950 to 2001 and included USFS wildland fires 10 acres and greater, and CAL FIRE fires 300 acres and greater. BLM and NPS joined the effort in 2002, collecting fires 10 acres and greater. Also in 2002, CAL FIRE’s criteria expanded to include timber fires 10 acres and greater in size, brush fires 50 acres and greater in size, grass fires 300 acres and greater in size, wildland fires destroying three or more structures, and wildland fires causing $300,000 or more in damage. As of 2014, the monetary requirement was dropped and the damage requirement is 3 or more habitable structures or commercial structures.

In 1989, CAL FIRE units were requested to fill in gaps in their fire perimeter data as part of the California Fire Plan. FRAP provided each unit with a preliminary map of 1950-89 fire perimeters. Unit personnel also verified the pre-1989 perimeter maps to determine if any fires were missing or should be re-mapped. Each CAL FIRE Unit then generated a list of 300+ acre fires that started since 1989 using the CAL FIRE Emergency Activity Reporting System (EARS). The CAL FIRE personnel used this list to gather post-1989 perimeter maps for digitizing. The final product is a statewide GIS layer spanning the period 1950-1999.

CAL FIRE has completed inventory for the majority of its historical perimeters back to 1950. BLM fire perimeters are complete from 2002 to the present. The USFS has submitted records as far back as 1878. The NPS records date to 1921.

 

Fire Perimeter Data Update Process

The current fire perimeter layer developed by BLM, CAL FIRE, NPS and USFS is the most complete digital record of fire perimeters in California. However, it is still incomplete in many respects. Fires may be missing altogether or have missing or incorrect attribute data. Some fires may be missing because historical records were lost or damaged, fires were too small for the minimum cutoffs, documentation was inadequate, or fire perimeters have not yet been incorporated into the database.

The statewide fire history GIS data layer is updated annually through four steps:

  1. Standardize and combine existing digitized fire perimeters into a statewide GIS layer,
  2. Identify and remove duplicate fires;
  3. Fill in the gaps in data; and
  4. Collect agency fire perimeters from the previous fire year, standardize, and add to the history GIS layer.

Fires from the latest fire year will be uploaded to the database once annually, in the early spring. CAL FIRE's intention is to release the updated perimeter database in April of each year. Whenever possible, CAL FIRE, the USFS, BLM, and NPS solicit additional fire perimeter data from other federal agencies (e.g. BIA, DOD) and local agencies, for incorporation into the fire perimeters history data layer.

 

Error Detection and Correction

Fire perimeter data from the statewide database are constantly under development. Potential errors with the fire perimeter database include duplicate fires and over-generalization. While the data capture process attempts to identify duplicate fires resulting from multiple data sources (i.e. the USFS and CAL FIRE both captured and submitted the fire perimeter), some duplicates may still exist. Additionally, over-generalization, particularly with large old fires may show unburned "islands" within the final perimeter as burned. Users of the fire perimeter database must exercise caution in application of the data. Careful use of the fire perimeter database will prevent users from drawing inaccurate or erroneous conclusions from the data.

duplicate fire perimeter example

In some cases, different agencies record differing fire perimeters for the same fire. Above you can see two instances of duplicate fires with different perimeters, the White Deer fire and the Pierce fire. In the Pierce fire the most accurate fire perimeter is preserved along with the best metadata, such as date, cause, etc. (see tables A and B below). *Note: only sampling of fires and not spatially accurate.

When comparing multiple data sets duplicates often arise and are managed by selecting the most accurate and complete record. Table “A” and “B” illustrate how attribute data from different agency records can be merged to produce the most accurate information for each fire record in the database. Cells containing * in table “A” and “B” represent data, which are preserved in the final database. In many cases only one agency recorded the fire perimeter, its cause, and date; therefore only one record exists.

Duplicate Records Table "A"
Agency: CAL FIRE Forest Service National Park Service
Fire Name: Pierce* Pierce Pierce
Cause:   Lightning*  
Agency: CAL FIRE* USF NPS
Year: 1987* 1987 1987
Month: 00 00 08*
Day: 00 00 29*

 

Duplicate Records Table "B"
Agency: CAL FIRE Forest Service National Park Service
Fire Name: Deer Fire White Deer* (not on National Park lands)
Cause: Human*    
Agency: USF CAL FIRE*  
Year: 1961* 1961  
Month: 00 08*  
Day: 00 30*  

 

Data Format

The data are maintained as an ArcGIS Feature Class, which provides effective tools for handling overlapping polygons (for instance areas that burn more than once). Data contained in this Feature Class come from many sources. Some sources are more accurate or complete than others. The "AGENCY" field identifies the data source. Not all sources report all information, thus some records will have fields with no values.

The fire perimeters database is an ESRI ArcGIS file geodatabase with three data layers (feature classes):

  • A layer depicting wildfire perimeters from contributing agencies current as of the previous fire year;
  • A layer depicting prescribed fires supplied from contributing agencies current as of the previous fire year;
  • A layer representing non-prescribed fire fuel reduction projects that were initially included in the database. Fuels reduction projects that are non prescribed fire are no longer included.

 

Future Developments

FRAP produces the annual statewide fire perimeter GIS data layer by combining digitized fire perimeters from BLM, CAL FIRE, NPS, and USFS. The long-range goal for maintenance of fire perimeter data will eventually decentralize the data capture process to the individual fire station level. Immediately following a fire event local fire station personnel will map fires into the database. This process will be facilitated by a user friendly computer application that connects the local field user to a client-server database in Sacramento. CAL FIRE implemented a similar process, Emergency Activity Reporting System (EARS), for non-spatial data in 1989.

The Fire Perimeter Database is maintained an an ESRI ArcGIS File Geodatabase. There are three feature classes (data layers) within the GDB. For 2017, these are:

  • firep17_1: depicting wildfire perimeters from contributing agencies current as 2017;
  • rxburn17_1: depicting prescribed fires supplied from contributing agencies current as 2017;;
  • Non_FireRX_Legacy13_1: depicting non-prescribed fire fuel reduction projects that were initially included in the database. Fuels reduction projects that are non prescribed fire are no longer included.

 

Fire Perimeters Attribute Table Item Definitions
ITEM NAME DATA TYPE DESCRIPTION Domain
---------------- ----------------- ------------------------- ------------
YEAR_ Text Fire Year No
STATE Text State Yes
AGENCY Text Direct protection agency responsible for fire Yes
UNIT_ID Text ICS code for unit Yes
FIRE_NAME Text Name of the fire No
INC_NUM Text Number assigned by the Emergency Command Center of the responsible agency for the fire No
ALARM_DATE Date Alarm date for fire No
CONT_DATE Date Containment date for fire No
CAUSE Integer Reason fire ignited Yes
COMMENTS Text Miscellaneous comments No
REPORT_AC Number Estimated area consumed in fire No
GIS_ACRES Number GIS calculated area in acres No
C_METHOD Integer Method used to collect perimeter data Yes
OBJECTIVE Integer Either suppression or resource benefit Yes
FIRE_NUM Text   No
State Coding:
Agency ID Description
CA California
NV Nevada
OR Oregon
AZ Arizona
Agency Coding:
Agency Description
BIA USDI Bureau of Indian Affairs
BLM Bureau of Land Management
CDF California Department of Forestry and Fire Protection
CCO Contract Counties
DOD Department of Defense
FWS USDI Fish and Wildlife Service
LRA Local Response Area
NOP No Protection
NPS National Park Service
PVT Private
USF United States Forest Service
OTH Other
Cause coding:
Cause Code Description
1 Lightning
2 Equipment Use
3 Smoking
4 Campfire
5 Debris
6 Railroad
7 Arson
8 Playing with Fire
9 Miscellaneous
10 Vehicle
11 Power Line
12 Firefighter Training
13 Non-Firefighter Training
14 Unknown/Unidentified
15 Structure
16 Aircraft
17 Volcanic
18 Escaped Prescribed Burn
19 Illegal Alien Campfire
Collection Method coding:
Cause Code Description
1 GPS Ground
2 GPS Air
3 Infrared
4 Other Imagery
5 Photo Interpretation
6 Hand Drawn
7 Mixed Collection Methods
8 Unknown
Objective coding:
Cause Code Description
1 Suppression (Wildfire)
2 Resource Benefit (WFU)