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Setting GIS on Fire

Alaska Region
Brian Sorbel
The National Park Service Wildland Fire Management Program relies upon GIS to meet its objectives. The integration of GIS with wildland fire management is pervasive throughout all levels and across all geographic areas of the NPS. The effective management of a complex process, like wildland fire, across a heterogeneous landscape intermingled with values to be protected requires the incorporation and interpretation of accurate spatial data. Maps have long been a part of the fire management process. It is not uncommon to find maps from the early 1900s depicting the extent of fire activity within the archives of many national parks (Figure 1). The climate of fire management within the national parks has changed considerably since the NPS Organic Act of 1916. With that change has come a corresponding transformation of fire management’s information and mapping needs. Increases in the number of visitors, the amount of infrastructure both within and around parks and in the information expectations of park managers, the media and the public necessitate accurate, timely and effective map products. Today’s fire management relies upon today’s mapping and geospatial technologies.

NPS Fire Management uses GIS for a variety of planning purposes. GIS data layers and GIS analysis provide NPS fire management with a comprehensive depiction of a park or preserve’s overall relationship with wildland fire. Vegetation and fuels layers describe the highly variable distribution of fuels throughout a park and provide estimates of expected or potential fire behavior across the landscape. When combined with topographic themes such as elevation, slope and aspect, fuels layers are used to actually predict fire spread and provide quantitative measurements of fire behavior using programs like FARSITE and FLAMMAP. Vegetation and fuels layers also provide the foundation for many other fire-related GIS themes such as Historic Natural Fire Regime, Crown Bulk Density and Duff Loading. Taken together, these GIS layers provide NPS fire managers and fuels specialists with a foundation view of the vegetation and fuels distribution upon which their parks future fire activity will be based.

Fire history themes, describing both the point location of all known fire ignitions, as well as the total area burned by all known large fires, illustrate the geographic extent of fire’s past effects on a park. In any park, both the vegetative conditions as well as the corresponding fire activity are spatially dependent variables. Observing the geographic extent of wildland fire’s past effects on a landscape increases fire managers understanding of fire’s historic processes within a park. Understanding the historical relationship of wildland fire with the landscape enables inferences of fire’s likely future effects as well. Fire history for Denali National Park and Preserve from 1950 – 2002 is displayed in Figure 2. It is obvious that the bulk of large fire activity in Denali is concentrated in the northwest portion of the park. Based on a GIS analysis of Denali’s fire history, both the presence of fire and a fire’s maximum potential size are highly dependent on the elevation at the point of ignition. Denali encompasses a broad elevation range from 69 meters to 6164 at the summit of Mt. McKinley. Within this range, fire activity has only been observed above 150 meters and below 1000 meters. Furthermore, as elevation increases, the size of fires tends to decrease. Below 300 meters, no fire has grown to a size greater than 125,000 acres in Denali since 1950. Between 300 meters and 550 meters, no fire has grown to a size greater than 10,000 acres. This trend of decreasing fire size with increasing elevation continues on up to the 1000-meter breakpoint of fire activity in Denali. In this case, one can make a reliable estimate of a new fire’s maximum potential size given the elevation at the point of ignition through an analysis of GIS fire history layers.
By themselves, GIS themes describing historic fire activity provide a wealth of information to resource managers and the public. When merged with other datasets in a GIS, the delivered value increases dramatically. Fire history layers can be combined with vegetation and fuels information to create layers describing Fire Return Interval Departure (FRID). FRID layers attempt to describe the relative degree of departure from historic fire return intervals across the landscape. In ecosystems where fire is a natural process, most vegetation types can be assigned a fire return interval value in years. A vegetation type’s fire return interval describes the period of time (on average) between naturally occurring fire events. Due to a variety of factors, some areas within the national parks have not experienced natural fire events within their predicted fire return interval. Some areas have even missed fire activity in more than one fire return interval. The absence of fire events within an area’s specified fire return interval can lead to an unnatural build-up of fuels and above-normal fire activity when it finally occurs. FRID layers recode the landscape to describe the number of fire return intervals that have been missed. They are created through an analysis of vegetation and fire history themes within a GIS. A given area with an average fire return interval of 30 years that has not experienced fire activity in 100 years has missed three fire return intervals and will be assigned such in Fire Return Interval Departure layers. Vegetation and FRID layers for Yosemite National Park are shown in Figure 3. Given this information, fire managers can prioritize fuels treatments for those areas with the greatest degree of departure from the norm.

The National Park Service Fire Management program also relies on GIS to meet the incident mapping needs of ongoing wildland and prescribed fires. While fires are burning, incident managers require accurate and timely GIS products for a variety of purposes. Fire perimeters are often mapped on a daily basis using handheld GPS (Global Positioning System) units. Map products depicting the current extent of the fire, as well as management actions which have been taken, are also generated daily and distributed to incident personnel through an Incident Action Plan. Fire progression maps display the size of a fire on each day over the course of an incident (Figure 4). Large format map products are printed out on plotters and used for daily briefings. One of the advantages of creating incident mapping products in a GIS is that those products can be exported to electronic formats and displayed to the media and public via the Internet. On a national scale, GIS fire perimeter layers are displayed on Internet Map Server applications like GeoMAC ( for viewing by the public, media and fire managers. Within the incident management organization, Fire Behavior Analysts (FBAN) and Long Term Analysts (LTAN) require GIS products and analysis to predict fire behavior using programs like FARSITE (Fire Area Simulator) and RERAP (Rare Event Risk Assessment Process). The utility of GIS in incident management continues even after the fire has been declared control. Satellite imagery can be used to delineate final areas burned and to provide measures of actual burn severity, the degree of environmental change caused by fire.
NPS Fire Management relies a great deal upon GIS to meet its objectives. To that end, the NPS Fire Management program works with the NPS GIS program at all levels to meet fire management’s mapping needs. In addition, NPS Fire Management has created a set of Fire GIS specialists at regional offices and select parks to assist with the most pressing needs. NPS Fire Management relies on a number of other partnerships to obtain effective GIS products. Working with the Inventory & Monitoring program, Fire Management has helped to prioritize the vegetation mapping efforts within the Park Service to insure that key fire parks receive high priority for the completion of vegetation layers. The NPS is also involved in a partnership with the USGS EROS Data Center to produce burn severity products using Landsat satellite imagery for all large fires on NPS lands. The NPS Fire Management Program also works with its interagency partners to meet common objectives in the application of GIS to wildland fire. The NPS actively participates in ongoing interagency training efforts related to fire and GIS. Currently, NPS staff assists in the coordination and training of the ‘GPS for Incident Support’, ‘GIS Technical Specialist (GIST)’ and FARSITE training courses (Figure 5). As part of the National Wildfire Coordinating Group (NWCG), the National Park Service also participates on interagency committees responsible for the coordination of GIS and information management activities within the interagency fire community. Interagency groups like the Geospatial Task Group seek to establish common GIS data standards and operating procedures with respect to wildland fire management.
NPS Fire Management uses GIS and related geospatial technologies in many ways. The challenge is not to discover new applications of GIS to fire management, but rather for fire management to keep up with the continuously evolving field of GIS.

Project Category: Fire
Partners Supported: Federal, state
National Level Initiative: Wildland Fire Management

Graphic Descriptions
Figure 1: Map of the 1931 Heart Lake Fire in Yellowstone National Park
Figure 2: Vegetation type and Fire Return Interval Departure in Yosemite National Park
Figure 3: Fire History and Predicted Maximum Future Fire Size in Denali National Park and Preserve
Figure 4: Incident Fire Progression map of the PW-3 Gin Flat Prescribed Burn in Yosemite National Park
Figure 5: Interagency Fire GPS training, Joshua Tree NP, March 2003
April 08, 2004