A coarse scale assessment and mapping effort was initiated to support national-level fire planning and risk assessments.
See the Software and Downloads section for information on:
Data Summary Tables: Historical Fire Regimes by Current Condition Class acreages
Narrative Document: Development of Coarse-Scale Spatial Data for Wildland Fire and Fuel Management
1. Potential Natural Vegetation Groups V2000
2. Current Cover Types v2000
3. Historical Natural Fire Regimes v2000
4. Fire Regime Current Conditions v2000
5. National Fire Occurrence, Federal and State Lands, 1986 - 1996, v1999
6. Potential Fire Characteristics v1999
7. Wildand Fire Risk to Flammable Structures v2000
Note: These coarse-scale data were developed for national-level planning. Summaries of the data were restricted to state or Forest Service regional scales. The data were not intended to be used at finer spatial scales.
This assessment and mapping effort was initiated as two associated projects. The first project, called Fire Regimes for Fuels Management and Fire Use, began in 1997 through an agreement with USDA Forest Service, Fire and Aviation Management, State and Private Forestry. This project involved mapping and characterization of historic natural fire regimes and current vegetation conditions, and development of an index of departure for use in national-level fire management planning. Development of the initial map of Historical Natural Fire Regimes for the conterminous United States was done under this agreement. Under the fire regime project, the concept of risk was defined as the 'risk of losing key components that define a system' or specifically, losses attributed to the occurrence or introduction of fire,either wildland or prescribed fire. Within that framework, we classify current conditions as a function of departure from historical natural conditions. The second project, now called Ecosystems at Risk, was undertaken to add a fire-related component to the USDA Forest Service's Forests at Risk project. The Joint Fire Sciences Program (JFSP) subsequently funded completion of these two efforts for interagency use in 1998, with specifications for development of several additional spatial data layers.
These data integrate biophysical information and pre-existing remotely sensed products. We have incorporated disturbance and successional processes, including development of stylized successional pathways for unique combinations of historical fire regime and potential natural vegetation. We organized and facilitated seven regional panels of expert ecologists, silviculturists, and fire managers to review and refine the spatial data layers, develop the pathway diagrams, and assign fire management condition classes. These data are intended for national, programmatic and strategic planning, and will be used by federal land managers, states, and other non-governmental organizations in fire and fuel management planning, assessments of ecosystem health, and risk assessments.
GOALS AND OBJECTIVES
To produce seven coarse-scale, 1-km2 resolution, spatial data layers for the conterminous United States to support national-level fire planning and risk assessments. Four of these layers were developed to evaluate ecological conditions and risk to ecosystem components: Potential Natural Vegetation Groups, a layer of climax vegetation types representing site characteristics such as soils, climate, and topography; Current Cover Type, a layer of current vegetation types; Historical Natural Fire Regimes, a layer of fire frequency and severity; and Fire Regime Current Condition Class, a layer depicting the degree of departure from historical fire regimes, possibly resulting in alterations of key ecosystem components.
The remaining three layers were developed to support assessments of potential hazards and risks to public health and safety: National Fire Occurrence, 1986 to 1996, a layer and database of Federal and non-Federal fire occurrences; Potential Fire Characteristics, a layer of the number of days of high or extreme fire danger calculated from 8 years of historical National Fire Danger Rating System (NFDRS) data; and Wildland Fire Risk to Flammable Structures, a layer of the potential risk of wildland fire burning flammable structures based on an integration of population density, fuel, and weather spatial data.
“Fire Regime Current Conditions” are qualitative measures describing the degree of departure from historical fire regimes, possibly resulting in alterations of key ecosystem components such as species composition, structural stage, stand age, canopy closure, and fuel loadings. For all Federal and non-Federal lands, excluding agricultural, barren, and urban/developed lands, 48 percent (2.4 million km2) of the land area of the conterminous United States is within the historical range (Condition Class 1) in terms of vegetation composition, structure, and fuel loadings; 38 percent (1.9 million km2) is moderately altered from the historical range (Condition Class 2); and 15 percent (736,000 km2) is significantly altered from the historical range (Condition Class 3). Managers can use these spatial data to describe regional trends in current conditions and to support fire and fuel management program development and resource allocation.