Forest Fires in the United States: 4 April 2000

Forest Fires in the United States

4 April 2000


According to United States Forest Service Fire News the Chico Air Attack base in California was opened on 2 April 2000, two months earlier than usual. Fires on the Mendocino National Forest and other parts of northern California prompted the move, and airtankers arrived two days ago from as far away at New Mexico.

The Town Fire northwest of Elk Creek is 80 percent contained at 1,140 acres (461 hectares [ha]), with over 500 personnel on the fire. Carlson’s Type 2 team is managing the incident. The 1660-acre (671 ha) Cabbage Fire north of Lake Pillsbury has 22 crews, four helicopters, and 26 engines on it, but containment efforts have been limited because of steep terrain, heavy fuels, spotting, and rolling material. The fire is at 20 percent containment. High stream levels and poor roads have prevented access to the fire, and division operations are concentrating on access information. Decreasing winds are forecasted, and an incident base is under construction. Middle Creek Campground and the Cabbage Patch Trail were closed to ensure the safety of firefighters and the public.

Smokejumpers from across the U.S. landed yesterday in Redding for a two-week intensive refresher course.

The Wildland Fire Assessment System (WFAS) is a contribution of “The Fire Behavior Research Work Unit”, Missoula (Montana USA). The broad area component of the Wildland Fire Assessment System (WFAS) generates maps of selected fire weather and fire danger components. Fire Danger (Potential) is a normalized adjective rating class across different fuel models and station locations. It is based on information provided by local station managers about the primary fuel model, fire danger index selected to reflect staffing level, and climatological class breakpoints. Low danger (class 1) is green and extreme potential (class 5) is red.

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Fig. 1. & 2. Fire Danger Forecast Maps of the United States for 3 April (observation time) and 4 April (forecast) 2000
(Source: Fire Behavior Research Work Unit, Missoula)

Wildland Fire Update (31 March 2000)
The National Interagency Fire Center (NIFC) provides new data of the current wildland fire season in the United States. These data were analysed after different geographic regions. Further, a  five-year wildland fire comparison statistic shows the number and the area of wildland fires from 1996 to 2000.

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Fig.3. Geographic areas and coordination centers
(modified map from National Interagency Fire Center (NIFC)).

Fire conditions in Arizona, New Mexico, Texas and Kentucky remain extreme. Several large and hundreds of small wildland fires were reported from the Southwest, Southern and Eastern areas during the past week.
While burning conditions in some states are severe, other states throughout the country are experiencing ideal conditions for prescribed fires. As of today, nearly 480,000 acres (194,249 hectares) of wildlands have been treated by prescription fires. Prescribed fires are planned under specified conditions intended to improve the health of the natural landscape and/or reduce hazardous build-up of vegetation that lead to devastating wildland fires.
Long-range, 30-day weather forecasts are predicting above-normal temperatures and below-normal precipitation for the southern tier of states from southern California to Florida and throughout the Midwest (see Fig.4. 30 and 90-day forecast maps).

Tab.1. Five-Year Wildland Fire Comparison Statistics Year-to-Date for the United States (31 March 2000)
(Source: National Interagency Fire Center (NIFC))

As of 03/27/00 Number of Wildland Fires Area burnt Acres Hectars 2000 20,346 569,567 230,495 1999 18,202 216,197 87,491 1998 8,505 147,095 59,527 1997 11,465 240,723 97,417 1996 24,191 524,235 212,150

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Fig.4. 30 and 90-day temperature and precipitation forecast maps (April and April to June 2000)
(Source: National Weather Service, Boise, Idaho)

Keetch-Byram Drought Index (KBDI) by Florida’s Division of Forestry / Forest Protection Bureau
John Keetch and George Byram developed the K/B index at the Southern Forest Fire Laboratory to evaluate the effects of long-term drying on litter and duff and subsequently, on fire activity (1968). The index is based on a measurement of 8 inches (20 cm) of available moisture in the upper soil layers that can be used by vegetation for evapotranspiration. The index measure is in hundredths (0.01) of an inch of water and has a range of 0 through 800, with 0 being saturated and 800 representing the worst drought condition. The index indicates deficit inches of available water in the soil. A K/B reading of 250 means there is a deficit of 2.5 inches (64 mm) of ground water available to the vegetation. As drought progresses, there is more available fuel that can contribute to fire intensity.
For further information on the KBDI please refer to Keetch-Byram Drought Index Revisited: Prescribed Fire Applications.

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Fig.5. Keetch-Byram Drought Index Map of Florida, 2 April 2000
(Source: Florida Division of Forestry)

The Florida Forest Fire Weather Index (FWI) System is part of the “Florida Fire Management Information System (FFMIS)” and consists of six components that account for the effects of fuel moisture and wind on fire behavior. The first three components are fuel moisture codes that follow daily changes in the moisture contents of three classes of forest fuel with different drying rates. The last three components are fire behavior indexes, representing rate of spread, amount of available fuel, and fire intensity; their values increase as fire weather severity increases. For detailed information on the Florida Fire Management Information System (FFMIS) the GFMC would like to refer to the original website.
According to the FFMIS for 1 April these parameters show various fire weather conditions for Florida.

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Fine Fuel Moisture Code

Duff Moisture Code

Drought Code

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Initial Spread Index

Buildup Index

Fire Weather Index

Fig.6.-11.  Output maps of the FFMIS, 2 April 2000
(Source: Florida Forest Fire Weather Index (FWI) System)

The Southern Area Coordination Center Morning Report (3 April 2000) is a narrative summary of fire activity within the Southern Area including number of fires, wildfires as well as prescribed burns, and area. (For detailed numbers of wildfires and prescribed burns, please refer to the original website of the report.)

SOUTHERN AREA: Southern Area Coordination Center: Fire danger is low to moderate in most areas with minor fire activity reported. Severe thunderstorm activity continues throughout the southeast with tornado watches from Louisiana through Mississippi and Alabama.
GEORGIA: Georgia Interagency Coordination Center: Fire danger is low with more rain forecasted for today.
KENTUCKY: Kentucky Interagency Coordination Center: Fire danger is low to moderate across the state. Light amounts of precipitation were received with more rain forecast for today and tomorrow.
SOUTH CAROLINA: South Carolina Interagency Coordination Center: Very little rainfall received so far.
TENNESSEE: Cherokee National Forest: The Jenkins Mountain fire on the northern Cherokee has grown to approximately 450 acres and is 90% contained. Four volunteer fire departments are assisting.

According to the Incident Management Situation Report three categories of fires are distinguished, such as:
1. Fires*
2. Prescribed Fires
3. Wildland Fire Use Fires**

*  This classification corresponds to the category “wildland fires” as defined by the National Interagency Fire Center (NIFC)
** A brief excursion to wildland fire terminology:

Wildland Fires: Fires occurring on any tpye of vegetation, regardless of ignition sources, damages or benefits.
Wildfire: Any uncontrolled wildland fire which (1) may require suppression response, or (2) any uncontrolled wildland fire which meets management objectives and is declared as a Wildland Fire Use Fire (see below) or syn. Prescribed Natural Fire or Prescribed Fire.
Prescribed Fire: Occasionally also called management-ignited fire, or prescribed burning, is a controlled application of fire to vegetation in either their natural or modified state, under specified environmental conditions which allow the fire to be confined to a predetermined area and at the same time to produce the intensity of heat and rate of spread required to attain planned resource management objectives.
Wildland Fire Use Fire: Naturally ignited fire which is managed to achieve resource benefits under close supervision (syn. Prescribed Natural Fire)

Incident Management Situation Report (31 March 2000):

Current Situation:
The Southern and Southwest Areas reported large fires to the National Interagency Coordination Center this week. Moderate initial attack activity occurred in the Eastern, Southern, and Southwest Areas and was minimal elsewhere. Very high to extreme fire indices were reported in Arizona, New Mexico, Texas, and Kentucky.
Outlook:
Arizona will be mostly cloudy this weekend with a chance of scattered showers in the south and snow in the north. High temperatures in the 40’s (5-10°C) in the north and 70’s (21-26°C) in the south. The rest of the week will be partly cloudy and warmer in the valleys. Temperatures will range from the 20’s (-6 to -2°C) in the mountains to the 80’s (27-30°C) in lower elevations.
New Mexico will be mostly cloudy this weekend with the chance of showers and possible snow in the higher elevations. High temperatures will be in the 70’s (21-26°C) in the south and 50’s (10-15°C) in the mountains. The remainder of the week will be partly cloudy with a slight chance of precipitation. High temperatures will be in the 40’s (5-10°C) in the mountains up to the 70’s (21-26°C) elsewhere.
Texas will be partly cloudy with a chance of showers or thunderstorms Tuesday. For the remainder of the week the highs will be in the 70’s (21-26°C) to 80’s (27-30°C) with little or no precipitation.
Kentucky will be partly cloudy and cool this weekend with a chance of showers on Sunday. The remainder of the week will be cooler with showers ending on Tuesday. Highs will be in the 60’s (16-20°C).
Tennessee will be mostly cloudy with a chance of showers this weekend. For the remainder of the week, with highs in the mid 60’s (16-20°C) to mid 70’s (21-26°C).
North Carolina will be partly cloudy with a chance of showers in the northwest this weekend. Highs will be in the mid 70’s (21-26°C) with cooler temperatures in the mountains. Chance of showers to continue on Monday and Tuesday with highs in the mid 60’s (16-20°C) to mid 70’s (21-26°C).

Tab.2. Fires and area burnt year-to-date (31 March 2000)
(Source: Incident Management Situation Report)

Geographic Area Number of Fires Area Burnt acre ha Alaska 0 0 0 Northwest 2 0 0 California 279 131 53 Northern Rockies 1 10 4 Eastern Great Basin 6 55 22 Western Great Basin 1 1 0.4 Southwest 577 192,467 77,889 Rocky Mountain 54 2,720 1,101 Eastern 2,339 48,067 19,452 Southern 17,087 326,115 131,974

Total United States

20,346 569,567 230,496

Tab.3.  Prescribed fires and area burnt year-to-date (31 March 2000)
(Source: Incident Management Situation Report)

Geographic Area Number of Prescribed Fires Area Burnt acre ha Alaska 0 0 0 Northwest 26 3,095 1,252 California 96 3,601 1,457 Northern 0 0 0 Eastern Great Basin 8 934 378 Western Great Basin 0 0 0 Southwest 389 32,203 13,032 Rocky Mountain 40 4,434 1,794 Eastern 87 19,060 7,713 Southern 748 415,658 168,211

Total United States

1,394 478,986 193,838

Tab.4.  Wildland Fire Use (WFU) Fires area burnt year-to-date (31 March 2000)
(Source: Incident Management Situation Report)

Geographic Area Number of WFU Fires Area Burnt acre ha Alaska 0 0 0 Northwest 0 0 0 California 1 0 0 Northern Rockies 0 0 0 Eastern Great Basin 0 0 0 Western Great Basin 0 0 0 Southwest 1 390 158 Rocky Mountain 0 0 0 Eastern 0 0 0 Southern 0 0 0

Total United States

2 390 158

Remarks on Prescribed Burning

At this time of the year prescribed burning operations are conducted routinely.

Fire is an important natural tool for ecosystem management. It can reduce dense vegetation improving wildlife habitat and lessening the potential for large, wildfire disasters. Land managers are directed to prepare a prescribed fire/burn plan for every area of public land that can burn. Some areas require total suppression while others will benefit from a wildland fire. Those areas that will benefit from a fire can be treated by a prescribed fire.

Especially, for the moment, in the southern and southeastern regions of the United States prescribed fire activities will be carried out in the following weeks and months. In this case, fire signals on satellite images can be traced back to this kind of land management activities.

In the Prescribed Fire Position Paper of the Forest Protection Bureau by the Division of Forestry in Florida, prescribed fire activity is described as a land management application that is essential to the practice of forestry, management of wildlife, preservation of endangered plant and animal species, improvement of range conditions and reduction of wildfire damage in the wildland/urban interface areas. While there is general public and landowner concern with increased smoke, reduced air quality, and liability; the general public and landowners benefit significantly from the reduction of devastating wildfire, improved wildlife habitat and forage, preservation of endangered and threatened plant and animal species, and improved management of forest resources. The prospect of severe reductions in the utilization of this management tool is of major concern to Florida’s natural resource managers and conservationists due to the subsequent loss of derived public and private benefits. They suggest the need for legislative attention.

Another report on nation-wide prescribed burning in the U.S.A. was published in  International Forest Fire News No.19 (September 1998).

A set of photographic documents on prescribed burning techniques and objectives in the Southeast can be visited in our photo archive.


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