Forest Fires in the United States: 23 May 2000

Forest Fires in the United States

23 May 2000

Discussions flared up again lately about the topic “prescribed burning”, the purpose to start a fire, if the procedure are appropriate, and should prescribed fires continue to be part of federal policy for forest management in light of the current calamity in Los Alamos, New Mexico.

The article Scientists say prescribed burns are needed by Judith Crosson, published by Environmental News Network on 19 May 2000, deals with the above mentioned questions. These questions have being asked over and over since the National Park Service deliberately set a fire in New Mexico earlier this month that soared out of control, scorching 47,000 acres , destroying 220 home. Scientists say that prescribed burns are necessary and aimed at cleaning up the debris on the forest floor to avoid more disastrous fires. A prescribed burn, undertaken under carefully controlled and monitored conditions, is aimed at removing the brush and other undergrowth that typically provides fuel for bigger fires that are often sparked in the West by lightning. However, fire doesn´t always follow plans. Alternative to remove underbrush could be a mechanically system, but that is too expensive. Federal land managers are moving on a narrow ridge. For instance, it is safer to order a controlled burn in the winter when there is more moisture. But more smoke will be produced in such conditions and that means health problems. On the other side spring and summer burns with less smoke pollution for the inhabitants are carried out under unstable conditions. Last year 1.4 million acres were put under controlled burn on U.S. Forest Service land, compared with 250,000 acres 10 years ago. In the past five years the U.S. Forest Service set 23,000 fires and 230 of them turned into wildfires.

The American timber industry is using the Los Alamos prescribed burn that got out of control as an excuse to push for more commercial logging in National Forests, ostensibly to reduce fire risk. This is ecological heresy. The truth is that timber sales are causing catastrophic wildfires on national forests, not alleviating them. In many cases, overly intensive industrial forest management opens up the understory, changing microclimate, and making conditions more conducive for large fires. Prescribed burns are an important tool in forest management.
(relayed text: Commercial Logging Doesn’t Prevent Catastrophic Fires, It Causes Them)

The four month period of January through April this year was the warmest such period on record in the United States, the National Oceanic and Atmospheric Administration (NOAA) said Friday. This was the warmest January through April in 106 years of record keeping, according to statistics calculated by NOAA’s scientists working from the world’s largest statistical weather database. The American southwest has been struck by a rash of wildfires in recent weeks, with one blaze sweeping the north rim of the Grand Canyon and another threatening the nation’s largest nuclear weapons lab in Los Alamos, New Mexico. Set deliberately to clear underbrush, the fires spread quickly through the ultra-dry forests.
(Year to Date: Hot and Dry – Forecast: Hot and Dry by ENVIRONMENT NEWS SERVICE (ENS)).

Wildland Fire Update for the United States on 22 May 2000 (National Interagency Fire Center (NIFC))
Wildland fire activity has decreased in the Southwest and Southern areas as five large fires continue to burn in New Mexico and Florida. Extreme fire conditions do exist however, in Arizona, New Mexico, Utah, Texas and Oklahoma. More than one million acres have been burned by wildland fires so far this year, which is about 300,000 acres above the four-year average.
Fire Weather
Near-record temperatures are expected throughout most of the Southwest today, along with low humidities ranging from 5 to 15 percent. Winds will be light and variable. Florida is expected to receive increased humidities and scattered showers and thunderstorms with light

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.

click here to enlarge (29 KB) click here to enlarge (27 KB) click here to enlarge (27 KB)

Fig. 1.-3. Fire Danger Forecast Maps of the United States and Alaska for 22 May (observation time) and 23 May 2000 (forecast).
(Source: Fire Behavior Research Work Unit, Missoula)

The Keetch-Byram Drought Index (KBDI) is a soil/duff drought index that ranges from 0 (no drought) to 800 (extreme drought) and is based on a soil capacity of 8 inches of water. Factors in the index are maximum daily temperature, daily precipitation, antecedent precipitation, and annual precipitation. KBDI = 0 – 200: Soil moisture and large class fuel moistures are high and do not contribute much to fire intensity. Typical of spring dormant season following winter precipitation. KBDI = 200 – 400: Typical of late spring, early growing season. Lower litter and duff layers are drying and beginning to contribute to fire intensity. KBDI = 400 – 600: Typical of late summer, early fall. Lower litter and duff layers actively contribute to fire intensity and will burn actively. KBDI = 600 – 800: Often associated with more severe drought with increased wildfire occurrence. Intense, deep burning fires with significant downwind spotting can be expected. Live fuels can also be expected to burn actively at these levels.

click here to enlarge (29 KB)

Fig. 4. Keetch-Byram Drought Index Map of the United States, 22 May 2000
(Source: Fire Behavior Research Work Unit, Missoula)

For further information on the Keetch-Byram Drought Index (KBDI) by Florida’s Division of Forestry / Forest Protection Bureau please refer to Keetch-Byram Drought Index Revisited: Prescribed Fire Applications.

Incident Management Situation Report (22 May 2000)
Current Situation:
New large fires were reported in the Southern Area. The Southern and Southwest Areas had moderate initial attack activity, while activity in the remainder of the nation was light. Demobilization is underway for the large fires in the Southwest Area. The National Interagency Coordination Center processed orders for radio equipment and miscellaneous overhead. Very high to extreme fire indices were reported in Arizona, New Mexico, Utah, Texas, and Oklahoma.
Arizona, New Mexico and west Texas will continue to be hot and dry. Isolated thunderstorms are possible over the west Texas and southern New Mexico mountains. High temperatures will be in the 80’s and 90’s. Minimum relative humidities will be 5 to 15 percent. Winds will be light and variable.
A weak cold front will move through Florida today, bringing mostly cloudy skies and a few showers and thunderstorms. High temperatures will be in the 80’s. Minimum relative humidities will be 40 to 50 percent. Winds will be light.
North and South Carolina will be partly cloudy with widely scattered afternoon showers and thunderstorms. High temperatures will be in the 80’s.

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 30 and 90-day forecast maps).

Tab.1. Five-Year Wildland Fire Comparison Statistics Year-to-Date for the United States (22 May 2000)
(Source: National Interagency Fire Center (NIFC)

As of 05/22/00 Number of Wildland Fires Area burnt Acres Hectars 2000 39,865 1,027,072   1999 38,769 715,714   1998 20,550 383,148   1997 25,747 415,500   1996 54,611 1,419,290

click to enlarge (120 KB)

Fig. 5. 30 and 90-day temperature and precipitation forecast maps (May and May to July 2000)
(Source: National Weather Service, Boise, Idaho)

These true-color images covering north-central New Mexico capture the bluish-white smoke plume of the Los Alamos fire, just west of the Rio Grande river. The middle image is a downward-looking (nadir) view, taken by the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA’s Terra satellite. As MISR flew from north to south, it viewed the scene from nine different angles. The top image was taken by the MISR camera looking 60 degrees forward along the orbit, whereas the bottom image looks 60 degrees aft. The plume stands out more dramatically in the steep-angle views. Its color and brightness also change with angle. By comparison, a thin, white, water cloud appears in the upper right portion of the scene, and is most easily detected in the top image.

click here to enlarge (29 KB)

Fig. 6. Multi-angle views of the Fire in Los Alamos, New Mexico, 9 May 2000
(Source: NASA’s Earth Observatory)

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.

Print Friendly, PDF & Email
WP-Backgrounds Lite by InoPlugs Web Design and Juwelier Schönmann 1010 Wien