Risk Migitation of the Wildland Urban Interface

Chapter 2

LITERATURE REVIEW

Most fire suppression experts believe that the threat of massive damage to human lives, private property, and natural resources is increasing (National Fire Protection Association 1987, Fischer and Arno 1988). Wildland fires are becoming a major concern. There are a number of reasons for this: 1. Human activity patterns have changed the landscapes over the past three decades. 2. Natural resources are too valuable to let fires burn uncontrolled. 3. Wildland fire fighting budgets are shrinking. 4. More people are escaping the cities into the wildlands. 5. Wildland fire fighters are untrained and/or ill-equipped to fight structure fires. 6. Climatic conditions such as drought can be like a match to volatile fuels (Chuvieco et.al, 1994). An impressive body of scientific evidence from fire history, fuel accumulation, and fire behavior studies makes it clear that much of North America is a fire environment where wildfire or a substitute recycling mechanism, such as prescribe burns, is inevitable (Anderson and Brown 1989, Arno and Wakimoto 1988, Wright and Baily, 1982).

Primary responsibility for wildland urban interface fire prevention and protection lies with property owners; private, state, and local governments. Property owners have responsibility for compliance with existing state statutes and local regulations. These primary responsibilities should be carried out in partnership with the Federal government and private sector areas (United States Department of the Interior, 1995). The current Federal Fire Policy states that protection priorities are: (1) life, (2) property, and (3) natural resources. These priorities often limit flexibility in the decision-making process, especially when a wildland fire occurs within the Interface. Wildland fire suppression resources must be diverted to protect property, often of less value, when adjacent to intermixed natural resources. During suppression of fires within the Interface, performance inconsistencies may result from a training dichotomy of two separate certification systems: structural fires and wildland fires. Firefighter safety is compromised when they are placed in a position of operating beyond their training, experience, and equipment capabilities. Because of a lack of information about fuels, hazards, and residence fire fighting operations in the wildland urban interface are not always well organized and safe. In addition, after-action reports indicate that fire suppression resources are often "over-mobilized," which results in inefficient use and over-utilization.

In 1988, $145 million was spent to suppress the Yellowstone area fires largely to combat threats to homes, resorts, and facilities; it took a heavy, October snowfall to finally extinguish the fire (Arno and Brown, 1989). Helicopters cost $103,396 per day, P3-A Orion aerial tankers cost $40,600 a day, and the payroll can cost tens of thousands of dollars each day (Williams, 1995). The Forest Service annual cost to maintain a standing force of 10,000 firefighters, 400 smokejumpers, 1500 fire trucks, 90 airplanes, and assorted specialized firefighting rigs is $189 million annually (McLean, 1993). In addition to high suppression costs, severe fires are extremely costly to lives, property, and natural resources. When homes and developments lie in the path of a wildfire, fire fighting efforts must be diverted to saving structures--which in turn allows the fire to grow and threaten more homes and forests, this is a growing nightmare for firefighters and land managers (Arno and Brown, 1989).

When fire is suppressed for long periods, epidemics of bark beetles, defoliating insects, and diseases often allow heavy accumulation of fuels, a prime requisite for catastrophic wildfires. Despite widespread adoption of the fire management concept a decade ago, forest fuels continue to increase faster than they are being recycled through harvesting, fire, and decomposition (Arno and Brown, 1989). Concerns about excessive smoke, the possibility of fire escapes, large fuel accumulations, steep terrain, and difficult access have limited the use of prescribe fire management. Dodge (1972) reported that because of misconceived public attitudes toward wildfire and increased fire fighting efficiency fuel loads across the nation were increasing dramatically. Low intensity fires play an important role in nutrient cycling (Harris and Covington, 1982), retarding invasion of non-native grasses and brush into native grasslands, and play an important role in the reproduction of many plant species (Cooper, 1961; Hanes, 1971; Parsons, 1989). Vegetation and forest fuel management has been hampered by a lack of public awareness of the fuel buildup problem, and by inadequate funding of fire fighting personnel, equipment, and training. In contrast, vast sums of money are spent attempting to control severe wildfires in untreated fuels (Arno and Brown, 1989).

Wildland Urban Interface In Arkansas

The 1990 Census ranked Arkansas 10th in rural population with 46 percent of its 2.3 million population living outside of urban areas. Urban areas are defined as those communities or areas with a population of 2500 or more. In Northwest Arkansas the two counties, Washington and Benton, have the highest number of farms and also ranks 2nd and 3rd in population. There are 1 million structures in Arkansas with 46 percent found in rural Arkansas (Arkansas Rural Development Study Commission, et al, 1997).

Wildfire in Arkansas

Historically, the southern United States has led the national wildland fire statistics in both frequency and size of area burned (Payne, 1982). Nationally, the history of fire in the south follows closely the history of fuels. Forest fuels increase following human activities like logging and conversion of open areas into timber producing lands. In fact, in the south, fire is necessary to hold in check the annul growth of shrub vegetation in favor of commercial species. In this century major fire years in the south have corresponded to periods of drought. In Arkansas, the drought years of 1930, 1938, 1952, 1963, 1980 resulted in heavy damage to the states timberlands (Payne, 1982). Socioeconomic changes have also led to increase fire activity. In the early years of the 20th century most of Arkansas' virgin pine forest were logged out leaving behind huge areas of slash. Exhausted agriculture lands, primarily cotton, were extensively abandoned. These areas were very susceptible to wildland fires. In 1930 a chemist developed methods for converting southern pines into pulp, necessary for production of paper (Payne, 1982). A key to success was keeping fire out of cutover areas until regeneration could take hold. Timber production came into direct conflict with the southern cattle producers using the rangelands for grazing, and herding which were dependent upon open ranges. Stodderd (1924) thought that fire may well be the most important single factor in determining what animal or vegetable will thrive in many areas.

In the early years Crossett Lumber Company of Arkansas was adamant about keeping fire out of the forest. This was important in order to reduce the amount of destruction to existing timber and the success of the next generation of young trees. Pines are most susceptible to fire when in a young plantation. The absence of fire led to an increase in fuel loads. As pasture and natural openings gave way to woods the understory roughage not only competed for available nutrients but provided wildfire with a fuel source and fire ladder into the crowns of surrounding mature pine forest.

Recent research (Kluender, et al, 1988, 1989) on wildfires in Arkansas examined fire statistics of the AFC's Individual Fire Reports from 1983 to 1987. These studies compiled county and AFC Fire Districts statistics of occurrence with the hope that new policies for fire prevention and suppression could be formulated. Arson was the overwhelming cause of fires, these fires were on average twice the size of all other types of fires.

Topography, climate, weather, and fuels play significant roles in determining both fire seasons and the severity of wildfires. Kluender et al (1988) discovered that northern Arkansas has one fire season, occurring in the spring with generally larger fires and more frequent fires and south Arkansas has two fire seasons, spring and fall, with generally smaller fires and slightly lower frequency of occurrence. The average number of wildfires in the Arkansas Ozarks is less than 100/week during most of the year, except, in the spring months when fire occurrence is almost 600/week. The average number of wildfires in the Arkansas' coastal plains ranges from a low of 50/week in January to slightly above 400/week in spring and fall months (Kluender, et al., 1988).

AFC's budget continues to be reduced during this period due to tight state governmental fiscal policies. The bulk of the AFC's funding for fire suppression and prevention comes from the severance tax or 'stumpage tax' applied to harvested timber and $0.15 per acre assessed to all private forest ownership (McFarland, Arkansas Forestry Commission, oral communication).

Fire suppression cost can be further refined by looking at the cost per acre to combat wildfire. The average size of a wildfire in north Arkansas is 22 acres and 15 acres in south Arkansas (Kluender, et al, 1988), the statewide average size is 18.5 acres. The budget cost is $87.00 per acre in north Arkansas and $127.00 in south Arkansas or $107 per acre statewide. Each fire in northwest Arkansas on average costs approximately $1,980 (18.5 acre times $107/acre suppression cost) to fight. With approximately 2,675 wildfires per year the total annual cost for fire suppression statewide could reach over $5 million. In 1995 there were 4,204 wildfire statewide potentially costing the AFC over $8 million dollars in suppression cost.

In September, 1995 wildfires burned 3,247 acres (1,314 Ha), with average fire suppression cost of $121/acre ($300/Ha) resulting in expenditures of $40,200 for fire suppression that month (Burton, Assistant State Forester, Protection Division, AFC, 1997, oral communications). Using the average fire suppression cost of $120/acre for all fires over 5 years, 1992 to 1996, the total fire suppression cost is in excess of $20 million or an average of $4 million per year. To the direct fire suppression cost add the normal cost of maintaining a large fire suppression force. In 1978 the USDA Forest Service revised its fire policy to emphasis economic efficiency. McKetta and Gonzalez-Caban (1985) developed economic models using 5 categories: fire prevention, fuel modification, fire detection, presuppression, and fire suppression. Their study found a wide range of cost estimates being used; estimated fire suppression cost were 32 to 138 percent higher than current planning figures. These cost do not include the cost from loss of life, injury, loss of property, and loss of earning potential due directly to fire.

Geographic Information Systems Analysis

Geospatial technologies such as Geographic Information System (GIS) and Global Positioning System (GPS) are important spatial tools used to develop information sets which provide insight into the dynamics surrounding a wildland fire. GIS provides the technology to store, manipulate, analyze, and display spatially oriented information layers. These information layers can be stacked and used to develop new polygon categories (models) based upon the interaction of each layer. Each layer may be weighted to provide more or less dominance as determined by testing the model. No research on spatial relationships between fuels, terrain, and climate has previously been undertaken in Arkansas.

Wells and McKinsey (1991) found that the accuracy and utility of most GIS fire behavior models was compromised when the process of generalizing vegetation components into fuel models takes place. Twenty-three different vegetation communities recorded on his study were placed into three generalized fuel models, experience has shown that some of the vegetation types lumped together have quite different flammability potential (Wells and McKinsey, 1991).

At California's Cuyamaca Rancho State Park, GIS was used to develop long range management plans from detailed information about climate, weather, topography, geology, soils, vegetation, fauna, and modern cultural features. Realizing the importance of fire's role in preserving native wildlands, prescribe fire becomes an important management tool. (Wells and Mckinsey, 1991). Wells and Mckinsey (1991) based their fuel model on those described by the National Fire-Danger Rating System (National Wildlife Coordination Group, 1981). They concluded that the GIS program was limited by the categories of fuel, the 23 vegetation classes were placed into three generalized fuel models.

Methodologies were develop which reduced the number of categories of risk potential matrix while preserving the integrity of the original categories of each of the potential components, discussed in the next chapter.