The devastation that accompanies each fire season in the United States has become alarmingly predictable. If has been replaced by when for many forest managers, rural communities, insurance providers and others living and working in fire-prone areas. Fortunately, innovative remote sensing analysis techniques can benefit fire-fighting professionals by providing a quantifiable data link for wildfire mitigation planning and action.

People living in many Western communities have grown accustomed to the pleasing view of a thick green carpet covering the terrain. But a visit to the local bookstore or historic society paints a much different picture of how that landscape looked in an unmanaged state. Foothills now thick with encroaching ponderosa were devoid of such sprawling tree stands only 100 years ago. Early photos show large isolated trees separated by vast expanses of native high prairie grasses. At higher elevations, thick Douglas fir and lodge-pole pine forests once were characterized as isolated stands in an extensive ecological mosaic of grassy parks, wetlands, aspen and conifer. Kept in check by annual fires for thousands of years, forest species of all varieties depended on nature to thin and renew their surroundings.
 

The National Interagency Fire Center estimates that in an unmanaged setting, 40 million to 50 million acres burned annually in what is now the lower 48 states. It wasn’t until the late 1800s, when a steady migration of white settlers came westward, that the cycle began to change. Following a particularly catastrophic fire season in the early 1920s, the newly established National Forest Service declared an all-out war on wildfires. The implementation and perceived success of that campaign grew under the watchful eye of Smokey the Bear and ever-growing departments of the Interior and Agriculture. Wildland firefighters were recruited, trained and deployed throughout the West. As a result of this suppression effort, the annual acreage consumed by wildfire dropped to roughly 5 million acres by the late 1960s, and the rate has remained steady ever since.

Early Policy Backfires

Although the policy of aggressive fire fighting appeared successful, a slow and dangerous paradox was evolving in the same ecosystems these policies were created to protect. With natural controls removed, more aggressive conifer seedlings took hold and began spreading into the grassy parks and prairie foothills. Open spaces within forest stands slowly disappeared, giving way to the dominant conifer species. Decades passed, and as these stands expanded and the open spaces filled in, species characteristics also began to change. Isolated stands became homogeneous, merging into vast seas of trees. Broken canopies closed. Trees began to compete for essential nutrients. Isolated old-growth ponderosa became lost in a carpet of seedlings that grew thin and weak as a result of ever-increasing competition.
 

Soon the stage was set for ecological disaster. Insect and disease outbreaks—once kept in check by stand diversity and isolation—now race across entire forested regions. Annual ground fires that were once a part of the balanced ecosystem now burn through choked forest canopies with such intensity that soils are actually sterilized of all organic material. Meanwhile, population density continues to increase in these fire-prone ecosystems, adding deadly potential to an already volatile situation.

 

Battling Back

Three times in the last four years, annual fire-suppression costs have topped $1 billion. Insurance losses are even more staggering. Northern California’s 1991 Oakland/Berkley Tunnel Fire alone resulted in more than $1.7 billion in insured losses. Insured losses from the Southern California fires of 2003 may top $2 billion. The bottom line is that even in a “good year” thousands of homes may be lost while suppression costs continue an upward spiral. The lowest common denominator, however, has no dollar figure. It is measured in human lives, and the losses mount every year.
 

Despite these statistics, urban congestion and pollution continue to provide the push, and the lure of a peaceful rural lifestyle continues to provide the pull. Homes are being built in record numbers within forest ecosystems, continually expanding the margins of what is called the “wildland/urban interface.” New mountain subdivisions and homesteads inevitably stress existing infrastructure, which is often inadequate to begin with. These circumstances, coupled with an attitude that “it will never happen to me,” create a situation in which voluntarily cutting down trees or raising property taxes to cover expanded fire protection isn’t high on the “to-do list.”
 

However, some industries and several government agencies are developing policies and procedures that are forcing changes in the public’s thinking. Firewise, a community fire-risk educational program (www.firewise.org), provides educational programs that are enlightening the public through community workshops. Insurance companies are directly challenging homeowners to either create defensible space in and around homes or lose coverage. Congress is appropriating funding to finance forest thinning in public lands and around high-risk communities. Fire-behavior research is accelerating, and acceptable standards for “defensible zones” are being established.
 

Despite this apparent paradigm shift, the daunting problem of fuels reduction on a national scale remains. The public, now aware of actions about to be taken, is generally skeptical. Bush administration plans to ease logging restrictions in national forests and streamline environmental-impact reviews and project-approval processes are being met with stiff resistance from environmental groups. There is a presiding fear that with such carte blanche, the logging industry will ravage the national forests with little regard for environmental impact or natural aesthetics. In addition, the hazardous-fuel problem is often tied up in dense stands of small-diameter timber for which there is little economic incentive for harvest. Lastly, the areas of highest potential for economic and human loss in a catastrophic wildfire are located within the wildland/urban interface, not remote regions of national forest.

Remote Sensing Solutions

Local, state and federal land managers are tasked with justifying forest-thinning projects and focusing mitigation dollars where they will be most effective. All forests—public and private—suffer from more than 100 years of fire suppression, so it is unreasonable to expect to completely alter that situation in the next few decades. The task is monumental, and progress will be gradual. Successful projects will be localized to the wildland/urban interface, and will be identified and prioritized based on quantifiable data with a standardized hazard-ranking system.
 

The critical variable in the equation is quantifiable data. For individual homes, defensible-space projects are easily planned and carried out based on subjective site inspections. However, the benefit of individual homeowners taking action is realized only when all neighbors do the same. One house, with adequate defensible space, is still at risk when surrounded by houses without. Larger areas—subdivisions, communities, counties or multicounty regions—require more efficient and cost-effective measures.
 

The development and use of remote sensing analysis techniques can provide a quantifiable data link for defensible mitigation planning and action. Remote sensing analysis classifies raw high-resolution imagery data into thematic data to identify the species, age and density of trees and various types of groundcover; then managers can use a geographic information system to analyze and model the data and develop treatment strategies.
 

In the summer of 2003, DigitalGlobe teamed with Colorado Springs-based Native Communities Development Corp. (NCDC) to develop such a solution using QuickBird submeter-resolution satellite imagery. QuickBird imagery provides the unique combination of a large-area ground footprint with the precision of 60-centimeter resolution—two necessary components for accurate feature extraction and forest-composition mapping in the wildland/urban interface. Although accurate forest-composition mapping is an integral component of mitigation planning and the project’s initial focus, it quickly became apparent that the full potential of the imagery and analysis for tactical wildfire support was hardly being reached.
 

According to William Whatley, director of operations for NCDC’s Satellite Imaging and Mapping Division, QuickBird imagery can readily address critical wildfire issues and concerns with four principal considerations:
 

1. Community Planning and Protection: What can be done to reduce the threat of wildfires to a community? Where are the most dangerous fuels presently located?

2. Community Fire Response: What needs to be known about a community and its resources if a wildfire is near or approaching? Where can adequate escape routes and safety zones be established? Will any medical facilities, nursing homes or schools need to be evacuated? Is water available to assist with attack and suppression activities?

3. Fire Behavior Prediction and Modeling: Where do the conditions exist that could propagate fire intensity and spread?

4. Fire Attack and Suppression: Where can fire fighters establish the nearest staging areas? How can they assist with community fire-response activities? Where can they acquire water for engines and heli-dip? How can they avoid wetlands and inadequate river/ stream crossings, as well as geographical hazards such as chimneys and box canyons?
 

To test the model’s accuracy and application potential, DigitalGlobe and NCDC are supplying imagery and analysis for a project focusing on a wildland/urban interface southwest of Denver, near Bailey, Colo.—an area known for rapid development and catastrophic wildfires. Dubbed the Front Range Fuels Treatment Project, it is led by the Colorado State Forest Service and the U.S. Forest Service, and supported by GIS software developer ESRI Inc, Redlands, Calif.

“The project will go a long way in determining the role high-resolution imagery and remote sensing analysis will play in future mitigation planning, as well as tactical fire-response planning,” says Whatley.

A Long Road Ahead

Skip Edel, GIS coordinator for the Colorado State Forest Service, sheds some light on the magnitude of the “interface problem” in Colorado alone.
 

“If you figure you have about 1 million people living in the ‘red zone,’ or high-risk areas [in Colorado], and 1,714 communities at risk are listed on the Federal Register, then you want to know where your treatment dollars will be most effective at reducing risk to life and property,” explains Edel. “Most of these population statistics have come from coarse-level assessments crossed with census information. Because that is way too many acres to treat, we need to acquire better data to prioritize treatments, and that leads into remote sensing solutions like those used in the project around Bailey. We need accurate data at the community level so we can be most effective in our treatments.”
 

The issues plaguing forested lands remain as another fire season approaches. The hills are choked with overgrown forests. Drought conditions persist. Insects and disease are poised to consume millions of acres. Home construction continues to expand the wildland/urban interface.
 

But positive change is taking place with increased funding, planning and education—both within Congress and by individual homeowners. Change may not come soon enough for the thousands of homes that probably will be destroyed this year, but the next fire season will reap the benefits of technology-based preparation. By using high-resolution satellite imagery and accurate remote sensing analysis techniques that directly support the requirements of forest mitigation and restoration, as well as the tactical wildfire planning needs of wildland/urban interface communities, goals will be targeted and reached with greater confidence, cost efficiency and accuracy.          

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