SANTA FE, N.M. — Wildland fires play an important role in many ecosystems, yet in the western United States, land managers have spent a century excluding it from the landscape. The resulting overgrown forests, along with hot and dry conditions, have changed the nature of fires when they do happen, making them more intense and more destructive. Figuring how best to respond is important for the health of our forests, the safety of nearby communities and the well-being of firefighters on the job – and it’s a task that can now draw on some of the most powerful computers in the world.
Safely reintroducing fire and enabling decision-makers to respond more effectively to wild blazes requires anticipating how fire will interact with the mountains and canyons, dynamic winds and mixed vegetation of the West. In the Southeast, where terrain is less of a factor, very active prescribed-fire programs let fire play its role in ecosystem management without endangering people or infrastructure. However, the dense vegetation in this region requires burning every few years, forcing prescribed fire practitioners to increase their understanding of “adequate but safe” conditions for burning and be more efficient when they do burn.
In all these cases, land managers and firefighting agencies need much more information about how fires behave, information that has been lacking.
Since wildfires are not new, why don’t we completely understand them? First, the questions being asked four decades ago were focused on fire prevention, whereas now they are about dealing with inevitable wildfires and ecosystem health, which have become more critical issues after a century of fire exclusion. Furthermore, wildfire behavior results from a baffling, complex interaction between fire, surrounding winds, vegetation and terrain. The vast number of fire scenarios prevents sufficiently measuring fire behavior without the help of sophisticated computer models that fill in the gaps or extrapolate into conditions outside of observations. Until recently, such models capturing the two-way feedback between the combustion processes and their surroundings have been impossible.