Drought Impacts on Wildfire Management
Wildfire—a critical ecosystem process—is a global phenomenon with natural (lightning) and human-caused sources of ignition. During drought conditions, fuels for wildfire, such as grasses and trees, can dry out and become more flammable. Drought can also increase the probability of ignition and the rate at which fire spreads.
Drought can be intensified by unusually warm temperatures. When combined with very low precipitation and snowpack, extreme heat can lead to decreased streamflow, dry soils, and large-scale tree deaths. These conditions create increased potential for extreme wildfires that spread rapidly, burn with more severity, and are costly to suppress.
The potential for wildfires can be reduced by reducing stand density (thinning), using prescribed burning, and letting some fires burn if they will not affect people. Frequent prescribed burning in fire-prone and fire-dependent (forests that require fire to maintain structure and function) southern forests has been a socially accepted practice for decades, illustrating how the negative impacts of wildfire can be reduced. In some instances, drought can actually reduce the potential for wildfires by reducing the amount of vegetation that is available to burn.
Even with these existing practices to reduce damaging wildfires and maintain ecosystem health, large and extreme burning wildfires continue to challenge fire suppression efforts and budgets. Projected warmer temperatures and a possible increase in the frequency of drought in some regions may require rethinking historical approaches to fire management. If drought-caused wildfire activity increases in the wildland-urban interface, suppression costs will also increase, potentially altering perceptions of management and risk in fire-prone human communities. Therefore, fire professionals have a need for drought information for fire behavior forecasts and long-term fuel management planning.
In an effort to provide that information, the NIDIS Drought and Wildland Fire Nexus (NDAWN) strategy was developed to improve the use of drought information by wildland fire management, air quality managers, fire meteorologists, and fire behavior analysts, and to enhance and develop products to improve firefighter safety, public health and safety, fuel treatment effectiveness pre- and post-fire, and meet overall land management objectives. Broader planning and preparedness topics, including preventing economic and infrastructure losses, are addressed in NDAWN as well.