Hot temperature key factor to predict risk of wildfires, finds study

Hot temperature is the most important factor in predicting the risk of wildfire than humidity, rainfall, and moisture, a new study has revealed.

The details were presented in the meeting of the American Association of Geographers.

Geography professor Susanna Tong and her students studied a variety of weather, microclimate and ground conditions in historic fires around Phoenix, Arizona, and Las Vegas, Nevada, to determine which might be the most important in predicting the risk of wildfire.

They found that temperature was a better predictor than humidity, rainfall, moisture content of the vegetation and soil and other factors.

"We examined a long list of data. The results show that the maximum temperatures had the highest correlation with fires. That makes sense because if you have high temperatures, a fire is easier to ignite," student Diqi Zeng said.

"The recent California wildfire, which is the deadliest and most destructive wildfire on record, showed clearly the devastating consequences. A better understanding of wildfire incidents is therefore crucial in fire prevention and future planning," their study said.

"What I'm trying to do is investigate the causal factors to create a risk map to examine where wildfires are most likely so people will be more informed," student researcher Wan said.

Researchers used geospatial and statistical tools to study the problem. They found that the lack thereof even months prior to an event was a contributing factor.

Likewise, the researchers found that wildfires were more likely to start in woodlands than pastures, possibly because more of those pastures are owned by ranchers who plan for fire by removing dead timber or brush and adding fire breaks.

The researchers studied vegetation cover and type, moisture level, proximity to roads and population centers and historic weather data. Fires can be more harmful to vegetation in semiarid Arizona and Nevada than parts of California that get far more rainfall, Tong said.

Finding long-term solutions to reduce fire risk will require a coordinated effort, Tong said.

Climatologists can build forecasts that help forestry officials plan for fire season and forestry officials can remove dead timber to minimize fires that do break out.

"It's a complex issue. Maybe better zoning regulations, better evacuation strategies, better forecasting, and better monitoring," Tong said.

"Because of global warming, wildfires are only expected to get worse.