Strong winds coupled with dry vegetation in the San Fernando Valley fueled the spread of two wildfires Monday, together burning an estimated 10,000 acres, fire officials said.
Thousands of residents in the area were forced to evacuate as the fires consumed dozens of residencies and caused the closure of most nearby schools. Officials said they were concerned that the fires could spread to the 118 freeway and as far as the Pacific Ocean.
Gov. Arnold Schwarzenegger called a state of emergency for Los Angeles and Ventura counties as a result of the growing wildfires.
The two major fires, the Senson Fire and the Marek Fire, consumed 10 homes and three dozen mobile homes, with smaller fires erupting in the San Bernardino region.
The Senson Fire has burned more than 5,000 acres.
The Marek Fire, at 20 percent containment level Sunday morning, was downgraded to 5 percent on Monday.
The eruption of fires in the area has become a common occurrence since the combination of dry vegetation with the moisture in the air creates an environment that is more susceptible to wildfires.
“If you wanted to design a climate that was conducive to fire hazard, you invent Southern California,” said Robert Fovell, an associate professor of atmospheric and oceanic sciences at UCLA. “Here’s the recipe: wet in the winter, long hot summer and Santa Ana winds in the fall.”
Fovell said that the strong winds from Santa Ana helped to spread the fire, adding that the winds have gotten faster during the past few days.
“Locally the winds can be even faster because the winds gets channeled through passes and canyons,” Fovell said. “A fire will spread faster if it’s hotter, drier and windier,” he said.
The cause of the fires is still unknown, though what caused it is irrelevant, said Richard A. Minnich, a professor of geography at UC Riverside.
He added that once the fires have escalated in size, there is little firefighters can do to prevent the fire from spreading.
“We have no capacity to put out fires once they’re large. … What we do is a pittance. It’s like putting a drop of water on an elephant and hope it cools off,” Minnich said.
Fire suppression, Minnich said, has increased the severity of the wildfires. He said that since small fires which break out during the summer are typically extinguished, the vegetation which would normally be burned by the fires is still in abundance during the fall season.
As a result, fires in the fall have much more fuel to burn, and are increased due to the strong Santa Ana winds.
“Because we’re putting fires out … we’re making the role of the Santa Ana winds (larger),” Minnich said.
The strong winds blowing through the area are also spreading the fine particular matter in the air, which for sensitive residents, can affect their health, said Dr. Marc Riedl, an assistant professor of clinical immunology and allergy at the David Geffen School of Medicine.
He said that though the air quality is worse for those closer to the affected region, students who suffer from asthma, emphysema or other respiratory symptoms can still be affected.
“It’s less of a risk here, but it is still a potential risk,” Riedl said.
He said that it is best for people who belong to those sensitive groups to avoid the outdoors.
“If one needs to be outside, it’s best to avoid intense exertion,” he added.