The cause of the Gifford fire, which has burned more than 82,000 acres in south-Central California since Friday, is still being investigated. But its origins came in a familiar setting: near a highway.
Humans start a vast majority of wildfires, and those fires frequently start near highways.
The Gifford fire began on Friday afternoon as four smaller fires along Highway 166 merged and burned on both sides of the road. It was 7 percent contained as of Tuesday morning and was threatening about 800 structures, according to fire officials in California, having burned through part of the Los Padres National Forest east of Santa Maria in San Luis Obispo and Santa Barbara Counties.
While the cause of the Gifford fire was still undetermined, its location near a highway raised the strong possibility that it was caused by cars.
Fifty percent more wildfires occur in areas within 200 meters of a road than would be predicted by random distribution, a 2007 study by the Pacific Biodiversity Institute found. In areas far from roads, there are many fewer wildfires, the study found.
Roughly 90 percent of fires are started by humans, and while discarded cigarettes and careless campfires can spark wildfires, blazes that begin near roads are often caused by cars.
The are several ways this could happen, according to the South Central Oregon Fire Management Partnership and other experts: Trailer chains or car parts like mufflers that drag underneath vehicles can cause sparks, as can brakes that have worn thin. Underinflated tires may cause cars to drive on exposed wheel rims, throwing off sparks that can ignite fires.
And when cars stop by the side of the road, even hot exhaust pipes or mufflers can ignite dry grass or brush.
The Gifford fire has prompted evacuation orders in some parts of San Luis Obispo and Santa Barbara Counties, although only a few hundred people were affected in the mostly sparsely populated area.
Hundreds of firefighters were focusing efforts on digging fire lines, which generally involves clearing an area of vegetation and digging or scraping down to the “mineral soil” to stop a fire from spreading. In an effort to contain the fire, they are building both direct fire lines at the fire’s edge and indirect lines farther away, officials said.
Temperatures in the area were expected to be in the mid-80s to lower 90s on Tuesday. Winds, which have been hitting 20 miles an hour, were expected to continue, possibly stoking the fire.
Through July 21, CalFire, the state’s fire agency, reported 4,423 wildfires, up 14 percent from the same period last year. The total acreage burned was up 76 percent. Both figures were also above the average over the past five years.
Victor Mather, who has been a reporter and editor at The Times for 25 years, covers sports and breaking news.
The post The Raging Gifford Fire, Like Many, Began Near a Highway appeared first on New York Times.
