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A charred landscape is left in the wake of the 250-square-mile Station Fire as firefighters work to complete the final defensible fireline to contain the massive fire in the San Gabriel Mountains on September 16, 2009 in the Angeles National Forest, northeast of Los Angeles.
Near Los Angeles County foothill cities, a team of federal scientists is studying environmental impacts from the Station Fire. Authorities will use that team's work to decide how to protect areas from flooding this winter.
The BAER team isn't about bears that are grizzly, or California Brown. "We get that a lot," says Jason Jimenez. He laughs politely. "BAER stands for Burned Area Emergency Response." Jimenez calls the Cleveland National Forest near San Diego his base.
Even as the Station fire chewed across L.A. County, he and about 30 other federal scientists swooped into the Angeles National Forest to observe what the fire left behind. "We are a collection of technical specialists," he says. "Hydrologists, geologists, soil scientists, archaeologists, botanists, and biologists. And other disciplines as well. And we come in to determine the effects."
Jimenez kneels in the dirt and ash, digging with a short handled shovel. As a soil scientist, he gets to do for a living what he loved to do as a kid. Although he and his shovel can't go every place the Station Fire burned, he does dig holes for sampling. Jimenez runs water from a squeeze bottle over soil at the surface and several inches down. "I look for beading. And I look for if that soil is going to repel water."
If it does, that's a condition called hydrophobicity. In a fire, a waxy substance from burned plants can become a gas that coats soil particles – making them water repellent. "We categorize that from low, moderate, and strong. Hydrophobicity!" It's a worry because water-repellent soil can speed flooding down a hillside. But where Jimenez stands, on a slope in the Big Tujunga area, plants weren't densely packed, thick, or overgrown. "There was not a lot of heat here. So I would classify this with a low burn severity."
Satellite imagery offers Forest Service recovery scientists the most basic information about the fire's severity and impact – especially in the 160,000-acre Station Fire. Helicopters give some scientists a bird’s eye view. While the fire's still active, that's a luxury.
Jimenez didn't go up in a helicopter, but another young team member did. A gangly hydrologist named Kyle Wright flashes ankle below too-short Forest Service-green pants. Wright and three others on the recovery team study how water moves over burned landscapes.
In the Angeles National Forest, Wright says there's plenty to do. "They have very flashy rain events. That's pre-fire. And those post-fire rain events will be only more amplified without the vegetation and ground cover after a fire," Wright says. "Flashy, meaning – your streams respond very quickly to rain events. Mostly because of steepness and the kind of storms that come through this area."
Wright's helping to make models that demonstrate how water will move down newly-burned hillsides. Forest officials will use those models to decide how to treat hillsides to protect people and property in cities below.
Where it's not too steep, that could mean adding mulch. Wright says it also could mean no treatment at all. "The last thing we want to do is treat an area that won't be effective and give other people a false sense of security in thinking it will return to pre-conditions in fire, and that's just not the case."
The Station Fire won't be 100 percent contained for a while – burning continues in steep inaccessible terrain. Later this week, the Burned Area Emergency Response issues its report. Another team of specialists will take over from there. Then forest managers and foothill dwellers will decide what to do with the report, as quickly as they can before the first fall rains.