Fighting wildfires with scientific data, research and instruments

Fighting wildfires with scientific data, research and instruments

24 June 2010

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USA — Humans cannot survive, unprotected, the fury of a raging wildfire.

But thanks to a unique research project set in the midst of a hillside conflagration, it is possible to experience such a blaze through vital data — heat, wind speed and other measured information — that one day might help firefighters save property and precious lives.

That’s the goal of the work of Craig Clements, a San Jose State University assistant professor of meteorology, who carefully watched over a controlled burn on Thursday that consumed East Bay grasslands. Clements and his team of graduate students watched 20-foot flames envelope their $20,000 steel tower, equipped with sensors, propellers and other computer-linked tools. In mere moments, the project went up in smoke — perfectly.

“It’s toasted!” Clements exclaimed. “That’s a good fire. Let’s see what the data looks like.”

Then they scrambled across a hot and charred landscape to inspect the results of their work.

The SJSU team seeks to fight fire not with water, but with math and physics. The researchers aim to describe the physical environment in a language that, when processed by powerful computers, can interpret and perhaps predict fire behavior far more accurately than is possible today.

All firefighting is dangerous, but wildfires bring poorly understood challenges of wind and difficult terrain. The biggest fires create hurricane-like conditions of hot air, fiercely blowing
wind and smoke that blocks the sun.

Such factors engulfed 14 firefighters in an instant, when a 2003 Glenwood Springs, Colo., fire suddenly shot up a ravine as if sucked through a chimney. Fast-shifting winds and topography are also blamed for five deaths in the 2006 Esperanza Fire in Riverside County, when flames exploded from a bowl-like gully.

What sets off such deadly fire whorls? How does fire induce its own winds — the updrafts along its face and the downdrafts behind it? These are the erratic behaviors Clements and his team hope to study.

Computer modeling to study such fires was conceived in the 1970s. But much of the work has been done in labs, on flat surfaces — not in nature.

“This research is huge,” said Dennis Burns, fire behavior analyst with the Livermore/Pleasanton Fire Department, who worked with the Clements team. “What we’re hoping is it will end up helping us predict fire behavior on slopes — how fast and with what intensity.”

“It helps with the accuracy and safety of firefighting strategies. When is it safe to push firefighters out front? When should we fight from the sides?” he said. “It will validate our fire-suppression strategies on slopes.”

The science of fires

Clements grew up in San Ramon and once dreamed of a career in glaciology. But while studying at the University of Houston, he recognized a void in fire science. He recently joined the faculty of SJSU, attracted to its esteemed program in meteorology, and is now combining his expertise in both weather and fire.

“The Midwest gets tornadoes and hurricanes. But this, a dry summer, is California’s severe weather,” he said. Last winter’s rains have produced the thickest grass growth in years, with seven tons of fuel per acre, compared to three tons per acre of recent years.

“Tornadoes chase trailer parks. Wildfires chase mansions,” he said.

He was invited to set up his research project, funded by the U.S. Forest Service, in the middle of Northern California’s largest fire exercise of the year, a 400-acre burn at Camp Parks in Dublin. Sixty engines and hundreds of firefighters from nine counties — including Santa Clara, Santa Cruz, San Mateo, Alameda and Contra Costa — participated in the drill.

For the past week, his team erected the project on a hillside, knee deep in thatch and thick oat grass, overlooking Tassajara Road and its subdivisions of million-dollar homes.

His SJSU team includes graduate students Dais Seto, 27, of Campbell; Allison Charland, 21, of Livermore; and Dianne Hall, 47, of Los Gatos, an electrical engineer now seeking to become a fire behavior analyst. SJSU hopes to expand this program, adding more Ph.D. prospects.

Raging flames

Along the tall steel tower, supported with guy wires, they secured a series of devices called anemometers, which measure wind speed, direction and air pressure. Other sensors placed in the dirt and every 3.3 feet up the tower recorded temperatures five times a second.

A different tool measured particulates and gases such as carbon monoxide and carbon dioxide. Time-lapse cameras, both traditional and infrared, measured and photographed the blaze as it burned up the slope.

They set up a weather balloon and a tool called SODAR, which uses sound waves to profile winds 200 meters high.

All the information — more than 250 megabytes a day — was to be shipped to distant laptops or a memory card in a fire-protected box.

Then the grass was ignited and went up in a roar. The team stood and watched from a safe distance.

As the flames crackled, Clements’ propellers spun and whirled chaotically; fire creates shifting wind gusts, like an eddy of water behind a rock. The entire project was concealed by thick smoke.

And just as quickly, it was all over.

The researchers jumped in their Toyota Forerunner and then studied the site, acrid smoke still swirling.

“We lost power,” Clements said, eying melted power cables. One set of propellers, made of carbon fiber, melted like a marshmallow. Some bearings were shot.

Then they opened the data box, still warm. Measured updraft: three meters a second. Radiated heat: 106 kilowatts per square meter. Ground temperature: 932 degrees Fahrenheit.

“It’s all there. We got data up to the point of failure,” he said. Now he and his team head back to the lab, for months of analysis.

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