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00000176-d8fc-dce8-adff-faff71c90000Idaho's wildfire season is here, and that means you're going to be hearing a lot of firefighting jargon to describe what's going on.We put together this list of key firefighting terms you're likely to hear in the next few months.GlossaryHotshots: A highly trained hand crew of wildland firefighters that works on the ground to contain a blaze. Crews usually operate in 20-person teams, and are sent in first to deal with the worst fire conditions on short notice. Hotshots have a high level of physical fitness. They can carry up to 50 pounds along with a chainsaw and shovel. There are more than 100 hotshot crews around the country, and the National Interagency Fire Center in Boise coordinates the crews.Hand crew: Wildland firefighters that could have different levels of training. They work on the ground with hand tools like shovels, chainsaws and axes. They dig fire lines (also called "firebreaks") to try and get the fire under control.Smokejumper: An elite firefighter that parachutes into remote wildland fires. They work to suppress and put out fires before they become a bigger problem, and can adapt to quickly changing situations. Smokejumpers have to be fit and highly trained. They carry heavy packs and protective suits and work in mountainous terrain. Idaho has three smokejumping bases in Boise, McCall and Grangeville.Fire lines or firebreaks: Usually about 10-12 feet wide, fire lines are cut with shovels and axes to contain and suppress a blaze. Hand crews -- including hotshots -- will dig lines and clear out brush so the fire will get choked off without fuel.Containment levels: The agency that manages a fire will say how "contained" a fire is. At 100 percent containment a fire isn't out. That means a complete fire line has been dug around the fire. A contained fire can quickly become out of control again with a shift in weather.Controlled fire: This is when a wildfire is considered out. Here's how the BLM office in Idaho Falls describes it: "Think of a container -- say, a mason jar. A fire is contained when it's all 'bottled in,' like in a container. The fire may still be burning, but if a distinct fire line is built around the entire perimeter so that there is no chance for the fire to escape or spot over outside the line, then the fire fighters declare the fire 'contained.' "Human caused: This means someone accidentally or intentionally caused a fire. This could be from a discarded cigarette, a embers from a campfire, or even sparks from a truck along a forested highway. As Smokey says, nine times out of 10, a wildfire is human-caused.Fire danger: This is a rating system from the U.S. Forest Service that helps predict how likely a wildfire could start in an area. It takes into account the weather forecast, terrain and personnel. "Low" means a blaze would likely not spread, while "moderate" means a fire could start but could be contained. "High" to "very high" means fires can catch and spread easily, while "extreme" means the conditions are so difficult and fast-changing that fighting the blaze directly is rare.Red flag warning: These warning are issued by regional National Weather Service offices, and help firefighting management teams understand the weather-related risks for fire starts. Drought and low humidity mixed with windy conditions usually spell a red flag warning. Burning bans sometimes come along with these warnings.Complex: Two or more larger wildfires in the same general area. A complex is managed by a unified team of firefighters.Air attack: Usually used during the initial stages of a small blaze, or as a suppression tool during large fires. Air attacks can drop fire retardant or water to help support hand and engine crews. Multi-engine or heavy air tankers, single-engine air tankers, and helicopters are the three most common types of aircraft that can be used. Multi-engine tankers carry the most retardant, while helicopters (or helitankers) can make more precise but smaller drops.Fire retardant: Also known as slurry, these USDA-approved chemicals are dropped by aircraft over wildfires that management teams believe could grow and become dangerous. It's often used to protect private property. A 2010 ruling from the U.S. District Court in Montana raised questions about its environmental effects.Incident management teams: Operating from level one through five, these teams of firefighters can be sent around the country to suppress fires. Type 1 and 2 IMT's often work on the most difficult and dangerous fires, and can include local firefighting resources.ResourcesWe also pulled together these key resources where you can find up-to-date information about wildfires.The National Interagency Fire Center coordinates fire management teams around the country, and is based in Boise. This year, NIFC predicted a higher level of fire danger in Idaho forests, while the grassland should get a bit of a break.The Bureau of Land Management's site will update Idahoans about fire restrictions on public land.InciWeb updates fire information around the country, giving handy info about road closures during the summer travel season. You'll also find maps, photos, and growth potential for a particular fire.And if you tweet, consider following these organizations and agencies for fire updates in 140 characters.

A Landslide Buried Boise In Mud 55 Years Ago, Scientists Say It Could Happen Again

historic photo, Cottonwood creek
Idaho Statesman, Boise Public Library

Since the devastating landslide hit the town of Oso, Wash. last month, people who live near hill slopes or mountainsides have been asking if something similar could happen to them. Though Boise has not seen the tragic loss of life the Oso slide brought, the city is no stranger to floods and mudslides near its foothills. Boise State University geology professor Jen Pierce knows landslides in Boise are still possible.

Pierce walks along Cottonwood Creek, a popular Boise recreation spot. It’s abandoned on this day due to a steady spring rain.

“When you look at the stratigraphy (that's geologist-speak for layers) in Cottonwood Creek, which I’ve done with my students, you can actually see evidence of large debris flows in this creak in the past,” She says.

That’s been going on for centuries. Notably, in 1959 tons of mud poured into Boise along this creek and others after a summer storm. It covered much of northeast Boise in 10 inches of mud.

But even though it’s raining we’re not in any danger.

“If we got this same amount of rain following a fire, this same amount of rain potentially could trigger a flood or debris flow,” Pierce says.

That’s what happened in 1959. The rain came after a big fire burned in the foothills. Landslides after fires are fairly common in Idaho. For example, Blaine County saw some after last year’s Beaver Creek Fire. Fire can lead to floods for a few reasons.     

Most importantly, fire gets rid of the plants on a hillside that hold the soil together.

Credit Adam Cotterell / Boise State Public Radio
Boise State Public Radio
Jen Pierce specializes in geomorphology, the processes that shape the earth.

“Also just the effects of fire itself,” Pierce says. “Fire limits the amount of water that can infiltrate through a hillside. So rain falls on those hill slopes, it doesn’t infiltrate, instead it runs off. As it runs off it gathers more and more sediment.”

Since 1959, a lot has been built in the areas most inundated with mud. That includes St. Luke’s Hospital, and further east, the Harris Ranch subdivision.

David Hayes lives just two ridges over from Cottonwood Creek at the base of the foothills. The 1959 fire that triggered Boise’s big mudslide started not far from his neighborhood. Standing in his front door, Hayes says he’s not concerned about fire. And even though he had to build a retaining wall on his property to keep the hillside in place, he never really considered the possibility of landslides.

“When we built a retaining wall we had a lot of interest from the city. They wanted the wall built to certain specs because of the instability of the soils around here,” Hayes says. “But I didn’t think about landslides when we bought.”

Hayes says he’s still not concerned about landslides even after the recent slide in Washington. He thinks the geologic features of the two areas are just too different. And he’s right about the differences. The conditions that caused Oso slide last month aren’t really found around Boise. The city is probably not in danger without a significant event like heavy rain after a fire. But Boise State geologist Jen Pierce says that’s a very real possibility.

“I am concerned,” Pierce says. “Fire and fire-related debris-flows present a significant hazard to residents in Boise.”

Pierce wants people who live in and near Boise’s foothills to be more aware of the risks of fire. And she wants officials to think more about Boise’s history of fire and landslides when planning new communities.

She thinks what happened in 1959 could happen again. That’s despite a monumental effort to make sure it wouldn’t. It was called The Boise Front Watershed Restoration Project.

The U.S. Forest Service made this film about it in the 60s.

Forest Service, BLM and other land management workers dug miles of horizontal trenches across the hill slopes. The trenching began less than two months after the fire and flood. It took 13 bulldozers 3,000 hours over the next few years to complete the project. In some places, you can still see the striped pattern those trenches created.

“Their purpose is to intercept the flow, to prevent it from accumulating, to prevent it from being larger,” says Terry Hardy the watershed program manager and burned area emergency response coordinator for the Boise National Forest.

Hardy says digging trenches across hill slopes is only done in the most extreme cases where there’s a high risk of future slides and loss of life. The post-1959 trenching project and others that followed it changed the look and ecology of Boise’s foothills. Five decades ago, the practice of contour trenching was viewed as a definitive solution. But since then, scientists have debated whether or not it actually works. Pierce says it doesn’t help much, and in some cases, may do more harm than good.

Boise Foothills
Credit Boise National Forest
Here's a photo of the foothills before the trenching, and what they looked like after man-made trenches were put in.

“There’s some pretty good evidence that by digging those trenches you can actually potentially increase the risk of future landslides because that creates areas for water to pool up,” Pierce says.

Others defend the use of trenching. As recently as 1996, the Forest Service dug trenches above Boise after a foothills fire increased the risk of floods. Terry Hardy says Boise’s foothill trenches have kept serious floods and slides from happening.

“Contour trenches, they’re designed for a certain level of storm event, so it should be effective up to that certain precipitation,” Hardy says. “You can’t protect against everything.”

In other words, Hardy believes the trenches will prevent floods and landslides if a big storm follows a fire, but maybe not a really really big storm.

Hardy and Pierce do agree that even after years of trenching and many other less visible prevention techniques, Boise could see another mudflow like the big one in 1959. Controlling how much rain falls, of course, isn’t an option. But here’s one more thing Pierce and Hardy agree on; the only sure way to prevent landslides in this area is to keep fires from starting and minimize their severity when they do.

Copyright 2014 Boise State Public Radio