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17,325 gardens and a scrapie thingie
Photo from InciWeb, Public domain, via Wikimedia Commons
“What people don’t often realize is that hand crews are kind of the cornerstone … putting in hand lines, that’s essentially the way we stop the fire from growing.”
— Mike Johnson, Assistant Fire Chief, Clark County NV
The basic strategy for fighting a wildfire is to clear a “containment line” around it — a perimeter around the fire that is cleared of anything that can burn to keep the fire from crossing — and let it burn itself out.
Doesn’t sound too bad, does it? Just bring in a bunch of bulldozers and large landclearing equipment, and start clearing.
Not so fast. Wildfires are, well, in the wild. That often means inaccessible areas with steep slopes and no roads. Places where you can’t readily get heavy equipment in.
This is where those hardworking dirt-covered fire crews in heavy clothing and backpacks come in. You know, the ones we see pictures of, swinging wicked-looking firefighting tools. They’re building “hand lines,” sections of the containment line that are carved out by hand and hard work.
This video will show you just how hard it is, what a “scrapie thingie” is, and how coordinated a hand crew is.
To get an idea of what building the hand lines in a large fire means, let’s look at an example.
Guesstimating hand lines in the Caldor fire
Containment map of the Caldor fire 2021-10-13
The 2021 Caldor fire in the Sierra Nevadas burned a total of 221,835 Acres (89,773 hectares). Assuming a rectangular perimeter gives us a minimum containment line of 74 mi (119 km). The map shows where the hand lines are, but it’s really hard to read. So, we’ll guess that they constitute about 10% of the containment line, call it 7 mi (11 km).
The rule of thumb is that a fire line (a section of the containment line) needs to be 1.5 times the height of the surrounding fuel. If we assume that we are in a mostly wooded area with trees and bush to an average height of 30 feet (9 m), our fire lines need to be 45 feet (13.7 m) wide, on average.
7 mi x 45 feet gives us an area of
1,663,200 sq ft (154,516 sq m)
that was cleared by hand crews in the Caldor fire.
To put that in perspective, the median vegetable garden in the United States is 96 sq ft (8.9 sq m). So hand crews cleared the equivalent of
17,325 vegetable gardens!
In 68 days. Working at elevations over 6000 ft (1828 m). Wearing a 45 lb (20.5 kg) backpack. Using Pulaskis, McLeods, and “scrapie thingies”!
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It ain’t over till it’s over
Photo from WikiMedia Commons
Just because the fire is gone, doesn’t mean the crisis is over. There is much to do after a fire has swept through your neighborhood.
Returning home
Here are some key safety steps Calfire urges you to take when returning home after being evacuated:
- First of all, do not return to your home until the evacuation order has been or fire officials tell you it is safe to return.
- Before inspecting your home, first check for the smell of gas.
- Look for smoke or sparks throughout the house and on rooftops.
- Do not drink or use water from the faucet until emergency officials say it is okay; water supply systems can be damaged and become polluted during wildfires.
- Discard any food that has been exposed to heat, smoke, flood waters, or soot.
Here’s Calfire’s complete two-page checklist of what to do when returning home after a wildfire.
Mobilize your community
Dealing with the aftermath of a recent wildfire shouldn’t be undertaken alone. Now is the time to work with neighbors: Who has special needs that perhaps you could help with? Who has resources that the neighborhood can share?
Beware that wildfire can cause instability to the ground around you.
“Wildfires dramatically change the landscape and ground conditions, which can lead to the increased risk of flooding even with light rains. … When these normal and protective functions are compromised or eliminated by a severe wildfire the potential for significant erosion, flooding, and debris flows is magnified.”(Calfire, Post-Wildfire Recovery)
Responding to these dangers and solving problems such as debris removal are best approached together.
It takes a long time to recover
Recovery from wildfire damage may require painful decisions, insurance claims, neighborhood clean up, and even home design and construction permitting. It can take years,
“The [neighbors] that I do speak with are on a journey of decision making about whether to rebuild or not. … one day it’s ‘Yes’, one day it’s ‘No’. … It’s over a year later, and nobody has started to rebuild in my neighborhood.”
(JS, after the 2020 CZU Lightning Complex Fire)
The good news is that there are many resources available to help you through the recovery process. CalFire lists non-government, state, and federal organizations that you can turn to. Also, there may be localized resources available to your community.
Finally, understand that recovery does happen and stability does return even though disaster does cause change,
“My neighborhood will never be the same. … People are gone. My dearest neighbors don’t live here anymore. … people whose children I knew since they were born. And just the character of the neighborhood changes, because some of the characters are gone. … But then, there are some situations … I’ve gotten closer to some of the neighbors that have survived, than I was with them before.”
(JS, after the 2020 CZU Lightning Complex Fire)
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Can Mary get arrested?
Photo by Flavio Gasperini on Unsplash
Mary has a little lamb. In fact, she has twenty-seven of them. One day, a wildfire breaks out. Mary, her farm, and all her little lambs are in the evacuation zone. Mary’s lambs and all their moms won’t fit into her pickup truck, so she doesn’t want to go.
Can Mary be arrested if she doesn’t leave?
The short answer, at least in California, appears to be a resounding “Yes! Uhm, no?”
According to California Code, Penal Code – PEN § 409.5:
“(a) Whenever a menace to the public health or safety is created by a calamity including a flood, storm, fire, earthquake, explosion, accident, or other disaster, officers … may close the area where the menace exists for the duration thereof … to any and all persons not authorized … to enter or remain within the enclosed area. …
(c) Any unauthorized person who willfully and knowingly enters an area closed pursuant to subdivision (a) or (b) and who willfully remains within the area after receiving notice to evacuate or leave shall be guilty of a misdemeanor.”
Seems pretty clear. If Mary stays, she “willfully remains within the area after receiving notice to evacuate” and is committing a misdemeanor. Right?
Yes, but, apparently, as long as she stays on the farm, Mary can’t be arrested. California law allegedly(1) prohibits making evacuation orders mandatory. So authorities can’t actually make Mary leave her farm. However, if she steps off her property, it’s another story.
That said, Mary, rather than worrying about legalities, please worry about lives. Yours and those of others.
You see, if you delay evacuating, you may suddenly be trapped by the fire and unable to get out at all. And, if you are in danger, hard-working firefighters may divert from actually fighting the fire to try to help you out. That puts their lives at risk and may let the fire grow even larger, threatening even more people and lambs.
Then, again, the hard-working firefighters may not come to help you. You see, that’s part of what evacuation orders mean. In the words of Ken, a Texan volunteer firefighter speaking in the wake of Hurricane Harvey,
“… and maybe people need to get educated on how we go about it. People do not understand what a mandatory evacuation means. It’s not just … It’s like, ‘Look, from this point on, we’re not gonna be able to provide any services to you.’”
California’s standard evacuation terminology is a little different from Ken’s:
- Evacuation Order: Immediate threat to life. This is a lawful order to leave now. The area is lawfully closed to public access.
- Evacuation Warning: Potential threat to life and/or property. Those who require additional time to evacuate, and those with pets and livestock should leave now.
Cal Fire uses two additional terms, specifically related to wildfire:
- Red Flag Warning: A weather event will occur within 24 hours that may result in extreme fire behavior.
- Fire Weather Watch: Weather conditions could exist in the next 12-72 hours that result in high fire danger.
Mary, we hope that you and your neighbors have talked about how you can help each other to evacuate yourselves, your families and your lambs safely, and that you have safe places to go to. When you get a Fire Weather Watch, please refresh those conversations and agreements. Make plans definite when you get a Red Flag Warning. If you get an Evacuation Warning, load ‘em up!
We want you, your lambs, and their moms to survive the fire safely and comfortably. We certainly don’t want any of you to get arrested!
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(1) See, for instance, Frontline Wildfire Defense: Some Evacuation-Weary Californians Refuse to Budge or KCRA 3: Here’s what to know about evacuation orders in California
How are wildfires measured?
Humans have been counting for a long time.
There is strong archeological evidence to support the hypothesis that we’ve been doing it for at least 50,000 years. Over time, mathematics has come to be known as a universal language. Globally, we may have different ways of representing numbers, but we have the same base understanding in mathematics.
Measuring a wildfire is by nature difficult. Depending on the type of fuel available to it, environmental and weather conditions, a wildfire may be considered either a healthy by-product of the natural cycle of life on Earth or a dangerous natural catastrophe endangering thousands of lives.
Regardless of viewpoint , disasters are generally classified by scales of intensity and severity. Tornados, for example, are typically measured on an “f scale” (f0-f5), a scale measuring wind speed and damage done to structures. For earthquakes, we typically use the Richter scale, a quantitative measurement of the size of the waves it generates. (Incidentally, have you seen our Ready, set, earthquake! video?)
Wildfires have their own measurements. They are classified in terms of fire intensity (how hot it gets), and burn severity (how much damage it does to its environment).
Fireline intensity is “the rate of energy or heat release per unit time per unit length of fire front(kW/m). Numerically, it is equal to the product of the fuel low heat of combustion (kJ/kg), quantity of fuel consumed in the flaming front (kg/m2),and the linear rate of fire spread (m/s).”
Got that? If so, here’s more about the difficulties of measuring and calculating fireline intensity and Byram’s fire intensity equation.
If not, then, in other words, how hot is the fire, how much fuel is it burning, and how fast is it spreading?
Burn severity is much easier to understand. Wildfires are classified into 3 buckets depending on how damaging the wildfire is to the soil and vegetation in the area. The higher the severity, the more damage done to the local environment, and the longer the environment will take to grow back.
- Low Severity: A fire that predominantly damages the understory of the environment, < 25% of trees or vegetation is damaged, and soil damage is minimal
- Moderate Severity: A fire that damages between 25% and 75% of vegetation, moderate levels of soil and mineral damage
- High Severity: A fire that damages > 75% of vegetation, extending into the canopy level. Soil and mineral levels suffer heavy damage
The simplest measure to understand the impact of a wildfire might just be its size, typically measured in square acres, miles or kilometers. These days, satellite imagery, cameras from planes, and even drone coverage (but don’t do this yourself…) can help us understand the impact, size and danger a wildfire may have, more accurately and in real time.
Wildfires also have a simple size classification system depending on the area burned.
Unfortunately, these days, the number of homes burned, number of lives lost, and estimated cost of damage done are all too familiar statistics for burn severity. In 2018, the Camp Fire fire killed 85 people, the deadliest fire in the last century.
No matter how they are measured, wildfires are dangerous. But you can help to prevent them, and you can prepare for them.
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The 5 phases of disaster management
Disaster management, one aspect of emergency management, provides a framework for understanding disasters and how we handle them.
There is some debate about the specifics, but the model we have found most useful defines 5 steps:
- Prevention – We can take actions to prevent a disaster from happening in the first place.
For example,in the United States, 90% of wildfires are caused by humans, and these fires are by and far the major threat to human habitation. . Between 1980 and 2007, in Idaho, more than half of such human-caused wildfires were started by campfires, smoking, or burning debris! - Mitigation – We can take actions to reduce the impact should disaster happen.
For example, we can harden our houses and clear combustibles from around them so that burning embers from wildfires are less likely to set them on fire. - Preparedness – We can be ready to take action should disaster happen.
For example, before a wildfire even starts, we can have evacuation plans and pre-packed bags or packing lists ready. Most communities provide localized preparation guides such as this evacuation guide from Fire Safe Marin. - Response – We can take actions to do what needs to be done to protect lives and well-being when a disaster actually happens.
For example, when a wildfire is burning and threatening the area , we can evacuate as quickly as possible to ensure our safety and get out of the way of firefighting efforts. - Recovery – We can take actions to rebuild stability and normalcy when a disaster has happened.
For example, after the fire has passed and evacuation orders have been lifted, we return to our homes to see what damage we and our neighbors have suffered. Then, we can think about rebuilding, and consider what we can do to prevent, mitigate and prepare for the next one.