Tag Archives: fire

Viewing the Yosemite Rim Fire in context: images, maps, and graphics

The Rim Fire burning in and around Yosemite National Park is generating national headlines due to its vast size and its threats to San Francisco’s water supply, the park’s majestic sequoias, and thousands of homes.

To put this fire in context, I’ve created a few of graphics that summarize recent fire seasons in California and the national picture thus far in 2013. You can download the PowerPoint deck and data at the bottom of this post.

Views of the fire

Before getting to the data, let me first share some compelling views of the Rim Fire. The nearly 190,000-acre blaze is big enough to be visible from the orbiting International Space Station. Here’s a photo that astronaut Karen Nyberg tweeted on Monday.

Here’s a time-lapse video, posted by park staff, that shows the Rim Fire’s growth.

You should also check out this stunning video of the fire, filmed from the perspective of a C-130J air tanker making drops of retardant (I recommend fast-forwarding to 4:00). The tanker is guided to its target by a smaller lead plane, and it’s interesting to hear the chatter among the pilots. Unfortunately, they haven’t figured out how to turn off the “landing gear” audible warning.

If you’re curious about the blaze’s footprint, ESRI has posted an interactive map of the Rim Fire, including its progression and perimeters of previous burns. Here’s a screen shot (click to enlarge).


EcoWest contributor David Kroodsma has put together an animated map of the fire’s progression.

Recent California fire history

The Rim Fire is currently the seventh-largest wildfire in California’s recorded history. Cal Fire says its data goes back to 1932, and the graphic below shows that seven of the 10 largest fires have burned in the past decade.

Largest wildfires in California history

As Cal Fire notes, there were big wildfires prior to 1932, and we know from tree-ring records and other research that lightning and Native Americans would start fires that sometimes grew very large. The Rim Fire is less than a quarter contained, so it may well rise in the rankings.

Looking back over the past decade, there has been a downward trend in the number of wildfires in California, something that isn’t seen in the national-level data. The number of acres charred by fires has varied considerably from year to year, but the previous four years were relatively tame.

California fire history

Cal Fire provides greater detail on the cause of wildfires than the National Interagency Fire Center (we present that data on this dashboard and this post). Below is a summary of wildfire ignitions in California. Lightning starts relatively few fires in the state and the cause of many blazes is never determined. The Rim Fire’s cause is under investigation.

Causes of wildfires in California

National picture: below-average fire season

The Rim Fire and the deaths of 19 firefighters in Arizona in June will make 2013 a historic fire season, but in something of a paradox, 2013 is on track to be a below-average year for fire activity on the national level. The graphic below, based on data from the National Interagency Fire Center, shows the acreage burned each year from January 1 to August 28. So far, 2013 is the second lowest total since 2004. The 3,686,318 acres that have burned this year is just 63% of the 2004-2012 average.

2013 wildfire season to date

We’ve still got a way to go in the 2013 wildfire season, but many areas in the Southwest and Southern Rockies have received a good soaking over the past two months, so they are unlikely to add to the total in any big way. Going forward, the potential for large fires will be greatest in California, Nevada, Oregon, and Idaho.

Wildland fire potential outlookOverall trend: larger fires

One of my main takeaways from analyzing wildfire data is that the numbers can jump around from year to year, and we shouldn’t put too much stock in any single data point. Relatively small fires can kill people and destroy hundreds of homes, while enormous blazes in wilderness settings can do wonders for ecosystems. Overall, the trend in recent years has been toward larger fires and more acres burned, as shown below.

Wildfires and acres burned: national overview since 1987

What’s not captured in these raw acreage totals is the real impact on the ground. What fraction of the landscape was nuked? How many acres are better off after a low-intensity burn? Reports from the fire lines and the imagery shared above suggest the Rim Fire is burning very intensely and could do considerable damage to the park’s resources and nearby residents’ homes.

Whatever the final acreage total, blazes like the Rim Fire are likely to become more common in the years and decades ahead, according to climate change projections. Andrew Freedman has a good discussion at Climate Central, which also provides this embeddable data visualization on Western wildfire trends.


Data sources

Data on California fires comes from Cal Fire and its 2012 red book. The agency also has PDFs showing the largest fires in terms of acres burned and structures lost.

The National Interagency Fire Center provides year-to-date totals for fires and acres burned on this page.

EcoWest’s mission is to analyze, visualize, and share data on environmental trends in the North American West. Please subscribe to our RSS feed, opt-in for email updates, follow us on Twitter, or like us on Facebook.

Arizona firefighter disaster could be pivotal moment

The shocking deaths of 19 firefighters yesterday in Arizona is a grim milestone in the history of wildland firefighting. Will the Yarnell Hill Fire also be a watershed event in how this nation approaches wildfires?

Sadly, it often takes a national tragedy to raise awareness of problems and force action on solutions.

We know wildfires are getting larger, more people are living in the fire-prone wildland-urban interface (WUI), and climate change will only make the problem worse.

What remains to be seen is whether the disaster will lead to changes in how the nation approaches the wildfire issue. Will it lead to more funding for hazardous fuels reduction and prescribed burns? Will it spur more regulations on development and building practices in the WUI? Will it change how wildland firefighters do their work and make fire managers more risk averse?

A historic tragedy

Looking back over the past century, I think the Yarnell Hill Fire ranks up there with the Great Fire of 1910 (see Stephen Pyne’s Year of the Fires  and Timothy Egan’s The Big Burn) and the Yellowstone Fires of 1988 (see Rocky Barker’s Scorched Earth) as defining moments in the history of U.S. wildfires. The 1910 inferno led to a massive increase in fire suppression; the Yellowstone blazes resulted in greater appreciation of fire’s benefits for many Western ecosystems.

The loss of 19 firefighters in one incident is actually a historic event for all of U.S. firefighting, not just the wildland form. It’s the greatest loss of life since 9/11 and it’s tied for sixth on the all-time list. Notice in the graphic below that almost all of these incidents happened decades ago (this data, from the National Fire Protection Association, has slightly different numbers for wildfire deaths than what the National Interagency Fire Center reports).

Deadliest incidents for U.S. firefighters

A growing problem

While the details from yesterday’s burnover are just emerging, we’ve known for many years that a tragedy like this could happen. We’ve had so many bad wildfires over the past decade or so that it seems the American public and media have become desensitized to hearing that hundreds of homes have been destroyed or hundreds of thousands of acres are ablaze.

The loss of 19 firefighters, however, is anything but normal and hard to ignore. The cynic in me says it may take a huge civilian death toll to really elevate the issue in the national consciousness.

Here are four of the key points that emerged from our research on wildfires:

1)      Wildfires are generally getting bigger

The graphic below shows an upward trend in the average size of U.S. wildfires since 1990. This is very high-level national data, but in another post we provide more detail on the increasing size and intensity of wildfires in the West.

Average size of U.S. wildfires

2) Many fire-prone ecosystems are out of whack

Decades of fire suppression in forests, woodlands, and grasslands that frequently burned under natural conditions has led to an excess of fuel in some areas. The map below shows that the natural cycle has been degraded in nearly all U.S. ecoregions, according to an analysis by The Nature Conservancy.

Condition of natural fire systems

3) More people are living in vulnerable wildland-urban interface

The map below shows where homes are most at risk from wildfires in Arizona. As the West’s population has risen, so has the number of people living in these higher-risk areas. Learn more about the WUI in this post.

Arizona WUI map

4) Climate change will exacerbate problem

Scientists have already found that the warming experienced over the past few decades in the West has led to an increase in wildfire activity. A 2006 paper in Science (graphic below) concluded that “large wildfire activity increased suddenly and markedly” starting in the mid-1980s, with most of the change due to a warming climate rather than fire suppression. Higher temperatures led to a thinner snowpack that melted earlier in spring, leading to more-flammable conditions in summer and a lengthening of the wildfire season by an average of 78 days.

Westerling et al graphic

We have more analysis and data on our main fire page and on dashboards that cover fire trends, suppression, firefighters, ignition, fuels, and the WUI.

Wildfire metrics send a clear signal that this problem is getting worse, especially in places like Arizona, but solutions are anything but simple. There’s no quick fix for forests and woodlands that are ecologically out of balance due to a century of fire suppression. There are already millions of homes in vulnerable locations and only so much that homeowners can do. Some local communities have taken big strides toward reducing their vulnerability and discouraged building in the WUI, but there is political resistance in the West to statewide mandates.

Fighting wildfires will always be an inherently perilous business, but perhaps the Yarnell Hill disaster will force the public and policymakers to confront this increasingly dangerous issue, evaluate the options, and take action.


EcoWest’s mission is to analyze, visualize, and share data on environmental trends in the North American West. Please subscribe to our RSS feed, opt-in for email updates, follow us on Twitter, or like us on Facebook.

Yarnell Hill wildfire is third-deadliest for U.S. firefighters

The Arizona Republic is reporting tonight that 19 firefighters have died in the Yarnell Hill Fire.

This disaster looks to be the third-deadliest incident in the history of U.S. wildland firefighting and the highest number of deaths in a single episode since 25 were lost in a 1933 fire in Griffith Park, California. The Great Fire of 1910 in the Northern Rockies claimed 72 lives, but there is a lack of data on firefighter deaths in the subsequent two decades.

We just published a post on wildland firefighter fatalities, based on data from the National Interagency Fire Center that is available here.

I’ve extracted all of the incidents in which more than 10 firefighters died and sorted them in the chart below (data is only available through 2011).

Deadliest incidents for U.S. wildland firefighters

A burnover was responsible for all of the deaths in the incidents shown above.

To put the 19 deaths in context, an average of 18 U.S. wildland firefighters have died each year over the past decade. Here’s the number of fatalities per year since 1910:
Wildland firefighter deaths: 1910-2011

You can explore this data and download images on our dashboard page.

EcoWest’s mission is to analyze, visualize, and share data on environmental trends in the North American West. Please subscribe to our RSS feed, opt-in for email updates, follow us on Twitter, or like us on Facebook.