2012 was a very busy wildfire season. The Federal government and some states exhausted their funds set aside for suppressing fires. The number of acres burned, 9,093,431 as of November 22, 2012, was the third highest since national wildfire statistics have been kept beginning in 1960. Remaining at the number one and two spots are 2006 with 9.9 million, and 2007 with 9.3 million.

You may not be able to say that a specific home run hit by Barry Bonds was caused by performance enhancing drugs, but the record he set in 2001 for the most home runs in a season is probably related to the steroids. While you can’t assume that a specific large fire was caused by global warming or a reduction in the number of ground and air firefighting resources available, when a trend is observed over a period of years it becomes more statistically significant and worthy of study.

Six of the last nine years had more burned acres than in any year between 1960 and 2003.

We constructed the charts below from statistics provided by the National Interagency Fire Center and the Alaska Division of Forestry, through November 22, 2012. While the numbers above include stats for the state of Alaska, the figures below do not include that state because fire management in Alaska is an entirely different animal. Some fires there are not suppressed at all, and many of them are only managed in a limited fashion. The number of acres burned in Alaska can vary widely, for example from 43,965 in 1995 to 6,645,978 in 2004. If you are going to analyze trends, we determined it is best to separate Alaska from the lower 49 states. While stats for the entire United States go back to 1960, it appears that the numbers prior to 1986 are suspect, perhaps as a result of a change in 1982 in the way the statistics were collected. We were able to find numbers for Alaska going back to 1990.

The average size of fires can tell you more than the raw number of fires or acres, because it can reflect changes in climate, or how the fires were managed or suppressed, such as the number of firefighters available, budget cuts or increases, or changes in the number of air tankers available (from 44 in early 2002 to 9 in 2012).

The number of wildfires has been decreasing, while the average size has been increasing rapidly.

We set another record in 2012 for the average size of a wildfire in the lower 49 states. In fact the previous record set only last year of 114 acres per fire was completely blown away by 48 percent, increasing to 165 acres per fire in 2012.

The bottom line

Whatever the reason is for having larger fires and burning more acres, the wildfire suppression paradigm we have been using for the last decade has become obsolete and we need to try something different. The declining budgets we have been seeing over the last several years are obviously not the answer. Neither is attempting to fight fires “on the cheap”.

Regular readers of Wildfire Today know that I like to present statistics, charts, and graphs about wildland fire size and occurrence. The first article on Wildfire Today on this topic was in January 19, 2008, and the last time was December 10, 2010. The final numbers for the 2010 calendar year for the United States are available, and I found a new source for crunching data, Many Eyes. So, there’s a new excuse reason for writing another article.

One statistic I concentrate on is the average size of fires, not so much the number of fires or the total acres burned each year, two stats that the mainstream media harps on. The average size is affected not only by the weather, but also by the fuel condition and age, how many fires were burning at the same time, the short-term availability of firefighting resources, the skill and efficiency of the firefighting effort, strategy used on fires, and the number of firefighting resources on the payroll of the firefighting agencies.

Here are a few new ways of visualizing the average size of wildland fires, in acres, in the United States, from 1960 through 2010. The data for the number of fires and acres burned each year came from NIFC. Then I spent some time with Excel and Many Eyes to develop these products.

Average fire size, 1960-2010, bubble chart. Data: NIFC/BG

Average fire size, 1960-2010, tree map. Data: NIFC/BG

Average fire size, 1960-2010, block histogram. Data: NIFC/BG

And the standard stack graph:

Average fire size, acres, 1960-2010, stack graph. Data: NIFC/BG

The average fire size in 2010 was 48 acres, compared to the average between 1960 and 2010 which was 37.

The chart below shows the average size of wildfires in the United States by decade.

The National Interagency Coordination Center has released a massive compilation of wildfire occurrence and mobilization statistics for 2010. The 70 pages of data is broken up into 5 .pdf documents that can be found HERE. Much of it is very interesting and points out the fact that the 2010 fire season was much less active than normal. (We provided some data on this subject on December 10.)

Below we include some excerpts from the report:

Continue reading →

We have been tracking the fire occurrence stats provided by the National Interagency Fire Center for several years. It is clear that the average size of fires has been increasing since 1970 while the average number of fires is decreasing.

We are having fewer, but larger fires. While the population in the country continues to grow, a person might think that the number of fires would increase. But some of the other factors that come into play are fire prevention programs and better technology for preventing fires.

There will be debate about why fires are larger. Climate change will be first on many people’s minds, but we must also consider the build-up of fuels as a result of fire suppression over the last 100 years. The chickens are coming home to roost.

This increase in fire size comes in spite of better management and technology in reporting fires, communications, water handling, incident management, and dispatching.

But better technology and management have their limits when it comes to putting out a massive fire. Large wind or fuel driven fires can only be followed by firefighters. We can chip away at the flanks or suppress the heel, but we can’t stop the forward progress of a raging fire until something changes…. the weather or the fuel. Or, as proven by Bill Molumby’s incident management team on the Indians fire east of Big Sur this summer, you have the luxury of time, distance, and very little private land, and you can backfire or burnout miles ahead of the fire.

The glamorous toys that politicians and extremist talk radio hosts clamor for (I’m talking to YOU, Roger Hedgecock and San Diego) such as water-scooping air tankers and night flying helicopters have their use, but they are totally ineffective in strong winds, when we are most likely to be losing homes and citizens. It can be too dangerous for pilots to fly under those conditions, and the retardant and water that is dropped is completely dispersed before it hits the ground.