Hello, CALS,
Happy Monday. Last week and this one are relatively quiet compared to the return of our terrific students the following week when classes restart and things really crank up for campus. In the meantime, we all get ready and continue the excellent and important work of the college.
I have a few thoughts on the intense and destructive wildfires in the Los Angeles area, and wildland fire in general. The total acres of wildfire in the U.S. over the past 100 years, with the earlier records less exact, has ranged from perhaps more than 40 million in some years 100 years ago, down to the 3-4 million acres a year range for several decades (from the late 1950s to the early 2000s), and now in recent years topping out approximately as follows:
- 2018 – 9 million acres
- 2019 – 5 million acres
- 2020 – 10 million acres
- 2021 – 7 million acres
- 2022 – 7.5 million acres
- 2023 – 3 million acres
- 2024 – 9 million acres
There are a host of reasons why we have wildfires, how they differ year-to-year, and how they are managed. There are no simple explanations or solutions. It is very much a moving target, and an alignment of conditions (think of the LA fires as a “perfect storm” of conditions). These include interacting factors such as recent past and current weather, the age, condition and ongoing management of vegetative cover, the state and tactics of fire management and fighting at any point in time, where people build homes and buildings in relation to vegetative cover and how commonly, and more. All of these things have changed over the previous decades and will continue to do so. The success of fire prevention and management, and the response and impact of wildfire when it does occur, is always in flux. The totally awful tragedy of it never changes, no matter the size of the fire.
Generally, wildland fire is not “put-out,” but rather contained, at best, and either burns itself out or the weather changes and precipitation puts it out.
It always takes three things to have fire – (1) ignition (natural lightning, electric discharge, cigarette or transportation wheel spark, for example) where there is (2) fuel ready to combust (dry enough given the intensity of the spark to actually ignite and sustain the burn), and (3) oxygen (that can be fanned by wind). It is important to know that not only is the likelihood and behavior of outdoor fire dependent on weather, but also that fire makes its own weather – usually in a way that intensifies the fire (think of the rising heat from a wildfire that draws in air from the surrounding area and thereby fans itself to burn even hotter). The spread of fire beyond its own boundaries is also weather dependent – with embers floating and blowing in the wind to “spot” new fires out ahead of the existing boundaries. More wind and more fire weather equals more flying embers, which can be remarkably large and travel distances of up to several miles. Sadly there are lots of media images of this happening in the LA fires even as I write this.
Here in Iowa and across the eastern half of the country, our conditions are much different than found further west in many regards, and hence our relative safety from the kinds of landscape-level wildfires often seen further west. Part of that is how our landscapes have been managed with regard to native vegetation, and the lack of dry lightning as a common phenomenon. But our region and landscape are not immune. You only have to look as far as the devastating (lands, buildings and people) forest and prairie fires of the past in our region, some with good records of devastating fires from the mid- to late-1800s (Peshtigo, Hinckley and Michigan fires), and some as recent as the Slave Lake, Canada, fires of the 2000s, for example.
In Iowa, consider these fire management resources from the Iowa Department of Natural Resources.
Let's all please be fire-aware and safe and pay attention to prevention, preparedness and response. It really matters. Some additional references:
- Steps to prepare for wildfires, how to stay safe during a wildfire and what to do afterward
- The first step to help avoid wildland fire disaster is acting wisely
- Confronting the wildfire crisis
- Wildland Fire Mitigation and Management Commission Report
- Funding the fight against uncontrolled megafires
Very best and great safety to you all. - Dan
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