Predicting a wildfire with data from space
WASHINGTON, D.C. — On average, wildfires destroy more than 2.4 million hectares (6 million acres) of land each year in the United States. Last year, the U.S. Forest Service spent more than $1 billion fighting those fires, mostly out West. Blazes start easily where there is plenty of dry fuel, such as dead grass, sticks and other dried plants. Knowing how much fuel is available can help fire management teams know where and when to be on high alert. And a Boston, Mass., teen has figured out a way to home in on such areas quickly. To do it, she turned her eyes to the skies.
Nadine Han, 13, is a seventh grader at Boston Latin School. Wildfires aren’t very common in New England, so you might not think a teen would have a lot of interest in them. But when Nadine built a robot three years ago with FIRST LEGO League, hers was designed to prevent wildfires. When the girl’s family visited Yellowstone National Park, later that year, what did they see? Evidence of wildfires. So Nadine followed up on that theme for her science fair project. She decided to find out whether satellite data might be used to predict when and where wildfires might ignite.
Her findings worked well to predict soil moisture — a gauge of how much dry fuel a region had. And they qualified her for a trip to Washington to compete in Broadcom MASTERS. MASTERS stands for Math, Applied Science, Technology and Engineering for Rising Stars. Every year, this event brings together 30 middle-school students from around the United States to show off their award-winning science fair projects and to compete in team challenges. The event was created and is run by Society for Science & the Public (which also publishes Science News for Students and this blog). Broadcom Foundation sponsors the competition.
Finding out where fires might flame
To determine whether an area has a lot of fuel around, specialists collect samples of plants in an area and calculate their fuel moisture. They’re probing how much water is present in plant tissue and debris, compared to the plants’ dry mass.
“Measuring fuel moisture is really labor intensive” — and therefore expensive, Nadine points out. So calculations of fire risk for any given area are not usually done very frequently, she notes. Nadine decided to see if there might be some lower-cost measure that could figure out fire risk for broad swaths of land. And what scans the entire nation frequently? Satellites!
The teen learned about a satellite called SMAP, which stands for Soil Moisture Active Passive. Launched by the National Aeronautics and Space Administration (NASA) in 2015, it detects how wet or dry the soil is. It also can tell whether that moisture is frozen or liquid. SMAP maps Earth’s entire land area every two to three days. Its data not only help scientists to forecast the weather, but also to predict droughts and floods.
SMAP’s data on soil moisture can be combined with other data to determine what’s known as the vegetation water content. This is the amount of water present in the plants. SMAP’s data and the vegetation water content data are both freely available from the National Snow and Ice Data Center. For her project, the teen downloaded a year’s worth of data (for March 31, 2015 to March 31, 2016).
She then compared these data with those for the same time period in the national Wildfire Assessment System. Its data, prepared by Forest Service specialists, estimate fuel moisture levels for the entire United States. The teen was looking to see if the two data sets correlated. She was looking for an apparent match between the fuel moisture and SMAP’s estimate of plant moisture levels for the same areas.
Although related, plant water levels and fuel moisture aren’t quite the same thing, Nadine points out. Plant water content, for example, doesn’t take into account dead debris on the forest floor. It also doesn’t quantify how much overall fuel there is in a forest.
In all, Nadine compared plant water content and fuel moisture data for 1,413 different locations. And she found a positive correlation between them. An increase in plant water content measured by the satellite was linked with an increase in fuel moisture as measured on the ground. For her study, 87 percent of the sites showed such a link.
“This… suggests that it’s feasible to use satellite data to estimate fuel moisture on the ground,” Nadine concludes. Fires are a natural part of life in the American West. In fact, they can occur almost anywhere. Several, for instance, are currently being fought in the East’s southern Appalachian Mountains. The teen now hopes her technique will help land managers determine fire risks more quickly.
Next, Nadine hopes to make a computer program that will estimate fire risk using satellite data. And she’s not alone. Other scientists also are trying to use satellite data to predict wildfires, even using SMAP data. When it comes to predicting fires, a few more eyes in the sky couldn’t hurt.
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(for more about Power Words, click here)
aeronautics The study of flight and development — or refinement — of craft to move through air or space.
average (in science) A term for the arithmetic mean, which is the sum of a group of numbers that is then divided by the size of the group.
blog Short for web log, these Internet posts can take the form of news reports, topical discussions, opinionated rants, diaries or photo galleries.
Broadcom MASTERS Created and run by the Society for Science & the Public, Broadcom MASTERS (Math, Applied Science, Technology and Engineering Rising Stars) is the premier middle school science and engineering fair competition. Broadcom MASTERS International gives select middle school students from around the world a unique opportunity to attend the Intel International Science & Engineering Fair.
computer program A set of instructions that a computer uses to perform some analysis or computation. The writing of these instructions is known as computer programming.
correlation A mutual relationship or connection between two variables. When there is a positive correlation, an increase in one variable is associated with an increase in the other. (For instance, scientists might correlate an increase in time spent watching TV with an increase in risk of obesity.) Where there is an inverse correlation, an increase in one value is associated with a decrease in the other. (Scientists might correlate an increase in TV watching with a decrease in time spent exercising each week.) A correlation between two variables does not necessarily mean one is causing the other.
data Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.
debris Scattered fragments, typically of trash or of something that has been destroyed.
drought An extended period of abnormally low rainfall; a shortage of water resulting from this.
engineering The field of research that uses math and science to solve practical problems.
forest An area of land covered mostly with trees and other woody plants.
fuel Any material that will release energy during a controlled chemical or nuclear reaction. Fossil fuels (coal, natural gas and petroleum) are a common type that liberate their energy through chemical reactions that take place when heated (usually to the point of burning).
microwaves An electromagnetic wave with a wavelength shorter than that of normal radio waves but longer than those of infrared radiation (heat) and of visible light.
middle school A designation for grades six through eight in the U.S. educational system. It comes immediately prior to high school. Some school systems break their age groups slightly different, including sixth grade as part of elementary school and then referring to grades seven and eight as “junior” high school.
moisture Small amounts of water present in the air, as vapor. It can also be present as a liquid, such as water droplets condensed on the inside of a window, or dampness present in clothing or soil.
monitor To test, sample or watch something, especially on a regular or ongoing basis.
National Aeronautics and Space Administration (or NASA) Created in 1958, this U.S. agency has become a leader in space research and in stimulating public interest in space exploration. It was through NASA that the United States sent people into orbit and ultimately to the moon. It has also sent research craft to study planets and other celestial objects in our solar system.
risk The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard — or peril — itself. Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.
satellite A moon orbiting a planet or a vehicle or other manufactured object that orbits some celestial body in space.
Society for Science & the Public (or SSP) A nonprofit organization created in 1921 and based in Washington, D.C. Since its founding, SSP has been not only promoting public engagement in scientific research but also the public understanding of science. It created and continues to run three renowned science competitions: The Regeneron Science Talent Search (begun in 1942), the Intel International Science and Engineering Fair (initially launched in 1950) and Broadcom MASTERS (created in 2010). SSP also publishes award-winning journalism: in Science News (launched in 1922) and Science News for Students (created in 2003). Those magazines also host a series of blogs (including Eureka! Lab).
vegetation Leafy, green plants. The term refers to the collective community of plants in some area. Typically these do not include tall trees, but instead plants that are shrub height or shorter.
weather Conditions in the atmosphere at a localized place and a particular time. It is usually described in terms of particular features, such as air pressure, humidity, moisture, any precipitation (rain, snow or ice), temperature and wind speed. Weather constitutes the actual conditions that occur at any time and place. It’s different from climate, which is a description of the conditions that tend to occur in some general region during a particular month or season.