Burning Questions: How can Remote Sensing Help Combat Wildfires in a Changing Climate?

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Tree-Killing Las Conchas Fire in New Mexico Credit: USGS/Craig D. Allen.

If you live in the West of the United States,   you may already know that this has been a banner year for fire. Worse yet, this banner year comes on the tail of a previous year noted for the largest fires on record in multiple U.S. states.

In 2013, from mid-June to mid-July, Colorado alone had more than 14 wildfires burning, an Arizona fire crew lost 19 members to flames, and thousands of California residents fled the San Jacinto Mountains before the threat of blazes. Even in late summer, as rains dampened some the flames in the Four-Corners area, the West Coast continues to fight multiple fires.

The U.S. is not alone in its scorching predicament.

Australia is now in winter, but in January people there experienced a heat wave so intense that weather reporters added a new color, purple, to their maps.  More than 150 fires moved across the Southeastern portion of the continent, burning around 1.2 million acres of land. Canada too has seen an unusually virulent fire season this year, with smoke that could be observed in Europe several days after fires began across the ocean.

What is causing these dangerously flammable seasons, and what can we do to address them? Wildfires have occurred throughout history, and many fires begin through natural causes. But fire records of the last several decades show a disturbing trend.

Understanding why wildfires have been so prevalent lately is a complicated topic.  Land use and vegetation change (both natural and human-influenced), fire policies, urban encroachment, and even the spread of invasive species like cheat grass may play a role. Furthermore, scientific studies suggest that climate change, in the form of rising temperatures and shifting weather patterns, also may contribute to wildfire incidence. Conditions such as below-average snowpack, or snowpack that melts earlier than usual in the season, can create longer dry seasons in the summer, raising the risk of fire (Running, 2006).

When facing such an arsenal of natural and manmade factors, we can only do so much to prevent wildfires from starting, especially when summers are dry.  Monitoring, however, is possible, and technology may offer some help.  Remote-sensing technologies are increasingly being used to track live fires and promote prevention by identifying potential “hot spots” and characterizing pre-fire conditions and risks. Governments and independent sources alike are exploring different ways of using satellite data to monitor fires.

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NASA satellite view of the Colorado Black Forest fire from June 12, 2013. Image Credit: NASA/Jeff Schmaltz.

The National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) have several missions that participate in fire monitoring. Satellites such as the Aqua and Terra satellites are equipped with MODIS (Moderate Resolution Imaging Spectroradiometer) technology, an instrument that records images of the Earth, covering the entire surface of the globe in around 1-2 days. Because these images are taken so regularly, they provide a record that can reveal what conditions looked like from space previous to a fire outbreak, where fires begin, and to what areas fires spread. These images are publically available, so fire-fighting operations can access them and use the data to build a stronger understanding of wildfire dynamics.  The higher the volume and quality of data available to plug into simulations, the more accurate models will become at predicting wildfire likelihood and severity—information that could translate into action that might help save lives and homes.

map or temperatures in russia

A map of temperature anomalies in Russia for a week in July 2013. Areas that are red show regions that are much hotter than usual. Image Credit: NASA/Jeff Schmaltz.

MODIS measurements of reflected visible light and heat emitted from the Earth offer specific information about land cover and ground surface temperatures. Areas that have dense live vegetation tend to reflect less visible light than areas that are more barren or drier. As a result, the combination of the imagery’s different spectral bands can reveal areas where vegetation is dead or desiccated, providing insight into which areas may be more susceptible to fire.

Because of its ability to sense areas of high heat, MODIS also can be used to track active fires and regions undergoing unusually high land-surface temperatures — in other words, areas with hot, fire-ready conditions. This can be particularly useful in large, remote areas, like sections of Siberia. The area near the town of Norilsk experienced temperatures 16 degrees Celsius (about 61 Fahrenheit) above average this summer, leading to concern about fires in the area.

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Drought Dries Elephant Butte Reservoir. Image Credit: NASA/Jesse Allen, Robert Simmon.

Remote sensing and satellite images also may be of help to on-the-ground public services. One example is the Vision 20/20 Initiative, which uses mapping technologies and data about human population demographics to help provide risk assessments for communities in the U.S. Across the ocean, IEEE (the Institute of Electrical and Electronics Engineers) and the GRSS (Geoscience and Remote Sensing Society) sponsored an International Geoscience and Remote Sensing Symposium held in Melbourne, Australia, this year. The event included a tour of fire ravaged areas and discussion on the role of remote sensing in fire prevention.

Climate scientists agree that an increase in global average temperature will likely continue in future years, at a rate that will be determined by how much humans are willing to diminish carbon emissions. Even if carbon emissions were stopped completely, the global temperature would still rise, albeit less steeply than otherwise (IPCC, 2007). Answering questions of how to prepare for the consequences is an urgent matter. In the coming decades, ingenuity, careful action, and perceptive use of technology may be the difference between a hot summer and burning summer.

References

IPCC, 2007. Summary for Policymakers. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambride University Press, Cambridge, United Kingdom and New York, NY, USA.

Running, Steven J, 2006. “Is Global Warming Causing More, Larger Wildfires?” 18 August 2006: Vol. 313, no. 5789, pp. 927-928. https://www.sciencemag.org/content/313/5789/927