The land is always changing, sometimes by human hands: cities are built, farms expanded, and forests logged. Other changes lie mostly outside people’s control: wildfires burn through communities, and hurricanes reshape coastlines. For most of the past four decades, observations from the Landsat satellite record show that humans have dominated changes to the U.S. landscape. Recent research revealed a shift in that trend, suggesting that disasters might be catching up.
In a NASA-funded study published in Nature Geoscience, scientists analyzed nearly 35 years of data from NASA/USGS Landsat satellites to better understand what has been shaping the continental U.S. landscape. The researchers, led by former Landsat science team member Zhe Zhu, found that “human-directed disturbances” like logging, agricultural expansion, and construction have declined, while “wild disturbances” like wildfires and hurricanes—disasters that can be influenced by human activity but are not controlled by people—have risen in frequency and intensity.
Robert Emberson, associate program manager for the NASA Disasters program and not affiliated with the study, said that understanding the forces transforming the U.S. landscape is critical for future planning. “If you know what’s causing them, you can begin to plan around disasters,” Emberson said. “Any understanding of causal factors impacts the adaptation strategy.”
This research is especially useful for policymakers working to prepare communities for resilience, he said. For example, a region expecting to see increased wildfires could strategically perform prescribed burns, remove brush or dry grass around homes, and construct new buildings with fire-resilient materials.
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