Over the past 30 years, wildfires have gotten bigger, stronger, and occurred more often.
Over the past 30 years, wildfires have gotten bigger, stronger, and occurred more often. As climates continue to warm, this trend will likely continue, causing disruption to landscapes and water systems alike.
Wildfires are destructive to ecosystems, but they can also set the stage for future issues. “After a wildfire, particularly a high-severity wildfire, you have significant impacts to the soil that affects the infiltration of water,” says Brendan Murphy, a research associate at Utah State University.
The inability of water soaking into the ground can trigger flooding and erosion, says Murphy, eventually leading to something called a runoff-generated debris flows. As the water flows along the land surface, it can pick up and carry sediment and rocks. “If you [pick up] enough,” he says, “You can get these big debris flows that can carry really large, course sediment downstream.”
Murphy says in the western U.S. these debris flows generally happen in smaller basins. “Some of that sediment will go into the river; some of it may actually stay stored in the valley for decades, if not thousands of years,” says Murphy.
Read more at Geological Society of America
Image: Wildfires can facilitate post-fire debris flows, depositing sediment into rivers. Over time, rivers can carry this sediment downstream, eventually reducing water storage in reservoirs. (Credit: Image by Brendan Murphy)
