After the Fire, What Happens to Water Yield?
Though forests and rangelands provide more than half of U.S. water supplies, the long-term impacts of fires, including wildfire and prescribed fire, on annual water yield have been less understood. Three case studies, recently published in the journal Ecohydrology, provide some answers. Eastern Threat Center researchers and partners from the Southern Research Station and U.S. Department of Energy’s Oak Ridge Institute for Science and Education developed an analytical framework to study three watersheds with different characteristics and climates that experienced different types of fire. Their study combined pre- and post-fire streamflow data, fire records, remote sensing images, and computer models in an effort to tease out climate effects and reveal the true impacts of fire on water yield. “The variable magnitude of increased water yield after a wildfire surprised us,” says Center hydrologist Dennis Hallema, the study’s lead author. “Wildfire has a much greater effect on water supply than prescribed burning, because it consumes more vegetation and its heat alters the ground in a way that reduces the amount of water that can infiltrate during a rainstorm.” Read more in CompassLive...
