Dirt goes downhill: Are we making better post-wildfire erosion control treatment decisions?
Major concerns after wildfires are the increased runoff and erosion due to loss of the protective forest floor layer, loss of water storage, and creation of water repellent soil conditions. To reduce the potential postfire erosion and flooding, various postfire mitigation treatments are commonly used on highly erodible areas when downstream values-at-risk are high. We have developed numerous online soil erosion prediction tools to allow for better post-fire land management decision-making. We have validated our model predictions with field studies throughout the Western US that encompass a range of rainfall regimes including monsoonal rains in the southwest (Arizona and New Mexico), thunderstorms in the Colorado Front Range and Northern Rockies, and wet frontal systems in Southern California and various erosion control treatments. For example, mulch treatments (agricultural straw, wood strands, wood shreds) reduce erosion and can be effective even for the higher intensity rainfall events. Our research results have brought a major shift in post-wildfire assessment methods and erosion management strategies.