After the Wildfire - Hydrologic and Water Quality Effects of Wildfire
Wednesday, May 16, 2018
12:00 - 1:00 PM Central
Education Track: Erosion & Sediment Control
Audience Level: Beginner to Intermediate
Price: $50 IECA Member | $65 non-member
Credit: 1 Professional Development Hour
According to the National Interagency Fire Center there were over 56,000 wildfires in the United States in 2017 through the end of November, burning over 9 million acres. The wildfires are devastating in terms of impacts to public lands and private property. October wildfires in Northern California led to 23 fatalities and destroyed nearly 9,000 structures, with insurance claims on the order of $9B, and the Thomas Wildfire, which continues to burn in December 2017 has destroyed more than a thousand homes in Southern California.
With climate scientists predicting warmer and drier conditions across the southwest in the future and urban and suburban development pushing closer and closer to forest boundaries, the increasing damages from wildfires are a trend that is expected to continue to increase in the future. The damages from the fires themselves tell only part of the story, with changes in hydrology due to wildfires leading to dramatically increased flood and mud and debris flow risks in the aftermath of the wildfires. The changes in hydrology are due to multiple factors including loss of canopy, loss of the forest floor duff layer, and temperature-induced changes in the soil that lead to hydrophobicity. For frequently occurring events (e.g. annual storm, 2-year storm) runoff rates and volumes can increase by a factor of 10 or more relative to pre-fire conditions.
This webinar will present information on the hydrologic and sediment transport effects of wildfires. The presenters will draw on experiences with post fire hydrology from wildfires including the Cerro Grande Wildfire that caused heightened flood risk for a nuclear facility at Los Alamos National Laboratory in New Mexico and the Missionary Ridge, Fourmile, Black Forest, and Waldo Canyon Wildfires in Colorado. The webinar will present the science behind hydrologic changes from wildfire and will provide examples of tools and methods that can be used to quantify changes to peak discharges, runoff volume, and sediment yield in a risk-based context.
- Participants will learn how wildfire affects hydrologic properties of watersheds and why there is a severe risk of flooding following wildfire.
- Participants will learn about typical ways to quantify changes in hydrology following wildfire
- Participants will learn about different types of measures to mitigate flood risk following wildfire, ranging from public outreach to explain risk to watershed-based treatments.