"Effects of Wildfires on Soils, Runoff and Erosion: Causes, Rehabilitation and Geomorphic Change," Lee MacDonald (Colorado State)

Start Date/Time: Wednesday, November 21, 2012, 2:30 PM
Ending Date/Time: Wednesday, November 21, 2012, 3:30 PM
Location: Electrical Engineering Building Room 403

Upcoming Special Seminar

"Effects of Wildfires on Soils, Runoff and Erosion: Causes, Rehabilitation, and Geomorphic Change"

Lee MacDonald, professor of Watershed Science at Colorado State University
Wednesday, November 21, 2012
2:30-3:30 pm
Electrical Engineering Building 403

Abstract: Large wildfires are becoming increasingly common, and are projected to further increase with climate change. High-severity fires are of greatest concern because of the dramatic shift from subsurface stormflow to Horton overland flow. This basic change can increase the size of peak flows and hillslope erosion rates by up to several orders of magnitude compared to unburned conditions. The resulting effects on downstream channels, flooding, water quality, aquatic habitat, and reservoir sedimentation are of great concern to land managers, the public, and water providers. In this seminar I will summarize over a decade of work on fires in several western states. The specific objectives are to: 1) identify the key causes of the observed change in infiltration and increase in water-driven surface erosion; 2) discuss how the rate of recovery can vary with site conditions; 3) use this understanding to explain the observed variations in the effectiveness of different post-fire rehabilitation techniques; 4) discuss the role of high-severity fires as a major driver of landscape evolution, and how the rate and type of change can vary with elevation zone, flow regime, and watershed location. The seminar will conclude with a discussion of critical research needs at both extremes: the effects of fires at the pore scale, and the need to scale up our shorter-term, hillslope results in both time and space.

Bio: Dr. Lee MacDonald is a recently retired (“reallocated”) professor of Watershed Science at Colorado State University and a Senior Research Scientist at the Natural Resource Ecology Lab. His specialty is the effects of land use change on runoff and erosion, particularly in forested areas. For the past decade he has focused primarily on fires and roads, and most of his publications and student theses are available from his web site: http://warnercnr.colostate.edu/~leemac/ or just type his name into google.