Debris flows and flash floods are among the most destructive hydrological consequences of wildfire in steep watersheds. The high likelihood of catastrophic wildfires in the western United States and the encroachment of human activities into steep fire-prone areas have created the need to better understand, predict, and mitigate these hazards. At the U.S. Geological Survey, reduction of public exposure to these hazards has been accomplished through efforts aimed at improving hazard assessment products and an early warning system run in collaboration with the National Weather Service.
Post-fire debris flows have been documented during the very first rainstorm following wildfire and may persist for several years thereafter. However, the duration of elevated debris-flow hazard following wildfire is poorly understood. The rate of watershed recovery is dependent upon several factors, including the amount of seasonal rainfall, vegetation regrowth, the recovery of soil properties to pre-fire conditions, and a net decrease in sediment availability. These factors are highly variable in both time and space, and an objective method for rapid assessment of watershed recovery does not presently exist, nor is it well-understood how these factors influence the rate of decreases in debris-flow likelihood and potential magnitude as watersheds recover from fire.
We seek a Mendenhall Fellow to advance the understanding of the influence of watershed recovery on debris-flow initiation and magnitude after wildfire. Research is expected to result in the development of a quantitative method for measuring recovery from remotely sensed imagery that can be linked to decreases in runoff production, erosion potential, and the likelihood and potential volume of debris flows. This method will be used to improve hazard assessment and early warning in the years following wildfire.
This research opportunity can capitalize on a rich data set documenting post-fire hydrologic and debris-flow response of recently burned watersheds in the western United States. In addition, the researcher would be expected to utilize existing remote sensing data to quantify post-fire watershed recovery. The datasets can be linked to examine the duration of post-fire flooding and debris-flow hazards in the western United States.
The postdoctoral fellow will have the opportunity to engage a research team of both USGS scientists and academic collaborators, with skill sets including numerical modeling, advanced geospatial analysis, quantitative geomorphology and hydrology, and assessment of geologic hazards. Additionally, the project will involve high levels of engagement with collaborators at the National Weather Service, U.S. Forest Service, various State Geological Surveys, and faculty and students at Colorado School of Mines.
Interested applicants are strongly encouraged to contact the Research Advisors early in the application process to discuss project ideas.
Proposed Duty Station: Golden, Colorado
Areas of PhD: Earth Science (geology, hydrology, geography, geophysics), engineering, physics, applied mathematics (candidates holding a Ph.D. in other disciplines but with knowledge and skills relevant to the Research Opportunity may be considered).
Qualifications: Applicants must meet one of the following qualifications: Research Geologist, Research Hydrologist, Research Geographer, Research Physical Scientist, Research Mathematician, Research Physicist, Research Civil Engineer, Research Engineer.
(This type of research is performed by those who have backgrounds for the occupations stated above. However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.)
Human Resources Office Contact: Audrey Tsujita, 916-278-9395, atsujita@usgs.gov
