Evaluating the controls of hillslope morphology on nonlocal sediment transport: analytical and experimental approaches

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Dr. Danica Roth has been granted an NSF EAR Postdoctoral Fellowship to carry out research and education plans at the University of Oregon and Vanderbilt University. The primary objective of this study is to establish and enhance the applicability of the nonlocal sediment transport numerical model in real landscapes. Nonlocal sediment transport processes include bioturbation by tree throw and burrowing animals, and fire-induced ravel. The project is composed of several distinct but complementary modules with a range of experimental, field- and data-driven components, and it naturally lends itself to outreach, education and mentorship at the K-12 and undergraduate-level. Dr. Roth will establish a new chapter of the NSF-funded Institute for Science and Engineer Educators' Professional Development Program at the University of Oregon, which will provide graduate students and postdocs with training in equitable, inquiry-based pedagogy. This program will be a venue to design a new field-based inquiry activity utilizing data from this study. The activity will be taught in the Hillslope Geomorphology class at the University of Oregon and made publicly available in online educational archives. The social relevance of topics encompassed by this project (e.g., erosional responses to fires and clear cutting) will also generate public interest and provide opportunities to increase awareness of these issues through public lectures, popular press pieces, and educational content published on YouTube and our web pages.This project will bridge the gap between the well-developed theoretical work on nonlocal transport and the need for field-based measurements and applications of nonlocal transport. This study will also generate valuable datasets on particle transport distances in a wide range of natural field settings. The nonlocal transport model will address one of the major weaknesses of existing models by taking into account roughness. The effects of roughness will be incorporated into the nonlocal formulation for particle disentrainment via its influence on critical slope and the probabilistic spacing of roughness elements. A modified PØclet number for the relative importance of local and nonlocal transport processes will be developed and field-tested in a range of natural settings. All analyses and theory will be informed and tested with field experiments to compare theoretical and measured particle travel distances and erosion rates in the Oregon Coast Range and the Painted Hills badlands in Central Oregon.