Author
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Bennett, Sean |
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Alonso, Carlos |
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Submitted to: American Geophysical Union
Publication Type: Proceedings Publication Acceptance Date: 10/15/2002 Publication Date: 12/9/2002 Citation: Bennett, S.J., Alonso, C.V. 2002. Physical and analytical modeling of upland soil erosion due to headcut migration. American Geophysical Union Abstracts, V. 83, p F560. Interpretive Summary: IS is not required for Abstract. Technical Abstract: On hillslopes and agricultural fields, discrete areas of intense, localized soil erosion commonly take place in the form of migrating headcuts. These erosional features significantly increase soil loss and landscape degradation, yet the unsteady, transient, and migratory habits of headcuts complicate their phenomenological and erosional characterization. Here a unique experimental facility was constructed to examine actively migrating headcuts typical of upland concentrated flows. Essential components of the facility include a deep soil cavity with external drainage, rainfall simulator, overland flow, and a video recording technique for data collection. These experiments provided unrivalled insight into steady state soil erosion processes, self-similarity of migrating headcuts, and integral time and length scales for headcut development. It will be shown that erosion processes are controlled by the characteristics of the overfall nappe and wall jets within the plunge pool and that modified jet impingement theory can be successfully applied to a migrating headcut. These experiements provided the insight as well as the conceptual framework for a complete analytical solution for predicting headcut migration rate, equilibrium scour depth, and total sediment flux in upland concentrated flows. |
