Author
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Hanson, Gregory |
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Submitted to: American Geophysical Union
Publication Type: Abstract Only Publication Acceptance Date: 4/28/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The effects of concentrated flow erosion can be observed across the landscape in the form of rills, gullies, and stream channels. One of the geotechnical aspects that controls the morphology of the landscape as a result of concentrated flow is the erodibility of the earthen material on the land surface. Prediction of the erodibility of soil material by flowing gwater is complex. The properties of earthen material that govern its resistance to erosion are numerous: antecedent moisture, clay type and content, density, soil structure, organic content, pore and water chemistry, etc. A submerged jet testing device has been developed for characterizing soil erodibility in the field and in the laboratory. This device has been developed based on a knowledge of the hydraulic characteristics of a submerged jet and the characteristics of soil material erodibility. The test is simple, quick, and relatively inexpensive to perform. The test is repeatable and gives consistent results, and the coefficients obtained from test results can be used in current equations to predict erosion. A jet index, Ji, was originally developed for the submerged jet test to allow comparison of the erosional resistance of soil, but the excess shear stress equation is commonly used to model the erosion of soil materials. Therefore, analytical procedures have been developed for determining the excess shear stress parameters from the submerged jet scour results. The jet apparatus is capable of applying a wide range of hydraulic shear stresses. Therefore, the coefficient of erodibility and critical stress for a wide range of soil materials can be determined. |
