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Erosion properties of cohesive sediments in the Colorado River in Grand Canyon
Author(s) -
Akahori Ryosuke,
Schmeeckle Mark W.,
Topping David J.,
Melis Theodore S.
Publication year - 2008
Publication title -
river research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.679
H-Index - 94
eISSN - 1535-1467
pISSN - 1535-1459
DOI - 10.1002/rra.1122
Subject(s) - geology , canyon , flume , sediment , geotechnical engineering , shear stress , silt , erosion , geomorphology , hydrology (agriculture) , materials science , flow (mathematics) , geometry , mathematics , composite material
Cohesive sediment deposits characterized by a high fraction of mud (silt plus clay) significantly affect the morphology and ecosystem of rivers. Potentially cohesive sediment samples were collected from deposits in the Colorado River in Marble and Grand Canyons. The erosion velocities of these samples were measured in a laboratory flume under varying boundary shear stresses. The non‐dimensional boundary shear stress at which erosion commenced showed a systematic deviation from that of non‐cohesive sediments at mud fractions greater than 0.2. An empirical relation for the boundary shear stress threshold of erosion as a function of mud fraction was proposed. The mass erosion rate was modelled using the Ariathurai–Partheniades equation. The erosion rate parameter of this equation was found to be a strong function of mud fraction. Under similar boundary shear stress and sediment supply conditions in the Colorado River, cohesive lateral eddy deposits formed of mud fractions in excess of 0.2 will erode less rapidly than non‐cohesive deposits. Copyright © 2008 John Wiley & Sons, Ltd.