CGRG Bibliography of Canadian Geomorphology
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Author : Carling, P.A.; and Tinkler, K.J.
Date : 1998
Title : Conditions for the entrainment of cuboid boulders in bedrock channels: an historical review of the literature with respect to recent investigations.
Publication : Rivers over Rock: fluvial process in bedrock channels. Edited by: Tinkler, K.J.; and Wohl, E.E. Geophysical Monographs. American Geophysical Union, Washington, DC.
Issue : 107:
Page(s) : 19-34.
Abstract
We present an historical perspective on the development of force-balance equations for initial motion of large boulders or cuboid blocks by sliding as well as by pivoting, although we concentrate on sliding motion. Particular attention is given to theoretical and experimental work which has relevance to the initial motion criteria of large rounded boulders or cuboid boulders in bedrock channels. Published, and some new, data concerning the friction coefficient and particle drag coefficient for sliding and rolling are reviewed. Recent study has indicated that incipient motion of large boulders on bedrock surfaces is associated with Froude numbers near 1 when flow depth may be of similar order to the boulder height such that flow regime transitions and ventilation may occur around and over the boulder. Consequently, the particular entrainment conditions associated with critical, unsteady, and non-uniform flow are discussed. Both isolated and grouped boulders are considered. Recommendations are made for further investigation.
Bibliography of Canadian Geomorphology