Bc. Eaton et Mf. Lapointe, Effects of large floods on sediment transport and reach morphology in the cobble-bed Sainte Marguerite River, GEOMORPHOLO, 40(3-4), 2001, pp. 291-309
Sediment transport rates were estimated for two flood events on the cobble-
bed Sainte Marguerite River in the Saguenay region, Canada. Morphologic met
hods were used to derive one set of estimates, and a combination of the Mey
er-Peter and Muller equation with a dimensionless sediment transport ratio
(after Dietrich et al. [Nature 340 (1989) 215]) was used to derive another
set of estimates. Both sets of estimates give consistent results for the fi
rst event (which had a decade-scale return period), and for the second even
t (which was the largest flood on record and had a century-scale return per
iod). The transport occurring during the second event was an order of magni
tude greater than that occurring during the first event: despite this dispa
rity in the transport intensity of the two events, the channel morphology r
emained qualitatively similar. The observed degree of channel stability is
attributed to a change of channel pattern and the initiation of bed degrada
tion following channel rectification in the 1960s. (C) 2001 Elsevier Scienc
e B.V. All rights reserved.