CGRG Bibliography of Canadian Geomorphology
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Author : Church, M.
Date : 2005.
Title : -The regulation of Peace River: a large-scale experiment on fluvial governing conditions
Publication : Annual Meeting of the Canadian Association of Geographer. Tuesday, May 31 to Saturday, to June 4, 2005. University of Western Ontario, London, Ontario.
Issue :
Page(s) :
Abstract
In 1967, closure of W.A.C.Bennett Dam created the world's (then) sixth largest hydropower project. The dam controls half the runoff from the 293 000 km2 basin, but most of the sediment load originates downstream in the Alberta Plateau. Hence, effects of these two principal governing conditions can be separated. The 378 km cobble-gravel reach down to Smoky River has effectively ceased to be alluvial. Aggradation is occurring at major tributary junctions, whilst the tributaries have degraded their lowermost reaches. Smoky River, the principal tributary, delivers a large sand load. The 250 km reach to Carcajou is sandy gravel and the final 600 km to the Peace-Athabasca delta is sand-bed. Aggradation, with an evolution toward low-order braiding, appears to be underway in the proximal sand-bed reach. More generally, channel shrinkage is controlled by the progradation of riparian vegetation onto former bar surfaces. In 1996, reservoir drawdown for dam repairs required full spillway flows for 8 weeks. Significant degradation was observed for the first time but overall changes were surprisingly modest, reflecting the refractory bed and the degree to which riparian vegetation has become established. Overall, sediment supply and flow competence are the principal controls of fluvial response in the system.
Bibliography of Canadian Geomorphology