CGRG Bibliography of Canadian Geomorphology
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Author : Foster, G.E.
Date : 1999.
Title : Morphology of three semi-alluvial stream channels in Southern Ontario.
Publication : Unpublished M.Sc. thesis. University of Western Ontario, London.
Issue :
Page(s) : 215 p.
Abstract
Streams in southwestern Ontario are commonly incised into a variety of erodible glacial materials, ranging from cohesive clay to boulders, which they often lack competence to transport. Detailed longitudinal profiles surveyed along three such 'semi-alluvial' channels (Dingman, Oxbow and Nissouri Creeks) indicate that pool-riffle spacing is short, irregular and morphology is poorly developed. Common features include a disordered bed material sequence, deep sculpted till-lined pools, multiple riffles, over-widened bends and till ledges. Stream rehabilitation is often based on simple assumptions of alluvial channel characteristics, such as a mean pool-riffle spacing of five to seven times the channel width. Various techniques for defining bedform spacing are investigated. Spacing is found to be sensitive to its definition, frequency distributions are positively skewed and both mode and mean spacings are less than 5-7 widths. Natural Channel Design and habitat restoration therefore needs to incorporate differences in pool-riffle features that exist in semi-alluvial streams.
Bibliography of Canadian Geomorphology