CGRG Bibliography of Canadian Geomorphology
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Author : Eaton, B.C.; and Church, M.
Date : 2008.
Title : Downstream hydraulic geometry, vegetation and bank strength.
Publication : Joint Annual Meeting of the Canadian Geophysical Union and the Canadian Geomorphology Research Group. May 11-14, Banff, Alberta.
Issue :
Page(s) :
Abstract
One of the more perplexing questions in fluvial geomorphology is why stream channel systems scale the way that they do. Across many environments all over the world, stream channel width and depth scale consistently with the so-call formative or bankfull discharge: width scaling behaviour has been empirically summarized in the ‘downstream’ hydraulic geometry relations, which in turn are used to drive more sophisticated numerical models of river channel behaviour and landscape evolution. However, a satisfactory quantitative model that explains the observed scaling behaviour remains elusive. I will present a simple, physically based model that relates stream channel morphology to the supply of water and sediment, as well as the typical conditions of the stream bank. In most situations, it turns out that bank strength (a key model constraint) is most strongly controlled by the typical riparian vegetation. Using an appropriate representation of the effect of vegetation on bank strength, our model successfully reproduces the typically observed hydraulic geometry functions, and also reproduces various atypical hydraulic geometries. Based on our findings, it seems clear that empirical hydraulic geometry relations in large part reflect the signature of vegetation as a geomorphic agent upon the landscape.
Bibliography of Canadian Geomorphology