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Interchannel hydraulic geometry and hydraulic efficiency of the anastomosing Columbia River, southeastern British Columbia, Canada
Author(s) -
Tabata Kevin K.,
Hickin Edward J.
Publication year - 2003
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.497
Subject(s) - geology , hydrology (agriculture) , geomorphology , columbia university , archaeology , geography , geotechnical engineering , sociology , media studies
The morphodynamics of the anastomosing channel system of upper Columbia River in southeastern British Columbia, Canada, is examined using an adaptation of conventional hydraulic geometry termed ‘interchannel hydraulic geometry’. Interchannel hydraulic geometry has some of the characteristics of downstream hydraulic geometry but differs in that it describes the general bankfull channel form and hydraulics of primary and secondary channels in the anastomosing channel system. Interchannel hydraulic geometry generalizes these relationships and as such becomes a model of the geomorphology of channel division and combination. Interchannel hydraulic geometry of upper Columbia River, based on eld measurements of ow velocity and channel form at 16 test sections, is described well by simple power functions: w bf = 3·24 Q bf 0·64 ; d bf = 1·04 Q bf 0·19 ; v bf = 0·30 Q bf 0·17 . These results, with other related measurements of ow resistance, imply that channel splitting leads to hydraulic inefciency (higher ow resistance) on the anastomosing Columbia River. Because these ndings differ from those reported in studies elsewhere, we conclude that hydraulic efciency does not provide a general explanation for anabranching in river channels. Copyright © 2003 John Wiley & Sons, Ltd.