Planform geometry and kinematics of confined meandering rivers on the Canadian Prairies.

摘要

The planform geometry and kinematics of migrating confined-meandering rivers at 24 locations in Alberta and British Columbia are examined. Migration rates range from 0.01 m/yr to 5.8 m/yr, consistent with those published for freely-meandering rivers. Relationships among planform geometry variables are also generally consistent with those described for freely-meandering rivers; exceptions are the increased ratios for channel wavelength/width and bend curvature. Attempts to predict migration rate based on channel flow and morphometry data are modestly successful. Stream power offers the best statistical predictor of migration rate, accounting for up to 52% of variance in migration rate. Bankfull width and mean annual flood account for respectively 32% and 30% of variance in migration rate. Bedload-transport rates are determined using morphologic methods for five of the sites. These estimates are consistent with the general trend of bedload-transport rates published elsewhere but are low when compared to rates for similar-sized drainage areas.;Keywords: fluvial geomorphology; confined meanders; planform geometry; channel migration; bedload transport; Canadian Prairies.