Fluvial geomorphology of undisturbed alluvial fan distributary systems, Queen Charlotte Islands (Haida Gwaii), British Columbia, Canada

This study examines the fluvial geomorphology of stream channels on pristine, old-growth alluvial fans in the wet temperate old-growth environment of the Queen Charlotte Islands (Haida Gwaii), British Columbia. The research provides baseline data to inform decisions regarding development and rehabilitation or restoration on disturbed fans. The morphology and hydraulic geometry of the channel, as it leaves the confined or semi-confined environment of the upland valley and issues onto the unconfined fan environment, is the focus of this study. A secondary objective is to describe the processes of sediment movement in the fan channels.; The sediment-sampling procedure followed for this study was an effective method for determining the average and range in grain size in the fan channels but does not capture in detail the complex longitudinal pattern of changing grain-size. There does not appear to be a strong inter-fan difference in grain size. Variations in sediment size appear to be more strongly related to channel processes such as bankfull discharge and stream power. (Abstract shortened by UMI.)...