Sediment transport and morphological response of a semi-alluvial channel : insights from a Froude scaled laboratory model
department or school: Arts, Faculty of
department or school: Geography, Department of
data provider: DSpace
degree campus: UBCV
creator: Luzi, David Steven
issued: 2014-08-11T14:29:10Z
issued: 2014
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Laboratory physical models have been used in geomorphology for over a century. Physical models are a useful tool for understanding and observing phenomenon that are difficult or impossible to observe in the field. The objective of this study was to understand the long-term evolution of a semi-alluvial channel in terms of its morphology and sediment transport under various scenarios of constant sediment supply and discharge. Specifically, the research aimed to investigate (1) effects of various flows and sediment feed rates on surface textures and sediment output, (2) relationship between channel storage, and the (3) morphology and sediment transport sediment transport processes and pathways. These objectives were addressed by building a Froude scaled physical model based on the irregular meandering planform of Fishtrap Creek, and conducting ten experiments of varying temporal lengths, discharge and feed rates. The model successfully replicated pool-riffle and plane-bed morphologies. The effects on the characteristics of the bed surface and transported sediment under differing regimes of discharge and sediment feed were investigated. Scaled formative flows ranging from 2-yr to over 150-yr return period events were employed. The results indicated that even with discharges exceeding the 10-yr event, full mobility was not observed. This slight but persistent size-selectivity produced long-term aggradation and surface coarsening. The effects of varying sediment supply and discharge in channel storage and morphology were explored. Results showed that sediment transport rates varied both spatially and temporally. The variability was more dependent upon changes in channel morphology than adjustments in the grain size distribution of the surface. Cycles of aggradation-degradation were observed to occur without changes in sediment supply of discharge and that they tended to occur in periods when sediment output approximately equaled sediment feed rates. Lastly, one experiment…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/49972
note: Sediment Transport andMorphological Response of aSemi-Alluvial ChannelInsights from a Froude Scaled Laboratory ModelbyDavid Steven LuziMSc, The University of British Columbia, 2000A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYinThe Faculty Graduate and Postdoctoral Studies(Geography)THE UNIVERSITY OF BRITISH COLUMBIA(Vancouver)August 2014c© David Steven Luzi 2014AbstractLaboratory physical models have been used in geomorphology for over a century. Physicalmodels are a useful tool for understanding and observing phenomenon that are difficultor impossible to observe in the field. The objective of this study was to understand thelong-term evolution of a semi-alluvial channel in terms of its morphology and sedimenttransport under various scenarios of constant sediment supply and discharge. Specifically,the research aimed to investigate (1) effects of various flows and sediment feed rates onsurface textures and sediment output, (2) relationship between channel storage, and the(3) morphology and sediment transport sediment transport processes and pathways. Theseobjectives were addressed by building a Froude scaled physical model based on the irreg-ular meandering planform of Fishtrap Creek, and conducting ten experiments of varyingtemporal lengths, discharge and feed rates. The model successfully replicated pool-riffleand plane-bed morphologies.The effects on the characteristics of the bed surface and transported sediment underdiffering regimes of discharge and sediment feed were investigated. Scaled formative flowsranging from 2-yr to over 150-yr return period events were employed. The results indicatedthat even with discharges exceeding the 10-yr event, full mobility was not observed. Thisslight but persistent size-selectivity produced long-term aggradation and surface coarsen-ing.The effects of varying sediment supply and discharge in channel storage and morphologywere explored. Results showed that sediment transport …
has type: Thesis/Dissertation
date issued: 2014-09
is shown at: 10.14288/1.0165910
language: eng
degree discipline: Geography
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivs 2.5 Canada
rights URI: http://creativecommons.org/licenses/by-nc-nd/2.5/ca/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/49972