Browse by author
Lookup NU author(s): Emeritus Professor Malcolm Newson
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Structured gravel river beds clearly exert a major influence on bed stability. Indexing structural stability by field measurements of bed strength neglects the processes operating to entrain and transport bed material in different parts of each structure. This study takes a morphological approach to interpreting the critical processes, using particle tracing to determine the movement of individual cluster particles over a range of flood event magnitudes and durations. The experiment was carried out on the River South Tyne, UK; it uses flow hydrographs measured nearby and also benefits from previous studies of historical development, channel morphology and sediment transport at the same site. More than 30 clusters were monitored over a seven-month period during which clusters occupied 7-16 per cent of the bed. Threshold flows delimiting three apparently contrasting bed sediment process regimes for cluster particles are tentatively set at 100 m(3) s(-1) and 183 m(-3) s(-1); durations of flow at these levels are critical for cluster development, rather than flow peak values. Wake particles are transported most easily. Flow straightening in the wandering channel planform reduces the stability of clusters, since mechanical strength is markedly reduced by this change of direction. The overall area covered by clusters between significant transport events varies little, implying a dynamic equilibrium condition. Copyright (c) 2005 John Wiley & Sons, Ltd.
Author(s): Wittenberg L, Newson MD
Publication type: Article
Publication status: Published
Journal: Earth Surface Processes and Landforms
Year: 2005
Volume: 30
Issue: 11
Pages: 1351-1368
ISSN (print): 0197-9337
ISSN (electronic): 1096-9837
Publisher: John Wiley & Sons Ltd.
URL: http://dx.doi.org/10.1002/esp.1184
DOI: 10.1002/esp.1184
Altmetrics provided by Altmetric
