Flow competence in relation to stream channel form and braiding

Research Article| September 01, 1979 Flow competence in relation to stream channel form and braiding G. H. CHEETHAM G. H. CHEETHAM 1 Department of Physical Geography, University of Uppsala, Box 554, S-751 22 Uppsala, Sweden Search for other works by this author on: GSW Google Scholar Author and Article Information G. H. CHEETHAM 1 Department of Physical Geography, University of Uppsala, Box 554, S-751 22 Uppsala, Sweden Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1979) 90 (9): 877–886. https://doi.org/10.1130/0016-7606(1979)902.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation G. H. CHEETHAM; Flow competence in relation to stream channel form and braiding. GSA Bulletin 1979;; 90 (9): 877–886. doi: https://doi.org/10.1130/0016-7606(1979)902.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract In order to assess the role of competence in the braiding process, a technique was devised to measure point instantaneous bed-shear stresses based on the principle of equating particle moments under controlled conditions. In particular, the effects of channel form and stage changes on bed-shear stress are examined. Measurements in nine different cross sections at two stage levels indicate a distinct contrast between parent channels and distributaries. High stresses were recorded in both at higher discharge, but on reduced stage, the stress in the parent channel decreased appreciably but remained moderately high in the distributaries. This spatial pattern of competence changes with stage was further demonstrated by the analysis of hydraulic exponents of discharge which implied a cross-over effect in sediment-transporting ability. Distributaries at high stage appear to become a sedimentary bottleneck relative to the parent channel, thus providing a mechanism for bar growth. Morphological developments demonstrated two superimposed forms of braiding, one consequent upon channel widening and loss of competence, and the other, inherent fluid instability of high-energy flow, producing channel wandering. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.