Dynamic single-thread channels maintained by the interaction of flow and vegetation

Abstract

Research Article| April 01, 2007 Dynamic single-thread channels maintained by the interaction of flow and vegetation Michal Tal; Michal Tal 1Department of Geology and Geophysics, University of Minnesota, St. Anthony Falls Laboratory, 2 3rd Ave. SE, Minneapolis, Minnesota 55414, USA Search for other works by this author on: GSW Google Scholar Chris Paola Chris Paola 1Department of Geology and Geophysics, University of Minnesota, St. Anthony Falls Laboratory, 2 3rd Ave. SE, Minneapolis, Minnesota 55414, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Michal Tal 1Department of Geology and Geophysics, University of Minnesota, St. Anthony Falls Laboratory, 2 3rd Ave. SE, Minneapolis, Minnesota 55414, USA Chris Paola 1Department of Geology and Geophysics, University of Minnesota, St. Anthony Falls Laboratory, 2 3rd Ave. SE, Minneapolis, Minnesota 55414, USA Publisher: Geological Society of America Received: 19 Aug 2006 Revision Received: 05 Dec 2006 Accepted: 08 Dec 2006 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2007) 35 (4): 347–350. https://doi.org/10.1130/G23260A.1 Article history Received: 19 Aug 2006 Revision Received: 05 Dec 2006 Accepted: 08 Dec 2006 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Michal Tal, Chris Paola; Dynamic single-thread channels maintained by the interaction of flow and vegetation. Geology 2007;; 35 (4): 347–350. doi: https://doi.org/10.1130/G23260A.1 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 SocietyGeology Search Advanced Search Abstract Most rivers on Earth today flow as a single channel, in some cases with occasional islands, and follow a more or less sinuous course. However, single-thread channels have proven difficult to reproduce and study experimentally: experimental self-formed channels tend to widen and subdivide, leading to a braided pattern. Cohesive sediment has been the main mechanism studied for stabilizing banks and producing a single-thread channel. We show how laboratory experiments using vegetation to stabilize banks can organize the flow and convert the planform morphology from braided to single-thread. Our experimental strategy, a repeated cycle of short periods of high water discharge alternating with longer periods of low discharge accompanied by plant seeding and growth, leads to the evolution of a dynamic self-maintaining single-thread channel with well-defined banks and floodplain. By eliminating weak flow paths, the vegetation “corrals” the water into a single dominant channel until the reduction in total wetted width leads to a new self-organized state in which the flow removes vegetated area as fast as it is produced. The new channel is deeper and has a broader distribution of depths than the braided one, with channel size adjusted to carry almost all the flood flow. The resulting system maintains a dynamic steady state via similar mechanisms to those that operate in meandering channels in the field, specifically erosion at the outside of bends, bend growth, and bar development. Our methodology provides a basis for experimental development of self-sustaining high-amplitude meanders and has applications for river management and basic research purposes. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.