Experimental Study of Channel Patterns

Abstract

Research Article| June 01, 1972 Experimental Study of Channel Patterns S. A SCHUMM; S. A SCHUMM Department of Geology and Engineering Research Center, Colorado State University, Fort Collins, Colorado 80521 Search for other works by this author on: GSW Google Scholar H. R KHAN H. R KHAN Department of Geology and Engineering Research Center, Colorado State University, Fort Collins, Colorado 80521 Search for other works by this author on: GSW Google Scholar Author and Article Information S. A SCHUMM Department of Geology and Engineering Research Center, Colorado State University, Fort Collins, Colorado 80521 H. R KHAN Department of Geology and Engineering Research Center, Colorado State University, Fort Collins, Colorado 80521 Publisher: Geological Society of America Received: 03 Aug 1971 Revision Received: 27 Jan 1972 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1972, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1972) 83 (6): 1755–1770. https://doi.org/10.1130/0016-7606(1972)83[1755:ESOCP]2.0.CO;2 Article history Received: 03 Aug 1971 Revision Received: 27 Jan 1972 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation S. A SCHUMM, H. R KHAN; Experimental Study of Channel Patterns. GSA Bulletin 1972;; 83 (6): 1755–1770. doi: https://doi.org/10.1130/0016-7606(1972)83[1755:ESOCP]2.0.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 A series of experiments was performed in a large flume to determine the effect of slope and sediment load on channel patterns. Sediment loads and slopes were closely related, and as slope and sediment loads increased, threshold values of these variables were encountered, at which channel patterns altered significantly. At a very low slope and sediment load, the channels remained straight, but at a discharge of 0.15 cfs, a meandering-thalweg channel formed at slopes greater than 0.002. With increased slope and sediment loads, thalweg sinuosity increased to a maximum of 1.25. At slopes greater than 0.016, a braided channel formed. The model channels responded to increased sediment loads by maintaining steeper gradients and by major channel pattern changes, but at very gentle slopes and at steep slopes, the channel could not be forced to develop a meandering thalweg.These experiments suggest that landforms may not always respond progressively to altered conditions. Rather, dramatic morphologic changes can occur abruptly when critical erosional and (or) depositional threshold values are exceeded.The meandering-thalweg channel was not a meandering channel. A truly meandering channel with a sinuosity of 1.3 formed when a suspended-sediment load (3 percent concentrations of kaolinite) was introduced into the flow. The clay stabilized the alternate bars, and scour and deepening of the thalweg resulted. This in turn lowered the water level at constant discharge, and the alternate bars emerged o t form point bars. A meandering-thalweg channel was thus converted to a meandering channel by the type of sediment load change that has accompanied climatic and hydrologic changes of the recent geologic past. 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.