Channel responses to varying sediment input: A flume experiment modeled after Redwood Creek, CaliforniaAuthor(s): Mary A. Madej; Diane G. Sutherland; Thomas E. Lisle; Bonnie S. Pryor
Source: Geomorphology 103(4): p. 507-519
Publication Series: Scientific Journal (JRNL)
Station: Pacific Southwest Research Station
PDF: Download Publication (1.11 MB)
At the reach scale, a channel adjusts to sediment supply and flow through mutual interactions among channel form, bed particle size, and flow dynamics that govern river bed mobility. Sediment can impair the beneficial uses of a river, but the timescales for studying recovery following high sediment loading in the field setting make flume experiments appealing.We use a flume experiment, coupled with field measurements in a gravelbed river, to explore sediment transport, storage, and mobility relations under various sediment supply conditions. Our flume experiment modeled adjustments of channel morphology, slope, and armoring in a gravel-bed channel. Under moderate sediment increases, channel bed elevation increased and sediment output increased, but channel planform remained similar to pre-feed conditions. During the following degradational cycle, most of the excess sediment was evacuated from the flume and the bed became armored. Under high sediment feed, channel bed elevation increased, the bed became smoother, mid-channel bars and bedload sheets formed, and water surface slope increased. Concurrently, output increased and became more poorly sorted. During the last degradational cycle, the channel became armored and channel incision ceased before all excess sediment was removed. Selective transport of finer material was evident throughout the aggradational cycles and became more pronounced during degradational cycles as the bed became armored. Our flume results of changes in bed elevation, sediment storage, channel morphology, and bed texture parallel those from field surveys of Redwood Creek, northern California, which has exhibited channel bed degradation for 30 years following a large aggradation event in the 1970s. The flume experiment suggested that channel recovery in terms of reestablishing a specific morphology may not occur, but the channel may return to a state of balancing sediment supply and transport capacity.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationMadej, Mary A.; Sutherland, Diane G.; Lisle, Thomas E.; Pryor, Bonnie S. 2009. Channel responses to varying sediment input: A flume experiment modeled after Redwood Creek, California. Geomorphology 103(4): p. 507-519
KeywordsSediment transport, storage, flume, aggradation, degradation
- The incidence and role of gullies after logging in a coastal redwood forest
- Shrinking streamflows in the Redwood Region
- Environmental impacts of redwood lumber: a cradle-to-gate assessment
XML: View XML