Edit document metadata
password
Password for the
Dietrich
collection.
action
edit
document metadata
(below)
delete
this document
(check this box and type password above)
move
or
copy
this document
(check this box and type password above)
title
author
editor
journal
publication date
Month
unknown
January
February
March
April
May
June
July
August
September
October
November
December
Day
unknown
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
notes
aDepartment of Earth and Planetary Science, University of California Berkeley, Berkeley, CA 94720; bDepartment of Geosciences, 509 Thornton Hall, San Francisco State University, San Francisco, CA 94132; and cStillwater Sciences, Berkeley, CA 94705
Any other info that should appear in the information we have about this document.
abstract
Meandering rivers are common on Earth and other planetary surfaces, yet the conditions necessary to maintain meandering channels are unclear. As a consequence, self-maintaining meandering channels with cutoffs have not been reproduced in the laboratory. Such experimental channels are needed to explore mechanisms controlling migration rate, sinuosity, floodplain formation, and planform morphodynamics and to test theories for wavelength and bend propagation. Here we report an experiment in which meandering with near-constant width was maintained during repeated cutoff and regeneration of meander bends. We found that elevated bank strength (provided by alfalfa sprouts) relative to the cohesionless bed material and the blocking of troughs (chutes) in the lee of point bars via suspended sediment deposition were the necessary ingredients to successful meandering. Varying flood discharge was not necessary. Scaling analysis shows that the experimental meander migration was fast compared to most natural channels. This high migration rate caused nearly all of the bedload sediment to exchange laterally, such that bar growth was primarily dependent on bank sediment supplied from upstream lateral migration. The high migration rate may have contributed to the relatively low sinuosity of 1.19, and this suggests that to obtain much higher sinuosity experiments at this scale may have to be conducted for several years. Although patience is required to evolve them, these experimental channels offer the opportunity to explore several fundamental issues about river morphodynamics. Our results also suggest that sand supply may be an essential control in restoring self-maintaining, actively shifting gravel-bedded meanders.
keywords
project
bibtex entry
Enter a reference in BibTeX format.
Back to
DocuBase
BNHM
University of California, Berkeley