How do braided river dynamics affect sediment storage?

May 09, 2013

Braided rivers, with their continuously changing network of channels, are highly dynamic systems. Four mechanisms of channel change and evolution are considered the classic mechanisms of braided river formation: development of central bars, conversion of single transverse bars to mid-channel braid bars, formation of chutes, and dissection of multiple-braid bars.

There have been few studies on how each of these braiding mechanisms contributes to changes in sediment storage and to the dynamics of a river. In one of the first field studies on the topic, Wheaton et al. analyzed repeat topographic surveys conducted over a 5- year period of the River Feshie, an active, braided, gravel-bed river in the United Kingdom.

They find that collectively, the four classic braiding mechanisms accounted for most of the change in sediment storage. However, their results highlight the critical role that bank erosion and other non-braiding mechanisms play in facilitating net increases in sediment storage by braiding mechanisms through providing an important local supply of sediment to feed those braiding mechanisms and through creating accommodation space where central bars can develop.

Explore further: As the river rises: Cahokia's emergence and decline linked to Mississippi River flooding

More information: Morphodynamic signatures of braiding mechanisms as expressed through change in sediment storage in a gravel-bed river, Journal of Geophysical Research-Earth Surface, doi:10.1002/jgrf.20060, 2013 http://onlinelibrary.wiley.com/doi/10.1002/jgrf.20060/abstract

Related Stories

For first time, meandering river created in laboratory

Sep 20, 2012

Natural rivers are not straight, and they are rarely idle. Instead, they bend and curve and sometimes appear to wriggle across the surface over time. That rivers can meander is obvious but how and why they do so is less well ...

River beds on the move: Shifting flood risk?

Apr 24, 2013

(Phys.org) —A detailed study of shifting river beds, conducted by researchers at the University of St Andrews, could hold the key to more accurate flood prevention.

Recommended for you

Fjords are 'hotspots' in global carbon cycling

10 hours ago

While fjords are celebrated for their beauty, these ecosystems are also major carbon sinks that likely play an important role in the regulation of the planet's climate, new research reveals.

Warm oceans caused hottest Dust Bowl years in 1934/36

10 hours ago

Two ocean hot spots have been found to be the potential drivers of the hottest summers on record for the Central US in 1934 and 1936. The research may also help modern forecasters predict particularly hot ...

Ocean currents disturb methane-eating bacteria

10 hours ago

Offshore the Svalbard archipelago, methane gas is seeping out of the seabed at the depths of several hundred meters. These cold seeps are a home to communities of microorganisms that survive in a chemosynthetic ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.