Dynamics of 30 large channel bars in the Lower Mississippi River in response to river engineering from 1985 to 2015

Dynamics of 30 large channel bars in the Lower Mississippi River in response to river engineering... Channel bars are a major depositional feature in alluvial rivers and their morphodynamics has been investigated intensively in the past several decades. However, relatively less is known about how channel bars in alluvial rivers respond to river engineering and regulations. In this study, we assessed 30-yr morphologic changes of 30 large emerged bars located in a 223km reach of the highly regulated Lower Mississippi River from Vicksburg, Mississippi, to the Mississippi-Atchafalaya River diversion. Landsat imagery and river stage data between 1985 and 2015 were utilized to characterize bar morphologic features and quantify decadal changes. Based on bar surface areas estimated with the satellite images at different river stages, a rating curve was developed for each of the 30bars to determine their volumes. Results from this study show that the highly regulated river reach favored the growth of mid-channel and attached bars, while more than half of the point bars showed degradation. Currently, the mid-channel and attached bars accounted for 38% and 34% of the total volume of the 30bars. The average volume of a single mid-channel bar is over two times that of an attached bar and over four times that of a point bar. Overall, in the past three decades, the total volume of the studied 30bars increased by 110,118,000m3 (41%). Total dike length in a dike field was found mostly contributing to the bar volume increase. Currently, the emerged volume of the 30bars was estimated approximately 378,183,000m3. The total bar volume is equivalent to ~530millionmetrictons of coarse sand, based on an average measured bulk density of 1.4t/m3 for the bar sediment. The findings show that these bars are large sediment reservoirs. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Geomorphology Elsevier

Dynamics of 30 large channel bars in the Lower Mississippi River in response to river engineering from 1985 to 2015

Loading next page...
 
/lp/elsevier/dynamics-of-30-large-channel-bars-in-the-lower-mississippi-river-in-pg3cF3WyKb
Publisher
Elsevier
Copyright
Copyright © 2017 Elsevier B.V.
ISSN
0169-555X
eISSN
1872-695X
D.O.I.
10.1016/j.geomorph.2017.09.041
Publisher site
See Article on Publisher Site

Abstract

Channel bars are a major depositional feature in alluvial rivers and their morphodynamics has been investigated intensively in the past several decades. However, relatively less is known about how channel bars in alluvial rivers respond to river engineering and regulations. In this study, we assessed 30-yr morphologic changes of 30 large emerged bars located in a 223km reach of the highly regulated Lower Mississippi River from Vicksburg, Mississippi, to the Mississippi-Atchafalaya River diversion. Landsat imagery and river stage data between 1985 and 2015 were utilized to characterize bar morphologic features and quantify decadal changes. Based on bar surface areas estimated with the satellite images at different river stages, a rating curve was developed for each of the 30bars to determine their volumes. Results from this study show that the highly regulated river reach favored the growth of mid-channel and attached bars, while more than half of the point bars showed degradation. Currently, the mid-channel and attached bars accounted for 38% and 34% of the total volume of the 30bars. The average volume of a single mid-channel bar is over two times that of an attached bar and over four times that of a point bar. Overall, in the past three decades, the total volume of the studied 30bars increased by 110,118,000m3 (41%). Total dike length in a dike field was found mostly contributing to the bar volume increase. Currently, the emerged volume of the 30bars was estimated approximately 378,183,000m3. The total bar volume is equivalent to ~530millionmetrictons of coarse sand, based on an average measured bulk density of 1.4t/m3 for the bar sediment. The findings show that these bars are large sediment reservoirs.

Journal

GeomorphologyElsevier

Published: Jan 1, 2018

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off