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Linking the historic 2011 Mississippi River flood to coastal wetland sedimentation

Nature Geoscience

By:
, , , , , , , , , , , , and
DOI: 10.1038/ngeo1615

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Abstract

Wetlands in the Mississippi River deltaic plain are deteriorating in part because levees and control structures starve them of sediment. In Spring of 2011 a record-breaking flood brought discharge on the lower Mississippi River to dangerous levels, forcing managers to divert up to 3500 m3/s-1 of water to the Atchafalaya River Basin. Here we quantify differences between the Mississippi and Atchafalaya River inundation and sediment-plume patterns using field-calibrated satellite data, and assess the impact these outflows had on wetland sedimentation. We characterize hydrodynamics and suspended sediment patterns of the Mississippi River plume using in-situ data collected during the historic flood. We show that the focused, high-momentum jet from the leveed Mississippi delivered sediment far offshore. In contrast, the plume from the Atchafalaya was more diffuse; diverted water inundated a large area; and sediment was trapped within the coastal current. Maximum sedimentation (up to several centimetres) occurred in the Atchafalaya Basin despite the larger sediment load carried by the Mississippi. Minimum accumulation occurred along the shoreline between these river sources. Our findings provide a mechanistic link between river-mouth dynamics and wetland sedimentation patterns that is relevant for plans to restore deltaic wetlands using artificial diversions.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Linking the historic 2011 Mississippi River flood to coastal wetland sedimentation
Series title:
Nature Geoscience
DOI:
10.1038/ngeo1615
Volume
5
Year Published:
2012
Language:
English
Publisher:
Nature Publishing Group
Publisher location:
London, UK
Contributing office(s):
National Wetlands Research Center
Description:
5 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Nature Geoscience
First page:
803
Last page:
807
Number of Pages:
4
Country:
United States
Other Geospatial:
Atchafalaya River