Efficient retention of mud drives land building on the Mississippi Delta plain
Many of the world's deltas – home to major population centers – are rapidly degrading due to reduced sediment supply, making these systems less resilient to increasing rates of relative sea-level rise. The Mississippi Delta faces some of the highest rates of wetland loss in the world. As a r...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2017-07-01
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| Series: | Earth Surface Dynamics |
| Online Access: | https://www.earth-surf-dynam.net/5/387/2017/esurf-5-387-2017.pdf |
| _version_ | 1828832445539024896 |
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| author | C. R. Esposito C. R. Esposito C. R. Esposito Z. Shen Z. Shen T. E. Törnqvist J. Marshak C. White |
| author_facet | C. R. Esposito C. R. Esposito C. R. Esposito Z. Shen Z. Shen T. E. Törnqvist J. Marshak C. White |
| author_sort | C. R. Esposito |
| collection | DOAJ |
| description | Many of the world's deltas – home to major population centers – are rapidly
degrading due to reduced sediment supply, making these systems less resilient
to increasing rates of relative sea-level rise. The Mississippi Delta faces
some of the highest rates of wetland loss in the world. As a result,
multibillion dollar plans for coastal restoration by means of river
diversions are currently nearing implementation. River diversions aim to
bring sediment back to the presently sediment-starved delta plain. Within
this context, sediment retention efficiency (SRE) is a critical parameter
because it dictates the effectiveness of river diversions. Several recent
studies have focused on land building along the open coast, showing SREs
ranging from 5 to 30 %. Here we measure the SRE of a large relict
crevasse splay in an inland, vegetated setting that serves as an appropriate
model for river diversions. By comparing the mass fraction of sand in the
splay deposit to the estimated sand fraction that entered it during its life
cycle, we find that this mud-dominated sediment body has an SRE of ≥ 75 %, i.e., dramatically higher than its counterparts on the open
coast. Our results show that transport pathways for mud are critical for
delta evolution and that SRE is highly variable across a delta. We conclude
that sediment diversions located in settings that are currently still
vegetated are likely to be the most effective in mitigating land loss and
providing long-term sustainability. |
| first_indexed | 2024-12-12T16:54:18Z |
| format | Article |
| id | doaj.art-db6d184f5e1e4b2f9a62616b0ea0b972 |
| institution | Directory Open Access Journal |
| issn | 2196-6311 2196-632X |
| language | English |
| last_indexed | 2024-12-12T16:54:18Z |
| publishDate | 2017-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Earth Surface Dynamics |
| spelling | doaj.art-db6d184f5e1e4b2f9a62616b0ea0b9722022-12-22T00:18:17ZengCopernicus PublicationsEarth Surface Dynamics2196-63112196-632X2017-07-01538739710.5194/esurf-5-387-2017Efficient retention of mud drives land building on the Mississippi Delta plainC. R. Esposito0C. R. Esposito1C. R. Esposito2Z. Shen3Z. Shen4T. E. Törnqvist5J. Marshak6C. White7Department of Earth and Environmental Sciences, Tulane University, 6823 St. Charles Avenue, New Orleans, Louisiana 70118-5698, USAnow at: The Water Institute of the Gulf, One American Place, 301 N. Main Street, Suite 2000, Baton Rouge, Louisiana 70825, USAThese authors contributed equally to this work.Department of Marine Science, Coastal Carolina University, P.O. Box 261954, Conway, South Carolina 29528, USAThese authors contributed equally to this work.Department of Earth and Environmental Sciences, Tulane University, 6823 St. Charles Avenue, New Orleans, Louisiana 70118-5698, USADepartment of Earth and Environmental Sciences, Tulane University, 6823 St. Charles Avenue, New Orleans, Louisiana 70118-5698, USADepartment of Earth and Environmental Sciences, Tulane University, 6823 St. Charles Avenue, New Orleans, Louisiana 70118-5698, USAMany of the world's deltas – home to major population centers – are rapidly degrading due to reduced sediment supply, making these systems less resilient to increasing rates of relative sea-level rise. The Mississippi Delta faces some of the highest rates of wetland loss in the world. As a result, multibillion dollar plans for coastal restoration by means of river diversions are currently nearing implementation. River diversions aim to bring sediment back to the presently sediment-starved delta plain. Within this context, sediment retention efficiency (SRE) is a critical parameter because it dictates the effectiveness of river diversions. Several recent studies have focused on land building along the open coast, showing SREs ranging from 5 to 30 %. Here we measure the SRE of a large relict crevasse splay in an inland, vegetated setting that serves as an appropriate model for river diversions. By comparing the mass fraction of sand in the splay deposit to the estimated sand fraction that entered it during its life cycle, we find that this mud-dominated sediment body has an SRE of ≥ 75 %, i.e., dramatically higher than its counterparts on the open coast. Our results show that transport pathways for mud are critical for delta evolution and that SRE is highly variable across a delta. We conclude that sediment diversions located in settings that are currently still vegetated are likely to be the most effective in mitigating land loss and providing long-term sustainability.https://www.earth-surf-dynam.net/5/387/2017/esurf-5-387-2017.pdf |
| spellingShingle | C. R. Esposito C. R. Esposito C. R. Esposito Z. Shen Z. Shen T. E. Törnqvist J. Marshak C. White Efficient retention of mud drives land building on the Mississippi Delta plain Earth Surface Dynamics |
| title | Efficient retention of mud drives land building on the Mississippi Delta plain |
| title_full | Efficient retention of mud drives land building on the Mississippi Delta plain |
| title_fullStr | Efficient retention of mud drives land building on the Mississippi Delta plain |
| title_full_unstemmed | Efficient retention of mud drives land building on the Mississippi Delta plain |
| title_short | Efficient retention of mud drives land building on the Mississippi Delta plain |
| title_sort | efficient retention of mud drives land building on the mississippi delta plain |
| url | https://www.earth-surf-dynam.net/5/387/2017/esurf-5-387-2017.pdf |
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