Featured Research

from universities, journals, and other organizations

Geologist calls for advances in restoration sedimentology to protect world's river deltas

Date:
November 7, 2012
Source:
Indiana University
Summary:
Rapid advances in the new and developing field of restoration sedimentology will be needed to protect the world's river deltas from an array of threats, geologists say.

The Okavango Delta from the air.
Credit: mariosforsos / Fotolia

Rapid advances in the new and developing field of restoration sedimentology will be needed to protect the world's river deltas from an array of threats, Indiana University Bloomington geologist Douglas A. Edmonds writes in the journal Nature Geoscience.

Related Articles


The commentary, published this week in the November issue, addresses the fact that land is disappearing from river deltas at alarming rates. And deltas are extraordinarily important: They are ecologically rich and productive, and they are home to about 10 percent of the world's population.

"There's a lot of talk about ecological restoration of the coast," Edmonds said. "But with delta environments, before ecological restoration can happen you have to stabilize the coastline."

Under naturally occurring processes, coastal land is both created and destroyed at river deltas. River sediment is deposited at the delta, building land. Erosion takes some of the land away. The rate of land growth or loss depends on the balance between "sources" and "sinks," which is influenced by the complex interaction of floods, ocean waves and tides, vegetative decay and wind.

But sea-level rise and coastal subsidence have tilted the scales toward land loss, and dams and levees built for flood control have interfered with the delivery of sediment. In the Mississippi River delta, the chief focus of the article, an expanse of land the size of a football field disappears every hour.

Edmonds says there is potential for restoring deltas by designing river diversions that direct sediment from rivers to areas where it can do the most good.

"The main challenges for restoration sedimentology," he writes, "are understanding the sources and sinks, and predicting the rate of land growth under any given river diversion scenario."

For example, river sediment must be deposited near the shore, not carried into the deep ocean, to help create land. Hurricanes and waves carry away that sediment in some circumstances but in others they encourage deposition.

Because of dams and flood-control barriers, the Mississippi River doesn't appear to carry enough sediment to offset sea-level rise and coastal subsidence. "From today's perspective," Edmonds says, "the future of the Mississippi River delta is grim. But river diversions have proven successful, and there is a lot we don't know about the sedimentological processes of land-building that may change projections."

For instance, much remains to be learned about the interaction of forces that affect delta sedimentology. The "most significant unknown," he says, is the contribution of organic matter from decomposing plants to land building -- it is estimated to be as high as 34 percent in the Mississippi delta.

"The idea is to better understand the pathways by which sedimentology constructs delta land and the sinks by which that land is lost," Edmonds said. "It's all about that balance. And the more we know, the better we can engineer scenarios to tip the balance in favor of building land as opposed to drowning land."

Edmonds holds the Robert R. Schrock Professorship in Sedimentary Geology and is an assistant professor in the IU Bloomington Department of Geological Sciences in the College of Arts and Sciences. His research focuses on the sedimentology, stratigraphy and geomorphology of depositional systems, which he studies using mathematical modeling, field observation and occasionally experimentation.


Story Source:

The above story is based on materials provided by Indiana University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Douglas A. Edmonds. Restoration sedimentology. Nature Geoscience, 2012; 5 (11): 758 DOI: 10.1038/ngeo1620

Cite This Page:

Indiana University. "Geologist calls for advances in restoration sedimentology to protect world's river deltas." ScienceDaily. ScienceDaily, 7 November 2012. <www.sciencedaily.com/releases/2012/11/121107091712.htm>.
Indiana University. (2012, November 7). Geologist calls for advances in restoration sedimentology to protect world's river deltas. ScienceDaily. Retrieved April 21, 2015 from www.sciencedaily.com/releases/2012/11/121107091712.htm
Indiana University. "Geologist calls for advances in restoration sedimentology to protect world's river deltas." ScienceDaily. www.sciencedaily.com/releases/2012/11/121107091712.htm (accessed April 21, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, April 21, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Newsy (Apr. 20, 2015) Five years on, the possible environmental impact of the Deepwater Horizon spill includes a sustained die-off of bottlenose dolphins, among others. Video provided by Newsy
Powered by NewsLook.com
Pee-Power Toilet to Light Up Disaster Zones

Pee-Power Toilet to Light Up Disaster Zones

Reuters - Innovations Video Online (Apr. 20, 2015) Students and staff are being asked to use a prototype urinal to &apos;donate&apos; urine to fuel microbial fuel cell (MFC) stacks that generate electricity to power lighting. The developers hope the pee-power technology will light toilet cubicles in refugee camps, where women are often at risk of assault in poorly lit sanitation areas. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Raw: Undersea Quake Shakes Taiwan

Raw: Undersea Quake Shakes Taiwan

AP (Apr. 20, 2015) A strong undersea earthquake struck between Taiwan and southern Japan on Monday, sparking a house fire that killed a person outside of Taiwan&apos;s capital. (April 20) Video provided by AP
Powered by NewsLook.com
Five Years Later, the BP Oil Spill Is Still Taking Its Toll

Five Years Later, the BP Oil Spill Is Still Taking Its Toll

AFP (Apr. 20, 2015) On April 20, 2010, an explosion and fire on the Deepwater Horizon rig in the Gulf of Mexico started the biggest oil spill in US history. BP recently reported the Gulf is recovering well, but scientists paint a different picture. Duration: 02:36 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins