Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



SHAKE AND BLOW
New tool could help predict, prevent surging waters in flood plains
by Staff Writers
Washington DC (SPX) May 16, 2017


illustration only

A group of international scientists studying China's Yellow River has created a new tool that could help officials better predict and prevent its all-too-frequent floods, which threaten as many as 80 million people. The tool - a formula to calculate sediment transport - may also be applied to studying the sustainability of eroding coastlines worldwide.

"Understanding the flow of sediment in rivers is important to the large number of people around the world who live near these waterways," said Judy Skog, a program director for the National Science Foundation's (NSF) Coastal SEES (Science, Engineering and Education for Sustainability) program, which funded the research.

Coastal SEES is largely supported by NSF's Geosciences Directorate, with additional funding from the directorates for Biological Sciences, Engineering, and Social, Behavioral and Economic Sciences.

"This study will lead to better predictions of when and where rivers transport sediment, and to an understanding of how that sediment flow is affected by conservation and management efforts, such as the removal of dams," Skog said.

Known in Chinese as the Huanghe, the Yellow River is considered the cradle of Chinese civilization, and is often called the "mother of China" for its nutrient-rich sediment, which benefits farmland along its banks. But its floods, which led to some of the deadliest natural disasters in recorded history, have also earned it the name "China's sorrow."

Fertile nurturer, wanton killer
Each of the river's identities - as the fertile nurturer and the wanton killer - derives from the same feature: the 1 billion tons of sediment that washes down each year from the Loess Plateau to the Bohai Sea. This huge sediment load can clog the river. When this happens, it not only floods but can change course.

"The Huanghe is probably the most studied fine-grained river in the world," said Rice University sedimentologist Jeffrey Nittrouer, a primary author of a new paper about the Yellow River that appears online this week in the journal Science Advances.

"Despite that, the typical formulas and relationships that are used to describe sediment flux in most other rivers don't work for the Huanghe," Nittrouer said. "They consistently under-predict the sediment load of the river by a factor of 20."

Nittrouer and lead paper author Hongbo Ma, also of Rice University, took sediment samples and created a 3-D map of the river bottom to create what they call a "universal sediment transport formula." The formula is the first physics-based sediment transport model capable of accurately describing how the Yellow River carries sediment, Nittrouer and Ma say.

"In terms of sediment transport, the Huanghe is almost the perfect river," Ma said. "Its bottom is nearly flat and featureless, which means it can use almost all of its energy for moving sediment."

Nittrouer, who has studied dozens of rivers on three continents, said he has not seen anything like the Yellow River.

"In lowland, sand-bed rivers like the Amazon, the Mississippi - you name it - only about 40 to 60 percent of the energy is used to transport sediment downstream," he said. "In the Yellow River, well over 95 percent of the energy is available to move sediment."

Nittouer said this means the Yellow River generates new land extremely efficiently each year, making it the best place to learn how to use sediment from rivers to enhance delta sustainability. Those lessons have applications for river systems worldwide.

"The best example in the U.S. is the Mississippi River, where there are significant efforts to replenish coastal Louisiana," he said.

New methods, old problem
For decades, Chinese engineers have tried to reduce the risk of Yellow River floods by periodically releasing massive amounts of lake water to scour the river's bottom and keep its sediment moving. Such scouring, however, may inadvertently increase the risk of flooding in certain parts of the river, according to the new model.

Although the scouring process clears silt, it also creates a rough-textured riverbed that reduces the amount of energy the river can use to move sediment. "Our formula indicates this will lower sediment transport efficiency by an order of magnitude," Nittouer said.

Nittrouer and Ma first visited the Yellow River in the summer of 2015. Their intent was to look at the geologic, socioeconomic and engineering lessons from China's efforts to control the river and direct the growth of its delta into the Bohai Sea.

In previous studies, Nittrouer found that river bottoms had features similar to desert sand dunes. The Yellow River, however, surprised him.

"I took one look at the readout on the boat and thought the instrument was broken," Nittrouer said. "The bottom looked flat as glass."

When he imaged the bottom of the Mississippi River, for example, Nittrouer saw formations up to 10 meters (33 feet) tall and spaced about 200 to 300 meters (656 to 984 feet) apart. In contrast, the data from the Yellow River showed 1 meter (3.3 feet) tall dunes every 500 to 2,000 meters (1,640 to 6,562 feet).

Using Nittrouer's data and other measurements from the lower Yellow River and its sprawling delta, Ma created a physics-based formula capable of accurately predicting the flux - the volume of sediment transported for a given time period - in the Yellow River.

"The aim is to look at the connectedness, in terms of sediment movement and water flow, among the river, the delta and the near-shore marine region," said Ma, whose research strikes a personal chord.

"I was born and grew up far from the Huanghe in the northeastern Heilongjiang Province," he said. "But, like many Chinese, I deeply feel the sorrow of the Yellow River, which has killed millions over the past 2,000 years."

Ma said he hopes the new formula will prove useful to the Chinese engineers who manage the flow of water and sediment from dams along the Yellow River.

Additional co-authors include Rice's Andrew Moodie, the University of Illinois at Urbana-Champaign's Kensuke Naito and Gary Parker, Tsinghua University's Xudong Fu and Baosheng Wu and the Yellow River Institute of Hydraulic Research's Yuanfeng Zhang and Yuanjian Wang. The National Natural Science Foundation of China also supported the research.

SHAKE AND BLOW
Eastern Canada is drying out after the worst flooding in a half-century
Montreal (AFP) May 11, 2017
/> Expect more floods, wildfires and other natural disasters than ever before, Canadian Prime Minister Justin Trudeau warned Thursday as he toured flood-ravaged Quebec province, citing climate change as the reason. "The frequency of extreme weather events is increasing," Trudeau told reporters on the ground after the helicopter tour. "And that's related to climate change. "So we're goin ... read more

Related Links
National Science Foundation
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

SHAKE AND BLOW
Healthcare bill inspires road rage: Tenn. woman tries to run Congressman off road

New fiber-based sensor could quickly detect structural problems in bridges and dams

Marine Le Pen: far-right firebrand who has shaken up French politics

20 sentenced to prison for deadly 2015 China landslide

SHAKE AND BLOW
A bath for precision printing of 3-D silicone structures

Physical keyboards make virtual reality typing easier

Inverse designing spontaneously self-assembling materials

Scientists create hologram that changes images as it is stretched

SHAKE AND BLOW
Fish should figure in to fate of nation's aging dams

Dying Guatemala lake underlines climate change threat

Teleconnection between the tropical Pacific and Antarctica

Large storms can flood aging sewer systems with harmful bacteria, viruses

SHAKE AND BLOW
Alaska Tundra Source of Early-Winter Carbon Emissions

Tillerson hosts Arctic forum in shadow of Russia spat

Irreversible ocean warming threatens the Filchner-Ronne Ice Shelf

Montana's glaciers are disappearing

SHAKE AND BLOW
Tillage farming damaging earthworm populations

Syngenta shareholders accept ChemChina offer

Conservation agriculture offers tired soil remedies

Can edible insects help curb global warming?

SHAKE AND BLOW
Another day on the job, in the eye of a hurricane

NASA spots Eastern Pacific season's earliest first tropical storm in satellite era

Eastern Canada is drying out after the worst flooding in a half-century

New tool could help predict, prevent surging waters in flood plains

SHAKE AND BLOW
Wounded author Kuki Gallmann vows return to Kenyan ranch

Gunfire as I.Coast troops resume protest despite 'apology'

Ivory Coast's rebel soldiers apologise to president

Army to protect Tunisia economy from protests: president

SHAKE AND BLOW
South African cave yields yet more fossils of a newfound relative

Changes in Early Stone Age tool production have 'musical' ties

Homo naledi's surprisingly young age opens up more questions on where we come from

Modern DNA reveals ancient origins of Indian population




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement