Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lewis and Clark data show a different Missouri River

11.05.2004


’Strapped in’ by wing dykes


Washington University earth and planetary scientists say the present-day Missouri River is narrower and more prone to flooding because of extensive damming of the river, especially in the 20th century


Lewis and Clark Missouri River data reveal a broader, healthier stream



The oldest data available on the Missouri River - from the logs of Lewis and Clark - show that water flow on the river today is far more variable than it was 200 years ago. The data also show that the river is some 220 yards narrower at St. Charles, Mo., today at 500 yards across than in 1804 when it spread out some 720 yards.

These changes are due to modifications of the river by the Army Corps of Engineers, say Robert Criss, Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, and Washington University undergraduate student Bethany Ehlmann, an earth and planetary sciences major in Arts & Sciences.


Ehlmann presented her and Criss’s findings April 1, 2004 at the 38th annual meeting of the North-Central Section of the Geological Society of America, held in St. Louis.

The emplacement of wing dikes and levees, mostly after World War I, and the building of six main-flow reservoirs between 1937-63 have created a river that Lewis and Clark would not recognize if they were here today. The structures on the river are responsible for a deeper river that is flooding more often in recent years, the researchers say.

"Flood stages are getting higher over time because of restrictions that have made river width narrower," said Criss. "If you make the river narrower to accommodate any given amount of flow, the river’s got to get deeper."

This restriction, Criss said, can be blamed on a four- to nine- foot increase in flood stages along the lower Missouri River. Wing dams, or wing dikes, are found approximately every 1,500 feet along the Missouri River, from outside St. Louis to Sioux City, Iowa, ostensibly for controlling the river for the barge industry.

"The ironic thing is that the Missouri River hardly has any barge traffic; most of that is on the Mississippi," Criss said.

"The whole river is strapped in and the flow is much more variable now than then."

According to Ehlmann, the modern Missouri-Mississippi River confluence near St. Louis shows greater average daily stage change and greater standard deviation - 8.5 /- 14.4 inches at St. Charles and 9.1 /-11.1 inches at St. Louis -- than did the river mouth at Camp Dubois (near St. Louis) in the winter of 1803-04 - 5 inches /- 5.2 inches.

In contrast, she said, at present-day Washburn, North Dakota (Fort Mandan, two hundred years ago), normal daily variability is between 1 to approximately 4 inches compared with an average stage variability of 4.1 /- 7.1 inches when Lewis and Clark made measurements.

A few days, however, show extremely large variability, greater than 20 inches. This, said Ehlmann, is "due to regulation by huge, nearby main stem reservoirs."

The conclusion from Ehlmann and Criss’s study is that "flow regulation by main stem reservoirs and numerous others on tributaries does not fully offset the large increases in flood stages and greater stage variability that are caused by channel restriction and development in the lower basin," according to the researchers.

Tony Fitzpatrick | WUSTL
Further information:
http://news-info.wustl.edu/tips/page/normal/840.html

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Cholesterol-lowering drugs may fight infectious disease

22.08.2017 | Health and Medicine

Meter-sized single-crystal graphene growth becomes possible

22.08.2017 | Materials Sciences

Repairing damaged hearts with self-healing heart cells

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>