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

More articles from Earth Sciences:

nachricht The shelf life of pyrite
14.10.2019 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen

nachricht Laser precision: NASA flights, satellite align over sea ice
04.10.2019 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel Material for Shipbuilding

A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.

The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...

Im Focus: Controlling superconducting regions within an exotic metal

Superconductivity has fascinated scientists for many years since it offers the potential to revolutionize current technologies. Materials only become superconductors - meaning that electrons can travel in them with no resistance - at very low temperatures. These days, this unique zero resistance superconductivity is commonly found in a number of technologies, such as magnetic resonance imaging (MRI).

Future technologies, however, will harness the total synchrony of electronic behavior in superconductors - a property called the phase. There is currently a...

Im Focus: How Do the Strongest Magnets in the Universe Form?

How do some neutron stars become the strongest magnets in the Universe? A German-British team of astrophysicists has found a possible answer to the question of how these so-called magnetars form. Researchers from Heidelberg, Garching, and Oxford used large computer simulations to demonstrate how the merger of two stars creates strong magnetic fields. If such stars explode in supernovae, magnetars could result.

How Do the Strongest Magnets in the Universe Form?

Im Focus: Liquifying a rocky exoplanet

A hot, molten Earth would be around 5% larger than its solid counterpart. This is the result of a study led by researchers at the University of Bern. The difference between molten and solid rocky planets is important for the search of Earth-like worlds beyond our Solar System and the understanding of Earth itself.

Rocky exoplanets that are around Earth-size are comparatively small, which makes them incredibly difficult to detect and characterise using telescopes. What...

Im Focus: Axion particle spotted in solid-state crystal

Scientists at the Max Planck Institute for Chemical Physics of Solids in Dresden, Princeton University, the University of Illinois at Urbana-Champaign, and the University of the Chinese Academy of Sciences have spotted a famously elusive particle: The axion – first predicted 42 years ago as an elementary particle in extensions of the standard model of particle physics.

The team found signatures of axion particles composed of Weyl-type electrons (Weyl fermions) in the correlated Weyl semimetal (TaSe₄)₂I. At room temperature,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

NEXUS 2020: Relationships Between Architecture and Mathematics

02.10.2019 | Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

 
Latest News

How to control friction in topological insulators

14.10.2019 | Physics and Astronomy

The shelf life of pyrite

14.10.2019 | Earth Sciences

Shipment tracking for "fat parcels" in the body

14.10.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>