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Floods

Myth vs Reality: Floods and Levees

 This short video addresses the misconception that levees and spillways might lessen flood damage.
Credits

Produced by the Space Telescope Science Institute’s Office of Public Outreach in collaboration with the NASA Earth Observatory.

All images, illustrations, and videos courtesy of NASA except:
·       Illustration of northwestern U.S. based on illustration from NOVA/WGBH “Mystery of the Megaflood” website
·       Glacial Lake Missoula painting courtesy of Byron Pickering
·       Dry Falls photo ©2004 Teri J. Pieper, www.byways.org
·       Palouse Hills photo courtesy of Lynn Suckow
·       Sea creature illustration copyright The National Library of Israel, Shapell Family Digitization Project _and The Hebrew University of Jerusalem, Department of Geography – Historic Cities Research Project
·       Photos of Mississippi River with debris courtesy of Thomas R. Machnitzki
·       Video of clouds over eastern U.S. courtesy of National Oceanic and Atmospheric Administration
·       Snow-to-rain animation by Marc Lussier, STScI
·       Satellite images of flooding in Birds Point–New Madrid Floodway courtesy of MODIS Today,
·       Space Science and Engineering Center, University of Wisconsin-Madison
·       Morganza Spillway video and photos courtesy of the U.S. Army Corps of Engineers
·       Photo of Mississippi River sediment plume entering Gulf of Mexico courtesy of Nancy Rabalais/Louisiana Universities Marine Consortium
·       Algae bloom photo courtesy of National Ocean Service/NOAA
·       Photo of fish kill on Grand Isle, Louisiana, courtesy of Kerry St. Pé
·       Mississippi River dead zone animation courtesy of National Oceanic and Atmospheric Administration
·       Photo of flooded farm near Vicksburg, Mississippi, courtesy of the National Weather Service
·       Map of Mississippi River course changes courtesy of the U.S. Army Corps of Engineers
 
Music courtesy of Associated Production Music
Written by Andrea Gianopoulos
Designed by Marc Lussier
Transcript

(SPEECH)
[UPBEAT JAZZ MUSIC]
 
(DESCRIPTION)
A banner is outlined in blue for the title, Myth vs Reality and it is split into two sections. An illustration with sea serpents surrounding a ship is above Myth. A row of trees standing in a flooded area is above reality. A dark, rotating planet floats in the background at the bottom. The Myth side is highlighted. Text, Levees and spillways always reduce damage from flooding.
 
The reality side is highlighted. Text, Constraining a river's natural flow pattern with levees will make a swollen river flow faster. The high, fast-moving water can eat away at levees, causing a breach. Floodwaters that break through a levee travel faster and with more force than a slowly rising river in its natural channel.