Delta switching, also known as avulsion, is the process by which some rivers--such as the Mississippi River--change their course near their deltas. The Murray River in Australia. ... The Mississippi River, derived from the old Ojibwe word misi-ziibi meaning great river (gichi-ziibi big river at its headwaters), is the second-longest river in the United States; the longest is the Missouri River, which flows into the Mississippi. ... Delta may refer to: Look up delta in Wiktionary, the free dictionary. ...

The flow of a river is controlled by its gradient, which decreases as it nears the ocean, becoming nearly zero at the delta's toe.^[5] Eventually, a delta can build so far out into the ocean that its gradient becomes too low to support the river's current; an event such as a flood can cause it to break a natural levee upstream, creating a new, steeper river channel that forms another delta.^[6],^[7] The abandoned delta eventually subsides.^[8] In the above two images, the scalar field is in black and white, black representing higher values, and its corresponding gradient is represented by blue arrows. ... A levee, levée (from the feminine past participle of the French verb lever, to raise), floodbank or stopbank is a natural or artificial embankment or dike, usually earthen, which parallels the course of a river. ...

References:

1. ^ Marshak, Stephen. (2001) Earth: Portrait of a Planet, New York: W.W. Norton & Company, ISBN 0-393-97423-5 pp. 528-9
2. ^ Stanley, Steven M. (1999) Earth System History. New York: W.H. Freeman and Company, ISBN 0-7167-2882-6 p. 136
3. ^ Marshak, pp. 528-9
4. ^ Stanley, p. 136
5. ^ Marshak, Stephen. (2001) Earth: Portrait of a Planet, New York: W.W. Norton & Company, ISBN 0-393-97423-5 pp. 528-9
6. ^ Stanley, Steven M. (1999) Earth System History. New York: W.H. Freeman and Company, ISBN 0-7167-2882-6 p. 136
7. ^ Marshak, pp. 528-9
8. ^ Stanley, p. 136