1 - Mississippi River Flashcards
What Hurricane (and what year) triggered a mass flood-mitigation objective in Mississpi?
Hurricane Katrina (2005)
How many levees were damaged by Katrina?
50 levees
What happened to the Mississippi in 1927?
Great Mississippi Flood of 1927 - Between April and May 1927, the most destructive flood in US history:
* 246 deaths
* 700,000 left homeless
* In today’s currency - $5B in property damage
* The river reached a width of 80 miles
What was the response from the US government after the Great Flood?
US government initiated the construction of a large-scale system of levees and dams along the Mississippi River carried out by the US Army Corps of Engineers
How many locks and dams were constructed?
30 locks and dams
What was the scale of the levee construction?
Levees corset thousands of miles of the riverbank to tightly control the river’s course and ability to overflow
What was the result of the levee construction and how did the governent respond?
Worsened floods and the construction of more and taller levees as a response
What is the process of intercepting with the natural flow of the river through constrcutions like levees called?
River engineering
What was the main consequence of the extensive river engineering?
The hydrological spiral
Explain the steps of the hydrological spiral, with particular reference to the Mississippi
- levees built
- water flows higher and faster in that concentrated area
- flooding worsens everywhere else, especially far downstream
- higher levees are built to protect more areas
- cycle repeats
What is the main issue with flood mititgation strategies along the Mississippi?
Levee-building remains the go-to solution
Shows short-term thinking with minimal consideration of the river system and integrated management
What is another consequence of levees? (especially for farmers)
They create a false sense of security = no flood insurance
How did the consequences of river engineering highlight the importance of natural features like floodplains in river systems?
Confining rivers disrupted their natural flow, worsening floods and revealing that wide floodplains exist to safely absorb and disperse excess water.
