Flooding and GIS

Hydrosphere

GLACIAL RIVER WARREN 3

Meandering Stream Channel 4

Delta 5

MS River Delta vs. “The Delta” GEOLOGIC vs. GEOGRAPHIC 6

The 2011 Floods

Why did it flood this year? Well above average precipitation over the entire Mississippi River watershed Six states had the wettest April on record These rain events coincided with the annual spring snowmelt Maybe add map of MS river watershed

Major Rain Events

Watershed-wide Flooding

Mitigation Attempts On May 3rd, the Birds Point-New Madrid levee was breached intentionally by the Army Corps of Engineers, flooding 130,000 acres. On May 14th, the Morganza Spillway was opened for the first time since 1973, redirecting a large portion of the floodwaters into the Atchafalaya River basin. On May 23rd, the Bonnet Carré Spillway is opened to protect New Orleans’ levees.

Records Set and Levees Tested Memphis, Vicksburg, and Natchez saw river crests higher than the Great Flood of 1927 flood. Floodwaters crested three feet below the level of the New Orleans levees. The 2011 flood was eventually considered a 500 year flood.

Levees

What is a levee? A place to drive your Chevy. An embankment alongside a river, built to prevent flooding of the surrounding land. A secluded place in the mountains where Confucian scholars go to write Chinese proverbs. A device used to control alligator populations.

What is a levee? A place to drive your Chevy. An embankment alongside a river, built to prevent flooding of the surrounding land. A secluded place in the mountains where Confucian scholars go to write Chinese proverbs. A device used to control alligator populations.

How does a levee work?

Pictures of Levees Above: This is a ground level view from the top of a levee. Above: This is an aerial view of a typical Mississippi River Levee. Right: Erosion can critically weaken a levee and make it more likely to fail in the event of a flood.

Bye-the-way…