The document summarizes a case study of the Mississippi River flood of 2008. Heavy rainfall in the Midwest US in June 2008, with some areas receiving over 10 inches of rain in a single day or over 12 inches for the month, caused widespread flooding along the Mississippi River. The flooding affected over 80 counties in Iowa and caused an estimated $8 billion in damages to crops. Measures to reduce flooding impacts include increasing vegetation to slow rainfall runoff, widening rivers to increase water flow capacity, and restricting building on floodplains.
2. Background to drainage basin
• Precipitation
• Interception – lack of vegetation cover
• Gradient
• Permeability of the surrounding area
• Small area of drainage basin
4. Where?
•Second longest river system in the United States.
•2,340 miles (3,766 kilometers)
•Source in north-western Minnesota, Mouth in the Gulf of Mexico
•East of United States, to the Rocky Mountains
5. When?
• Spring 2008 – Heavy Rain Begins
• June 4th- Indiana
• June 7th – Wisconsin (Tornadoes)
• June 9th- Iowa
• June 10th – Illinois
• June 14th – Michigan
• June 27th- Missouri
6. What? How?
• Rain, For example 10 inches in Wisconsin
• During the course of the first half of June, 2008, much of the Midwestern U.S.
received copious amounts of rainfall as one storm system after another
traversed the region.
• •Stations reported values ranging from 6 to 10 inches (150 to 250 mm) for the
day across parts of the state.
• •3 miles east of Center Point, IN with 9.5 inches (241 mm), an unofficial report in
Edinburgh, IN indicated that 10.71 inches (272 mm) fell on June 7th, which one
might expect to see less frequently than once every 1000 years.
• •June rainfall totals exceeded 12 inches (305 mm) across large portions of the
region, with Martinsville, IN reporting a total of 20.11 inches (511 mm) of rain for
the month
10. Primary Effects
• As of June 25, 83 of Iowa's 99 counties
were declared disaster areas by Governor
Chet Culver.
11. Secondary Effects
• One third of total US Corn crop and 30% of the
total US Soya bean crop
• American Farm Bureau federation estimates that
crop loses will exceed $8 billion dollars.
• The Iowa Renewable Fuels Association
indicated that some 300 million gallons of the
state's 2.2 billion gallons of biofuel refineries
were still offline by the end of June due to
flooding.
13. Avoidance of Flooding
• Not caused by humans, not really
avoidable, but….
• Increase the vegetation density in the
drainage basin
• Widening the river to increase flow rate
• Not build on flood Plaines – decrease the
affects of flooding
• Lengthen the river
