AMSL 101 Lecture : 7Natural_Disasters_Flood_Lecture_Outline.docx
Document Summary
The great midwestern flood of 1993 saturated with water: abnormally high rainfall in many midwest states, record flood stage levels recorded, covered nine states and 400,000 square miles, the preceding winter and the first half of 1993 were 50 to 100 percent wetter than average, so most of the ground was, flood waters lasted 200 days, over 1,000 levees were topped or failed (levees fail by overtopping, breaching, bank erosion, slumps or seepage), fifty deaths, over billion in damage, only 5. 2% of households had flood insurance. To predict flooding for a particular stream, geologists make use of long term records of previous floods on that stream. The recurrence interval (also called the flood frequency) is the average length of time, in years, between floods of a particular size, or magnitude. Again, it is important to remember that this wording reflects the average time interval between floods of a particular size.
