Flood Frequency Analysis

Sheila Roberts, Bowling Green State University
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This assignment asks students to do a flood frequency analysis to determine the size and stage of various floods and determine if the town of Crawford, OH is likely to be flooded or not. Outcomes: learn to work with quantitative data, learn to use Excel, be able to use USGS data.

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This assignment is given in a 3000-level environmental geology course. A similar assignment is given as a lab in the 1000-level physical geology course.

Skills and concepts that students must have mastered

understand retrun period for floods
be able to draw graphs and write equations in Excel
be able to do simple algebra

How the activity is situated in the course

Stand alone exercise


Content/concepts goals for this activity

Understand flood frequency

Higher order thinking skills goals for this activity

obtain online data
analyze data
interpret data
understand uncertainty

Other skills goals for this activity

Description and Teaching Materials

flood frequency assignment (Acrobat (PDF) 35kB Apr30 12)

Teaching Notes and Tips

The USGS water data has some "problems" in the file, including the format used for the data of the peak stream flow. If students don't look at the graph of discharge vs time, they will get it wrong. Also, there are two years that are listed twice and two missing years.


  1. Grading
    Did students check to see if their results were reasonable
  2. Reviewing results with students in class (show them that people estimated different stages and discharges for various floods, how the flooded area on the topo map was a little different)

References and Resources