Flood Frequency and Risk Assessment
In this lab, students calculate recurrence intervals for various degrees of flooding on a portion of the Des Moines River in Iowa, based on historical data. Then they plot these calculations on a flood frequency curve. Combining flood frequency data with a topographic map of the region, students do a risk assessment for the surrounding community.
- Be able to define river stage
- Be able to describe recurrence interval in your own words, and relate it to the probability of a particular level of flooding
- Be able to describe how recurrence interval is determined, including what data are necessary to calculate it
- Be able to explain why it is difficult to make long-term predictions of large-scale disasters
- Know how often, on average, a typical river (like the Des Moines) overtops its banks
- Be able to describe some of the problems associated with flooding of the Des Moines River
Context for Use
This activity was designed to be started in a laboratory period and completed outside of class to be turned in the following week. Students work in groups and turn in one set of products.
Description and Teaching Materials
Teaching Notes and Tips
To do the lab as written, you need data on the Des Moines River. Alternatively, it would be fairly easy to adapt to a different river, as long as the USGS has a gaging station there.
It is necessary to obtain topographic maps and profiles of the Des Moines River around Des Moines, IA. Basic tools are also needed and are listed on the first page of the Activity Sheet.