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Latest Earthquake | Chat Share
Topics: Floods, watersheds
Length: One class period
Type of Resource Being Described: Hands on activity
The size or magnitude of a flood is described by the term "recurrence interval", which is determined by studying a long period of flow records for a stream. This activity demonstrates the occurrence of a particular flood event and shows that floods do not necessarily occur every 10, 50, or 100 years, as is commonly thought. In this activity, students use macaroni or beans to calculate the statistics of flood recurrence (see back side of poster).
Students should understand:• How many times a 100-year, 50-year, 10-year, or 5-year flood is likely to occur• Discuss ways in which to protect individuals and property from floods
Each group will need:
If sufficient material are available, divide the class into small groups. Provide each group with a container of 100 items. Explain to the students that each item in the container represents a flood event. The single items represents the 100-year flood event, the two items of the same color represent the 50-year flood event, the 10 items of the same color represent the 10-year flood even, the 20 items of the same color represent he 5-year flood event, and the 67 items of the same color represent no flooding. Student will be selecting 100 different items from the container, simulating 100 years of stream flow.
Identify one student in the group as the note keeper. The note keeper is to make a table with column headings of 100, 50, 10, 5, and 1. This individual needs to keep track of each item that is selected from the container. There will be a total of 100 items selected from the container.
Designate one student to hold the container above the heads of the other students in the group while they take turns selecting one item at a time from the container. After the note keeper has tallied the selection, the student should return the item back to the container prior to selection nof the next item. Students will make a total of 100 selections from the container, after the 100th selection, the note keeper is to total all the selections by individual flood events and make a grand total of all selections.
When all the groups have finished, make a master list of each groups' results on the chalkboard so all the students can share the results.