Rain Erosion-Does the Rate of Water Effect Erosion?

Kyle Johnson, Jordan Elem. School, Jordan, MN
Based on an original activity from FOSS KIT, Water Observations, page 21, and adapted to Unit D of Water Weather in Macmillan McGraw-Hill Earth Science Fourth Grade.
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Summary

In this earth science classroom/outdoor lab, students investigate whether the rate of water falling affects the amount of erosion. Students will create a hill slope using outside soil and a tray bucket to make an angle. Two plastic cups with different number of holes will represent the varying rain falling rates. Each group will come up with data to represent their experiment and the amount of soil moved with the different rate of water falling. This experiment could lead to further questions: how does grass or rocks effect soil erosion, does erosion lead to floods, and how can we stop erosion?

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Learning Goals

This activity is guided for students to discover that the rate of water (rain) has an affect on erosion. The faster the rate of rain the more the erosion (soil movement). Students could question further on how do floods happen, what type of weather brings the most erosion, which could lead to further inquiry lessons. Key vocabulary include: erosion, flood, rate, absorption, slope, soil, floods, drought, runoff, pore spaces, and transpiration

Context for Use

This activity would be appropriate for third or fourth grade level, with 20-30 students. The setting could be a classroom or an outside the classroom activity. I would say a two-day lesson with 45 minutes each day. The investigation might lead to further questions by students, which would make another day an option. The students should have some background on the water cycle and introducing vocabulary words in the context of the lesson. Words like: runoff, rate, floods, absorption, erosion, filter and water cycle, would be introduced to the students during the lesson. Equipment for the lesson would include: dirt from surrounding classroom grounds, measuring cups for dirt, tubs (2ft.), rulers to place cups on for level surface over the tub (set cups with an equal amount of water on the back edge of the tub and the front of the cup will rest on the ruler which needs to be taped to the tub, cups, nail to poke holes in the cups to get different falling water rates, tinfoil to divide tub into two area for comparison, and water.

Description and Teaching Materials

Students will use a guided inquiry to discover how falling water rates effect soil erosion. Students will set up the material mentioned in the above area and collect data on their finding after the inquiry. Based on the data collect the students will report back to the group to see if they came to any conclusion about water rate falling and erosion. Students might have to try the experiment more than once to see if the data collected is accurate. Before starting the lesson I will introduce water and how gravity tends to pull water down a slope. This will be introduced using wax paper and water droplets, so students can see what happens to a drop of water when placed on a slope. The students will then investigate does the size of a water droplet change the speed on a slope. After the introduction students will hopefully be able to transfer that experiment to the one described in this activity and relate that the more water falling the greater the erosion factor. Concluding this activity with discussion on what might happen after a heavy rainfall or levy dam breaking. This discussion will hopefully lead to further inquiry questions, which could be done in class or on the student's own time for an enrichment activity.

Teaching Notes and Tips

I think the set up and the measuring of soil will be the most difficult for young students. Making sure that the two sides of the experiment are the same except for the amount of holes in each cup will be the challenge for each group. I have not done this lesson with my classes yet, but I am looking forward to the inquiry part for students. In the past we have looked at pictures on erosion and read about water and flooding.

Assessment

Students will be accessed on how they worked in a group on this activity and be graded in their science notebook on the details recorded in them. Each student should be able to come up with a conclusion based on the data collected in their group and how that relates to our world today.

Standards

4.3.2.3.1. Water circulates through the Earth's crust, oceans, and atmosphere in what is known as the water cycle.

References and Resources