Erosion and Prevention of Erosion

Abstract: Erosion is an elementary grade science concept. In the Next Generation Science Standards 2nd graders are expected to know that “Wind and water can change the shape of the land.(2-ESS2.A). Additionally 2nd graders are expected to know that “There is always more than one possible solution to a problem, it is useful to compare and test designs (2-ETS1.C)” This lesson uses a student designed investigation to explore erosion and various ways to prevent erosion from occurring.

Introduction

Erosion: the wearing away of land by wind, water, or other natural agents. Overarching Questions: “How do wind and water change the shape of the land?” and “In what ways can erosion be prevented?”

- The first question guides the initial discussion and exploration, performed on day one. - The second question guides the exploration and discussion for the second half of

the two-part lesson.

Learning objectives for the full, two-day student exploration are:● Students will design an investigation model to test their ideas about what causes the

shape of the land to change.● Students will articulate the effects of wind and water on the shape of the land based on

their investigation observations, and will understand and articulate the concept of “erosion.”

● Students will compare and contrast a minimum of two solutions designed to prevent or slow weather from changing the shape of the land.

DAY ONE

Discussion:Day one’s lesson logic flow:

● When wind hits land repeatedly, parts of the land move.● When water hits land repeatedly, parts of the land move.● Therefore, wind and water can change the shape of the land.

The two day exploration of erosion was introduced to students through a series of pictures, giving them the most concrete example possible. Students were first shown a picture of a rock then were shown a picture of the same rock 100 years later. When students were shown the first picture they were simply asked “What do you observe?” then they were shown the second picture and asked the same question. I then told students that the picture was taken in the same location a hundred years apart and the posed the question: “How is this possible?”.

Students brainstormed ideas as a large group. To help in their understanding the “in-between” years were given to students so that they could see the progression of the effects of erosion on this particular rock.

Students responded with: rain, wind, acid rain, etc. Eventually, a student offered the term erosion. Immediately, the student was asked to define what the term meant so that I could determine whether or not he understood the vocabulary that he was using. I then asked for someone else to describe it in a different way to ensure that all students were actively mentally engaged and understanding the content.

Exploring and Testing Erosion:

After the initial discussion about the pictures and what caused the rock to disappear over time, I asked students how they could test their ideas of what had caused the rock to erode over time. Students worked collaboratively in their full groups (5-6 students) to design an experiment that tested both the effects of wind and water. Students were made aware of the supplies that were available: Tub, cups, soil, foil and a blow dryer. Students were given the freedom to use the supplies as needed. Most groups chose to use the dirt as a “rock”, the blow dryer as wind, and the water to represent rain.

The students were asked to articulate their investigation design (verbally and through a drawing) before given the supplies to ensure that all students understood what they wanted from the investigation and how it was going to prove their predictions. Students decided that they would test the effects of wind and water separately in their investigation

While the students were running their investigation, I asked them questions about their observations: “What do you see happening?” “How does this align with what you thought was going to happen?”. I acted as a guide for students, rather than providing direct instruction for students while they completed their investigation. At the end of the class period on day one, I asked students to again tell us what erosion meant and relating it to their investigation to ensure that the concept was understood by all.

DAY TWO

Discussion

I started day two of our erosion exploration by re-engaging my students. This was done by asking questions such as “what can you tell me about our investigation last week?” and “we used the word erosion, what does this mean?” My goal here was two-fold. I wanted to ensure that students recalled what they did the week prior to allow for a smooth transition into part two of the investigation, but also wanted to ensure that they understood the vocabulary and the concepts associated. The students discussed how last week they tested the effect wind and water had on soil and that both of these elements changed the shape of the land. They also defined erosion as the movement or change of soil and rock by wind and water.

The discussion then launched into a conversation prompted by questions like “Where can erosion happen? What factors contribute to erosion? and “Why would erosion be a bad thing?” The goal here was for students to start understanding erosion on a deeper level. I wanted students to make the connection that erosion could happen anywhere, including their backyard and that this has many negative side effects. Finally, to conclude the introduction students were asked to think about why humans would want to stop erosion. By asking this question, students were required to think about the nature of science and how culture affects the way we think about erosion.

Exploration of Erosion Prevention

The day two exploration on erosion was presented to students through the question “what are ways to prevent erosion?” Students were prepared for the question based on the conversations had in the introduction about where erosion occurs and why it is bad. As students began to brainstorm, the teacher began to set out supplies to help spark students thinking. Students had popsicle sticks, rocks, aluminum foil, and saran wrap available to them. Students were asked to work in small groups to draw and articulate a plan before creating an actual model. The goal of having students work in smaller groups was for them to realize that there is more than one way to approach the problem and multiple solutions.

Once students were able to articulate their plan and explain their rationale and predictions for when wind and water were added they were able to set up their investigation. While students were working to set up their model the teacher was touching base with each group. The teacher was asking questions about why students were setting up their model a certain way, what they anticipated happening when wind and water were added, and how they thought this week’s investigation would differ from last.

After each group of students set up their investigation, we came back together as a whole group to test the model as a large group. Some models the students came up with included a wall of rocks, a wall of rocks surrounded by popsicle sticks, and a moat, The purpose for doing this was for students to see each model and further understand that there may be more than one solution to a problem. If one of the models didn’t work, it also allowed students to see that some approaches are more effective for preventing erosion than others.

Promoting Student Reflection

It was evident through the “competitive” chatter from students that they needed time to discuss and analyze why it is important to design and test multiple ideas. A large group discussion regarding the Next Generation Science Standard (2-ETS1.C) occured to promote a positive environment for students to discuss their ideas. Providing time for students to reflect on their creation process and learning is an important part of science exploration.

The students were first asked, “Why do you think you came up with different ideas?” Their responses showed that they understood that people are ambiguous and are not always creating the same answers to problems. One boy replied, “Well we had two different groups so each group had their own ideas of what would work best to prevent erosion.” Another student

added that, “...people are not all the same, so everyone will have different ideas. Some might be similar, but no one will create two of the same thing.”

To follow up with those responses, this question was asked, “Why do you think it is a good thing to come up and test different ideas?” Students first discussed their thoughts with their small group before sharing out individually with the large group. Some groups needed a bit of a prompt to help guide their thinking, so asking students to think about the investigation today and how they tested several ideas can help provide a scaffold to the question..

One student’s response was, “I think its a good thing to have multiple ideas and test them because how do you know if only one design will work?” Students seemed to agree with his statement and showed an understanding of the importance of testing multiple ideas. They were able to come to this conclusion by relating their observations and experiences from the investigation to their thinking.

Nature of Science

While aspects of the lesson demonstrated the nature of science throughout the entire two day unit, students were not asked to “think” about some of those concepts until the final discussion on Day Two. Referring to the previous section on “Promoting Student Reflection”, after students understood why it is important to create and test multiple ideas, they were asked, “How is this like what real scientists do?” Students were eager to respond and one girl stated, “We were like real scientists because we designed two ideas for a problem and tested both of them to see which one worked best. Real scientists do that for a lot of different types of problems.” Students understood that what they created and experienced during the unit is similar to what real scientists do everyday.

In addition to making the connection to real scientists, throughout the lesson students were demonstrating several nature of science concepts. Students worked collaboratively to solve problems in a creative way. Throughout the entire unit, students worked with their small groups to have discussions and to design a solution to help prevent erosion. Because there were two groups, there was more than one design that was created and tested, showing that in science multiple ideas are created and experimented with. Lastly, students used their creativity and imagination to design what they thought would be the best solution in preventing erosion.

Assessment

Assessment for this investigation is formative and closely aligned with the learning process, the Next Generation Science Standards, and the objectives for the lesson. Students demonstrated their understanding of the effects of weather on the land by creating their own models and determining how best to make the model investigation authentic. The students demonstrated their understanding of erosion on the second day by developing a variety of ways to prevent erosion and testing those ideas with a second model. Additionally, student understanding was assessed based on their verbally articulated answers to questions about their investigation observations, their inferences, and their overall understanding of erosion.

Conclusion:

This lesson is an example of inquiry-based learning. Students learn by contemplating, discussing, and testing their own ideas, rather than through direct teacher instruction. Instructors guided the investigation using open ended and thought provoking questions and students were responsible for designing their own investigation and making meaning of the things they observed. Through this type of inquiry, students will be able to develop a robust understanding of the content and begin to think about aspects of the nature of science and how they were present in the investigation.

References

Second Grade Science. (n.d.). Suffolk Teaching Activities & Resources. Retrieved April 29, 2014, from http://star.spsk12.net/science/science_02.htm

The Next Generation Science Standards | Next Generation Science Standards. (2014, January 1). The Next Generation Science Standards | Next Generation Science Standards. Retrieved April 29, 2014, from http://www.nextgenscience.org/next-generation-science-standards

Erosion and Prevention of Erosion – Student Samples