Lesson 1: Why care about our water?
_Lesson Goal:_
To understand why it is important to study our freshwater resources.
_Duration:_
1 to 2 - 50 minute class periods
_Teacher Background:_
The purpose of this unit is to increase student awareness about the part humans play, both positively and negatively, in the health of our freshwater supply. And ultimately, to inspire students to protect their water resources. Healthy freshwater is tied to the well-being of living things on our planet. No matter where you choose to live, you are connected to a watershed, and your actions influence the health of the water systems at the end of your watershed and beyond. Students will explore our freshwater resources by working together in groups to predict the availability and distribution of freshwater on Earth. Once they compare their predictions to the actual availability and distribution of freshwater, they will learn that freshwater makes up a very small portion of the total water on Earth, and that Michigan is fortunate to have a significant amount of that fresh water. Finally, they will explain the importance of taking care of water resources using reasoning and evidence from various sources of information (including their own experiment).
_Student Performances:_
Describe the importance of freshwater for life on Earth.
Describe the uneven distribution of freshwater on Earth.
Understand the importance and responsibility of taking care of water resources in local communities and beyond.
_Michigan Science Standards:_
_Vocabulary:_
Distribution, lake, ice cap, glacier, river, groundwater, atmospheric moisture
_Materials:_
_Lesson Prep:_
For each group of students, label the 5 clear plastic cups using a permanent marker: “lakes,” “ice caps and glaciers,” “rivers,” “groundwater,” and “atmospheric moisture.” Label the 2-liter bottles with “oceans.”
Make copies of the Lesson 1 Student Worksheet.
See this video for a recorded classroom example of the activity, “Where is Water on Earth?”
_Lesson Steps:_
Engage
Students will watch this video, “Welcome to Pure Michigan” (Video is linked on the Unit Slides).
Using the video as a springboard for discussion, students will discuss the question, “Why care about water?” Supporting questions include, but are not limited to the following:
How do humans depend on water?
What are ways that Michigan’s abundance of water impacts its economy?
How do other living things depend on water?
What could happen if our water resources were not healthy?
Students will watch a second video, “What is a Watershed?” After watching the video, class discussion will focus around the following prompts:
How do watersheds work?
The video stated that we all live in a watershed. How do your actions affect the water sources around you?
Optional: Students can discover the name of the watershed they are a part of using the following map system: https://mywaterway.epa.gov/community
Explore
Distribute one copy of the student page, “Where Is Water on Earth?” to student groups, along with five clear plastic 9-oz. cups, a 100-ml graduated cylinder, and a 2-L bottle filled with water representing all of the water on Earth.
In the first column of the table, students will rank how much water they think is found in each of the six water body types on Earth. Students will also list the percentages they predict for each type of water in the “prediction” column.
Next, in student groups, they will come to group consensus on their predictions about how water is distributed, using the 2 liter bottle and cup model (see directions on student worksheet). They will also calculate the percentages of each type of water, according to their predictions.
Explain
Gallery walk - Students will walk around to each group, noting the similarities and differences in water distribution among the groups.
As a whole class, students will discuss the similarities and differences between the groups’ predictions.
Then, the teacher will share the actual percentages in the table below. After students write the actual percentages in the column on their student worksheet, they will discuss similarities and differences in their group, followed by a class discussion around the following question: “What surprised you?”
Source: U.S. Geological Survey (2005). Earth’s Water Distribution, Washington, D.C., USGS.
Students will analyze the data related to the uneven distribution of freshwater (see question on student worksheet).
Elaborate
Students will analyze an additional graph and maps in the Unit Slides (“Distribution of Earth’s Waters,” “Water Stress in the U.S.,” and “Water Stress in the Great Lakes”).
Evaluate
Students will develop reasoning and evidence to answer the lesson question, “Why Care About Our Water?” using what they learned in the lesson (see student worksheet).
_Additional Resources:_