Embedded Files
Lesson Overview
Lesson Overview
Guiding question: How can we “create” more water?
Time Estimate: 90 minutes
Purpose: Introduce students to the solutions and technological innovations that currently exist and the affordances and constraints of what we currently know.
Overview: In this unit, students will explore how the world is using technology to address the water crisis. Students will investigate why some solutions work for some countries but do not work for others.
Design Principles:
Global and Local dynamic
Affordances & limitations of science
Background Knowledge: This lesson will not require the students to have extensive background knowledge, but the teacher will need to be familiar with emerging technologies concerning the water crisis. We recommend these resources for the following topics: desalination, green infrastructure, and irrigation techniques.
Common Misconceptions:
Safety:
Unit Connections:
📂 Materials
📂 Materials
Teacher Materials:
Teacher slides titled: 4.2 How can we “create” water?
Make sure the video on slide 2 is loaded beforehand.
Student Materials:
Student Worksheet 4.2 Comparing Perspectives
Instructional Sequence
Instructional Sequence
Materials: Teacher Slides: 4.2 How can we “create” water?
Introduce technologies (slides 1-6)
Introducing that we replicate water cycle processes in our technologies.
The purpose of introducing this idea is that the water cycle has worked for humankind forever, and it can continue providing humans with enough water to meet our needs if we find ways to conserve and protect our water. Our growing population, climate change, and increased pollutants are threatening the processes that have worked since the start of Earth. Therefore, we are developing technologies that replicate this life-saving natural process to provide freshwater to populations. This is why learning about the water cycle is relevant to our individual lives.
📒 Instructional Support
Desalination has an amazing output- freshwater! But it also can come with some drawbacks, such as requiring a lot of energy to produce the freshwater, and along with producing freshwater, a byproduct called brine can be harmful to marine life when put back into the ocean.
These are not reasons not to use desalination, but they are considerations that should be taken seriously when deciding to invest in desalination. This conversation with students should introduce that there are benefits and drawbacks to desalination, which is why there is never one right answer to the water crisis.
The video link at the bottom of the slide is if students do not understand the general idea and process of desalination. The video does not need to be watched to continue with the lesson, but it can provide more information about saltwater becomes freshwater if needed.
Comparing Perspectives:
Materials: Comparing Perspectives
⏰ Recommendations for timing & modifications
This activity can be skipped if time does not allow; however, it is an important activity for getting students to evaluate the complexity of selecting a solution to invest in (a topic they will need to understand for their final project).
📒 Instructional Support
Students can read both articles, or you can divide them into groups of four where two students read each article, work together to understand the main points, tone of the article, and position of the author, then share with their other group members.
✍️ Assessment Opportunity
Comparing Perspectives
What to look for?
Students should be able to read and understand the author of each article’s point of writing the article, and what they want the reader to consider after reading the article. Students should understand that a solution that works in one part of the world is not necessarily a solution that will work elsewhere, so students should explore the ways that culture is a factor in making these decisions.
Additional Technologies (slides 8-10):
The last three slides are packaged as skipped slides to start. They touch on three other methods of protecting and conserving water that are used across the world: drip irrigation, wastewater reuse, and green infrastructure. These will provide students with more options to explore in their final project.
⏰ Recommendations for timing & modifications
There is also a student resource sheet titled “Innovations Information” that contains the same information, and students can use it for their final project instead.
Use your discretion about how and when to introduce these other technologies.
Information for Planning & Teaching
Information for Planning & Teaching
Background Knowledge
Background Knowledge
Desalination is the process of removing salt and other impurities from seawater or brackish water to make it suitable for human consumption and various other uses. There are two primary methods: thermal desalination and reverse osmosis. Thermal desalination involves heating seawater to produce steam, which is then condensed to obtain fresh water. Reverse osmosis uses high pressure to push seawater through a membrane, separating the salt and impurities from the water molecules. Desalination is a critical water resource solution in many regions with limited freshwater availability. Middle Eastern countries, such as Saudi Arabia, United Arab Emirates, and Israel, heavily rely on desalination to meet their water needs. Additionally, countries like Australia, Spain, and the United States (particularly in California and Texas) have implemented desalination projects. However, Australia and the United States have expressed varying opinions on desalination. While desalination provides a solution to water scarcity, it is essential to discuss the potential environmental impacts. The desalination process requires energy, which can contribute to greenhouse gas emissions and climate change. The disposal of concentrated brine (a byproduct of desalination) can harm marine ecosystems if not properly managed. Lastly, desalinated water tends to be more expensive compared to traditional freshwater sources. Discussing the economic aspects of desalination can help students understand the financial considerations involved in implementing and maintaining desalination plants. It is important to address the challenges of making desalinated water affordable and accessible to all communities.
Lesson Timing
Lesson Timing
If time is short, and students do not have time to read both passages, teachers can follow a jigsaw method similar to the one explained in lesson 4.1.
Student Ideas & Experiences
Student Ideas & Experiences
Just like adults, students will also have varying opinions about desalination. Students may be influenced by the viewpoints prevalent in their communities. If they live in coastal areas where desalination projects are being considered or implemented, they might have a more positive outlook and support the idea because it is a service to their community. Or, these same students may have concerns about the potential environmental impacts of desalination. They may wonder about energy consumption, carbon emissions, and the disposal of brine by-products. Some students may question whether desalination is a sustainable and eco-friendly option. Conversely, students from inland regions might have less exposure to desalination discussions and hold varying opinions based on local water availability.
Students might have questions about the taste and quality of desalinated water. They may wonder if it matches their expectations and preferences for freshwater. Some students may be hesitant to embrace desalinated water if they have concerns about taste or if they have limited exposure to it.
Science Practices
Science Practices
Teaching Cases
Teaching Cases
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