Teaching Water Transparency

Water transparency is an anchoring phenomena that can lead in multiple directions. Below is a sequence of lessons for Grades 4 -12 that lead towards understanding what water transparency is and how it relates to erosion and geology.

Content

We think of water as transparent. Fill a clear glass with drinking or distilled water and you will be able to see through it. But if you fill that same glass with surface water--water in lakes, rivers, and streams--you may find that the water is more cloudy than clear. There are both natural and human caused reasons for this cloudiness.

An important natural factor in determining water transparency is geology. If the landscape surrounding the water body has a lot of rock like there is in the Black Hills, that water body will have clear, transparent water. The rain and snow melt that runs into the river, lake or stream will not erode the rock quickly and will not carry much into the water. However, if the surrounding landscape has a lot of soft sediments like the Badlands, the water body will be very cloudy or turbid since the ground is easily eroded and is washed into the water during rain and snow melt.

Water can also be cloudy due to things like algae growth or microscopic aquatic animals living the water. Surface water is a habitat for both plants and animals.

But geology and living organisms are not the only factor in water transparency. Humans can impact the water as well in how they use the land. Crop agriculture which disturbs soil and urban development where sediment and pollutants run into the storm drains rather than soak into the ground will cause water to become cloudy.

This sequence of lessons below will help your students explore and explain the phenomena of water transparency. If you wish to extend the learning about water clarity you can also include dissolved oxygen, water temperature, and macroinvertebrate surveys for older students since they are measurements that can be impacted by water transparency. Of course other parameters such as pH and conductivity as can be included as part of a larger unit on water quality as the educator's time and equipment permit.

Pedagogy

The phenomena of water transparency can be presented after introductory activities about the hydrosphere and water cycle or it can be presented by itself. A constructivist approach calls for students to experience water clarity, ideally in a hands-on experiential way, before they experience the activities that explain how water can become cloudy. This approach heightens students' curiosity, engaging them in the question of why. Why is our water more/less clear than water in a different part of the state or country?

An important "hook" is comparing data since almost everyone I have worked with wants to know how their data stands in relation to other data. This is how, in part, we make sense of data.

Sequence

Below is a sequence of GLOBE and Project WET activities for a unit on water transparency.

  1. Introduction to the Hydrosphere Learning Objective: To understand the scope and structure of the hydrosphere.

    • Blue Planet/Drop in a Bucket Learning Objective: Be able to quantify the amount of water in the Earth (4-12)

    • Incredible Journey Learning Objective: Understand how water moves through systems and spheres. (4-8)

    • Seeing Watersheds Learning Objectives: To understand how watersheds, a major organizer of surface water, function. (4-12) Extension from Branching Out (WET 1.0), similar to Potato Island (4-12)

  2. Explore Phenomena - Water Transparency Learning Objective: Explain what water transparency is and how to collect the data.

  3. Explaining the Data Learning Objective: Explain the causes of water turbidity and why it varies according to location.

    • What is erosion (YouTube video) Learning Objective: Demonstrate how water erodes soil and how vegetation can influence erosion.

    • Project Seasons - Soil on the Run Learning Objective: Examine and explain erosion using a model.

    • Healthy Water, Healthy People - Turbidity or Not Turbidity Learning Objective: Explain how erosion impacts water transparency. (6-8)

    • Data comparisons Learning Objective: Apply understanding of South Dakota's geology to explain differences in water transparency readings. (4-12)

    • Project WET Guide 2.0* - Just Passing Through Learning Objective: Explain how vegetation cover (biosphere) interacts with the soil (pedosphere) to impact water transparency (hydrosphere). (4-8)

    • Project WET Guide 2.0* - Color Me a Watershed Learning Objective: Apply understanding of how changes in watershed impact water transparency. (6-12)

    • Project WET Guide 2.0* - Sum of the Parts Learning Objective: To understand man-made impacts on water transparency. (4-12)

  4. Extending the learning: Water Temperature and Dissolved Oxygen

  5. Extending the learning: Macroinvertebrates

    • Project WET Guide 2.0* - Water Quality: Ask the Bugs! (6-12) or Macroinvertebrate Mayhem (4-5) Learning Objective: To apply understanding of water quality impacts to aquatic life.

    • GLOBE Freshwater Macroinvertebrate Protocols. (8-12) Learning Objective: Collect and analyze macroinvertebrate samples.

    • Discovery Swap (4-8) Learning Objective: Observe, document and identify a macroinvertebrate.

6. Extending the learning: Nonpoint Source Pollution: Dead Zones and Oceans

* Project WET Guide 2.0 is available through online or in person trainings. See the Professional Development page for information on the online trainings. Contact Water Transparency Project coordinator for information about in person trainings.

Standards

Standards inform much of what is done in the classroom. The Water Transparency Project is designed to address multiple standards in both science and geography. Below are the science and geography standards that relate to water transparency. Also included are the relevant conceptual understandings for science

Fourth Grade

Conceptual Understanding: Four major Earth systems interact. Rainfall helps to shape the land and affects the types of living things found in a region. Water, ice, wind, organisms, and gravity break rocks, soils, and sediments into smaller pieces and move them around. Earth’s physical features occur in patterns, as do earthquakes and volcanoes. Maps can be used to locate features and determine patterns in those events.

  • 4-ESS2-1 Make observations and/or measurements to provide evidence of the effects of weathering or the rate of erosion by water, ice, wind, or vegetation. (SEP: 3; DCI: ESS2.A, ESS2.E; CCC: Cause/Effect)

  • 4-ESS2-2 Analyze and interpret data from maps to describe patterns of Earth’s features. (SEP: 4; DCI: ESS2.B; CCC: Patterns)

  • 4.G.2.1 Compare and contrast regions of South Dakota to one another

Fifth Grade

Conceptual Understanding: Four major Earth systems interact. Rainfall helps to shape the land and affects the types of living things found in a region. Water, ice, wind, organisms, and gravity break rocks, soils, and sediments into smaller pieces and move them around. Societal activities have had major effects on land, ocean, atmosphere, and even outer space. Societal activities can also help protect Earth’s resources and environments.

  • 5-ESS3-1 Obtain and combine information about ways individual communities use science ideas to protect the Earth’s resources and environment. (SEP:8; DCI: ESS3.C; CCC: Systems

Middle School

Conceptual understanding: Water movement causes weathering and erosion as well as changing landscape features. Human use of resources can have an impact on the Earth and its systems. Decisions to reduce the impact on Earth and its systems depend on understanding climate, science, engineering capabilities, and social dynamics.

  • MS-ESS3-3 Apply scientific principles to design a method for monitoring and minimizing a human impact on the environment.* (SEP: 6 ; DCI: ESS3.C; CCC: Cause/Effect, Technology)

  • MS-ESS3-4 Construct an argument supported by evidence for how increases in human population and per capita consumption of natural resources impact Earth’s systems. (SEP: 7; DCI: ESS3.C; CCC: Cause/Effect, Technology, Nature Science/Consequence-Actions)

  • 7.G.1.1 Gather information, analyze data and demonstrate navigation with a map

  • 7.G.1.2 Construct maps or other geographic representations and explain the spatial patterns of cultural and/or physical characteristics

High School

Conceptual Understanding: In South Dakota, the use, management, and protection of natural resources have an economic, social, environmental, and geopolitical impact. Human activities in agriculture, industry, and everyday life have major impacts on the soil, air, and water of South Dakota.

  • HS-ESS2-4 Plan and carry out an investigation of the properties of water and its effects on Earth materials and surface processes. (SEP: 2; DCI: ESS1.B, ESS2.A, ESS2.D; CCC: Cause/Effect)

  • HS-ESS3-6 Use a computational representation to illustrate the relationships among Earth systems and how those relationships are being modified due to human activity. (SEP: 5; DCI: ESS2.D, ESS3.D; CCC: Systems)

  • 9-12.G.7.1 Analyze key processes that have resulted in changes within Earth’s physical and human systems

  • 9-12.G.7.2 Elaborate upon the interaction of physical and human systems and their influence on current and future condition