Erosion and Deposition: Moving Earth Materials

Active learning works well for this topic because students need to visualize processes they cannot easily observe. Hands-on simulations and collaborative discussions help them connect abstract concepts like energy loss in deposition to concrete outcomes. These methods also address common misconceptions by exposing students to the full range of erosion agents beyond rivers and oceans.

• 7th Grade
• Science
• 3 activities
• 25 min–55 min

Learning Objectives

1. Compare and contrast the erosional and depositional landforms created by glacial and riverine processes.
2. Explain the role of vegetation in mitigating soil erosion by analyzing case studies.
3. Analyze how specific human activities, such as deforestation and urbanization, accelerate natural erosion rates.
4. Design a model that demonstrates the transport and deposition of sediment by wind or water.

Simulation Game

⏱ 55 min·Small Groups

Simulation Game: Stream Table Erosion and Deposition

Groups use sand trays with a slight slope and add water to simulate a stream. First, they observe erosion and deposition patterns on bare sand. Then they add moss, grass plugs, or sponge pieces as 'vegetation' for a second run. Students compare channel shape, amount of material removed, and deposition patterns between runs and connect their findings to the role of vegetation in preventing soil loss.

Prepare & details

What role does vegetation play in preventing the loss of soil?

Facilitation Tip: During the Stream Table Erosion and Deposition activity, circulate with guiding questions to help students notice how slope and water volume change sediment transport.

Setup: Flexible space for group stations

Materials: Role cards with goals/resources, Game currency or tokens, Round tracker

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Think-Pair-Share

⏱ 25 min·Pairs

Think-Pair-Share: Human Acceleration of Erosion

Show before-and-after satellite images of an area before and after deforestation or major construction. Students individually estimate the change in erosion rate and list the specific factors responsible, then share with a partner. The class discusses management practices (cover crops, silt fences, terracing, riparian buffers) that could reduce the erosion rate.

Prepare & details

How do human activities accelerate the natural process of erosion?

Facilitation Tip: In the Human Acceleration of Erosion Think-Pair-Share, provide real-world photos of construction sites or farmland to anchor the discussion in observable evidence.

Setup: Standard classroom seating; students turn to a neighbor

Materials: Discussion prompt (projected or printed), Optional: recording sheet for pairs

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

Gallery Walk

⏱ 40 min·Small Groups

Gallery Walk: Erosional and Depositional Landforms

Post eight stations with photographs and brief descriptions of landforms created by different agents: a river delta, a glacial U-shaped valley, a desert sand dune, an alluvial fan, a sea stack, a loess deposit, a landslide scar, and an oxbow lake. Groups rotate and match each landform to its erosion agent, noting one observable feature that distinguishes it from a landform made by a different agent.

Prepare & details

Compare and contrast the erosional and depositional features created by glaciers and rivers.

Facilitation Tip: For the Gallery Walk of Erosional and Depositional Landforms, assign small groups to prepare a 60-second explanation of their landform’s formation process before rotating.

Setup: Wall space or tables arranged around room perimeter

Materials: Large paper/poster boards, Markers, Sticky notes for feedback

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Teaching This Topic

Teachers should avoid presenting erosion as a single process limited to water. Instead, frame it as a set of mechanisms that vary by environment and energy level. Research suggests students grasp these concepts better when they first explore one agent through simulation, then compare across agents. Emphasize the role of energy loss in deposition, as this concept unifies many examples.

What to Expect

Successful learning looks like students accurately explaining how different agents move and deposit sediment. They should connect process to landform, such as linking glaciers to U-shaped valleys or wind to sand dunes. Evidence of understanding includes correctly labeling landforms in a gallery walk and citing specific examples in discussions.

Watch Out for These Misconceptions

Common Misconception

During the Stream Table Erosion and Deposition activity, watch for students who assume all erosion happens in water. Redirect them by asking: 'Where else might sediment move if water isn’t present?'

What to Teach Instead

During the Think-Pair-Share on Human Acceleration of Erosion, have students analyze an image of a desert dust storm or a hillside landslide to recognize wind and gravity as major agents.

Assessment Ideas

Quick Check

After the Gallery Walk of Erosional and Depositional Landforms, provide images of new landforms and ask students to identify the primary agent and explain their reasoning in 2-3 sentences.

Discussion Prompt

During the Think-Pair-Share on Human Acceleration of Erosion, listen for students to describe how deforestation increases runoff and how terracing can reduce erosion on steep slopes.

Exit Ticket

After the Stream Table Erosion and Deposition activity, students receive a card with the prompt: 'Explain how a decrease in slope changes deposition at the mouth of the stream table.' They write a response citing evidence from their observations.

Extensions & Scaffolding

• Challenge early finishers to design a landform with two agents working together, such as a river depositing sediment at the base of a glacier’s terminal moraine.
• Scaffolding for struggling students: Provide a word bank of landforms and agents during the gallery walk to reduce cognitive load.
• Deeper exploration: Ask students to research a local landform and trace its erosional and depositional history using digital mapping tools.

Key Vocabulary

Erosion	The process by which soil, rock, and sediment are worn away and transported by natural forces like water, wind, ice, or gravity.
Deposition	The geological process in which sediments, soil, and rocks are added to a landform or landmass, occurring when the transporting agent loses energy.
Mass Wasting	The downslope movement of rock, regolith, and soil under the direct influence of gravity, such as landslides and mudflows.
Alluvial Fan	A fan-shaped deposit of sediment formed where a stream emerges from a narrow valley onto a plain.
Glacial Till	Unsorted sediment deposited directly by a glacier, often containing a wide range of particle sizes from clay to boulders.