Unit Plan 29 (Grade 4 Science): Weathering & Erosion

Focus: Measure and observe the effects of weathering and erosion by water, ice, wind, and vegetation, and explain how these processes shape Earth’s surface over time.

Grade Level: 4

Subject Area: Science (Earth Science)

Total Unit Duration: 5 sessions (one week), 50–60 minutes per session

I. Introduction

In this unit, students explore how Earth’s surface is constantly changing through weathering (breaking rocks into smaller pieces) and erosion (moving those pieces). Through hands-on investigations, simple measurements, and before/after comparisons, they observe the effects of water, ice, wind, and plant roots. Students connect their observations to real-world landforms like cliffs, riverbanks, and hillsides, and explain how small changes over time can create big differences in landscapes.

Essential Questions

• How do weathering and erosion change rocks and soil over time?
• What roles do water, ice, wind, and vegetation play in shaping Earth’s surface?
• How can we use measurements, diagrams, and models to show evidence of weathering and erosion?
• Why does it matter for people and communities to understand how the land is changing?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Describe and distinguish between weathering (breaking down) and erosion (moving) of rock and soil.
2. Make observations and/or measurements of simple models (e.g., stream tables, ice-in-cracks models, wind trays) to provide evidence of weathering or erosion.
3. Compare “before and after” surfaces using drawings, photos, or simple measurements (e.g., depth of channels, amount of material moved).
4. Explain how water, ice, wind, and vegetation can each contribute to changing Earth’s surface in different ways.
5. Use their investigation results to create a Weathering & Erosion Explanation that links evidence to changes in landforms.

Standards Alignment — 4th Grade (NGSS-Aligned)

• 4-ESS2-1 — Make observations and/or measurements to provide evidence of the effects of weathering or water/ice/wind erosion.
  • Example: Compare how a slope looks before and after water is poured over it, or measure how far soil moves in a wind or water tray.

Success Criteria — Student Language

• I can explain the difference between weathering (breaking) and erosion (moving).
• I can observe or measure changes in a model to show that weathering or erosion happened.
• I can describe how water, ice, wind, or plants changed the land in our investigations.
• I can create a model or diagram that shows before and after changes to a land surface.
• I can write or say an explanation that uses evidence from my investigations to show how Earth’s surface changes over time.