🎯 Learning Intention

I will understand how coordinate systems and projections affect the accuracy and appearance of digital maps.

✅ Success Criteria

I can explain the difference between geographic and projected coordinate systems and describe why distortion occurs.

🌍 Why Are We Learning This?

All maps lie—but good cartographers know how and why. Understanding coordinate systems ensures accuracy in GIS analysis and decision-making.

💻 Formative Lecture

Topic: Understanding Map Distortion

• Geographic Coordinate System (GCS): uses latitude & longitude on a curved Earth.
• Projected Coordinate System (PCS): flat map projection optimized for area, distance, or shape.
• Examples: Mercator, Lambert, Robinson.
• Demonstrate in ArcGIS: switch projection and watch the world “stretch.”

Check for Understanding:

Why can’t we map the round Earth on a flat surface without distortion?

🧰 Work Time

• Students open ArcGIS Online → Map Viewer → Change Projection.
• Observe how shape and scale shift under different systems.
• Record one note per projection in journal or shared doc.

🌀 Wrap-Up

Discuss: Which projection would you trust for measuring land area? Why?