Section 1
Rivers Sculpt Valleys and Floodplains
Moving water creates V-shaped valleys in mountains and wide floodplains in lowlands. During floods, streams deposit sediment onto floodplains, making the soil fertile for growing crops.
In this Grade 6 Earth Science lesson from Chapter 5, students learn how moving water shapes Earth's surface through the processes of erosion and deposition, forming landforms such as floodplains, alluvial fans, and deltas. Students also explore how drainage basins and divides organize the flow of water across landscapes, and how water moving underground creates features like sinkholes and caves. A hands-on investigation connects these concepts by having students model how streams shape the land.
Section 1
Rivers Sculpt Valleys and Floodplains
Moving water creates V-shaped valleys in mountains and wide floodplains in lowlands. During floods, streams deposit sediment onto floodplains, making the soil fertile for growing crops.
Section 2
Streams Form Meanders and Oxbow Lakes
Water erodes the outside banks of streams while depositing sediment on inside banks, creating curved paths called meanders. When streams cut new paths during floods, abandoned meanders become crescent-shaped oxbow lakes.
Section 3
Moving Water Creates Fans and Deltas
Streams deposit sediment in fan-shaped patterns where they slow down. Alluvial fans form at mountain bases, while deltas develop where rivers enter oceans, building up land over thousands of years.
Section 4
Acidic Water Dissolves Underground Limestone
Rainwater containing mild acid seeps underground and dissolves limestone rock, creating caves and caverns. When cave roofs become too thin and collapse, sinkholes form on the surface.
Section 5
Divides Separate Water's Flow Direction
Ridge-like divides separate drainage basins, causing water to flow in different directions. The Continental Divide sends water west toward the Pacific Ocean or east to the Atlantic Ocean and Gulf of Mexico.
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Section 1
Rivers Sculpt Valleys and Floodplains
Moving water creates V-shaped valleys in mountains and wide floodplains in lowlands. During floods, streams deposit sediment onto floodplains, making the soil fertile for growing crops.
Section 2
Streams Form Meanders and Oxbow Lakes
Water erodes the outside banks of streams while depositing sediment on inside banks, creating curved paths called meanders. When streams cut new paths during floods, abandoned meanders become crescent-shaped oxbow lakes.
Section 3
Moving Water Creates Fans and Deltas
Streams deposit sediment in fan-shaped patterns where they slow down. Alluvial fans form at mountain bases, while deltas develop where rivers enter oceans, building up land over thousands of years.
Section 4
Acidic Water Dissolves Underground Limestone
Rainwater containing mild acid seeps underground and dissolves limestone rock, creating caves and caverns. When cave roofs become too thin and collapse, sinkholes form on the surface.
Section 5
Divides Separate Water's Flow Direction
Ridge-like divides separate drainage basins, causing water to flow in different directions. The Continental Divide sends water west toward the Pacific Ocean or east to the Atlantic Ocean and Gulf of Mexico.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter