Delta: The Formation and Characteristics

A delta is a landform that forms at the mouth of a river, where it meets a body of water, such as an ocean or a sea. Deltas are unique and complex landforms that are shaped by the deposition of sediment carried by the river. They are important ecological areas and are often home to diverse wildlife and vegetation.

Formation of a Delta

1. Erosion: The river carries sediment and erodes the land upstream. This sediment is then transported downstream towards the river mouth.

2. Deposition: As the river reaches the body of water, its velocity decreases, causing it to deposit the sediment it carries. Over time, this deposition builds up to form the delta.

3. Progradation: The deposition of sediment continues to extend the delta outward into the body of water, creating new land.

Characteristics of a Delta

1. Multiple Channels: Deltas often have multiple distributaries, or channels, through which the river water flows into the body of water.

2. Sediment Layers: Deltas are comprised of distinct layers of sediment, with the coarsest material found closest to the river mouth and the finest material farther out.

3. Wetlands: Deltas are characterized by wetlands and swamps, which provide important habitats for various species of plants and animals.

4. Shape Changes: Deltas are dynamic and constantly changing due to the deposition and erosion of sediment, as well as the influence of tides and currents.

Study Guide

1. What is a delta?
A delta is a landform that forms at the mouth of a river, where it meets a body of water.

2. How does a delta form?
A delta forms through the erosion and deposition of sediment carried by a river, leading to the buildup of land at its mouth.

3. What are the characteristics of a delta?
Deltas have multiple channels, distinct sediment layers, wetlands, and are constantly changing in shape.

4. Why are deltas important?
Deltas are important ecological areas and provide habitats for diverse wildlife and vegetation.

Now that you have learned about the formation and characteristics of deltas, you can explore further by studying specific examples of famous deltas around the world, such as the Nile Delta or the Mississippi Delta.

[Delta] Related Worksheets and Study Guides:

• Weathering of rocks and soil formationScience • Seventh Grade
• Agents of Erosion and DepositionScience • Seventh Grade