Chapter 4 Erosion and Deposition

Lesson 1Water Erosion

How does Moving Water Cause Erosion?

Erosion is the process in which sediment that has been broken down through weathering is moved.Agents of Erosion are:1. Water2. Wind3. Glacial (ice)4. WavesMoving water is the major agent of the erosion that has shaped Earth’s land surfaces.

Water Erosion

Water causes erosion through the following ways:1. Runoff2. Stream and rivers3. Ground water

Water Erosion: Runoff

Runoff is water that is moving over land, usually downhill.As water moves over the land it carries particles with it, as these particles and sediment are moved, the shape and surface of the land changes.

Stream and River FormationStreams are formed from runoff flowing down hill. As the water flows and carries particles, different stream formations begin to form.1. Rills and Gullies2. Streams and rivers3. Tributaries

Rills and Gullies

Rills and Gullies are small tiny grooves formed by running water down a hill. Rills are small and as they become bigger they become gullies.

Streams and Rivers

Gullies join together to form a larger channel called a stream.A stream is a channel in which water is constantly flowing down a slope.Eventually a stream can meet up with other streams and create larger channels of continues water called rivers.

Water Erosion

Water erosion is the movement of particles, sediment and such through the means of flowing water.Through erosion a river creates valleys, waterfalls, flood plains, meanders, and oxbow lakes.

Water Deposition

Deposition is the process in which sediment that has being moved lands and deposits itself somewhere new.Deposition creates landforms such as alluvial fans and deltas.

Alluvial fansAn alluvial fan is a wide, sloping deposit of sediment formed where a stream leaves a mountain range.

Deltas

A delta is the result of a landform that has being created from sediment deposited where a river flows into an ocean or lake.