Streams and Rivers cont’d Video: Grand Canyon Sediment Transport

Velocity (all notes) The speed at which a river flows. Greater velocity = greater Erosion

Velocity In a straight channel: Fastest toward the center Fastest just below the surface

Factors Affecting Velocity Slope: The steeper the gradient, the faster the stream. Discharge: The more water present, the faster the stream Width of the Channel: the more narrow the channel, the faster the stream *Remember the garden hose*

Velocity and Meanders Water moves faster on the outside curve. Water moves slower on the inside curve.

Velocity and Sediment Size The greater the velocity, the greater the sediment size which can be carried.

Deposition The leaving behind (dropping) of sediment as the stream’s velocity slows Gradual process

Factors affecting Deposition Particle Size: the largest particles drop out first. Particle Shape: Round particle settle faster Particle Density: Denser particles settle faster.

Sorting Since sediment drops out in stages, deposition by streams creates layers. Layers can be horizontal or vertical.

Horizontal Sorting Large particle fall close to shore Smaller particles settle out further from shore Streams emptying into oceans

Vertical Sorting Occurs when sediment is deposited in calm water ( ex. a lake) Large particles on the bottom, smallest on top.

Meanders and Deposition As water slows down on the inside curve, sediments drop out creating a point bar.