Erosion and Deposition by streams
bvbjordynErosion and Depostion by streams
By Jordyn Carselli
Factors that influence stream velocity
Velocity: Speed; change in distance divided by change in time; sometimes velocity is used to include both speed and direction
1. slope: Where a stream flows down a steep slope velocity will increase which will result in increased erosion. Where that stream then flows onto a gentler slope velocity decreases and deposition will result. This process will reduce the slope of steep stretches and increase the slope of flatter stretches resulting in a more even slope through the course of the stream.
2. Age:Youthful Stream Valleys have steep-sloping, V-shaped valleys and little or no flat land next to the stream channel in the valley bottom. Mature Stream Valleys have gentle slopes and a flood plain; the meander belt width equals the flood plain width.Old Age Stream Valleys have very subdued topography and very broad flood plains; the flood plain width is greater than the meander belt width.
3. Channel: Depends on how clearly the path is, and how wide the width is.
4. Shape: The particles shape depends on how fast or slow the rate of settling is.
Pg 6 ESRT
Stream features
Meander
V-Shaped valley
Flood plains
Deltas
Av-shaped valley is a stream feature because it affects the speed of water in the streams.
Deltas are stream features because they form from deposition of sediment carried by a river as the flow leaves its mouth. Over long periods, this deposition builds the characteristic geographic pattern of a river delta.
Flood plains are stream features because the flat region next to a stream or river that can be covered by water, and is naturally subject to flooding.
A meander is a stream feature because it is a curve that develops in the path of a river when the river flows over relatively flat land.
Factors that influence the deposition of transported particles
Watershed: an area or ridge of land drained by a particular river, or stream; drainage basin.
Size: The smaller particles settle more slowly than the larger particles, due to the pull of gravity. The smaller particles tend to stay in suspension for longer periods of time.
Velocity: The velocity of the transporting stream determines when sediments will be deposited. If the stream slows down during a drought period the carrying power will decrease and the particle sizes carried and deposited will also decrease. If a stream is flowing faster due to flood conditions then the carrying power of the stream will increase and the sizes of particles deposited will increase as well.
Density: The density of particles also influences the rates at which sediments settle out of running water and wind. If particles are the same size but have different densities the higher density particle will settle faster.
Weather: The weather affects the transportation depending on if there is wind, ice, and water.
Weight: The weight depends on the type of rock and what has happened to it.
Different types of sorting of sediments by a stream
The different types of sorting by sediments in a stream is horizontal and vertical sorting. Horizontal sorting is when a form of graded bedding that occurs at the bottom of a body of water. The principle says that smaller colloids (particles) settle farther in the strata while larger particles settle closer to the source of water. Vertical sorting is alignment of sediments in vertical position. Vertical sorting is alignment of sediments in vertical position. the sedimentation of mixed particles in order of big, medium, small.
