3-3 The force of moving water
Wind, erosion, and deposition may form sand dunes and loess depositis. (A loess deopsit is wind formed deposit made of fine particles of clay and silt.)
As repeated waves hit the beach, some of the beach sediment moves down the beach with the current, this is a process called Longshore drift.
Most sediment washes or falls onto the river as a result of mass movement and runoff. The other sediment erodes from the bottom or sides of the river.
ABRASION~~ The waering away of rock by grinding action. This occurs when particles of sediment in flowing water bump into into the streambed again and again.
Abrasion causes sediment particles to grind down. For an example, large boulders become smaller as they are moved down a streamed.
The power of a river to cause erosion and carry sediment depends on several factors.
A river's slope, volume of flow, and the shape of tis streambed all affect how fast the river flows and how much sediment it can erode.
SLOPE~~ A river's slope is the amount the river drops toward sea level over a given distance.
VOLUME OF FLOW~~ A river's flow is the volume of water that moves past a point on the river in a given time.
During a flood, the increased volume of water helps the river to cut more deeply into its banks and bed.
The volume of flow may move huge boulders as if they were pebbles.
STREAMBED SHAPE~~ A streambed's shape affects the amount of friction between the water and the streambed.
TURBULENCE~~ Instead of the water in a river moving downstream, the water that is turbulence moves in every which way in a type of movement.
As repeated waves hit the beach, some of the beach sediment moves down the beach with the current, this is a process called Longshore drift.
Most sediment washes or falls onto the river as a result of mass movement and runoff. The other sediment erodes from the bottom or sides of the river.
ABRASION~~ The waering away of rock by grinding action. This occurs when particles of sediment in flowing water bump into into the streambed again and again.
Abrasion causes sediment particles to grind down. For an example, large boulders become smaller as they are moved down a streamed.
The power of a river to cause erosion and carry sediment depends on several factors.
A river's slope, volume of flow, and the shape of tis streambed all affect how fast the river flows and how much sediment it can erode.
SLOPE~~ A river's slope is the amount the river drops toward sea level over a given distance.
VOLUME OF FLOW~~ A river's flow is the volume of water that moves past a point on the river in a given time.
During a flood, the increased volume of water helps the river to cut more deeply into its banks and bed.
The volume of flow may move huge boulders as if they were pebbles.
STREAMBED SHAPE~~ A streambed's shape affects the amount of friction between the water and the streambed.
TURBULENCE~~ Instead of the water in a river moving downstream, the water that is turbulence moves in every which way in a type of movement.
checkpointWhat are Potential and kinetic energy?
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section reviewHow can moving water on Earth's surface do work?
How does a river collect sediment? What are three factors that affect a river's sediment load? Describe three ways that sediment moves in a river? What effect does increased slope have on a river's speed and sediment load? Explain. |
key ideasWhen gravity pulls water down a slope, water's potential energy changes to kinetic energy, and it does work.
Most sediment washes or falls into streams, or is eroded from the streambed by abrasion. The greater a river's slope or volume of flow, the more sediment it can erode. |
key termsenergy
abrasion friction potential energy load turbulence Kinetic energy |