Topic 1-Rivers Flashcards
Define velocity and discharge
Velocity: This is speed at which water flows
Discharge: This is the volume of water flowing through a river.
Define Interlocking Spurs?
Near their source, rivers are small and do not have a lot of power. They tend to flow around the slopes of a valley called spurs. Rather than being able to erode them the spurs are left interlocking. This is where one side of the valley overlaps with the spurs from the other side.
What is mass movement?
Mass movement: this is the movement of rocks and soil down the slope due to gravity. There are a few types: soil creep which is where individual particles of soil move slowly down the slope, sliding and slumping where material moves rapidly down the slope in one go ( landslide). In a slump material often rotates as it moves.
Flows: masses of soil or rock usually mix with water flow like liquid down the side.
Define a Levees?
Formed in the lower cause of the river and made through deposition of materials from earlier causes of the river. Levees are raised banks on the lower course of the river.
What are the dIfferent features of a river?
The source: is where the river starts it could be a spring, a lake, a melting glacier or a hollow where a lot of water is collected. The area surrounding the location is known as the river basin as it adds to the river.
Tributaries: they are smaller rivers that join main rivers.
The watershed: this is the divided ln between the river basis Nd the next river basin. It is usually a ridge of higher land.
Valley: an area with higher land on either side.
Confluence: Is the point where two rivers join.
Floodplain: it is the flat land beside the river which may flood when the river overflows.
The Mouth: this is where the river flows into the lake or the sea. A wide river mouth into the sea is called an estuary. Here fresh water mixes with sea water.
Define scree?
Loose pieces of rock with sharp edges. they are broken off by freeze thaw action, then they roll down the mountains and gather at the end of a slope
Define an Oxbow lake?
An oxbow lake starts as a meander during a flood, which cultus across the meander forming a new channel. Sediment is deposited across the sides of the new channel. The loop gets sealed off and an oxbow lake is formed.
Name the 3 types of weathering:
Chemical weathering such as, acid rain.
Biological Weathering such as, plants growing into rock cracks.
Mechanical Weathering such as, freeze-thaw weathering.
What are the four types of erosion?
Attrition: rocks and stones knock each other and seat each other away.
Abrasion: sand and stones scrap the banks and bed of a river which wears them away.
Solution: water dissolves solvable minerals so slowly the bed and banks are worn away.
Hydraulic Action: water is forced into cracks in the bank which breaks up the bank
Define Meander?
Water flows fastest on the outer curve of the bend, and slowest on the inner curve. The outer curve gets eroded whereas material is deposited in the inner curve. Over time the outer bank gets worn away and the inner one becomes built up. The bend then grows into a meander.
What is a V-shaped valley?
A Shape Valley: Through the process of erosion this land form
Is created. What happens is the sides collapse on the river banks of a river from the repeated process of erosion this slowly takes the form of a V-Shape ValLEY.
