Chapter 5 : Rivers Flashcards
River Thames. The water cycle. How rivers shape the land. Landforms created by rivers. Thames estuary. Floods. Flood protection.
How is a waterfall formed?
1 : Soft rocks is eroded first, leaving the hard rock to erode slowly.
2: The water continues to erode the soft rock, leaving a ledge and making the pool of water below deeper and wider.
3: Over time, the hard rock is eroded and the ledge falls into the pit of water.
4: The steps are repeated
What is an oxbow lake?
An oxbow lake is a U-shaped lake near the river. It is a meander that was cut off from the river.
How is an oxbow lake formed?
An oxbow lake is formed when erosion causes a meander to get narrower and narrower. The river takes and shortcut and eventually, the meander is cut off from the river.
What is a meander?
A meander is a bend or curve in a river.
Name 4 keywords from erosion
Solution, hydraulic action, attrition, abrasion
What are the river processes?
Erosion, transportation and deposition
Name 4 keywords from transportation
Traction, suspension, solution, saltation
What takes place in the upper course of the river’s long profile?
Erosion
What takes place in the lower course of the river’s long profile?
Deposition
What takes place in the middle course of the river’s long profile?
Both erosion and deposition
What does erosion mean?
Erosion means to wear away
What is the difference between traction and saltation?
Traction is larger rocks and stones roll along the river bed. Saltation is when smaller stones bounce along the river bed.
Explain abrasion.
Abrasion is when rocks and stones hit and scrape against the river bed, wearing it away.
Explain attrition.
Attrition is when rocks and stones hit and scrape against each other, wearing each other away.
Explain solution (in erosion)
Water dissolves soluble materials from the beds and banks.
Explain bedload.
Bedload is when heavier materials are carried along the river bottom.
Explain suspension.
Suspension is when small particles of rocks and sand are carried along, causing the water to appear muddy.
What is a confluence?
The point where two rivers meet.
What is the start of a river called?
The source
What is the mouth of a river?
The mouth of the river is where the river joins the sea
List the steps on how rainwater reaches the river
What is the flat land beside the river which may flood?
Floodplain
What is a tributary?
Tributaries are smaller rivers that join the main one.
The dividing line between one river basin and the next is the
watershed
What is hydraulic action?
Hydraulic action is when the pressure from the water forms cracks in the river’s banks.
