Erosion Flashcards
What is erosion?
Erosion is the process that wears away the river bed and banks. And also breaks up the rocks that are carried by the river
How many types of Erosion are there?
4
What are the names of the 4 types of erosion?
Hydraulic action, Abraision, Attrition , solution
What is Hydraulic action?
The power of the water of the river as it smashes against the river banks. And air becomes trapped in the cracks of the river banks and bed and causes the rocks to break apart.
What is Abrasion?
when pebbles grind along the river bank and bed in a sand-papering way
What is Attrition?
When rocks that the river is carring they knock against each other. They break apart to become smaller and more rounded.
What is Solution?
When the water dissolves certain types of roks e.g. limestone.
What is the name of Erosion that is like sandpaper to the riverbed?
Abrasoin
Name 4 factors that affect the rate of River Erosion
- Gradient
- Rock Resistence
- Discharge (The amount of water flowing per second)
- Velocity
How does Gradient affect Erosion?
A steep gradient pulls the water down cutting and eroding the channel
How does Rock Resistance affect erosion?
If the rock is more erodible (soft rock) it will erode quicker than harder rocks
How does Discharge affect erosion?
The more water in the river the more power it has
Explain a V-Shaped Valley - Exam Response
See page 14 of PP 18/10
- The River erodes downwards
- Boulders, Stones & Rock particles
are bounced & scraped along the
channel bed - The river cuts down
- The steep sides are weathered
- This breaks up and loosens the
Soil & Rock - This material is then pulled by
gravity down the slope or washed
into the river by rainwater.
THE END RESULT IS A STEEP SIDED VALLEY WITH THE SHAPE OF THE LETTER V
What is an interlocking spur
Where a river flows around harder rock it cannot cut through to form spurs
