Water on The Land Flashcards
What is a river’s course?
The path of the river as it flows downhill
Describe the valley and channel shape in the UPPER COURSE:
V-shaped valley, steep sides. Narrow, shallow channel
Describe the valley and channel shape in the MIDDLE COURSE:
Gently sloping valley sides. Wider, deeper channel
Describe the valley and channel shape in the LOWER COURSE:
Very wide, almost flat valley. Very wide, deep chanel
What effect does vertical erosion have?
It deepens the river valley and channel, making it V-shaped. Dominant in the upper course.
What effect does lateral erosion have?
Widens the river valley and channel. Dominant int he middle and lower course.
What are the 4 processes of erosion?
Hydraulic Action, Solution, Abrasion and Attrition
What are the 4 methods of transportation?
Traction, Solution, Saltation and Suspension
What is Hydraulic Action?
The force of the water breaks rocks and particles away from the river channel
What is Solution?
River water dissolves some times of rock, and carries the dissolved particles with it
What is Abrasion?
Eroded rocks picked up by the river scrape and rub against the channel, wearing it away.
What is Attrition?
Eroded rocks picked up by the river smash into each other and break into smaller fragments. Their edges are also rounded off.
What is Traction?
Large particles like boulders re rolled along the river bed by the force of the water.
What is Saltation?
Pebble sized particles are bounced along the river bed by the force of the water
What is Suspension?
Small particles like silt and clay are carried along by the water
What is deposition?
When a river drops eroded material as it looses velocity and energy