EQ4 Flashcards
What is meant by the long profile of the river
The long profile of a river shows river gradient changes as it flows from the source to mouth
How does the river landscape change along its profile
As you go down the river the gradient will decrease , it will be highest at the source and slowly decrease
As you go down the flood plain becomes a lot wider because there is more river discharge that erodes away at the edges of the river
Bed load size will also decrease because there is a higher velocity downstream meaning the rocks will erode quicker and become smoother
Compare hydraulic action and abrasion
Hydraulic action is when water hits the cliff face eroding it while abrasion is when the water body chucks the rocks at the cliff face . Or when the water erodes the water bed
Define weatherinb
When rocks are slowly worn away due to physical, human or chemical factors
Compare freeze thaw weathering and biological weathering
Freeze thaw is when water gets into permeable rock and slowly freezes over time due to this the rock cracks while biological weathering has nothing to do with water it is about when animals or roots wear away from the rock
What is traction
What is suspension
Large boulders rolling on the sea bed
Water transports small rocks
How is waterfalls formed
Often in upper stages of river . Water flows over different bands of soft and hard rock. It erodes over time meaning the soft rock can no longer keep up the hard rock . The overhang collpases forming a plungepool. The waterfall retreats back over time due to constant erosion
How are u shaped valleys formed
Rivers high in the mountains flow down eroding the landscape vertically. The river cuts a deep notch into the landscape. As the river erodes more the valleys rock is exposed to more freeze thaw weathering which will loosen it . When the rock falls the valley sides begin to steepen helping with erosion . The rocks are transported downstream and the channel becomes wider creating a v-shape with interlocking spurs
How do interlocking spurs form
As the river erodes the landscape in the upper course bit begins winding and and swerving trying to avoid soft rock creating a zipper shape .
How do meanders form
In the middle course in the river there is more energy and a high volume of water in a narrow space . Due to this it erodes lateral to the right and left which eventually forms a bend .
How does an oxbow lake form
After a long period of time the meander becomes very curved and eventually turns narrower and the river cuts off forming an oxbow lake
How does a flood plain form
They are made by a meander eroding sideways as it travels downstream , when a river breaks its banks it leaves behind alluvium . This gradually builds up forming a flood plain
How do levees form
The natural movement of a water body pushes sediment up to the side creating a natural levee . The banks of a river are often elevated
How do deltas form
When a river reaches a lake or the sea water it slows down and drops the sediment it was carrying if not transported it will build up forming deltas
How does climate change effect the river landscape
FOR every one degree of increase you are able to store 6 percent more water vapor. More water vapor will lead to higher concentrations of precipitation which will fill up water bodies quicker leading to an increase of floods
