Restless Earth
GCSE Geography| Topic 2| Water On The Land What are the Key Ideas for this Topic?
The Shape of river valleys changes as the river flows downstream
River Features & Landforms
Storm Hydrographs
Flooding in MEDC’s and LEDC’s
Hard and Soft Strategies for River Management and Reservoirs
The Shape of river valleys and River Processes
A rivers long profile changes over its course.
Every river has:
An Upper Course
Middle Course
Lower Course
Long Profile- shows how the gradient of a river changes along its length.
Cross Profile- shows what a cross section of a river looks like at a specific point.
Why does the upper course have a different cross profile from the lower course?
In the upper course of a river valley, vertical erosion is dominant.
This makes the valley shallower than in the lower course.
In the lower course of the river valley, lateral erosion is denominate.
This makes the valleys much wider than the upper course.
Erosion, Transportation & Deposition
Erosion
Erosion-the process of the river bed, sediment and valley being gradually worn away. There are four types of erosion:
Hydraulic Action: The force of the water breaks down particles away from the river channel.
Abrasion: Eroded rocks picked up by the river scrape and rub against the channel, wearing it away. Most erosion happens by abrasion.
Attrition: Eroded rocks picked up by the river smash into each other and break into smaller fragments. Their edges become rounded as they rub together.
Solution: River water dissolves some types of rock, e.g. chalk and limestone.
Transportation
Transportation - the process of a rivers eroded material moving downstream. This also happens in four different ways:
Traction: Large particles like boulders are pushed along the river bed by the force of the water.
Saltation: Pebble sized particles are bounced along the river bed by the force of
The Shape of river valleys changes as the river flows downstream
River Features & Landforms
Storm Hydrographs
Flooding in MEDC’s and LEDC’s
Hard and Soft Strategies for River Management and Reservoirs
The Shape of river valleys and River Processes
A rivers long profile changes over its course.
Every river has:
An Upper Course
Middle Course
Lower Course
Long Profile- shows how the gradient of a river changes along its length.
Cross Profile- shows what a cross section of a river looks like at a specific point.
Why does the upper course have a different cross profile from the lower course?
In the upper course of a river valley, vertical erosion is dominant.
This makes the valley shallower than in the lower course.
In the lower course of the river valley, lateral erosion is denominate.
This makes the valleys much wider than the upper course.
Erosion, Transportation & Deposition
Erosion
Erosion-the process of the river bed, sediment and valley being gradually worn away. There are four types of erosion:
Hydraulic Action: The force of the water breaks down particles away from the river channel.
Abrasion: Eroded rocks picked up by the river scrape and rub against the channel, wearing it away. Most erosion happens by abrasion.
Attrition: Eroded rocks picked up by the river smash into each other and break into smaller fragments. Their edges become rounded as they rub together.
Solution: River water dissolves some types of rock, e.g. chalk and limestone.
Transportation
Transportation - the process of a rivers eroded material moving downstream. This also happens in four different ways:
Traction: Large particles like boulders are pushed along the river bed by the force of the water.
Saltation: Pebble sized particles are bounced along the river bed by the force of