Physical UK Landscapes Flashcards
What are the characteristics of a rivers upper course?
Steep, v shaped, steep sides, narrow, shallow
What are the characteristics of a rivers middle course?
Medium gradient, gentle sloping sides, wider, deeper
What are the characteristics of a rivers lower course?
Gentle gradient, very wide, almost flat valley sides, deep
What is vertical erosion?
Erosion that deepens the valley making a v shape. It is dominant in the rivers upper course due to rough particles being scraped along the river bed
What is lateral erosion?
Lateral erosion widens the river valley during the formation of meanders and it is dominant in the middle and lower courses
Outline the four types of erosion.
Hydraulic action
Abrasion
Attrition
Solution
Outline the four types of transportation.
Traction
Salutation
Solution
Suspension
What is hydraulic action?
A type of erosion where the force of the water breaks rock away from the river channel
What is abrasion?
A form of river erosion where rocks picked up by the river and scrape the channel bed, wearing it away. This is the most common erosion
What is attrition?
A from of erosion where eroded rocks smash into each other and break into smaller fragments, it causes the size of sediment to decrease between the source and mouth
What is solution?
A type of erosion where rocks are dissolved by the river
A type of transportation where rocks and minerals are dissolved and carried down the river
What is traction?
A form of transportation where large particles like boulders are pushed along the river bed by the force of the water
What is saltation?
A form of transportation where pebble sized particles are bounced along the river bed by the force of the water
What is saltation?
A form of transpiration where small particles are carried along by the water, suspended in it.
How are waterfalls formed by erosion?
They form where hard rock meets soft rock.
The softer rock is eroded more than the hard rock cresting a step in the river
As the water goes over the step it erodes the softer rock more and more which creates a waterfall
How are gorges formed by erosion?
Where a waterfall is present.
The softer rock underuse the hard rock and it collapses
The collapsed rock swirls around in the waterfalls plunge pool eroding the soft rock further
More undercutting causes the river to retreat further creating a steep sided gorge
Explain the creation of interlocking spurs?
In a rivers upper course most erosion is vertical this creates steep sided valleys.
Because the aren’t powerful enough to erode laterally they wind around mountains
The hillsides that interlock with a river in the middle are called interlocking spurs
how is a meander formed by erosion and deposition?
Rivers have a faster current on the outside of a bend due to less friction.
So more erosion takes place on the outside which forms cliffs
Eroded material is deposited on the inside of the meander due to a lack of force to carry the sediment
Describe the characteristics and formation of a floodplain.
Floodplains are wide valley floors which get flooded
When a river floods it deposits material which increase the height of a floodplain
Explain the characteristics and formation of a levee
Levees are natural embankments along the edge of rivers
They are formed when eroded material is deposited in a floodplain
Heavier materials drop closer to the river creating levees
What are the characteristics of estuaries
They are areas at the mouth of the river where the valley is near sea level
Here, the river level increase and decreases daily
When the river is high material is deposited creating mudflats
What is slip of slope?
An area in a meander where deposition occurs
Where can you find an estuary?
They are the transitional zone between river and coastal environments
What are pools?
Pools are normally found on the outside of a meander that are normally deep and the fast flow erodes a deep pool
What are riffles?
Riffles are shallow areas in a river, normally caused by the deposition of cause sediment
What is the example of a river valley?
River tees
Through which towns does the river tees run?
Darlington and Middlesbrough
What is the main landform that can be found on the river tees?
The high force waterfall can be found along with a gorge. The water drops 20m and was formed due to a resistant band of igneous rock.
What is igneous rock?
Cooled volcanic lava
Outline the physical factors effecting flood risk.
Precipitation
Geology
Steep slopes
Outline the human factors effecting flood risk.
Urbanisation
Deforestation
Agriculture
How can precipitation contribute to flood risk?
Torrential rain can lead to flash floods as rivers cannot hold the large amount of water
How can geology contribute to flood risk?
Impermeable rock such as clay can encourage water to flow overland j to rivers, causing flooding to be more likely
How can steep slopes contribute to flood risk?
They encourage a rapid transfer of water towards river channels
How can urbanisation contribute to flood risk?
Building on a floodplain creates impermeable surfaces like tarmac. The rapid movement of water makes flooding more likely
How can deforestation contribute to flood risk?
Water that falls on trees is transpired or stored. When trees are removed more water is suddenly available