Uk Physical Landscape Flashcards
Igneous rock
Earths oldest rock. Formed from lava and magma
Most igneous are resistant to erosion
Granite, basalt
Sedimentary rock
Formed from sediments eroded and deposited by rivers, the sea or on the sea bed
Limestone, shale
Metamorphic
Sedimentary rocks that were heated and compressed during igneous activity
Slate, marble
What is scree
Rock fragments on the ground due to freeze thaw weathering
One way human activity has influenced UK’s landscape
In the Yorkshire dales a lot of farming took place therefore farming may harm the environment.
Trees and other vegetation need to be cleared for space
What are hard rock coats made of
Consists resistant rocks such as igneous granite and resistant sedimentary rocks such as sandstone and limestone or chalk
What do soft rock coats consist of
Less resistance rocks such as clays and shales as they erode more easily
What is a discordant coastline
Where the strata are at right angles to the coast. These have different rock types
What is a concordant coastline
Where the strata is parallel to the coastline. Concordant coasts have the same type of rock parallel to the coastline
Explain the formation of a cave, arch, stack and stump
- Large crack opened up by hydraulic action
- The crack grows into a cave by hydraulic action and abrasion
- Cave becomes larger
- cave breaks through headland forming natural arch
- Arch is eroded and collapses
- Leaves a tall rock stack
- Stack erodes forming a stump
What causes waves
Wind. When wind blows across the sea, friction between the wind and water surface cause waves
What does the wave size depend on
Wind strength and how Lomb the wind blows for
What is a fetch
The length of water the wind blows over
What is constructive wave
Wave that has strong swash and slow backwash. These waves build up a beach
Sand is deposited
What are destructive waves
Strong backwash and weak swash
They erode beaches
Create a steep beach profile
Explain the process of a wave cut notch
- Abrasion forms a wave cut notch
- Notch grows and a cliff overhang develops
- Overhang becomes unstable and collapses forming rock debris amd the debris protects tye cliff base for, further erosion
- Rock debris is then eroded over time by attrition opposing the cliff to erosion again
What is the main way sediments are transported along the coastal
Longshore drift
How are spits formed
When prevailing winds blow at an angle to the coastline resulting in long shire drift. The long shire drift carries materials across a bay and to the end of a headland
What four impacts of human activity affect the coast
Development
Agriculture
Industry
Coastal management
How does development put pressure on coats
Housing - many people who work in London can no longer afford housing there so move to the coast as its cheaper
Office development- people can’t afford property in London anymore
How does agriculture affect the coastline
Climate change and rising sea levels are likely to lead to flooding by salt water during winter high tides which could threaten the pastures
Increase soil erosion and sedimentation
Why is London at risk of rising sea levels
Because London is a low lying area
What 2 ways are there of managing the coast with sea defences
Hard and soft engineering
What is hard engineering
Using concrete and steel structures such as sea walls to stop waves
What is soft engineering
Using smaller structures often built from natural materials to reduce wave energy
Negatives of hard engineering
Very costly
Often makes a coast look unnatural or ugly
What are 4 choices government can make about managing the coast
Hold the line
Advance the line
Strategic retreat
Do nothing
What is hold the line
Use sea defences to stop erosion so the coast stays where it is today - very expensive
What is advance the line
Use sea defences to move the coast further into the sea - very expensive
What is strategic retreat
Gradually let the coast erode and move people and business’s away from the area at risk
What is the do nothing management
Take no action at all, let nature take its course
Boscastle flood case study causes
2004 - caused by heavy rainfall causing two rivers to burst their banks close to the village. 2Bill litres of water rushed down the valley into boscastle
Confluence of 3 rivers - paradise, valency , Jordan
Boscastle impacts
Cars, walls and bridges washed away
Church filled with six feet of mud and water
Loss of tourism
Responses of boscastle flood
Prince Charles - duke of Cornwall made a large donation to a fund to help rebuild
Somerset levels flood (2014) causes
Jet streams - lots of wind and cause rain
Storms
Less dredging causing flooding
Somerset impacts
Greater storminess with damaging winds
Higher longer lasting floods
Higher spring tides
More storm surges
Somerset responses
Dredging the rivers to make them deeper so they can contain more water
How is a waterfall formed
Hard rock on top of soft
Soft rock erodes undercutting the hard rock
Hard rock is left overhanging and collapses as it isn’t supported
Fallen rocks crash into plunge ball
Erosion continues
How is a waterfall formed
Hard rock on top of soft
Soft rock erodes undercutting the hard rock
Hard rock is left overhanging and collapses as it isn’t supported
Fallen rocks crash into plunge ball
Erosion continues
Info of upper course of river
Long vertical V shaped Narrow Slowest Vertical erosion
Info of middle course
U shaped
Deeper
Lateral and vertical erosion
Info on lower course
Widest Short vertical Long horizontal Fastest Lateral erosion
How are meanders formed and what happens
When the river erodes laterally to the right and left and then forms large bends called meanders
Water flows in a helicoidal flow and sends the rivers energy laterally
The thalweg is forced to the outer bend where it undercuts the bank which forms a river cliff when eventually collapses
Overtime the meander creates an ox bow lake
What does the Bradshaw model show
River discharge, channel width and depth, velocity and sediment load volume increase downstream
Sediment particle size, channel bed roughness and slope angle decrease downstream
How do you lay out a storm hydrograph
Rainfall (mm) on left , river discharge (cm/s) on right, time in hours on bottom
What affects the shape of hydrographs
Interception by trees reduces risk of flood
Size of drainage basin - longer for water to travel
Urbanisation - greater surface run off
Facts about happisburgh
Not enough houses to make it worth protecting
One of the dates eroding places in the world
Some houses only worth 1 pound
Why is happisburgh eroding
Sedimentary rocks such as clay and soil so very easy to erode especially with the destructive waves
Narrow beaches which give little protection from storms
Sea levels rise and climate changes
What were some attempts of saving happisburgh
In 1950s timber groynes were built but destroyed by waves
In 2006 the governments aid the area should be allowed to retreat
Impacts of happisburgh erosion
Neighbours have abandoned their houses
12th century church will be lost
18 listed buildings could be lost
Where is happisburgh located
Norfolk coats
