The Uk Evolving Plusical Landscape Part 2 Flashcards
How does climate change lead to rising sea levels and how is it a problem
Thermal expansion melting ice caps and temporary rise due to low pressure storm systems
It’s increasing marine erosion
What is the (ICZM)and what does it do
The intergrated costal zone management
Decides which areas to protect and how
What is cost benefit analysis
Looking at economic cost ,social and environmental impact agains benefits of protection
Give examples of hard engineering and give prices
Sea walls 6000 per meters
Groynes 1000 per metre
Give examples of soft engineering and give explaination
Beach replenishment-rebuilding beaches as a natural defence
Slope stabilisation-holding cliff in place with planting/meshing
What is strategic realignment
Where some part of coasts are allowed to flood in order to target management into other areas of coastline
How can coastal management be investigated
Qualitative(judgment)and quantitative (numbers)
Sediment analysis
Cost benfit analysis
Groyne measurements
Where for rivers start
The upper cource
What happens in the upper cource
It has a steep gradient and sediment is added to river by weathering of slope sides
Erosional processes dominate creating narrow shallow channels
overtime due to lower energy young rivers oftern unable to cut through areas of greater resistance so river reroutes and curls around them creating interlocking spurs
What 2 other landscape features are in the upper cource
Waterfall and gorges
Why are sediment bigger and angular in the upper cource
Discharge is low and so is velocity
What are freatures of the mid cource
Slope angle reduces
River wider and deeper
Vertical and lateral erosion occurs
Sediment is smaller and more rounded
Features of lower cource
Very low gradient
River widens and deepens
Channel is smooth so less friction so velocity is highest
Sediment load is high
What are the 4 erosinao procces and give definition
Hydraulic action(air forced into gaps in rock )
Abrasion (wearing away of rocks by friction
Attrition(stones bang together and break )
Solution (chemical dissolving of rock
Give the transportation processes and give definition
Traction(larger stones rolling on riverbed)
Saltation(smaller stones bouncing along)
Suspension (small participles carried along in water)
Solution(dissolved particles carried in water
How is a river formed in a v shape valley and how is the v made
Vertical erosion occurs in upper cource creating a small river
The sides of valley are eroded causing mass movemonet and soil creep on valley sides creating v shape
What is a waterfall
Hard rock overlaps soft rock
Overtime erosion creates a deep plunge pool undercutting harder rock overhang
This unsupported rock collapse’s adding debris and creating a gorge
How are ox box lakes created
river flows side to side eroding areas of weakness
Fasted flowing water hits outside of bend causing undercutting and outer steep bank called a river cliff
On inside of bend river flows more slowly depositing material creating a slope called slip off slope
Overtime meander erodes further
Neck of meander breaks through as river continues through new straight channel
What are Flood plains and levees and how are they formed
Floodplain formed by lateral erosion as river winds across valley floor
point bar-material deposited on inside of bend
When river floods it adds further material to floodplain
Over time procces repeats and natural banks called levees are formed
What are deltas and how do they occur
D shaped areas of deposition at mouth of river
Occur when river enter another body of water
What is a normal hydrograph and what does it show
Is a way of showing how a river responds to a rainfall event
Rainfall shown as bar chart
Discharge calculated (width multiplied by depth multiplied by the velocity of river)
Lag time (Time between peak rainfall and peak discharge)
What does a flashy hydrographic show
Will have a steep rising limb a short lag time
What does a less flashy hydrograph show
Shape will have a low rising limb long lag time and gentle falling limb
When is high rainfall more likely to happens and what effects can that create
May -July
Surface become saturated creating surface run off
What has urbanisation done to surface runoff
Increased it
What problems did the river Severn when it comes to flooding and the impact it had
Lack of defences
The large catchments led to flooding
Tewkesbury Abby flooded for the first time in 250 years 3 died 48000 homes were flooded ,20000pound repair cost
Schools abs buisness were shut
What are the pros and cons of flood calls
Pro
Prevent water from spreading into small scale areas
Con
Expensive and look unatural
What are the pros of embankments
Pro
Successful in stopping this he spread in small areas
Can be made for environmentally friendly with earth and grass
Pros and cons of flood Barrie’s
Pros
Cheap
Con
Risk of not installing time
What are the pros of river restoration
Cheaper than hard engineering
Slows the river down
Creates natural rivers for wildlife and recreation
