Phisical Landscapes In The Uk Flashcards
What creates waves in the sea ?
Wind
What is the fetch ?
How far the wave has travelled
what are two types of waves ?
Constructive
Destructive
Whats the water that rushes the beach called ?
Swash
Whats the water that flows back into the sea ?
Backwash
Whats the characteristics of a destructive wave ?
weak swash and strong backwash
the strong backwash removes sediment from the beach
What are the characteristics of a constructive wave ?
strong swash and weak backwash
the strong swash brings sediments to build up the beach
Whats freeze thaw weathering ?
(contain holes) or permeable (allow water to pass through) this allows them to crack after frozen
What a re the 4 steps of freeze thaw ?
- Water enters the cracks in the rock
- Water freezes expanding the rock
- The ice melts and water makes its way deeper into the cracks
- Process repeats eventually splitting the rocks
What is biological weathering ?
Plants and animals can also have an effect on rocks. Roots burrow down, weakening the structure of the rock until it breaks away
What are the steps of biological weathering ?
- Roots grow into small cracks in the rock
- The cracks become larger
- This causes the rocks to break away
What is chemical weathering ?
Rainwater and seawater can be a weak acid over time they can become dissolved by the acid in the water making the rock damaged
What are the three types of mass movement ?
Rockfall
Mudflow
landslide
What 4 ways cause erosion ?
Hydraulic action
abrasion
Attrition
Solution
What is attrition ?
this is when rocks that the sea is carrying knock against each other
what is abrasion ?
this is when pebbles grind along a rock platform, much like sandpaper. Over time the rock becomes smooth
what is hydraulic action ?
is the sheer power of the waves as they smash against the cliff
What is solution ?
this is when sea water dissolves certain types of rocks
What does hydraulic action cause ?
Wave cuts in rock that can cause the walls to erode over Time
what 4 ways can sediment be transferred ?
Solution
Suspension
Saltation
Traction
What is solution ?
when minerals in rocks like chalk and limestone are dissolved in sea water and then carried in solution
What is saltation ?
where small pieces of shingle or large sand grains are bounced along the sea bed
what is suspension ?
particles such as silts and clays are suspended in the flow of the water
What is traction ?
where pebbles and larger material are rolled along the sea bed
What is the movement of sediment along a coastline called ?
Longshore drift
what can erosion cause ?
Different landforms such as e.g
Headlands
Bays
Wave cuts
Caves, arches, stacks and stumps
What is a spit formed by ?
The deposition of sediment
What is a spit ?
spit is an extended stretch of sand or shingle jutting out into the sea from the land
What do bars create ?
Lagoons
What are some hard engineering strategies ?
Sea walls
Rock armour
Gabions
Groynes
What are groynes ?
Wooden or rock structures built out at right angles into the sea
What are gabions ?
Rocks are held in mesh cages and placed in areas affected by erosion
what is rock armour ?
Large boulders placed at the foot of a cliff
What are sea walls ?
Concrete walls that are placed at the foot of a cliff to prevent erosion,They are curved
What are some soft engineering strategies ?
Beach nourishment
Reprofiling
What is beach nourishment ?
Sand is pumped onto an existing beach to build it up
what is reprofiling ?
The sediment is redistributed from the lower part of the beach to the upper part of the beach
What is Waterfall ?
A waterfall is a sudden drop along the river course. It forms when there are horizontal bands of resistant rock
What are the steps to form a waterfall ?
- The soft rock is eroded quicker than the hard rock and this creates a step.
- As erosion continues, the hard rock is undercut forming an overhang.
- Abrasion and hydraulic action erode to create a plunge pool.
- Over time this gets bigger, increasing the size of the overhang until the hard rock is no longer supported and it collapses.
- This process continues and the waterfall retreats upstream.
A steep-sided valley is left where the waterfall once was. This is called a gorge
Where in the rivers course do meanders form ?
Middle course
How are meanders formed ?
Lateral erosion starts to widen the river. When the river flows over flatter land they develop large bends.
What to processes act on the formation of a meander on the bend ?
Hydraulic action
Abrasion
How do oxbow lakes form ?
The river meanders at two near areas of land, over time the bends erode and eventually connect causing a straight river and eliminating the meanders
This causes an oxbow lake
What is a floodplain ?
A floodplain is an area of land which is covered in water
What is an estuary ?
An estuary is where the river meets the sea
What are some flood risks ?
relief
Heavy rainfall
Vegetation
What are some hard engineering strategies for rivers ?
Dams
Straightening
Embankments
What is floodplain zoning ?
Allowing only certain land uses on the floodplain reduces the risk of flooding to houses and important buildings