3) Distinctive Landscapes - Also See Book Flashcards
How are waterfalls formed?
River flows over soft and hard rock
Soft rock erodes more quickly
Undercuts leaving overhang
How are gorges formed?
In a waterfall, the overhand drops into the plunge pool, so the waterfall retreats
This valley is a gorge
How is a V shaped valley formed?
The rivers flow down and erode the landscape
This creates a deep notch
Lateral erosion deepens the sides and bottom
= V shaped valley
How is a flood plain formed?
Formed by deposition of materials
How are levees formed?
A build up of alluvium on river bank
Raises bank
How is a meander formed?
Water erodes laterally to form meanders
The erosion deepens the meander on the outside and deposition is on the inside
How is an oxbow lake formed?
From a meander- the neck gets tighter and breaks
The water takes the shortest route
As there is no water in the oxbow lake, it will eventually dry up
what are the four groups of characteristics that make a landscape?
biological
physical
variables
human
what does periglacial mean?
located on the margin of past glaciers
where are the upland areas in the UK? Give an exampe
along west side north-west highlands southern uplands cumbrian mountains brecon beacons (scotland and wales)
where are the lowland areas of the UK? give an example
scottish islands along east side the Fens Flemborough Head Isle of Man (england)
what is superficial rock?
surface rock
what is bedrock?
the solid rock underlying superficial rock
what is weathering?
the breakdown of rocks in situ
what does in situ mean
stationary
process of chemical weathering?
acidic rain falls onto rock
acid slowly eats into rock and softens it
these cracks get deeper and deeper
the rock crumbles at surface
example of rock severely affected by chemical weathering?
limestone
process of freeze thaw weathering
water gets into a crack and freezes
as water turns to ice, it expands
it forces crack to widen
rock cracks
process of biological weathering
seed falls into rock
seeds starts to grow roots
roots force rock to widen and crack
process of onion skin weathering
when rock is hard, the outer layer expands
when rock gets cooler, it contracts
this constant movement causes outer layer to break off
how is a limestone pavement formed?
weak acidic rain reacts with limestone and breaks it away
what is a clint in a limestone pavement
a large block of rock
what is a gryke in a limestone pavement
the gaps between clint
what forms a scree slope
when loose debris settles at the bottom of a slope
how does a soft bedrock influence the location?
slumped
what is slumping?
when rock and soil slide downhill in layers
what does saturated mean
when the soil is so wet it can’t hold anymore soil
what does impermeable mean
rocks that don’t allow water to pass through them
what does undercut mean?
the base of a cliff has been eroded so isn’t supporting the land above
what is weathering?
the effect the weather has on the landscape
what is mass movement
movement of surface material caused by rockfalls or landslides
what is a rotational slip?
a landslide when the floor is curved
process of slumping
soft rock absorbs water
it becomes saturated so cant hold anymore
water acts as a lubricant between rock layers so they slip off
what is the load?
the material carried by a river
what is erosion?
the breakdown and movement of rock
what is hydraulic action?
when air forces into cracks by pounding waves forces them to break apart and collapse
what is attrition
when small rock fragments erode a surface
what us corrosion (abrasion)
when rock fragments wear away the river walls and bed
what is corrosion (solution)
when the chemicals in the water wear away the rock of the river bed
name four factors that affect the rate of erosion
gradient of river bed
rock type
bedload
human factors
how does gradient affect the rate of erosion?
the steeper the river bed, the more energy the particles have so the faster they move
how does rock type affect rate of erosion?
weaker, softer rocks will erode faster
how does bedlam affect rate of erosion?
the more bedload, the faster the erosion
how do human factors affect rate of erosion?
changing the landscape will change the time taken for water to get to a river, changing the volume
what is traction
when large boulders roll along and erode river bed
why does the bedlam of a river decrease the closer it gets to the sea?
some of it will have been deposited already through meanders etc
what are the three processes of movement in the river
erosion - transportation - deposition
what is saltation?
when the bedlam is bounced along the river bed
what is suspension?
small particles are carried in the water
what is solution?
minerals are dissolved and carried in water
the 6 stages of a geographical enquiry
planning stage data collection data presentation data analysis conclusion evaluation
what is discharge of a river
the volume of water passing through the cross section of a stream in a set time
what is the occupied channel width?
the distance of the channel measured at the water surface
what is the channel depth?
the height from the water surface to river bed
what is the average velocity
the speed the river is travelling in m/s
what is the load quantity
the total mass carried by a river
what is the load particle size
the way in which the reload changes in size
what is the channel bed roughness
the resistance offered by the riverbed
what is the gradient?
the slope of the river channel
how does discharge change as you go downstream?
increases
how does occupied channel width change as you go downstream?
increases
how does channel depth change as you go downstream?
increases
how does velocity change as you go downstream?
increases
how does load quantity change as you go downstream?
increaess
how does particle size change as you go downstream?
decreases
how does channel bed roughness change as you go downstream?
decreases
how does gradient change as you go downstream?
decreases
how to measure channel width?
use a tape measure stretched across the water surface
how to measure channel depth
use a metre ruler or pole and measure at regular intervals
how to measure velocity
tie how long it takes a floating object to travel a set distance
how to measure load size
grab first pebbles touched
measure length and width in each location
limitations of measuring channel depth
strong current can affect result
debris in way
limitations of measuring velocity
must be visible at all times
people could interfere
limitations of measuring channel width
could dip under water
limitations of measuring particle size
different peoples opinions on what is small and big
where is the current of a river fastest?
on the outside of the bend
where does lateral erosion occur?
on the outside of a bend
where is river slowest?
inside of bend
where does deposition occur?
inside of bend
how does a meander turn into an oxbow lake?
erosion narrows neck
river takes path of least resistance
what are floodplains?
the area of land over which water spreads when a river floods
where are the larger pieces of rocks deposited when a river floods and why?
closer because they are heavier
what are the two components that floodplains are covered with?
alluvium and silt
what is the hard rock found at high force called?
whinstone
what is the waterfall we are studying called?
high force
what is the name of the town in a meander?
Yarm
what two features can we see at high force?
waterfall and gorge
how was high force formed?
the water flowed over the hard whinstone and off the edge
hydraulic action eroded the softer rock beneath it
the whinstone collapses and the waterfall retreats, forming a gorge
what is hard engineering?
putting in man made structures
what is soft engineering?
more natural structures
what does the size of a wave depend on? (3)
the strength of the wind
length of time that the wind blows
the distance that the wind has to cross
what is swash?
the water that runs up a beach
what is backwash
the water that recedes back down a beach
how is a cave formed?
the sea attacks a wave cut notch to make it bigger into a cave
how is an arch formed?
the cave is continually eroded until it cuts straight through the rock
how is a stack formed?
the roof of the arch is undercut until it collapses
how is a stump formed?
a stack is eroded further so it gets smaller
how is a headland formed?
the softer rock of the bays has been eroded so the more resistant rock of the headland sticks out
how are beaches formed?
by constructive waves depositing sediment
how is a bay formed?
the soft material is easily eroded so it retreats
what is a concordant coastline?
made of one type of rock
what is a discordant coastline?
made of multiple types of rock
how is a levee formed?
when a river floods, it deposits the heavier material net to the banks, forming levees
where are the glaciated areas of the UK?
grampian mountains north west highlands loch lomond lake district snowdonia
how are spits formed?
longshore drift by constructive waves
how does geology make a landscape distinctive?
the harder rock isn’t easily eroded so leaves jagged peaks
