Topic 4 - Specification Flashcards
give an example of an upland area in Scotland
grampians
what is the highest mountain in the UK
Ben Nevis
are the Grampians densely or sparsely populated
sparse
where do upland areas tend to be in the UK
north and west
where do lowland areas tend to be in country
south and east
what is the Cheshire plain mainly used for and is it lowland or upland
lowland - dairy farming
lowland Cheshire plains are very ___
fertile
what were the Cheshire plains formed by
deposition of material eroded by glaciers
snowdonia is a ___upland with rock from ___
glaciated
extinct volcanoes
snowdonia contains ___valleys
glaciated
the weald is a wide __between the ____hills of the ___
valley
parallel
downs
the weald used to be covered in ___but is now mainly ___
forest
agricultural
what is igneous formed by and give an example and state a characteristic
hard - magma cools and hardens and leaves crystals
granite
how is sediment formed and give 3 examples
layers of sediment are compacted
Carboniferous limestone, shale, clay, chalk
what are carboniferous limestone and chalk formed by
Dead Sea creatures’ skeletons and shells
which is harder limestone or chalk
limestone
what are clay and shale formed from
mud and clay minerals
clay and shale are ___(property)
soft
what are metamorphic rocks formed by
other rocks changing under heat and pressure
metamorphic rocks are the ___(property) versions of other rocks after heat and pressure
harder
give 2 examples of metamorphic rock and what rock they are formed from
shale compacted to make slate (metamorphic)
which is then compacted to make schist(metamorphic)
how have active volcanoes shape the UK landscape
created upland areas
as we used to be. much closer to the plate boundary 520 million years ago
and active volcanoes spewed lava which cooled to form igneous rock
give 2 ways in which plate collisions influenced the UK landscape
the plates folded and uplifted creating mountain ranges like the grampians and lake district pennines
intense heat and pressure formed metamorphic rocks in Scotland and Northern Ireland
give 2 ways plate movements influenced the UK landscape
created carboniferous limestone deposits in the southwest of England and south Wales and Peak District
as we used to be much closer to the tropics and we were partially underwater and so sea creatures lived and died forming the rock - upland areas
these shallow seas and swamps also formed chalk and clay - lowland areas in southern England
(245-280 million years ago)
give 2 metamorphic rocks that form upland landscapes and describe 2 features of the upland landscapes they form and why
slate and schist
rugged land - as resistant/hard + easily split into thin slabs(slate) and small flakes(schist)
waterlogged/acidic soils - as impermeable
why is slate and schist hard and resistant but easily split into thin layers/small flakes(do each separately)
slate - it is formed in layers creating weak planes in the rock -
schist - it has bigger crystals, and formed of slate which has layers and splits into small flakes
which is harder - chalk or clay
chalk
give 2 things in lowlands that chalk forms
escarpments and cliffs
in chalk landscapes one side of the hill is more__and the other is more ___
steep, gentle
what feature can chalk rock lead to and why in Lowland landscapes to do with water
springs - as it is permeable and water flows through then when meets impermeable rock it becomes a spring
clay is very __and easily ___ and therefore what does it form (landscape type)
wide flat valleys - soft, eroded
clay is ___and for that reason water flows over the ___and forms what 3 things
impermeable
surface
lakes, rivers, streams
what type of landscape does granite form
upland
why does granite form upland landscape
it is very resistant
what feature is formed in upland landscapes due to granite rock and why
tors
granite has lots of unevenly spread joints which mean areas with more joints are weathered more quickly so some parts stick out (tors)
granite is ___so this creates __. describe the feature they create
impermeable
moorlands
waterlogged land, acidic soil, low growing vegetation
give a feature created using rain with limestone rocks and explain its creation
limestone pavements (and caverns and gorges)
in the joints the rain perfumes carbonation weathering which leads to flat areas with deep cracks
as limestone is ___(water thing) it creates what 2 features
resurgent rivers
dry valleys
what are resurgent rivers, why do they happen and with what type of rock
limestone - when limestone with water running through at the surface meets impermeable rock underneath
where did ice come up to in the last ice age (name some areas it covered as well)
as far as the bristol channel
Scotland, northern England, Wales, Northern Ireland
how did ice affect upland area such as the __and what features did it form
Lake District
eroded
u shaped valleys
large parts of ____are covered by till deposited by what
eastern England
melting glaciers
what is till
clay, sank and rock
when do glaciers deposit lots of material
when they melt
how did glacial meltwater and deposits affect the lowland landscape of the UK
deposited till
give 4 physical processes which alter the landscape
weathering
erosion
post glacial river processes
slope processes
give the 3 types of weathering
mechanical
chemical
biological
what is weathering
breaking down rock into smaller pieces
what is erosion
wearing something away and removing it
give 3 things that can erode the landscape (one in past, 2 now)
glaciers (ice)
river
sea
give 2 ways post glacial processes affected the UK landscape
melting glaciers added power to rivers - eroded the landscape
melting glaciers left landforms like hanging valleys when melted
give. 4 types of mass movement (under the branch of slope process)
rockfall, slides, slumping, soil creep
give 2 examples of how climate can affect physical processes
cold climate makes freeze thaw weathering more likely
wet climate makes erosion by rivers more likely
how can a form of weathering + glacial processes + slope processes form a thing and give names/examples
freeze thaw weathering on the back wall of the corrie (a basin hollowed out by glaciers)
breaks up rocks and makes ROCK FALLS
which form __scree slopes__
give an example of a tarn formed in a corrie which was hollowed out by ice
Llyn Idwal
what is a u shaped valley created by, describe it and give one thing that could be found in it
eroded by ice
flat floor and steep sides
misfit river (too small to have created the u shaped valley
give 1 climatic and 1 geological reason there are lots of streams in snowdonia and describe what they form (a landform)
lots of rain, impermeable rocks
gullies in corries as they erode them
the downs are __ (rock)____(feature/landform) and the weald is a ___(rock) _____(description of landscape)
chalk escarpments
clay - large flat area
the weald is hilly/flat
flat
give one river process acting in the weald and an example of the river
river Arun
meanders over the impermeable clay
and widens valley floor
give one way the climate of the UK influences the weald lowland landscape
very wet
floods rivers
deposits silt
forming flood plains
how were dry valleys formed
glacial period
cold = freeze thaw weathering
glacial snow melt leads to streams with much more water
erodes valleys (now dry as water flows through the permeable chalk
give 1 way farming has influenced landscape to do with forest
forest cleared for space for farming
give 1 way land ownership/farming has influenced the landscape
hedgerows and walls mark out fields
give 3 different types of farming (suited for different landscapes)
arable
dairy
sheep
what type of landscape is good for arable farming and an example
flat land with good soil
east England d
what is arable farming
growing crops
what type of area is needed for dairy farming
warm and wet with large, grassy fields
give an example of an area in England used for diary farming due to good landscape and climate for it
south West England
where does sheep farming take place? how has it changed the landscape
harsher upland conditions
decreased trees on hills as young trees are eaten/tramples before they mature
give 3 uses of woodland
timber recreation conservation
there is lots of/very little natural woodland left in the UK
very little
what type of forests gave been planted for timber what shape
coniferous (evergreen) forests
straight lines
how has people wanting to return the land to its natural state affected woodland distribution and type
deciduous forests planted
give 4 factors which can influence where settlements were originally developed
water supply
shelter from wind and rain
bridging points over rivers
availability of resources (wood)
(Also how easily defended)
give 3 ways the formation of urban settlements has influenced the landscapes
land concreted over for roads and buildings
rivers diverted into underground channels
rivers straightened/embankments made
what has concreting land affected
drainage patterns
what is mechanical weathering
breakdown of rock without. affecting chemical composition
what type of mechanical weathering affects coasts
salt weathering
how does salt weathering work
seawater gets in cracks
water evaporates depositing salt crystals
expansion
pressure on rock
widens it and breaks it up
what is chemical weathering
breakdown of rock by changing chemical composition
what conditions does carbonation weathering take place in and what type of weathering is it
warm and wet - chemical
how does carbonation weathering work
sea/rainwater has dissolved co2
makes weak carbonic acid
the carbonic acid reacts with rock which contains calcium carbonate (such as carboniferous limestone)
dissolves rocks
what is in rocks which reacts with carbonic acid in rain
calcium carbonate
what is biological weathering
breakdown of rock by living things
give an example of biological weathering
plant roots pushing rock apart by getting into cracks - breaks it down
what is mass movement
shifting of rock and loose material down a slope due to gravity
what does mass movement cause on the coasts
rapid coastal retreat
give the 3 types of mass movement
slides
slumps
rockfalls
what are slides
material shifts ina. straight line
what are slumps
material shifts with a rotation
what is a rockfall
material breaks up and falls down a slope
what makes mass movement more likely (2 reasons)
material being full of water - makes it heavy and lubricates it
what is a rockfall
material breaks up and falls down the slope
give 3 ways waves erode the coast (3 types of coastal erosion)
hydraulic power
abrasion
attrition
how does hydraulic power work
waves compress air inside cracks in rock
pressures rocks
as this repeats repeated compression widens cracks
makes bits of rock break off
what is abrasion
eroded particles in water scrape and rub against rock - removing small pieces
what is attrition
particles in water smash into each other
break into smaller fragments
and edges are rounded off
__rocks are more __to erosion so It takes longer to be ___by coastal processes
hard
resistant
eroded
what are joints and faults
cracks and weaknesses in rock
rocks with lots of __and__erode faster
joints and faults
what is a discordant coastline
coast with alternating bands of hard and soft rock at right angles to the coast
what is a concordant coastline
alternating bands of hard and soft rock parallel to the coast
give 2 landforms more common on discordant coastlines
bays and headlands - as the bands of rock are eroded at different rates
concordant coastlines have fewer __as they erode at same rate
erosional landforms
differences in __-can impact coastal processes and vary with the seasons
temperature
give an example of temperature affecting coastal erosion
mild/warm temperatures increases rate of salt weathering as the water evaporates faster
more __in winter leads to ___winds leads to more __energy, ___waves which ___erosion of the cliffs
storms
stronger
high energy
destructive
increase
describe how high rainfall in storms in winter (climate influencing coastal erosion) increases coastal erosion
makes cliffs saturated and makes mass movement more likely
how does the prevailing wind in the UK (name it) affect coastal erosion
warm south westerlies - makes the south coast more exposed to the winds and storms they bring from the Atlantic Ocean
what kind of winds are common on the east coast of the UK
cold northerly winds
what are waves that erode called
destructive waves
give 3 characteristics of destructive waves
high
steep
high frequency (10-14 per minute)
the ___in a destructive wave is more powerful than the ___
backwash
swash
what is backwash
the movement of water back down the beach
what is swash
the movement of water up the beach
storms increase the ___power of destructive waves leading to an increased rate of ___retreat
destructive
coastal
where do waves cause most erosion in a cliff
at the foot
what is formed at the foot of a cliff due to erosion
a wave cut notch
the rock above a wave cut notch becomes __and eventually ___
unstable
collapses
explain how a cliff retreats and what form does it lead to
wave cut notch is created then enlarged until the rock above collapses and is washed away and a new one is created and the process repeats
leaves a wave cut platform behind
hard rock cliffs tend to be more ___ and soft rock ones more ___
vertical
sloping
soft rocks/rocks with lots of __have a low resistance to ___
joints
erosion
hard rocks with a ___structure have a high resistance to ___
solid
erosion
rock that is eroded quickly forms a ___with a gentle slope
bay
resistant rock is eroded more slowly and is left ____making a ___with __sides
jutting out
headland
steep
what are headlands made of
resistant rocks with weaknesses (like cracks)
repeated erosion by ___power and ___enlarges the cracks in the headland causing a ___to form
hydraulic
abrasion
cave
what forms after further erosion to a cave
an arch
give an example of an arch
Durdle door in Dorset
after an arch collapses due to erosion what is created
a stack
what is a stack
an isolated rock separate from the headland
give an example of a stack
old harry in Dorset
what is transportation
movement of material
how is material transported along coasts
longshore drift
waves follow the direction of what
the prevailing wind
what Angle to waves hit the coast at
an oblique angle (not a right angle)
the swash carries material up the beach in the same/different direction as waves
same
the backwash carries the material at __angle to the coast
right
the movement of longshore drift is a _____
zig zag
What do constructive waves do with material
deposit it
what is deposition
material carried by seawater dropped on the coast
when does deposition by waves occur
when water slows down and isn’t moving fast enough to carry all its sediment
what are constructive waves
waves that deposit more material than they erode
give 3 characteristics of constructive waves
low
long
low frequency (6-8 per minute)
the __is greater than the __in constructive waves
swash
backwash
what 2 things can constructive waves deposit and what does this form
sand and shingle
beaches
give 2 coastal landforms caused by deposition
spits
bars
where do spits form
at sharp bends in the coastline
give an example of a sharp bend in the coastline
a river mouth
what transports sand and shingle past the sharp bend in the coast and where is it deposited
longshore drift
the sea
strong __and ___can curve the end of a spit and what is this called
wind and wave
recurved end
what is the area behind the spit protected form and therefore what happens there
waves
material accumulated and plants grow there
give 2 things that the sheltered area behind a spit can form
a mud flat or salt marsh
what is a bar
when a spit joins two headlands
what forms behind the bar
a lagoon (as cut off from sea)
what do stacks look like on a map
little blobs in sea (caves and arches can’t be seen due to rocks above them)
what are cliffs shown as on maps
little black lines
what are wave cut platforms shown as on the coast
bumpy edges
what are shingle beaches on a map
white or yellow with speckles
what are indirect effects of human activity
the result of direct affects
give 4 ways human activity is impacting the coast
agriculture
development
industry
coastal management
how can using land for agriculture lead to more erosion
the land has low economic value
so is often left unprotected
give 2 ways vegetation on coasts due to agriculture can change the stability of cliffs
more vegetation for grazing land binds soil and stabilises clifftops
clearing it for arable farming can expose soil and make it vulnerable to weathering by wind and rain
how can marshland and its agricultural uses affect coastal erosion
it is sometimes reclaimed and drained for agricultural use which reduces the flood barrier it provides
coastal areas are never/often developed
often - as they are popular places to live and work
more settlement leads to more ____(positive effect on coastline) and why
coastal defences
to protect homes and businesses
what is an indirect effect of development on the coast
changes transportation and deposition of material
restricting sediment supply
makes them narrower
more vulnerable to erosion
how can quarries (as part of industry) affect coastal weathering
expose large areas of rock - makes more vulnerable to weathering and erosion
how has the construction industry affected coastal erosion
gravel extracted from some beaches
to make concrete
removes material from the coast and increases risk of erosion
how do ports (as a result of industrial growth) affect coastal erosion
increase building on salt marshes (flat and sheltered ideal for ports)
salt marshes are natural flood barriers
so building makes land more vulnerable to erosion
salt marshes are natural __ ___
flood barriers
what is coastal management
protecting coastal landscapes from erosion
what is an indirect effect of coastal management
alters sediment movement
reduces protective beach material further along
increasing erosion there
how do coastal defences directly affect erosion
reduce it
preventing landscape from changing (retreating)
where is the holderness coastline
east coast
how much land in the holderness coast is lost each year
1.8 m ( in come places such as great Cowden it is over 10m per year)
the holderness coast has one of the highest/lowest rates of erosion in Europe
highest
how long is the holderness coastline
61km
where does the holderness coastline stretch from and to
flamborough head (headland) and spurn head(spit)
in great Bowden what is the rate of erosion
10 m per year
what are the cliffs on the holderness coastline made of
boulder clay
boulder clay is easily ____and is likely to ___when wet
eroded
slump
beaches on the holderness coastline are ___
narrow
where do waves that hit the holderness coastline come from
north east
Norwegian Sea
why are the waves in the holderness coast so erosive
they travel a long distance and increase in power
over __km of the holderness coastline is protected by what
11
hard engineering strategies
what is the population of hornsea
over 8 000
what is the population of withernsea
over 6000
give an example of important infrastructure along the holderness coast (transport)
B1242 road
give an example of an important piece of infrastructure on the holderness coastline
gas terminal at easing ton
what % of gas does the terminal at easing ton supply and where is it
25 and its right on the edge of the cliff
what coastal defences have been made at mAppleton
groynes
there are __and a __at Hornsea and withernsea
groynes
sea wall
give an example of how groins are causing indirect problems for coastal erosion
they narrow beaches further down coast - great Cowden - from the groins (at Appleton)
what is the direction of longshore drift in the holderness coast
south
how does stopping erosion of material further up the coast affect areas further down the coast with respect to flooding (specific example)
material eroded and usually transported down the Lincolnshire coast to the humber estuary however with less of it there is increased risk of flooding in the humber estuary
as less material to slow the floodwater down
coastal retreat on the Lincolnshire coast has increased/decreased and why
less new material added (as less erosion) - so increased
what is at risk of being eroded away and why
spurn head
as less material is added to it
protected areas of the holderness coast are becoming what
headlands
the areas protected are becoming more expensive to maintain on the holderness coast - why?
they are becoming headlands
being eroded more heavily
give 2 things due to climate change that are making coastal flooding more likely
increased storm frequency
rising sea levels
what areas does rising sea levels pose a threat to
low lying areas/ coastal areas
how could increasing sea levels lead to flooding
higher tides
coastal floods more frequent
how could rising sea levels lead to more erosion
higher tides removes more sediment
less material to protect from sea - narrower beaches
how can storms frequency increasing, increase coastal erosion
give sea more erosional power
hard rock areas more vulnerable
soft rock eroded faster
how does increasing frequency of storms affect transportation of material and hence erosion on coasts
more energy to transport material as
high energy waves can move material greater distances
so some areas starved of material
makes these areas vulnerable to erosion and flooding
what could become more frequent as storms become more frequent combined with sea level rise
storm surges
how can climate change/coastal erosion threaten people in terms of habitation
permanent flooding could destroy some habitations
how could coastal erosion threaten industry
coastal industries shut down due to damage to buildings and equipment like fishing boats
give an example of a threat to infrastructure from coastal erosion
roads and rail affected such as in Dawlish when storms affected parts of the track
how can coastal erosion threaten businesses on coasts
puts people off visiting (stops tourism) - threatens nearby businesses who rely on the industry - loss of livelihoods
how could ecosystem organisms on coast be threatened by coastal erosion/flooding
Seawater has a high salt content
can kill organisms
how could coastal flooding threaten agriculture
high salt water content sea water
can decrease soil fertility
how can coastal flooding damage plants
force of floodwater
uproots trees and plans
and can drown them if left standing
give an example of how coastal flooding can threaten conservation areas
lagoon can be conserved
then bar eroded
destroying bar
what is hard engineering
man made structures to control the sea, reduce flooding and erosion
what is soft engineering
scheme using natural processes and knowledge to reduce effects of flooding and erosion
give 2 examples of hard engineering
sea wall
Groynes
give 3 examples of soft engineering
beach replenishment
slope stabilisation
strategic realignment
what is sea wall
concrete wall that reflects waves
what are 2 benefits of sea walls
prevents erosion and flooding
give 2 disadvantages of sea walls
Creates strong backwash
which erodes under the wall
very expensive to build and maintain
what are groynes
wooden/stone fences at right angles to the coast
to trap material transported by longshore drift
what are 2 advantages of groynes
create wide beaches
slowing waves
protecting against erosion and flooding
cheap
give 1 disadvantage of groynes
starve beaches further down coast
making them narrower
and increasing erosion there
what is beach replenishment
sand and shingle added to upper part of beach
where can the material for beach replenishment be found
lower down beach or seabed
give 2 benefits of beach replenishment
reduces flooding and erosion
as makes wider beaches (which slow waves/absorb wave energy)
give 3 disadvantages of beach replenishment
can kill organisms (as taking material from the seabed)
very expensive
has to be repeated
what is slope stabilisation
reinforce slopes by adding concrete nails and metal netting
give 1 benefit of slope stabilisation
prevents mass movement by increasing strength of slope
give 2 disadvantages of slope stabilisation
very expensive
can be difficult to install
what is strategic realignment
removing existing defences and allow land behind to flood
what are 2 benefits of strategic realignment
land becomes marshland - new habitats
flooding and erosion reduced behind it
give 1 disadvantage of strategic realignment
disagreements about what should be flooded (farming would affect farmers’ livelihoods)
give 1 benefit of the do nothing approach
its free
give 2 disadvantages of the do nothing approach
infrastructure and businesses and homes lost + people move away
what does sustainable coastal management mean
controlling erosion and flooding without problems elsewhere or affecting inhabitants
management strategies have to be cheap - why?
to avoid conflicts about the spending of public money
what does ICZM mean
integrated coastal zone management
what does the ICZM do
protects the coasts while taking people’s interests into account
ICZM is a short/long term approach that can be adapted to ___needs and is ___
future
sustainable
long
what is the course of a river
the path as it flows downhill
what are the 3 courses of a river
upper middle and lower
what is the lower course close to
the mouth of the river
what do rivers form as they flow downhill (2)
channels and valleys
give 3 things that river do
erode transport deposit
what changes the shape of the valley and channel
whether erosion or deposition is the dominant process
what is the long profile of a river
how gradient changes over the courses
what is the cross profile of the river
what the cross section looks like
where is the source of a river usually
in an upland areas
what is the gradient in the upper course of the river long profile
steep
what is the gradient in the middle Course of river
medium
what is gradient in lower Course of river
gentle
what type of valley is at the upper course of the river
v shaped valley with steep sides
what type of valley is in the middle course
gently sloping valley sides
what type of valley is the lower course
very wide and almost flat
what is the channel like in the upper course
narrow and shallow
what is the channel like in the middle course
wider and deeper
what is the channel like in the lower course
very wide, deep
what are the two directional types of erosion
vertical or lateral
what type of erosion dominates to create a v shaped valley at the __course
vertical
upper
how does vertical erosion happen in upper course
high turbulence
scraped the rough and angular particulates
along the river bed
causing downwards erosion (intense)
what type of erosion widens river valley
lateral
where is lateral erosion dominant
middle and lower courses
(forming meanders)
where is the river eden
north west England
where does the river eden run between
Lake District and pennines
how long is the river eden
145 km
where. is the source of the river eden
pennine hills south cumbria
where is the mouth of the river eden
solway firth - Scottish border
give an example of a place on the lower course of the river eden
Carlisle
how many m above sea level is the source of the river eden
600m
what type of rock area is the source of the river eden found in
hard, resistant rock area
what is the discharge like at the upper course of the river eden
low
what is the velocity like at the upper course of the river eden - why?
low - friction from the rough channel sides and bed
what are the stones in the river like in the river eden
large and angular
what are the middle parts of the river eden basin made from
sandstone
sandstone is ___and easily ___which means the river creates a ___valley due to more ___erosion
soft
eroded
wide
lateral
discharge increases in the middle course - why
more tributaries join the main river
what is the river’s sediment load like in the middle course of the river and why
smaller and more rounded as erosion continues
in the lower course of the river what is the valley like
very wide and flat
when the eden reaches carlisle how far is it above sea level
only a few metres
what is the river’s velocity at the lower course and why
high
little friction with smooth sides
what is the discharge of the river eden in the lower course and why
high
meets two other river (Caldew and Petteril)
what is the river channel like in the river eden lower course
wide and deep - more than 50m wide
what is the sediment load of the river like at the lower course of the river eden
well rounded and fine - carried by suspension or solution
how does freeze thaw weathering work and what type of weathering is it
mechanical
water gets into cracks in rock (granite for example which has cracks)
water freezes and expands
pressures rock
thaws and contracts releasing pressure
repetition of this process breaks up rock
give 4 erosional processes in river channels
hydraulic action
attrition
abrasion
solution
most erosion in the river happens by ___
abrasion
what is attrition and why does it change the particle size of sediment carried by a river
rocks picked up by river and smashed into each other and break into smaller fragments
edges become rounded offs they rub together
what is solution
when water dissolves some types of rock
give examples (2) of types of rock that are dissolved by the river
chalk and limestone
give the 4 transportation processes
traction
suspension
saltation
solution
what is traction
large particles (boulders) pushed by force of water along river bed
what is suspension
small particles carried along by water
give examples of particles carried by suspension
silt and clay
what is saltation
pebble sized particles bounced along river bed by the force of the water
what is solution
soluble materials dissolve in water and carried
give the order of biggest to smallest materials transported by each of the transportation processes
traction
saltation
suspension
solution
what is deposition
when a river drops eroded material
when does deposition happen in a river
when it slows down
give 4 reasons a river deposits stuff
water volume falls
amount of eroded material increases
water is shallower(eg on side of a bend)
river reaches the mouth
give 2 landforms found in the upper course of the river
waterfalls and gorges
where do waterfalls form
when a river flows over an area of hard rock followed by soft rock
the softer rock is eroded by __and __more than the harder rock which creates a __in the river (waterfall formation_
hydraulic action
abrasion
step
after a step what is created through more downwards erosion
a steep drop
what happens to hard rock eventually after a waterfall is formed
it is undercut by erosion
becomes unsupported
and collapses
how is a plunge pool created after hard rock is undercut
collapsed rocks erode softer rock by abrasion at the foot of the waterfall
after repeated undercutting and collapsing the waterfall ___leaving a steep sided__
retreats - gorge
where are interlocking spurs found in the river
upper course
why are interlocking spurs found in the upper course of a river
they have no lateral erosion as not powerful enough so have to wind around high hillsides
what 2 things form meanders
erosion deposition
where in a river do meanders form
middle and lower
where is the current of the river faster and why
on the outside bend as its deeper=less friction (helicoidal flow)
more___takes place on the outside bend forming __
erosion
river cliffs
material is deposited on the __bend forming what
inside - slip off slopes
meanders eventually turn into what
the ox bow lake
what is the first stage of oxbow lake formation
neck gets smaller as erosion causes the outside bends to get closer
what I the second stage of oxbow lake formation
river breaks through neck (usually with a flood)
river flows through the shorter, straighter course
what is theist stage of ox bow lake formation
deposition cuts off the meander
what is a floodplain
wide valley floor which is flat and gets flooded
how does deposition on floodplains happen
water floods, slows down, deposits eroded material it is transporting
eventually floodplains get higher/lower due to what
higher - deposition
what makes the floodplain wider
meanders migrate across the floodplain
how is the valley floor flattened
meanders migrate downstream
deposition at slip off slopes does what to the flood plain
builds it up
what are levees
natural embankments along the edges of a river channel
Whereis the heaviest material deposited in a flood
closest to the river channel as dropped first when river slows down
why do levees happen
heaviest material deposited first in a flood
builds up over repeated time and floods
what are deltas
low lying areas where the river meets the sea/lake
when they meet the sea or a lack what are rivers forced to do
slow down
how does a river channel get split into lots of smaller rivers at the mouth and what are they called
sea doesn’t wash up deposited material
builds up
makes distributaries
after distributaries are formed what is then formed
deltas
give an example of a delta
nile delta in Egypt
what do contour lines tell you
the direction a river flows
give 2 pieces of evidence for waterfalls on a map
black blocky lines and close contour lines
how can you tell a river is in the upper course
high land
lots of contour lines in short distance
narrow thin blue line
steep valley
how can you tell a river is in the lower course on OS map
nearby land is low (less than 15 m)
few contour lines
wide river (thick)
large meanders/ox bow lake
give 3 things that shape river landscapes
climate
geology
slope processes
rivers in wetter climates have a higher___and hence a higher rate of ___ - why?
discharge
erosion
as more power to erode
more erosion in a river increases what
the river’s load
what else increases apart from erosion when there is a higher discharge and why
transportation
more energy to carry material
weathering can increase the river’s what and give an example which is influenced by the climate
load
colder= more freeze thaw weathering
rivers flowing through hard rock have a faster/slow rate of erosion
slow
softer rock areas have a high/low sediment load and why
high - more erosion
landscapes with more resistant rocks have steeper/gentler valley sides
steeper
how do interlocking spurs form
softer rock is eroded first
leaves areas of harder rock sticking out
what can add lots to a river’s load
mass movement such as slumping
mass movements are more likely when and why
colder weather - as freeze thaw loosens material
rainy times- as ground is saturated and heavier and less stable
what is soil creep
soil moves down a slope due to gravity
what is soil creep caused by
expansion and contraction of soil
water adds weight and expands it - moves down slopes
when dries out it contracts
what type of material does soil creep add to the river’s load
fine
what do hydrographs show
change in river discharge
what is river discharge
volume of water flowing per second
what is river discharge measured in
cumecs - cubic metres per second
what do storm hydrographs show
changes in river discharge around the time of a storm
what is peak discharge
highest discharge in period of time
what is lag time
delay between peak rainfall and peak discharge
what is rising limb
increase in river discharge as rainwater flows into river
what is falling limb
decrease in river discharge as it returns to normal
why does lag time happen
rainwater doesn’t land directly in channel - delay is its getting to the channel
give 3 ways water gets to the river channel
surface runoff
infiltration
flowing slowly underground
what is surface runoff
flowing quickly overland
what is infiltration
soaking into the ground
more runoff leads to ___lag time and makes hydrograph rising limb ___
lower - steeper
give 5 physical factors that affect shape of hydrograph
geology
soil type
slope
drainage basin type
antecedent conditions
give 2 human factors that affect shape of hydrograph
urbanisation
deforestation
how can geology decrease lag time
water can’t infiltrate impermeable rocks- increases runoff
how can soil type affect lag time
impermeable soils (like clays) can’t absorb water as fast as more permeable soils - increases runoff
shallower soils are saturated faster - increases runoff
what type of soils absorb more water
sandy soils
how can slopes affect lag time
steeper slope = less infiltration = more runoff
how can drainage basin type affect lag time and discharge
circular drainage basins have shorter lag time and higher discharge
compared to narrow ones
why do circular basins lead to shorter lag time
as water reaches channel at same time - but in narrow ones it takes a long time for water from one end to reach the other end
how can antecedent conditions affect lag time
very wet or cold weather
can increase runoff
as soil is saturated or impermeable
how does urbanisation affect lag time (2)
water can’t infiltrate impermeable surfaces like tarmac or concrete = more runoff
and gutters and drains take runoff to rivers
rapidly increasing discharge
how does deforestation affect lag time
trees uptake water
store it
reducing runoff
so cutting them down
increases runoff
and increases discharge
reducing lag time
flooding in the river eden is common/not common
common
give an example of an area prone to flooding
carlisle
what is the climate in cumbria
mild and wet - one of wettest parts of UK
what are the prevailing winds in cumbria
south westerly
the eden basin is bordered by what type of rock
hard, impermeable rock - Lake District and north pennines
more runoff
___is common on higher ground in winter months and __melt can add lots of water to river in ___space of time
snow
snow
short
give 3 physical factors increasing risk of flooding in cumbria
wet climate
impermeable rocks bordering the basin
snow in winter
give one way urbanisation has increased risk of flooding in river eden (specific example)
Carlisle - more tarmac - more runoff - less absorption and storage of floodwater - less infiltration as less vegetation
give 1 way deforestation by humans has affected risk of flooding in river eden
natural woodland and heath cleared in upland areas
increasing surface runoff
how has the draining of the eden valley changed flood risk and why was it drained
drained to be suitable for farming
increased flood risk as drainage ditches water flows rapidly into the channel
when was there severe flooding in carlisle
5th and 6th of December 2015
__2015 was the second __ ___ ever recorded in cumbria
November
wettest
November
give 3 human activities which increase risk of flooding in river eden
deforestation
urbanisation
drainage
during storm __more than ___mm of rain fell across cumbria in __hours and this was the __rainfall ever recorded the UK
Desmond
300
24
highest
the lag time in 2015 eden river was short/long
short
what blocked bridges and smaller channels and forced water out of the river channel
debris carried by floodwater
___surfaces in carlisle made water runoff into ___systems which couldnt cope and overflowed
impermeable
drainage
give 1 human factor leading to flooding in the eden basin in 2015
insufficient drainage
give 2 reasons for increased flood risk in the UK
increased frequency of storms and land use change
why is frequency of storms increasing
climate change
storms are becoming more __with more ___rainfall increasing the scale of floods
extreme
intense
more periods of__weather makes the ground ____and flooding more likely
wet
saturated
as the population grows __areas expand leading to more/less impermeable surfaces
urban
more
removing __and permeable surfaces leads to what
water that should’ve been infiltrated and stored in soil/plants flows downstream
lots of __is taking place on floodplains - increases risk in these areas
Development - building houses
give 3 ways storms are making flooding more likely
more frequent
more rainfall intensely
wetter climate -saturated
give 5 threats to people from floods
killed
infrastructure damaged (such as roads/bridges/railways)
floodwater contaminated with sewage = lack of clean drinking water
possession damage
homelessness
businesses forced to shut due to damage/disrupted power = losing livelihoods
give 4 ways floodwater threatens the environment
pollution of rivers as contaminated with sewage and rivers - damage to habitats
farmland ruined by silt
river banks eroded - can widen channel and increase downstream deposition
force of water can uproot trees and plants or drown them if left standing
give 2 types of engineering to deal with flooding
hard and soft
give 4 types of hard engineering for rivers
flood walls
embankments
flood barriers/gates
demountable flood barriers
what are flood wals
artificial barriers - increase height of river banks
allow it to hold more water
give 3 costs of flood walls
unsightly
block view of river
expensive
what are embankments
high banks along or near river banks
stop river flowing out in a flood and protect buildings/infrastructure nearby
give one advantage of embankments
can be made of earth or natural materials = less unsightly than floodwalls
give 2 costs of embankments
expensive
risk of severe flooding if embankments break
give an example of a floodgate
thames barrier
where are floodgates built
on river estuaries to stop flooding from storm surges/high tides
what happens when a surge is forecasted
floodgates shut to protect large areas of land
give 2 costs of floodgates
very expansive
need regular maintenance
what are demountable flood barriers
temporary protections against flooding
what is one risk of flood barriers
they might not be put up in time as they are only put up when there is a flood forecast
give 1 cosy and 1 benefit of demountable flood barriers
expensive but don’t spoil look of locations
what is flood plain retention
maintaining flood plain by not building on it
what is a benefit of flood plain retention
slows floodwater and maintains the plain’s ability to store water
give 1 cost and 1 benefit of flood plain retention
free
but restricts development so can’t be used in urban areas
what is river restoration
making river more natural by removing man made levees so flood plain can naturally floos
what is 2 benefits of river restoration
little maintenance required
less risk of flooding downstream as discharge reduced
give 1 cost of river restoration
can increase local flood risk without any other measures to prevent major floods
