Physical Landscapes of the UK Flashcards
where are the main upland areas in the UK
usually in the north and west
- grampian highlands, scotland
- pennines, cumbria
- snowdonia, wales
- dartmoor, devon
pros of dams and reservoirs. is it a hard or soft engineering strategy?
- provides drinking water, power generation or flood control
- electricity generation without pollution (hydroelectricity)
- recreation (picnics)
HARD STRATEGY
cons of dams and reservoirs. is it a hard or soft engineering strategy?
- expensive
- building large dams can cause damage ie earthquakes
- prone to flooding which can destroy natural & human landscapes
- interferes with fish/wildlife
HARD STRATEGY
pros of channel straightening. is it a hard or soft engineering strategy?
- water moves quickly out of area
- water doesn’t travel as far
- reduces risk of flooding
HARD STRATEGY
cons of channel straightening. is it a hard or soft engineering strategy?
- more erosion downstream so causes flooding downstream
HARD STRATEGY
pros of embankments. is it a hard or soft engineering strategy?
- can be used as a path of pedestrians
- increases capacity of river
- concrete embankments can slow down bank eroision
- earth embankments can provide habitats for wildlife
HARD STRATEGY
cons of embankments. is it a hard or soft engineering strategy?
- banks are often not built high enough = serious flood
- concrete embankments are ugly & spoil the view
- reduce the type of farming type that can be undertaken in that area
HARD STRATEGY
pros of flood relief channels. is it a hard or soft engineering strategy?
- river discharge reduced
- gates on channels meaning the release of water can be controlled
HARD STRATEGY
pros of flood warning & preparation. is it a hard or soft engineering strategy?
- give ppl time to save their belongings from being ruined
SOFT STRATEGY
cons of flood warning & preparation. is it a hard or soft engineering strategy?
- doesn’t stop flood from happening
SOFT STRATEGY
cons of flood plain zoning. is it a hard or soft engineering strategy?
- expansion of urban area is limited if there aren’t any suitable building sites
- no help in cities already built on
SOFT STRATEGY
pros of flood plain zoning. is it a hard or soft engineering strategy?
- the risk of flooding is reduced (impermeable surfaces arent created ie building/road)
- impact of flooding is reduced (no buildings to damage)
SOFT STRATEGY
cons of planting trees. is it a hard or soft engineering strategy?
- less land for farming
SOFT STRATEGY
pros of planting trees. is it a hard or soft engineering strategy?
- discharge & flood risk reduced
- vegetation reduces soil erosion
SOFT STRATEGY
cons of river restoration . is it a hard or soft engineering strategy?
- different and more hostile species may be carried upstream bc of the stronger current possibly endangering species
SOFT STRATEGY
pros of river restoration . is it a hard or soft engineering strategy?
- supports biodiversity
- pipelines help collect excess sewage
SOFT STRATEGY
cons of flood relief channels. is it a hard or soft engineering strategy?
- expensive
- relief channel floods
- only works if there’s farmland upstream
HARD STRATEGY
define a hard engineering strategy
involves building structures to defend places from floodwater
define a soft engineering strategy
involves working with natural river processes to manage flood risk
describe river restoration
- makes river more natural by removing man-made levees so flood plain floods naturally
describe planting trees
- planting trees in river valley - more interception, less lag time
describe flood warning & preparation
- warns ppl about floods through TV & radio
describe flood plain zoning
- restrictions prevent building on parts of a flood plain likely to be flooded
describe flood relief channels
- make offshots of river. diverts water around important areas
describe embankments
- raised walls along river banks
describe channel straightening
- course is straightened. cuts off the meanders
describe dams and reservoirs
- storage for water. dams built across rivers in upper course of the reservoir
locate an example of a flood management scheme in the UK
- morpeth is situated in the north east of england in northumberland
- 15 miles from newcastle n the river Wansbeck
what caused the morpeth floods
- prolonged rainfall (150mm) the previous day
- river valley is narrow & deep = large surface runoff
- wet summer = saturated soil
what was done to manage the river after the morpeth floods
- tree catching poles (catch debris preventing them travelling downstream)
- water from a dam holding 1.3 mill cm3 water was slowly let out reducing flood flow in morpeth
- improved existing flood walls making them higher & stronger
- built specially designed flood walls made of reinforced concrete so not porous. local residents (flood wardens) lock them in a flood.
give 2 economic issues with the management of flood management in morpeth
- expensive
- mitford estate received compensation to allow dam to be built on their property
give 1 environmental issue with the management of flood management in morpeth
- endangered species had to be hand moved (white clawed crayfish)
give 4 social issues with the management of flood management in morpeth
- costs £25 mill on a small town - disagreements
- unaesthetically pleasing (needs to fit in with history of the town)
- 7 houses were too expensive to protect (1 mill)
what is a levee (characteristics)
- raised river banks (2-8m in UK)
- composed of gravel & stones
- steep sided (steeper on the channel side than the land side)
- fairly flat top
what is a floodplain (characteristics)
- large area of flad land
- made of sedimnets s v. fertile
what is a estuary (characteristics)
- high tida range
- v. wide
- tidal bores (huge waves that funnel up the river casuing great damage to the river banks & vegetation)
- ## mudflats. the river deposits its sediment
how are levees formed (explanation)
- a river birsts its banks.
- friction reduces velocity & causes deposition (heaviest is deposited first)
- with each flood banks can build up higher
- over time the bank will get thicker
how are floodplains formed (explanation)
floodplain is a wide flatter valley floor that surrounds the river
- a meander is eroded sideways causing a river to break its banks
- during a flood, sediment is deposited (smallest on the outside as river starts to lose energy)
- this creates levees
how are estuaries formed (explanation)
- the freshwater of a river & its sediments meet the saltwater of an ocean & its materials forming sandbanks.
- sea water entering the estuary is diluted by the fresh water flowing from rivers and streams
this creates areas of shallow water
name the 5 types of erosion
- hydraulic action
- abrasion
- attrition
- solution
- vertical/ lateral erosion
name the 4 types of transportation
- traction
- saltation
- suspension
- solution
which landforms form bc of erosion
interlocking spurs
waterfalls
gorges
which landforms form bc of erosion AND deposition
meanders
oxbow lakes
which landforms form bc of deposition
levees
floodplains
estuaries
locate an example of a UK river valley
the river tees, north east of england
name & locate where major land-forms caused by erosion & deposition in an example of a UK river valley
- interlocking spurs found at upper course
- waterfall (high force - 212m high) found at upper couse. cuts quite a deep gorge into the waterf
- meanders at middle course in egglescliffe
- large meanders at lower course
- levees at Croft on Tees on south side of river
- big estuary made up of mudflats & embankments
what is the gradient, valley, river, size of load & process involved like in the upper course of a river?
- steep gradient
- steep sided, V-shaped valley (interlocking spurs)
- river is narrow, shallow & turbulent
- large bedload (rocks/boulders)
- mostly erosion involved
what is the gradient, valley, river, size of load & process involved like in the middle course of a river?
- gentle gradient
- wider valley, flat river floor
- river is wider & deeper
- smaller material in the load
- mostly erosion & deposition involved
what is the gradient, valley, river, size of load & process involved like in the lower course of a river?
- very gentle gradient
- very wide valley & flat river floor
- wide, deep river
- mainly suspended load
- mostly deposition involved
what is hydraulic action
- fast flowing water pushes air into the cracks, compressing the air
- when the wave retreats, compressed air blasts out
- this can force the rock apart & over time cause the channel to break up
define abrasion
- sediment is thrown against the cliff by waves
- this wears the cliff away & chips bits of rock off the cliff
define attrition
sediment knocked off the cliff by hydraulic action/abrasion is swirled around by waves
- constantly collides with other sediment & gradually gets worn down into smaller, rounder sediment
define solution (erosion)
- acid rainwater in the sea dissolves material from the rock
what is solution (transportation)
materials being carried in the water that have been dissolved, called solute land
what is suspension
fine or very small particles suspended in the water & carried along, making the water look muddy/murky
what is saltation
small pebbles are moved when one hits another causing it to bounce along the river bed.
what is traction
big rocks & boulders being rolled along the river bed. this needs a lot of energy
why might a river deposity its load
it doesnt have enough energy to transport the load, dropping the larger stones first. reasons for this:
- drier weather (less water so less energy)
- river slows in speed (less speed so less energy ie inside bend of a river)
- river floods (water goes onto floodplain & deposits layers of silt/clay (ALLUVIUM) this is fertile so good for farming)
what is the deposited material by a river called
sediment
how are interlocking spurs formed
- ..- upper course of valley is steep sided & made of hard rock. vertical erosion occurs here
- ..- although the hard rock is difficult to erode, freeze thaw action gradually widens the valley
- this allows the river to take a winding path - ..- river takes the easiest path through the valley aroundthe sections of hard rock that overlap like a zip
how are meanders and oxbow lakes formed
- a meander is a curve in the river. water flows faster on the outside bend
- lateral erosion occurs of the outside bend, making the bend more pronounced
- a swans neck in the meander is formed as erosion continues
- in time of flood the river cuts through the neck & a new river channel is created
- this leaves behind a crescent shaped lake called an oxbow lake
what is freeze thaw action. what type of weathering is it?
- rocks are weakened by water getting into cracks
- as it freezes it expands & puts pressure on the surrounding rock. the crack is widened
- eventually the crack widens so much that it breaks the rock apart
MECHANICAL WEATHERING
how are waterfalls & gorges formed
- waterfalls formed when the river flows over a layer of hard rock on top of softer rock
- as the river flows the softer rock is eroded by hydraulic action & abrasion and a plunge pool starts to form at the base o the waterfall
- over time, erosion of the plunge pool increases until the overhang cannot be held up
- overhang collapses to the base of waterfall leaving large angular rocks.
- the process starts again & waterfall retreat up the valley
give the order of the water cycle
1 - evaporation from ocean & transpiration from trees. then gas cools & condenses
2 - condensation
3 - precipitation
4 - surface runoff
- infiltration (downward entry of water into the soil/rock surface)
- percolation (the flow of water through soil & porous rock)
5 - groundwater flow
-
how & why does land use in urban areas affect the risk of flooding
- increases flood risk
- urban areas have higher concrete/ tarmac use
- this is impermeable so there’s more surface runoff & water gets into the river channel quicker
give human factors that affect flood risk
- land use in urban areas
- land use in rural areas
- deforestation
- agriculture
give physical factors that affect flood risk
- precipitation (snow/rain/hail)
- — heavy rainfall
- — prolonged rainfall
- geology
- — impermeable rock
- — permeable rock
- relief (how steep the land is)
- — steep land
- — flat land
how & why does land use in rural areas affect the risk of flooding
- decreases flood risk
- rural areas have more permeable surfaces (ie grass/ crops), less surface runoff & more groundwater flow/transpiration
- this means water gets into the channel slower
how & why does deforestation affect the risk of flooding
- increases flood risk
- less transpiration & interception as trees wouldn’t be there to slow down the water
- this means the water travels faster to the channel
how & why does agriculture affect the risk of flooding
- increases flood risk
- if overused, the soil can be dry & impermeable causing more surface runoff
- this means the water travels faster to the channel
how & why does relief affect the risk of flooding
STEEP LAND
- increases flood risk
- increases the rapid transfer of water towards the channel
FLAT LAND
- increases flood risk
- water has nowhere to go (the water collects in pools)
how & why does geology affect the risk of flooding
IMPERMEABLE ROCK
- increases flood risk
- travels over land into the river channel quicker as more surface runoff/ less percolation
PERMEABLE ROCK
- decreases flood risk
- water can soak into the rock as its less dense, decreasing surface runoff
how & why does precipitation affect the risk of flooding
HEAVY RAINFALL (in large amounts for a short time)
- increases flood risk
- water would travel faster as the volume is massive & would overuse the permeable land, so more flash floods
PROLONGED RAINFALL
- increases flood risk
- if it rains on flat land it can’t soak the water up so is saturated
define river basin
the area of land drained by a river
define hydrograph
a graph that shows the relationship btwn precipitation & river discharge
define drainage density
the number of streams in a particular drainage basin. the higher the drainage density the quicker the water drains into a river
define river tributary
a stream/smaller river that joins a larger stream/river
describe the features of destructive waves
- high & close together
- strong backwash & weak swash
- erode the beach (destroy)
- make a steep beach
describe the features of constructive waves
- low & far apart
- strong swash & weak backwash
- build up the beach by deposition
- make a gentle beach
what is onion skin weathering. what type of weathering is it?
when the change in temperature during the day & night weakens the rock causing it to peel off
- it occurs usually in deserts
MECHANICAL WEATHERING
what is the process of longshore drift
- the prevailing wind blows diagonally meaning the swash goes onto the beach at an angle
- the backwash comes away from the season at 90* bc of gravity
- material is carried along the beach in a zigzag pattern
how is a discordant coastline formed
- the sea erodes the softer rock quickest forming a bay
- the harder rock is left sticking out into the sea as a headland
how is a concordant coastline formed
the hard rock is parallel to the sea so is more resistant to erosion
describe the formation of headlands & bays
- weaker bands of rock ie clay erode more easily to form bays
- the tougher more resistant rock ie limestone are eroded slower & stick out into the sea to form headlands
- as the bays are sheltered, deposition takes place & sand beaches form
- most occur at discordant coastlines bc diff types of rocks at the coastline will be eroded at diff rates
explain the formation of a wave cut platform
- erosion is concentrated in 1 place where high & low tide levels are. hydraulic action & abrasion erode a notch in the cliff
- weathering attacks the top & face of the cliff making it weaker
- over time notch deepens, undercutting the face of the cliff & collapses into the sea, breaking into small rocks
- the rocks are smoothed by abrasion into a platform of rock jutting out the sea (wave cut platform)
- this process continues & the cliff retreats
how are caves, stumps, stacks and arches formed?
- large crack opened up by hydraulic action
- crack grows into a cave by hydr. act. & abrasion
- cave becomes larger
- cave breaks through the headland forming a natural arch
- arch is eroded & collapses (this is sped up by freeze - thaw action)
- this leaves a tall rock stack
- the stack is eroded forming a stump
howre spits formed?
- Longshore drift moves material along the coastline.
- A spit forms when the material is deposited.
- Over time, the spit grows and develops a hook if wind direction changes further out.
- Waves cannot get past a spit, which creates a sheltered area where silt is deposited and mud flats or salt marshes form.
how is a beach formed
- beaches are deposits of sand & pebbles that lie between high & low tide
- theyre formed by constructive waves where the swash is stronger than the backwash
- the foreshore (inter-tidal zone is repeatedly covered then uncovered by changing tides)
- the ridges thatre called berms may have more than one tide level & are the result of the deposition of material by low-energy waves.
characteristics of beaches
- sandy/pebbly
- steep/gentle
- narrow/wide
- can have sand dunes at the back
how is a sand dune formed
- towards the back of a beach, sand gathers around deposited materials ie wood/rocks called embryo dunes
- these develop when vegetation grows around embyro dunes
- ## in time, rotting vegetation makes sand more fertile & more plant grow in the “back dunes”
what is a beach bar
- it’s a spit thats grown across a bay, trapping water behind it (lagoon)
what is a spit
- a long narrow finger of sand/ shingle fitting into the sea from the land
what is a spit
- a long narrow finger of sand/ shingle fitting into the sea from the land
locate a place where coastal management has taken place
- holderness, east coast of england
give facts about holderness coastal management. SMPs (shoreline management plans)
- avrg. rate of erosion along the coast 1.5m per year
- 3.6km of concrete sea walls with groynes built in Bridlington to stablilise the beaches
- 1.9km concreate seawalls w groynes & rock armour built in Hornsea
- 24 caravan parks must locate 400m away from the coast as part of a ‘roll back’ policy
- revetment built using 60,000 tonnes of rock in Mappleton
advantages of managed retreat
- over time land becomes marshland, protecting land behind from flooding & erosion
- cheap & easy. doesnt need maintaining
- marshland creates habitats for plants & animals
what is managed retreat
- removing current defences & allowing the sea to flood the land behind
disadvantages of managed retreat
- land is lost to the sea. choosing areas to flood causes conflicts ie flooding farmland affects livelihood of farmers
- ## saltwater negatively affects existing ecosystems
what is dune regeneration. is it a hard or soft engineering technique?
creating/ restoring sand dunes by nourishment/ planting vegetation to stabilise land
SOFT
advantages of dune regeneration
- provides a barrier btwn land & sea
- wave energy absorbed which prevent flooding & erosion
- stabilisation is cheap
disadvantages of dune regeneration
- protection is limited to a small area
- nourishment is v. expensive
what are sea walls. are they a hard or soft engineering technique?
- concrete walls designed to reflect the waves back out to sea and / or absorb their energy
- sometimes it has a promenade built on it
what are groynes. are they a hard or soft engineering technique?
- wooden/ stone groynes are built on the beach at right angles to the coast.
- they stop longshore drift by trapping sediment, building up the beach
what is rock armour. is it a hard or soft engineering technique?
big boulders placed at the base of the cliff to dissipate the energy of the waves
what are gabions. are they a hard or soft engineering technique?
- steel cages filled with pebbles
- they’ re placed on sandy beaches at the foot of cliffs
what are beach nourishment and beach reprofiling. are they a hard or soft engineering technique?
sand & shingle from the seabed or lower down the beach that is added to upper parts of the beach
disadvantages of sea walls
- expensive to build & maintain
- creates strong backwash which erodes under the wall
disadvantages of groynes
- unaesthetically pleasing
- repairs are expensive
- ineffective in stormy condition & need regular maintaining
disadvantages of rock armour
- unaesthetically pleasing & covers large areas on the beach
- litter becomes trapped in it
- can be moved by strong waves so need to be replaced
disadvantages of gabions
- when damaged, are dangerous as ppl cut themselves
- unaesthetically pleasing
- wire corrodes over time
disadvantages of beach nourishment and beach reprofiling
- taking material from the seabed can kill organisms ie coral
- expansive
- must be repeated
advantages of sea walls
- prevents eroion of the coast
- acts as a barrier to prevent flooding
advantages of groynes
- cheap & last upto 40 years
- act as windbreakers
- ppl can walk on them so dont take up too much of the beach
advantages of rock armour
- boulders absorb wave energy so reduce erosion & flooding
- fairly cheap to make
advantages of gabions
- cheap & easy to construct
- last a long time 20 - 25 years
- absorb wave energy so reduce erosion
advantages of beach nourishment and beach reprofiling
- creates water beaches slowing the waves
- gives greater protection from flooding & erosion
