distinctive landscapes

define a landscape

a landscape comprises all of the visible features of an area of land, it can contain both natural features and man-made features

what are the differences between built and natural landscapes?

• natural/physical landscape elements are mountains, coastlines, valleys, plains, rivers and lakes

• built/human landscape elements have buildings and other man-made structures, infrastructure and the way the land is used, fences and pylons

how are upland, lowland and glaciated landscapes distributed in the uk?

• upland areas are mostly found in the north and west of the uk

• lowland areas are mostly found in the south and east of the uk, lowland areas are close to sea level and lie below around 200m

• glaciated landscapes tend to be found in upland areas in the north and west of the uk

what are the characteristics of upland landscapes in the uk?

• geological characteristics:

  -higher altitude

  -poor soils

  -v-shaped valleys

  -waterfalls

• climate characteristics:

  -heavy rain

  -cold temperature

• human characteristics:

  -sheep farming

  -sparsley populated

what are the characteristics of lowland landscapes in the uk?

• geological characteristics:

  -lake district

  -flat land

  -lower altitudes

  -large rivers

  -beaches

• climate characteristics:

  -less rain

  -milder temperatures

• human characteristics:

  -dense population

  -cities

  -dairy and arable farming

what are the characteristics of glaciated landscapes in the uk?

• geological characteristics:

  -high altitude

  -glacial lakes

  -u-shaped valley

• climate characteristics:

  -colder temperature

  -heavy rain

• human characteristics:

  -sheep farming

  -sparsely populated

what is the rock cycle and how have rocks made uk landscapes distinctive?

• the rock cycle is when igneous rock is weathered to form sedimentary rock which can later form igneous rock again

• igneous rock is formed when magma cools on the surface of the ground eg, granite

• sedimentary rock is formed when the skeletons of marine organisms or broken rock fragments which have been laid down are compacted at the bottom of the ocean eg, limestone

• metamorphic rock is formed when heat and pressure is applied to an existing sedimentary or igneous rock which changes its structure to form metamorphic rock eg, slate

what is the geology of britain?

igneous and metamorphic rocks are found in the north west, sedimentary is found in the south east

how does the geology of britain affect the landscape?

• the cuillin hills on the isle of skye are formed of granite, granite is a type of igneous rock, it is a very hard rock which weathers and erodes slowly, this means that it forms highland areas, such as hills and mountains

• granite is an impermeable rock, so water cannot pass through it, this makes the soil waterlogged and so there are many rivers and lakes

• as well as this, the soil is acidic and not very fertile so areas with granite bedrock are not good for growing crops and are mostly used for growing coniferous trees or grazing sheep

• as the land is high and steep there are very few settlements there

what is the uk climate?

• climate is the long-term average of temperature and precipitation experienced at a location

• the uk has a temperate climate- not usually too hot or cold, average is around 13-14°c

what factors of climate affect landscapes?

• as you go up north, the temperature decreases by 1°c every 100m

• some countries experience a rain shadow eg, england, the rain shadow is how the mountains on the south west of england prevent rain from reaching the south east, so when the prevailing winds are forced to go up higher, more moisture is lost

• relief rainfall is formed when the air cools as it rises over relief features such as mountains and hills, as the air rises, it cools and condenses and forms rain

• some countries have a maritime climate, uk brings wet air and rain and stops temperatures becoming extreme, the uk is heavily influenced by the sea

how does the climate of the uk affect the landscape?

• the isle of skye is a cold and wet area in scotland

• when temperatures fluctuate to around 0°c, water begins to enter the cracks of rocks, when it reaches this area, the water will freeze into ice causing the rock to expand which puts pressure on other rocks

• this process repeats causing the rock to be worn out, this causes steep mountains

• rain is slightly acidic meaning that as it rains it reaches the alkaline and carbonate rocks which causes them to be weathered down causing the rocks to be jagged rather than smooth

how has human acitivity impacted landscapes in the uk?

• when the normans invaded in 1066, they began farming, so they destroyed trees for more land

• in the 1600s, the english navy needed resources and later on the industrial revolution took off so they needed a lot more land

• however, from a period of time in 1900, forestry commision was set up and they decided to begin planting more trees

how has human activity affected lowland landscapes in the uk?

• forestry:

  -many uk lowland areas have been planted with trees after the revolution

• settlements:

  -trees have been cleared so that people can build homes

  -natural harbours were sites for fishing villages

  -springs gave people fresh water

• transport:

  -areas have been cleared to build ways for people to travel

• agriculture:

  -drainage ditch, built to drain water from agriculture to allow crops to grow

  -trees have been cleared for agriculuture

how has human activity affected upland landscapes in the uk?

• tourism:

  -very popular in upland areas

• wind farms:

  -built on hill tops exposed to the wind

• hunting:

  -poor quality land can be used to rear deer or grouse

• forestry:

  -coniferous trees grow on better, well-drained land

• hydro-electric:

  -generated by building a dam

• farming:

  -sheep are grazed on hill sides and crops are grown in valley bottoms

what are geomorphic processes?

geomorphic processes change the shape of the landscapes, they include, weathering, mass movement, erosion, transportation and deposition

what is weathering and what are the types of weathering?

weathering is the action of weather, plants and animals on rock, the rocks are broken down but are not removed, this is different to erosion where the rocks are removed, types of weathering include:

• mechanical:

  -when natural forces physically break up rocks, this happens in the uk through freeze-thawing, in areas where temperatures drop below freezing, water in the rock can freeze, as the water freezes it expands and weakens the rock from the inside, as temperatures go up and down from above to below freezing, this process keeps happening and the rock gets broken apart

• biological:

  -plants or animals can physically break apart rocks with their roots or via burrowing

• chemical:

  -this happens when chemical reactions take place in rocks, rainwater contains weak acids that can dissolve some of the rock, this weakens the rock, making it easier to erode and more likely to break apart, calcium carbonate based rocks like chalk can be particularly affected by these acids

what is mass movement and how does it occur?

• mass movement is when material falls down a slope eg, cliff or valley side

• it happens when the force of gravity acting on the slope is greater than the force supporting it

• examples include: slumping and landslide

• slumping:

  -usually occurs in softer rock, erosion at the base of the cliff can accelerate the process

  -appears to create steps as sections of the top of the cliff slide downwards

  -is often brought about by precipitation as this makes softer permeable rock heavier

• landslide:

  -erosion at the base of a cliff can accelerate the process

  -results in a pile of loose rocks at the base of the cliff

  -often brought about by precipitation which lubricates the slide plane

  -occurs in more resistant rocks which can slide in large chunks

how do waves erode?

• hydraulic action:

  -waves crash against the coast forcing air into cracks and breaking up the rock

• attrition:

  -pebbles picked up by the waves, bash into each other, wearing down into smaller, rounder particles

• abrasion:

  -waves pick up rocks from the seabed and smash them against the coast, wearing it away

• solution:

  -rocks like limestone slowly dissolve in the water

describe the formation of headlands and bays

• headlands and bays are formed with a discordant coastline (a discordant coastline is found when bands of rock lie perpendicular to the sea)

• the waves first meet the headland, however as it is made of hard rocks it is difficult to break down

• when the waves meet the headland, the energy is concentrated on the soft rock

• this is hydraulic action, the force of water crashing against the coastline causes the rock to be carried away

• the waves pick up rocks from the seabed and smash them against the coast, this is abrasion

• hard rock erodes slowly forming a headland, soft rock erodes quickly forming a bay

describe the erosion of a headland, cave, arch, stack and stump

• cracks at the base of the headland become exposed through hydraulic action, which pressurises air, forcing the crack to widen

• cracks are further widened by weathering processes such as carbonate dissolution which affects chalk

• over time the cracks widen and develop, further processes of abrasion and hydraulic action will deepen the notch to form caves

• as a result of wave refraction, which distorts the wave direction, destructive waves concentrate their energy on the sides which deepens the cave

• wave refraction affects all three sides of a headland, if two caves are aligned the waves may cut through to form an arch, wave-cut notches widen the base of the arch

• vertical joints are exposed to tall breakers associated with destructive waves, joints can be weathered from above through carbonation in limestone

• over time the arch becomes unstable and it collapses under its own weight to form a stack

• the stack is further eroded at its base, sub-ariel processes continue to weaken the stack from above

• eventually the exposed stack will collapse to form a stump, the broken material is further eroded through attrition and transported away to be deposited within the bay

what is a beach?

a beach is made of material deposited by waves on the coastline, they are usually made of sand and pebbles, they are an area of land between the low water mark and high water mark

what are the characteristics of a beach?

• gently sloping land

• often found in bays or along straight stretches of coastline

• tourist resorts often have groynes to keep the beach in place

what are the two types of waves and their characteristics?

• constructive:

  -they are usually found on gently sloping beaches

  -the swash is more powerful than the backwash and deposits sediment on beaches

  -they break infrequently at a rate of 10 or fewer per minute

  -they are long in relation to their height

• destructive:

  -the backwash is much stronger than the swash and is therefore able to carry sand and pebbles away from the shore

  -they are high in proportion to their length

  -they are generally found on steep beaches

  -they break infrequently at a rate of 10-15 every minute

what are some examples of transportation?

• suspension:

  -fine, light material is carried along by the river

• traction:

  -large boulders and rocks are rolled along the river bed

• solution:

  -minerals are dissolved in the water

• saltation:

  -small pebbles and stones bounced along the river bed

what is longshore drift?

• longshore drift is the zig-zag movement across a beach

• the swash is the foreward movement of water up the beach as the waves break

• the backwash is the movement of water down the beach due to gravity after a wave breaks

• in the uk the prevailing wind blows from the southwest

how are spits formed and what conditions help the formation of spits?

• spits are created when the coastline ends or changes direction and the process of longshore drift continues

• conditions that help the formation of spits:

  -a change in the shape of the coastline

  -a rapid movement of sediment (lsd)

  -large volumes of sediment are available

  -a shallow seabed

  -area that is sheltered from strong winds

  -low wave energy

  -opportunity for sediment to be vegetated which establishes the spit as a permenant feature

• if the spit has a lot of hooks it’s called a compound spit, if it has one it’s called a single spit

what are some characteristics of jurassic coast?

• swanage bay

• old harry

• sandbanks

• ballard down

what are the geomorphic processes which have formed named landforms?

• mass movement on the clay cliffs to the north of swanage bay

• deposition of small sediment on swanage beach

• there’s erosion of cliffs at ballard down

• transportation along the coast at swanage bay via lsd towards the north

how have the geology and climate influenced geomorphic processes?

• the jurassic coastline is made up of alternating layers of sedimentary rock, it is a discordant coastline
  →the layers include chalk and clay

• chalk is a more resistant rock, it’s porous and permeable

• clay is a less resistant rock, it’s impermeable

• jurassic coast receives:
  -an annual rainfall of 800mm
  -an average annual temperature of 10°c
  -temperature range of 12°c
  -prevailing wind direction from the sw

how have the landforms of the jurassic coast been influenced by the geology and climate?

• swanage bay:

  geology:

  -discordant coastline

  -clay and sand

  -wave refraction at headlands

  climate:

  -stronger winds and more erosion in winter

  -calmer winds and more deposition in summer

• stack and stump:

  geology:

  -discordant coastline

  -made of chalk

  -chalk is more affected by weathering than many other rocks

• formation of a spit:

  geology:

  -presence of large volumes of sediment (gravel and pebbles) from erosion of cliffs to the west in the past

  -large volumes of sediment help create depostional landform

  climate:

  -south westerly prevailing wind means lsd moves material east along the coast

how does human activity impact the landscape?

• lots of coastal erosion and long-term sea level change associated with climate change

• risks of landslides and rockfalls due to mass movement

• tourist infrastructure: roads and buildings on top of cliffs puts extra weight on the cliffs which can cause them to collapse

  →could affect properties and infrastructure in swanage

what is hard and soft engineering?

• hard engineering: works against natural processes to protect the coastline by building artifical structures, it tends to be more expensive as it needs to be continually maintained

• soft engineering: works with natural processes to protect a coastline by using ecological principles, it tends to be less expensive as it’s easier to maintain

how have coastal management schemes impacted the landscape?

• sea wall:

  -a large concrete structure to relect wave energy back out to the sea, costs up to £6 million per km to build

  -protects the cliffs against erosion and can prevent coastal flooding in some areas

  -land and buildings are also protected from erosion, they last a long time

  -very expensive to build and the cost of maintenance is high, can also look unsightly impacting tourism

• groynes:

  -strong wooden structures sticking out into the sea, they trap sand, stopping lsd causing the beach to widen and giving more protection to the coastline behind, each groyne costs about £10,000 to build

  -they produce an attractive beach for tourists, they protect the coastline behind the beach and it is not as expensive as the seawall

  -they can be seen as unattractive and can cause erosion further along the coast and they need regular maintenance

• beach nourishment/sand replenishment:

  -provides material to build up the beach which protects the cliffs from incoming waves, costs about £2000 per metre

  -it provides a natural defence against erosion and coastal flooding, beaches also attract tourists and it is relatively inexpensive

  -not a long term solution, the beach can be lost rapidly in storms

  -marine life and the sediment movements in an area may be severely disrupted

what are some details of the coastal management schemes along the jurassic coast?

• 18 timber groynes were put in place in 2005

• 90,000 m³ of sand was deposited on the beach

• estimated cost of £2.2 million

what are the parts of a river?

• drainage basin- the area of land drained by a river

• watershed- the edge of highland surrounding a drainage basin

• source- where the river begins

• confluence- the point at which two rivers or streams meet

• tributary- a stream which joins a larger stream

• mouth- the point where the river comes to the end

• river channel- holds the water in the river

how is a v-shaped valley formed?

• rivers begin high up in the mountains so they flow quickly downhill eroding the landscape vertically

• the river cuts a deep notch down into the landscape using hydraulic action, when the sheer force of the water gets into small cracks and breaks down the sides of the river valley

• as the river erodes downwards the sides of the valley are exposed to freeze-thaw weathering which loosens the rocks (some of which will fall into the river) and steepens the valley sides

• the rocks which have fallen into the river assist the process of abrasion and this leads to further erosion

how are waterfalls formed?

• a waterfall is formed when a harder, more resistant rock eg, granite is on top of a weaker, less resistant rock eg, sandstone

• as the less resistant rock is on the bottom is softer it erodes quicker meaning a plunge pool is formed, an over deepened area is created by erosion such as hydraulic action of the softer rock

• the overhang collapses as it is weakened by erosion and weathering and is pulled down by gravity

• the overhang is then further eroded via abrasion

• the waterfall retreats back upstream to create a gorge

what are the river landforms and processes in the middle course?

• middle course:

  -valley floor developing v-shaped

  -wider river channel

• on the outside bend of a meander, that’s where the thalweg travels as it is so fast

• due to the helicoidal flow the sides of the meander are eroded by abrasion and hydraulic action meaning a lot of material is deposited to the other side on a slip-off slope, this happens on the inside of the meander as water flows more slowly

• the result of the thalweg is that abrasion is greater and it makes the water deeper and over time the meanders become more sinuous

how is an oxbow lake formed?

• due to hydraulic action and abrasion on the outside of a bend and deposition on the inside, the shape of a meander will change over a period of time

• erosion on the outside bend narrows the neck of the land within the meander and as the process continues, the meandars move closer

• when there is a period of very high discharge eg, a flood, the river cuts across the neck, taking a new straighter and shorter route

• deposition will occur to cut off the original meander, leaving an ox-bow lake

what are river levees and floodplains?

• when the river is in flood, the water flow slows meaning energy is lost, coarser, heavier material is deposited on the bank and finer material is deposited further away

• when the river is at low flow, the river’s velocity slows down and the volume falls, this causes the deposit of material on the bed

• after repeated floods the river banks form levees and the bed may be raised so much that the river rises above the flood plain, this can lead to more flooding

• a floodplain is formed, a floodplain is an area of low-lying ground next to a river, it is formed when a river flood deposits fine silt or alluvium

background information on the river wye

• the river wye is the 5th longest river in the uk at over 210km in length

• the source of the river wye is in plynlimon (cambrian mountains) in wales

• the mouth of the river wye is in the seven estuary

how do geomorphic processes change on the upper course?

• erosion- vertical erosion occurs due to gravitational pull

• transportation- small pieces of eroded material are transported as solution

• deposition- little if any deposition occurs

• size of load- large load size eg, boulders

• landforms- v-shaped valleys and waterfalls

how do geomorphic processes change on the middle course?

• erosion- lateral (horizontal) erosion occurs due to volume and speed of the flowing water

• transportation- medium and small pieces of eroded material are transported via saltation

• deposition- occurs when the water flow is at its slowest eg, inside of a meander

• size of load- medium load size eg, pebbles

• landforms- meandars and oxbow lakes

how do geomorphic processes change on the lower course?

• erosion- less erosion occurs as the flow of the water slows down nearer the mouth of the river

• transportation- large pieces of eroded material are rolling along the river bed by traction

• deposition- occurs as the flow of the water slows near the mouth of the river

• landforms- floodplains and levees

what’s an example of v-shaped valley on the river wye?

plynlimon hills

• climate:

  -plynlimon- high mountains equals high rainfall

  1,400mm per year (1.4 metres) - most rain in january 157 mm

  -high levels of erosion as a result of lots of rainfall

  -cold temperatures in winter and variations in temperature between night and day leads to freeze thaw weathering

• geology:

  -plynlimon- the cambrian mountains are 2,500 feet high and made of hard, impermeable rock eg, shales and gritstone, the increased rate of surface runoff has created steep v-shaped valleys

what’s an example of a waterfall on the river wye?

cleddon falls

• climate:

  -during the winter months with high rainfall, the stream transforms into fast flowing cascading waterfalls

  -high rates of erosion in winter

  -limestone is dissolved by water in weathering and erosion

• geology:

  -limestone exists above sandstone (which erodes and weathers quicker)

what’s an example of a floodplain and levee on the river wye?

wye floodplain

• climate:

  -flooding occurs mainly in winter as a result of higher rainfall

• geology:

  -fine sediment is deposited on the floodplain, larger material which forms levees is carried downstream from areas of more resistant rock

what’s an example of a meandar on the river wye?

ross on wye

• climate:

  -high flow in winter causes greater erosion on the outside of the bend and allows deposition to occur on the inside of the bend at the top of the slip off slope (because most of it is submerged in winter)

  -in summer less erosion occurs, deposition occurs lower down the slip off slope (water level is lower)

• geology:

  -at ross on wye, weak mudstones have been eroded through lateral erosion to create wide meanders

what’s an example of an oxbow lake on the river wye?

letton oxbow lake

• climate:

  -letton oxbow lake doesn't dry up to become a meander scar (dried up oxbow lake) as it is topped up when the river overflows during flooding in winter

  -high flow (in winter) is also responsible for initially cutting off the meander

• geology:

  -the weak mudstones that have been eroded through lateral erosion to create wide meanders, have also helped create letton oxbow lake

evaluation of the human activity agriculture on the river wye basin

• what this involves:

  -agriculture is farming including cultivation of the soil for the growing of crops

• how does this impact geomorphic processes:

  -deforested areas means there is less interception by plants, water flows off the surface more quickly and increases peak discharge in rivers, encouraging erosion and where flooding occurs, deposition

• what are the impacts of this on the landscape:

  -higher levels of biodiversity, but fewer trees

  -increased rates of deposition further downstream

evaluation of the human activity afforestation on the river wye basin

• what this involves:

  -planting trees in areas there weren’t any trees previously

• how does this impact geomorphic processes:

  -increases interception storage, reduces rates of run off by increasing surface cover

  -chances of mass movement is reduced by planting trees which intercept rainfall and help bind the soil’s surface together

• what are the impacts of this on the landscape:

  -trees change the appearance of the landscape

  -it shapes the landscape by slowing both the formation of erosional features and the development of levees and floodplains

  -trees can reduce the height of a flood by 20%

evaluation of the human activity flood management on the river wye basin

• what this involves:

  -hard and soft engineering to protect people’s settlements from floods

  -some areas can use the landscape to make sure excess water flows into floodplains that are zoned for that purpose

• how does this impact geomorphic processes:

  -encourages the river to behave more naturally and increases erosion

• what are the impacts of this on the landscape:

  -slows the rate of water entering the channel via surface run off

  -alters the appearance of the landscape