Distinctive Landscapes Flashcards (copy)

what are landscapes

the visible features that make up the surface of the land

what are the four elements that make up a landscape

natural/physical, biological, human and variables

what is a built landscape

landscape with lots of infrastructure

what is a natural landscape

landscape with mainly naturally occurring things and is most likely a rural area

what is a lowland area

an area of land below 200m

where are upland areas in the uk

mainly north in scotland and some in the east in wales

how does altitude affect temperature

temperature drops 1degree per 100m of altitude

how did glaciated areas create upland areas

uk mountains were sculpted by actions of ice

how does granite create a distinctive landscape

it is impermeable so becomes waterlogged making it infertile so the land is used for sheep farming. also it is hard so erodes slowly causing upland areas

what rock is there in the south downs

chalk

how does chalk create a distinctive landscape

it is permeable making it well drained so it is used for crop farming. also it is soft so erodes quickly causing lowland areas

how does climate affect upland areas

low temps so more freeze-thaw weathering so more rough rocks

how does climate affect lowland areas

high temps and some rain so good for plants causing biological weathering

whats the difference between weathering and erosion

weathering is the breakdown of rocks at the earths surface by weather conditions. erosion is due to movement

chemical weathering

rain dissolves co2 in the air so rainwater is naturally acidic. it collects in cracks of rocks dissolving them

mechanical weathering

when rainwater collects in rock cracks it freezes and expands making crack bigger. it melts and this repeats until rock splits

biological weathering

roots force into rocks splitting them apart. animals burrow in softer rocks

what are geomorphic processes

processes that change the shape of the land

what are sub ariel processes

land based processes which alter the coastline shape

what is longshore drift and what does it cause

zig zag movement of material along a beach due to swash from prevailing wind and backwash from gravity. it causes spits to have a bent end

what is a spit and how is it formed

a curved beach which extends out to sea and is formed when there is a change in direction in the coastline and longshore drift continues

what are the 4 transportation processes

suspension, solution, traction and saltation

suspension

fine and light material is carried along by the river

solution (rivers)

minerals are dissolved in the water

traction

large rocks are rolled along the river bed

saltation

small pebbles are bounced along the river bed

what is the difference between constructive and destructive waves

constructive waves have stronger swash and destructive waves have stronger backwash

what are the 4 types of erosion

hydraulic action, attrition, abrasion and solution

hydraulic action

waves crash against the coast, breaking up the rock

attrition

pebbles are picked up by the waves and bashed into each other to wear down into smaller more rounded particles

abrasion

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

solution

rocks dissolve in the water

what is mass movement and what are the two types

when material falls down a slope. rotational slumping and landsliding

what causes a cliff to slump

when it rains water goes through the sand and sits on top of clay cliff because sand is permeable and clay is impermeable. the clay dries out in the sun creating cracks and water goes into cracks reducing friction. combination if weight and gravity and reduced friction causes slump

what are landslides and how are they caused

when a block of rock moves downhill along a bedding plane. caused by earthquakes or heavy rainfall when the slip surface becomes lubricated and friction is reduced

what is the difference between hard engineering and soft engineering

hard engineering works against natural processes and soft engineering works with natural processes

how are headlands and bays formed

headlands are made of harder rock so erodes slower causing it to protrude out to sea. bays are made of softer rock so erode faster through hydraulic action and abrasion causing a curved beach with headlands either side

cave

indentation in base of headland. formed when sea erodes a crack

arch

area of hard rock with a hole that goes through the headland so it is unsupported below. formed when sea erodes cave all the way through

what is the process of longshore drift

the prevailing wind is the direction the wind usually blows from the south west which causes waves to move in the same direction as the prevailing wind so when the wind blows at an angle to the coast the swash will move sediment up the beach in that direction. the backwash will move sediment back towards the sea due to gravity and over time particles move along the beach in a zig zag movement which is longshore drift

stack

a stack of rock next to a headland formed when the top of an arch collapses

how are v shaped valleys formed

rock is hard and impermeable in some upland areas causing rainwater to flow overland into the river. the water has lots of energy so the river to erodes vertically through hydraulic action making the rocks either side steeper and unsupported so rockslides happen and the river further erodes through abrasion

how are waterfalls formed

hard rock on top soft rock underneath. soft rock erodes faster through hydraulic action because is less resistant creating plunge pool. hard rock overhangs and eventually falls after being weakened by weathering erosion and pulled down by gravity and is used for abrasive erosion. waterfall retreats leaving a plunge pool

how are gorges formed

a narrow steep sided valley formed when a waterfall retreats

what is a meander

a bend or curve in a river

how are meanders formed

on the outside bend of rivers water moves faster because it is deeper so there is less friction and the water has more energy causing it to laterally erode the river cliff through hydraulic action forcing it outwards. on the inside bend of rivers water moves slower so there is more friction and the water has less energy so it is unable to carry the silt causing it to be deposited on the inside bend creating a slip off slope. a combination of these processes results in a curve in the river

how is an ox bow lake formed

on the outer bends of a meander there is lateral erosion because the water is deep so has less friction more energy and is faster causing the meander neck to narrow. when it floods water flows over the neck creating a new channel and an old one which is the ox bow lake but the water is fastest in the new channel because it is the easiest way to flow so the water in the old channel is slower and has less energy causing deposition. as deposition builds up the ox bow lake is eventually cut off from the river channel and is left to evaporate and fill up again at a time of flood

what is discharge

volume of river in cumecs

why does water move fastest in the lower course of the river

there is more water and discharge is higher so there is less friction so it has more energy and can move fastest

what is a flooplain

an area of low lying ground next to a river

how is a floodplain formed

when a river floods water spreads across the floodplain and then evaporates off leaving a layer of deposited fine silt or alluvium

what are levees

embankments either side of a river

how is a levee formed

a river floods over the floodplain because the river channel can’t hold all the water causing water to slow down and energy is lost so water drops heavier coarser material on the bank and finer material further away.. during warmer times of the year there are droughts so river is at low flow and is shallower so has less energy causing it to deposit material on the bed. after repeated floods the river banks form levees but when it is warmer the bed is raised and eventually rises so much that the river rises above the floodplain leading to more flooding and the process repeats

where is the source of the river Wye

Plynlimon in the Cambrian mountains in Wales

where is the mouth of the river Wye

in the Severn estuary

where are levees formed in the river Wye

below Hereford

where is the waterfall in the river Wye

Cleddon Falls

where was a weir removed in the river Wye

in the river Monnow a tributary of the river Wye

what did removing the weir in river monnow lead to

increased rates of erosion at 1.5 meters per annum

what was done to combat increased rates of erosion on the river Wye

willow was planted on the banks

where and when have trees been planted in the upper course of the river Wye

in Plynlimon hills since WWII

what is the geology like in cleddon falls to create a waterfall

there is sandstone above limestone

what is the geology like in Plynlimon

the cambrian mountains are made of shales and gritstone

how high is the source of the river Wye in Plynlimon

762 meters high

how much rain is there per year in Plynlimon

1400 mm

how much rain is there in January the wettest month of the year in Plynlimon

157mm

what and when are the coldest temperatures of the year in Plynlimon

average daytime temperature of 3c in feburary

how much does water expand when it freezes

10%

what has been done in Hereford to reduce the amount of flooding

letton lake has been changed by humans to store more water by being widened and deepened

what are the clay cliffs in swanage made of

wheldon beds and greensand

what is the stack from the chalk headland in swanage called

old harry rocks

what are the conditions of climate in May in Swanage which allow biological weathering

average daytime temperature of 12c and 53mm of rainfall

what are the conditions of climate in September in swanage which allow rotational slumping

average daytime temperature of 14c and 70mm of rainfall

how did beach replenishment happen in swanage bay

in 2005 90000m3 of sand was deposited on the beach widening it to 14m

what hard engineering happened in Swanage bay

in 2005 18 timber groynes were added

how does the length of the beach in swanage affect the rate of erosion

the clay cliffs with a 14m beach erode at 0.5m per annum but the cay cliffs in the land owned by the national trust with a 7m beach erode at 1m per annum

what layers could be added to GIS and why

speed of rivers - rate of erosion

geology - how it has changed

prevailing wind direction - direction of LSD

house prices - should defences be put in place

temperature and rainfall - rate of weathering