distinctive landscapes

what are the four landscape elements?

1. physical

2. biological

3. human

4. variable

what are physical elements?

mountains, coastlines and rivers

what are biological elements?

vegetation, habitats and wildlife

what are human elements?

buildings, infrastructure and structures

what are variable elements?

weather, smells and sounds/sights

what is igneous rock?

volcanic/molten rock brought up to the earth’s surface and cooled into solid rock

what is sedimentary rock?

rock made from broken fragments of rock worn down by weathering on Earth’s surface

what is metamorphic rock?

rock that is folded and distorted by heat and pressure

what are soils created from?

weathered rocks, organic material and water

what has an influence over the fertility of soil?

rock types

what is the difference between the soils in lowland and the soil in the uplands?

lowland areas have deep soil whereas uplands have thin soil

how has human activity affected landscape?

• farming has changed the vegetation which grows

• much rural landscape has been replaced by urban sprawls

• infrastructure such as roads and pylons cover most of the uk

• much of the uk’s woodlands have gone

• increasing population of the uk means more houses are needed

• uk’s marshes and moorlands are heavily managed by people

where does a low amount of precipitation occur?

in the lowlands

what do the uplands experience then?

more weathering, eroison and massmovement

what is mechanical weathering?

weathering that is caused by the physical action of rain, frost and wind

what is chemical weathering?

the action of chemicals within rain dissolving rock

what is biological weathering?

rocks that have been broken down by living organisms

what happens in freeze thaw weathering?

1. water seeps into cracks and fractures in the rock

2. when the water freezes, it expands. this wedges apart the rock

3. with repeated freeze- thaw cycles, the rock breakes off

what are the four types of erosion?

1. attrition

2. solution

3. abrasion

4. hydraulic action

what is attrition?

when rocks bash together to become smoother and smaller

what is solution?

a chemical reaction that dissolves rocks

what is abrasion?

the hurling of rocks at the base of a cliff to break pieces apart

what is hydraulic action?

when water enters cracks in a cliff, air compresses causing the crack to expand

what is transportation?

a natural process by which eroded material is carried and transported

what are the four modes of transportation?

1. solution

2. suspension

3. saltation

4. traction

what is solution (transportation)?

minerals dissolving in water and being carried along

what is suspension?

when sediments are carried along in a flow of water

what is slatation?

when pebbles bounce along a sea/ river bed

what is traction?

boulders that roll along a river/sea bed by the force of flowing water

what is mass movement?

a large movement of soil and rock debris that moves down slopes in response to the pull of gravity in a vertical direction

what are the steps of mass movement?

1. rain saturates the permeable rock above the impermeable rock making it heavy

2. waves or a river will erode the base of the slope making it unstable

3. eventually the weight of the permeable rock above the impermeable rock weakens and collapses

4. the debris at the base od the cliff is then removed and transported by waves or river

what is deposition?

when the sea or river loses energy, it drops the sand, rock particles and pebbles it has been carrying

how does a coastal stack form?

1. hydraulic action widens cracks in the cliff face over time

2. abrasion forms a wave cut notch

3. further abrasion widens the wave cut notch to form a cave

4. caves from both side of the headland break through to forma an archm

5. weather above/ erosion below- arch collapses leaving a stack

6. further weathering and erosion leaving a stump

state three hard engineering coastal defences?

1. groynes

2. sea walls

3. gabions or rip rap

what are groynes?

wood barrier that prevent longshore drift so the beach can build up

what is good about groynes?

the beach is still accessible

what is bad about groynes?

no more deposition further down the coast= erodes faster

what are sea walls?

concrete walls that break up the energy of the wave. has a lip to stop waves going over

what is good about sea walls?

• long life span

• protects from flooding

what is bad about sea walls?

curved shape encourages erosion of beach deposits

what is gabions or rip rap?

cages of rocks/ boulders absorb the waves energy, protecting the cliff behind it

what is good about gabions?

• cheap

• local material can be used to look less strange

what is bad about gabions?

will need replacing

state two soft engineering defences?

1. beach nourishment

2. managed retreat

what is beach nourishment?

beaches built up with sand so waves have to travel further before eroding cliffs

what is good about beach nourishment?

• cheap

• local material can be used to look less strange

what is bad about beach nourishment?

will need replacing

what is managed retreat?

low value areas of the coast are left to flood and erode naturally

what is good about managed retreat?

• reduces flood risk

• creates wildlife habitats

what is about managed retreats?

compensation for land

how do bays and headlands form?

1. waves attack the coastline

2. softer rock is eroded by the sea quicker forming a bay

3. more resistant rock is left jutting out into the sea

4. this is a headland and is now more vulnerable to erosion

how does a spit form?

1. swash moves uo the beach at the angle of the prevailing wind

2. backwash moves down the beach at 90° to coastline, due to gravity

3. zigzag movement (long shore drift) transports material along the beach

4. change in prevailing wind forms a hook

5. sheltered area behind spit encourages deposition, salt marsh forms

how does a waterfall form?

1. river flows over alternative types of rocks

2. river erodes soft rock faster creating a step

3. further hydraulic action and abrasion form a plunge pool beneath

4. hard rock above is undercut leaving cap rock which collapses providing more material for erosion

5. waterfall retreats leaving steep sided gorge

what happens in the upper course of a river?

near the source, the river flows over a steep gradient from the hill/ mountains. this gives the river a lot of energy, so it will erode the riverbed vertically to form narrow valleys

what happens in the middle course of a river?

here the gradient gets gentler, so the water has less energy and moves more slowly. the river will begin to erode laterally making the river wider

what happens at the lower course of a river?

near the river’s mouth, the river widens further and becomes flatter. material transported is deposited

how do oxbow lakes form?

1. erosion of outer bank forms river cliff. deposition in the inner bank forms slip off slope

2. further hydraulic action and abrasion of outer banks causes the neck to get smaller

3. erosion breaks through the neck so river takes the fastest route, redirecting the flow

4. evaporation and deposition cuts off main channel leaving an oxbow lake

how do floodplains and levees form?

when a river floods, fine salt/ aluminium is deposited on the valley floor. closer to the river’s banks, the heavier materials build up to form natural levees

state some soft engineering for river management schemes?

• afforestation

• demountable flood barriers

• managed flooding

what is afforestation?

planting trees to soak up rainwater to reduce flood risk

what is managed flooding?

naturally allowing areas flood to protect settlements

state some hard engineering for river management?

• straightening channel

• artificial levees

• deepening or widening river

what does straightening the channel do?

increases the velocity to remove flood water

what do artificial levees do?

heightens river so flood water is contained

what does deepening or widening river do ?

increases capacity for a flood