Topic 3 - Distinctive Landscapes (new) Flashcards
What is meant by a built/natural landscape?
A landscape that has predominantly human created infrastructure and structures.
Distribution of upland, lowland and glaciated landscapes in the UK.
Upland distribution in the UK - North and West, typically in Scotland and Wales.
Lowland distribution in the UK - South and East, typically Kent and East Anglia.
Glaciated landscape distribution in the UK -Snowdonia in NW Wales
Characteristics of upland landscapes.
- Geology
- Climate
- Human activity
- Geology:
Higher elevation areas above 400m
Made from older sedimentary rocks such as limestones and sandstones - less resistant to erosion so form high elevation lands. - Climate - prevailing winds hit upland areas so air is forced to rise CCCR - so usually wet and snowy.
- Human activity - army training exercise, outdoor pursuits eg observing nature.
Characteristics of lowland landscapes.
- Geology
- Climate
- Human activity
- Geology
- Lower elevation areas below 200m.
- Made from younger sedimentary rock such as clays, sand and rock - less resistant to erosion.
- Climate
- Most found in rain shadow downwind of mountains. Here, air S-W-E-C = clear skies so low rainfall.
- Human activity
- Farming and agriculture - fertile land to grow arable crops and rearing cattle.
- Businesses - eg LDN ad economic hub.
Characteristics of glaciated landscapes.
Geology
- Mountainous areas shaped by ice.
- Made from igneous rock such as granite and metamorphic rock such as gneiss and slate. - These rock are resistant to erosion so form high mountainous areas.
Climate
- Air is forced to rise over high elev. mountainous areas so C-C-C-R
Human activity
- Hydroelectric power-schemes
- Outdoor pursuits eg hiking.
Define these geomorphic processes that are involved in shaping landscapes:
1- weathering (mechanical, chemical, biological)
2- mass movement (sliding, slumping)
3- erosion (abrasion, hydraulic action, attrition, solution)
4- transport (traction, saltation, suspension, solution)
5- deposition.
Weathering; the disintegration of rocks in situ
Mechanical - The disintegration of rocks due to physical movement, eg freeze-thaw weathering breaking f rocks.
Chemical - The disintegration of rocks due to chemical reactions, eg carbonation of carbonate rocks.
Biological - The disintegration of rocks due to plants and animals, eg roots growing into cracks.
Mass movement; when weathered or disintegrates loose rocks move down slopes due to the influence of gravity.
Sliding - occurs when bedding planes are sea-ward dipping and so weathered rock slabs slide over the sloped rock surface.
Slumping - Occurs when heavy rain soaks permeable clay cliffs, the clay becomes heavier and is pulled down by gravity. At the same time, water lubricates the individual clay particles resulting in the cliff slope losing cohesion. And so the clay slumps down the slope along curved planes and this is called rotational slumping.
Erosion; the wearing away of rock (softer and less resistant rock erodes more quickly than harder and more resistant rock).
Abrasion; When pebbles are thrown against the cliff or river bank by the river and break off pieces of the cliff/bank.
Hydraulic action - When waves hit a cliff, the air in the cracks of the cliffs become compressed due to stress on the crack and widen.
Attrition - Occurs when rocks collide and break into smaller rocks or become more rounded as their sharper corners are broken off.
Solution - When natural acidic rivers slow over carbonate rocks like limestone and dissolve them.
Transport - When energy is used to move eroded and weathered sediment.
Traction - When heavy cobbles are rolled by fast flowing rivers or powerful waves.
Saltation - When smaller pebbles and send are temporally lifted by rivers or waves resulting in them bouncing along.
Suspension - when fine sediment, like fine sand or silt are continuously carried by rivers or waves.
Solution transportation - When calcium carbonate limestone rocks are eroded by solution, the solution f calcium bicarbonate can be transported in streams and rivers.
Longshore drift - The zig-zag movement of sediment along a coast due to the prevailing winds causing swash and backwash. HOW? Waves wash up the beach at the same angle (swash), and gravity pulls the waves down the slope perpendicular to the coastline (backwash). This swash-backwash movement transports sediment along the coastline through saltation and/or suspension.
Deposition;
- When rivers lose energy, waves slow down and grow smaller and eventually cannot transport sediment anymore. Now sediment is dropped off aka deposited.
Formation of headlands:
- Form on a concordant coastline where bands of rock are perpendicular to the coastline.
- Here, tougher and more resistant rock such as limestone erode slower to form headlands.
Formation of bays:
- Form on a concordant coastline where bands of rock are perpendicular to the coastline.
- Here, softer and less resistant rock like erode faster due to abrasion and hydraulic action causing coastline to retreat and create bays.
Formation of a cave:
- Rocks have natural cracks called joints and faults, these are marks of weaknesses.
- Here, the joints are attacked by mechanical and chemical weathering to form gaps.
- Hydraulic action further widens these gaps .
- Large vertical joints close to the high tide mark are attacked by mechanical weathering and hydraulic action eventually developing into caves.
Formation of an arch:
- A cave needs to have developed on a headland bay.
- Here, mechanical and chemical weathering attacks the joints and faults at the back and roof of the cave
- Hydraulic action widens the weathered gaps and roof and back of the cave.
- This continues to widen so much so the cave gets deeper growing into the other side of the arch.
Formation of a stack:
- An arch needs to have developed on a narrow headland.
- Mechanical and chemical weathering attack the joints and faults at the sides of the roof and arch thus loosening the rock.
- Hydraulic action now attacks the sides of the arch making the bottom of the arch wider.
- If the arch is permeable rock rain can soak into the arch and make it heavier.
- The heavy weathered rock collapses causing a mass movement, forming a stack (a tall rocky pillar).
Formation of a beach:
- These occur in sheltered bays where energy levels are low.
- Constructive waves, where swash is stronger than backwash, push sediment in an onshore direction building up beaches.
- These summer waves produce beach profiles that are high, wide and gently sloping.
- Destructive waves, where backwash is stronger than swash, pull sediment off the beach eroding the beach.
- These winter waves build beach profiles that are narrower and steeper.
Formation of a spit:
A spit is a finger of sediment sticking out into the sea.
- Spits form when the coastline suddenly change direction.
- Prevailing winds make the waves approach the beach at an angle.
- Waves wash up the beach at the same angle as prevailing winds.
- Gravity pulls the wave back down the beach perpendicular to the coastline (LSD).
- ## When coastline changes direction LSD continues to transport sediment out to sea form a spit.
Formation of waterfall:
Form when a layer of tough resistant rock sits on a layer of weaker and less resistant rock. So during periods of high river flow rivers erode at the lower resistant rock forming rock overhang.
Formation of a gorge:
Caused by repeated water fall recessions ^^
