Distinctive landscapes Flashcards
what is a landscape
all of the visible features that make up the surface of an area of land
What are the elements of a landscape?
- Natural/physical (mountains, rivers, lakes),
- human (houses, buildings, roads),
- biological (trees, grass, animals),
- variable (weather, cloudscape).
Where are uplands found in the UK?
Mostly in the north and west: Northern Ireland, Scotland, Wales, and North England (including Lake District). - climate is cold / wet
Where are lowlands found in the UK?
In the south and east: Central and Southern England. - climate is warm
What types of rocks are there?
Igneous rock, sedimentary rock, and metamorphic rock.
How does igneous rock form?
Forms when magma from the mantle cools down and hardens.
What are examples of igneous rocks?
Granite and basalt.
How does sedimentary rock form?
from marine organisms’ skeletons and other sediments being compacted at high pressures at the bottom of the ocean
What are the main types of sedimentary rock in the UK?
Limestone and chalk.
What is metamorphic rock?
heat and pressure being applied to existing igneous/sedimentary rocks which changes its structure
What are examples of metamorphic rock?
Shale becoming slate, and slate becoming schist.
What types of rocks are found in upland areas?
Mostly igneous and metamorphic rock.
What types of rocks are found in lowland areas?
Sedimentary rock.
What are geomorphic processes?
Methods involved in changing the shape of the landscape.
What is weathering?
The breakdown of rock in its place of origin.
What are the types of weathering?
Mechanical, biological, and chemical.
What is mechanical weathering?
Breakdown of rocks due to temperature changes (freeze-thaw).
What is biological weathering?
Rock breakdown due to the action of plants and animals.
What is chemical weathering?
Rock decomposes due to chemical reactions.
What is the process of freeze-thaw weathering?
Water seeps into cracks, freezes, expands, and causes the rock to break down. the process repeats, putting more pressure on the cracks in the rock, causing them to split further open until the rock breaks open
What is the process of biological weathering?
Plant roots enter cracks, grow, and cause the rock to break.
What is carbonation in chemical weathering?
where weak acid in rain reacts with the calcium carbonate in rocks and dissolves it
What is mass movement?
Downhill movement of material under the influence of gravity.
What are the types of mass movement?
Rockfall.
Mudflow.
Landslide.
Rotational slip
What is erosion?
Process by which rock, sand, and soil are broken down and carried away.
What is hydraulic action?
when the force of water compresses air into cracks, causing a pressure buildup and breaking down the rock
What is abrasion/corrasion?
rocks / Sediments grind against a river’s bank or bed, causing erosion.
What is solution?
Slightly acidic water dissolves soluble rocks, leading to movement of minerals ( erosion )
What is attrition?
Sediment particles knock against each other, breaking into smalle, rounded pieces.
What are the methods of transportation in rivers?
Traction, saltation, suspension, and solution.
What is longshore drift?
Movement of water and sediment down a beach caused by waves.
What is deposition?
Where sediment is dropped when a river or sea loses energy.
What conditions encourage deposition in rivers?
Lack of precipitation, decreased gradient, slower flow, entering a sea/lake.
What conditions encourage deposition along the coast?
Too much material, too little wind, waves entering sheltered areas.
What are destructive waves?
Waves that erode the beach, with stronger backwash than swash, a high frequency and short wavelength
What are constructive waves?
Waves that build beaches, with stronger swash than backwash., long wavelength and low frequency
What are headlands and bays?
Formed by alternating bands of hard and soft rocks along a discordant coastline.
What are cliffs and wave-cut platforms?
Cliffs are shaped through erosion; wave-cut platforms form at the foot of cliffs.
what is the order of stump formation
crack, cave, arch, stack, stump
How does beach formation occur?
the sea deposits alluvium, resulting in beaches that gently slope inland via constructive wave movement through deposition
What is a spit?
An extended, downward stretch of sand or shingle formed by longshore drift which is joined to the land at one end
how is a spit formed ?
- when coastline ends and process of longshorts drif continues = sediment is deposited off the coast - if conditions are right the sediment will build up to form new land which extend out along existing coastline , the end of the feature will be curved by wave action and wind impact.
what are conditions that help formation of spit
- large volumes of sediments
- rapid rate of movement of sediment along coast
- shallow off shore gradient = sediment is deposited in shallow areas and can build up faster so it is sheltered from strong winds
how is a V-shaped valley formed ?
hydraulic action and abrasion happen in the river, causing the river to erode vertically
the slopes of the river are weathered
materials move down the valley sides and a v-shaped valley is formed
How is a waterfall and gorge formed?
- when river flows over bands of less resistant and more resistant rocks
- less resistant rocks are eroded faster = a steep gradient between hard and soft rock= river flows faster and as it flows over the sudden drops marked by edge of more resistant bands of rocks it created rapid
- over time soft rock is eroded quickly and drop = steeper = overhang of hard rock
- deep plunge pool formed at bottom of drop and turbulence in pool causes the waterfall to retreats,
- the gorge will form when waterfalls retreat upstream
What are meanders?
Bends in the river formed by lateral erosion and deposition.
how are meanders formed ?
- as river flow around meander bend , energy of water and sediment that it carries erodes the outside of the bend
- overtimes meander bends can become larger
- due to continual erosion , ends of meander bend become closer and neck of meander narrows
- when river floods river cuts through the neck to take a shorter route and creates a new channel
- old bend will be cut off from main channel = forms curved oxbow lake
What are oxbow lakes?
Formed when a meander is cut off from the main river channel.
how are levees formed
as the river floods, it deposits alluvium on the surrounding areas
the water drops the heavier sediment first, so more alluvium is deposited close to the river channel
after the process repeats, the sediment build up forms levees
What are floodplains and levees?
Flat expanses of land formed by sediment deposition during floods.
how are floodplains formed
- as the river loses energy, there is less vertical erosion and more lateral erosion due to meanders
during floods, water leaves the river and deposits silt across the valley - the heavier material are dropped first
the valley becomes wide (due to meanders) and flat (due to floods)
What is the River Wye case study?
The River Wye is over 150 miles long and descends over 700m along its course.
What geomorphic processes shape the River Wye?
Rapid river flows, mass movement, freeze-thaw, hydraulic action, and abrasion.
What human activities impact the River Wye?
Leisure, agriculture, vegetation management, and risk reduction for mass movement.
What geomorphic processes shape a river?
Geomorphic processes shape the river by creating waterfalls in the upper course, meanders in the middle course, and floodplains in the lower course.
What human activities impact rivers?
Human activities include leisure and tourism (rock climbing, canoeing, kayaking), agriculture (chicken farming), and vegetation management.
How does vegetation management affect runoff?
Vegetation management reduces rates of runoff by increasing surface cover and improving interception storage.
How can landslide risks be reduced?
The risk of landslides may be reduced by planting trees, which intercept rainfall and help bind the soil surface together.
What is the impact of afforestation on the River Wye?
Afforestation has stabilized slopes along the River Wye, reducing the amount of mass movement.
How does improved slope stabilization affect flooding?
Improved slope stabilization helps with flooding by allowing more water to be held in the channel, but it can increase erosion downstream.
What are the geomorphic characteristics of North Norfolk?
North Norfolk has a soft, impermeable clay base with soft, permeable gravel above, and underlying chalk rock.
What happens when water is trapped in cliffs?
Trapped water increases pressure in the cliff, reducing its strength and potentially causing landslides or slumping.
What is the effect of wave erosion on cliffs in North Norfolk?
Cliffs made of soft varied materials are vulnerable to wave erosion and mass movements caused by undercutting.
What is the direction of longshore drift in North Norfolk?
Longshore drift operates from east to west along the coastline.
What sea defense systems are used in North Norfolk?
Sea defense systems include rip-rap barriers, sea walls, gabions, and groynes.
What is the purpose of rip-rap barriers?
Rip-rap barriers are large rocks placed in front of cliffs to slow down erosion.
What are sea walls made of?
Sea walls are made of concrete to reflect and absorb wave energy.
What are gabions used for?
Gabions are wire cages filled with stone, used to reduce erosion.
What are groynes?
Groynes are barriers placed perpendicular to the coastline to slow down sediment movement.
What is the government’s policy in North Norfolk?
The government is enforcing a do nothing policy of managed realignment.
What are the four main strategies for defending coastlines?
The four strategies are: no active intervention, hold the line, managed realignment, and advance the line.
What is ‘no active intervention’?
‘No active intervention’ means no planned investment in defenses as costs outweigh benefits.
What does ‘hold the line’ mean?
‘Hold the line’ means maintaining sea defenses to keep the shoreline in its current position.
What is ‘managed realignment’?
‘Managed realignment’ allows the shoreline to move naturally while managing the process.
What does ‘advance the line’ entail?
‘Advance the line’ involves building new sea defenses where costs are justified.
What sampling method was used in Reculver fieldwork?
Random sampling was used to reduce bias.
What was a limitation of the pebble shape and size data?
The data was inconclusive due to a sample size that was too small.
How was the beach profile measured?
The beach profile was measured using a clinometer, ranging poles, and a tape measure.
What was a potential error in measuring the beach profile?
Results may have human errors despite being accurate.
What is the significance of wave count in Reculver fieldwork?
Wave count is important as longshore drift requires constructive waves.
What issue affected the wave count data?
The data was an anomaly due to higher than average wind speeds.
How was wave direction data collected?
Wave direction was repeated several times for an average, and data was accurate and reliable.
