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What makes the Brecon Beacons unique? (4)
Glaciated upland region
6.1m people visited in 2019, spending £197m
Mountain range and national park located in South Wales.
Located North of Cardiff along the A470.
What do people do in the Brecon Beacons?
Millions enjoy leisure activities such as walking, jogging, cycling and visiting key physical/human attractions.
Where are sites most likely to deteriorate in quality?
At honey pot sites.
What is a honey pot site?
Sites that attract the largest number of tourists because they are exceptionally beautiful or interesting and accessible by road and within easy reach of people living in larger towns or cities.
6 positive impacts of human activity on a welsh landscape?
Investment in tourism industry creates jobs and helps to diversify the economy.
Increase in rural income from higher number of tourists visiting the area.
Greater investment in the local area in terms or roads and other infrastructure.
Locals can benefit from the increased service/facility provision in the area.
Local people have an improved standard of living and quality of life.
Mixing of cultures and people in honeypot sites encourages inclusion and diversity.
5 negatives of human activity on a welsh landscape?
Increased visitor numbers causes congestion on narrow country roads.
Footpath erosion, litter and car parking resulting from the large visitor numbers creates problems for the area.
At honeypot sites, shops selling essential goods become replaced with souvenir shops.
Welsh speaking communities become diluted due to visiting non-Welsh speakers.
House prices rise due to increased second home ownership, outpricing locals.
What are the different conflict groups for a national park? (5)
Farmers - don’t want tourists on their land, leaving gates open and dropping litter.
Locals - don’t want too many tourists as it causes pollution and congestion.
Environmentalists - don’t want too many tourists because of footpath erosion and land degradation at key honey pot sites.
National Park Wardens - don’t like house builders as it would destroy land.
Tourists - Mining and quarrying spoils scenery.
Define ‘sustainable tourism’.
It is the maintenance of the quality and productivity of a tourist area for the benefit of future generations.
Solutions to these social issues:
Vandalism and trespassing.
Honeypots cause overcrowding/congestion.
Conflict over landuse.
Provision of picnic areas; park wardens
Develop alternative honeypots; direct visitors to other attractions
Restrict tourist access; separate activities
Solutions to these economic issues:
Seasonal jobs
Local people too reliant on tourism
Provide tourist attractions to encourage visitors all year
Encourage the development of alternative types of employment
Solutions to these environmental issues:
Footpath erosion
Destruction of vegetation
Litter
Cars parked on grass verges or in narrow lanes
Congestion on narrow country roads
Heavy lorries, local and tourist traffic
Eyesores
New routes planned; signposted routes; artificial surfaces laid
Areas fenced off; education of visitors; landscaping
Provision of litter bins
Car parks; one way systems; park and ride schemes
Roads closed to traffic in tourist season; park and ride; pedestrian provision
Scenic routes separating local and tourist traffic; screen behind trees
New constructions limited in height
Ways to get rid of the 3 types of pollution at welsh landscapes?
Visual - height restrictions on buildings; building materials used; design codes; trees to screen unsightly buildings.
Air - Promote public transport; emissions taxes; plant trees to offset the carbon dioxide emissions.
Noise - Trees as buffer zones; cycle provision.
Why is pollution an issue caused by tourists? (3)
Drop litter that can get into river and streams and damage the environment.
Pollution from exhausts of many tourist vehicles that visit the national park, this also causes noise pollution which disturbs the wildlife.
Some tourist attractions are ugly and look unsightly.
How do tourists contribute to footpath erosion on Pen y Fan? (4)
Do not stick to the footpath, trample on grass, compact soil, killing vegetation.
Soils exposed to elements.
Habitats of animals are damaged causing further environmental degradation.
Footpaths widen and less vegetation results in increased rain run-off, increasing the flood risk.
What is a drainage basin?
An areas of land drained by a river and its tributaries.
Define watershed.
The upland boundary/edge of the drainage basin.
What is the source and a mouth of a river?
Where the river starts and where the river flows into the sea.
What’s a channel?
A wide river mouth.
What’s a tributary?
A smaller river that flows into a bigger river.
What’s the confluence?
The junction where two rivers meet (V-shaped).
What’s a meander?
A bend in the river.
Whats an estuary?
A wide river mouth.
Hydrological cycle - Define evaporation
When water is heated and becomes water vapour and rises.
Hydrological cycle - Define condensation
When rising water vapour cools and changes state to water droplets.
Hydrological cycle - Define precipitation
Water that falls from the air in the form of rain, snow, sleet or hail.
Hydrological cycle - Define interception
When vegetation catches the falling water.
Hydrological cycle - Define transpiration
The direct loss of moisture to the air from vegetation (respiration).
Hydrological cycle - Define stem flow
The movement of water down the vegetation towards the ground.
Hydrological cycle - Define overland flow
The fastest lateral flow of water on top of the soil, once saturated.
Hydrological cycle - Define infiltration
The downward movement of water through soil pore spaces.
Hydrological cycle - Define through flow
The lateral movement of water through the soil - not as fast as overland flow.
Hydrological cycle - Define percolation
The downward movement of water through rocks.
Hydrological cycle - Define groundwater flow
The slowest lateral movement of water through the rocks.
Hydrological cycle:
surface storage
vegetation storage
soil storage
groundwater storage
channel storage
Water stored on the surface in puddles, ponds, lakes etc.
Water stored in vegetation.
Water stored in the pore spaces of soil particles.
Water stored underground in the rocks.
Water stored in the river channel itself.
Hydrological cycle - Define:
Flow
Store
Input
Output
Processes by which water moves through the system.
Places within the system where water is held.
Where water enters the drainage basin through precipitation.
Where water exits the drainage basin through being carried out to sea.
Why does not all precipitation reach rivers and streams? (3)
Lost through interception and transpiration.
Stored in sinks such as oceans, lakes, the soil or underground in the rock.
Flow on the surface as a river or stream that eventually runs into the sea.
What is a river discharge and what is measured in?
It is the amount of water in the river channel at a given time. It is measured in cumbers (cubic meters per second).
What is the river’s regime?
The name for when the river’s discharge will vary over the course of the year.
Why are river discharge levels higher in the winter? (4)
More rainfall, frozen ground, less evaporation, less interception and transpiration (trees loose leaves in winter)
Why are river discharge levels lower in the summer? (3)
Less rainfall, increased evaporation, and increased interception and transpiration.
What is erosion? What are the three forms?
Erosion is the wearing away of the river bed and banks by the water in the river channel. It occurs under high energy conditions. A river can erode in three ways: hydraulic action, abrasion and solution.
How does hydraulic action erode a river?
The force and weight of the water loosens rock in the bed and banks of the river. The erosion will be greater if the rock underneath is very strongly jointed.
How does abrasion erode a river?
Rocks and stones transported by the river score and scrape the riverbed and sides.
How does solution erode a river?
The water in the river reacts chemically on the underlying rock and dissolves it.
What is the difference between vertical and lateral erosion?
Vertical erosion makes the river deeper whilst lateral erosion makes the river wider.
How does the rate of erosion change as you flow downstream?
As a river flows downstream it releases energy. About 95% of the energy is used to overcome friction with the riverbed and banks. The higher the energy level of a river, the more capable is of eroding.
What is transportation?
The movement of rock and soli downstream by the river.
What are the 4 ways of a river transporting its load and their definitions.
Traction: The larger rocks and boulders are dragged along the riverbed - needs the most energy.
Saltation: Pebbles bounce along the riverbed in a leap frog movement.
Suspension: Finer materials (silt and clay) float along the surface within the flow of water.
Solution: Rock that has been dissolved as is in an invisible state - needs the least energy.
Why does the river bed become smaller and rounder as you flow downstream?
Due to attrition, which is where pieces of rock carried by the river bump and bash against each other as they are transported downstream and so becoming increasing smaller in size.
What is deposition? (3)
Is where a river puts down (deposits) the material it has been transporting.
The material deposited is alluvium or silt.
Occurs in low energy conditions, where the gradient is flat, and along the banks where the current is weaker.
River characteristics in upper course (4)
River is fast flowing due to the steep gradients.
Narrow
Contains little water.
River winds around interlocking spurs.
River characteristics in lower course. (2)
Runs slowly due to gentle gradients.
River has become wider and deeper as it carries more water from the tributaries.
Valley characteristics in the upper course. (4)
Steep sided, deep and narrow.
V-shaped in cross section.
River occupies all of the valley floor.
Riverbed is rocky with lots of rocks and boulders.
River characteristics in the lower course? (4)
Valleys form an open V shape in cross section.
Land is flat with gentle slopes.
In times of heavy precipitation, the river floods its banks easily because the land is so flat.
When a river floods its banks, it spreads alluvium. This is very fertile and farmers use it to grow crops and pasture.
What are interlocking spurs?
Hills that stick out into the V shaped valley and interlock. The river bends around these spurs.
What are the 5 factors affecting the rate of erosion and how do they affect it?
Geology/rock type - hard impermeable rocks, like granite, are more resistant to erode, whereas soft permeable rocks are more susceptible to erosion, like sandstone.
Energy conditions - the river has more energy in the upper course where the gradient is steeper, and so gravity speeds up the flow, increasing erosion; the river has less energy in the lower course of the river, reducing erosion and increasing deposition.
Greater discharge - if there is more water in the channel, it flows faster and speeds up erosion.
Gradient - steep gradients mean there is greater energy and therefore erosion. flatter gradients mean that there is less energy and therefore less erosion.
Channel Width - The narrower the river channel, the less friction with the river bed as there is less surface area, and so the river has more energy.
What are the isovel levels throughout the river.
Greater in the centre due to a faster speed, lower near the bed and banks due to friction leading to a slower speed.
How do geology and river processes interact to form waterfalls? (6)
Formed when there is hard, impermeable rock e.g. granite, over top of softer, permeable rock e.g. sandstone.
As the water flows, the soft rock is rapidly eroded by hydraulic action.
The harder rock remains, forming an overhang as it is not easily eroded by hydraulic action.
Overtime, this overhang will undergo gravitational collapse and fall into the plunge pool.
Then, the plunge pool is deepened and widened through both attrition and hydraulic action.
This is a cyclical process and so will constantly repeat, causing the waterfall to retreat, leaving behind a steep-sided gorge.
Niagara Falls as a case study. (5)
Located between New York and Canada.
Second largest in the world in terms of volume of water flowing over its edge.
Formed approx. 10,000 years ago when glaciers melted at the end of the last ice age.
Hydroelectric power is the largest electricity produced in New York.
Very popular for tourism and is areas main industry, bringing in lots of money and jobs for locals.
Large scale landforms in a river - V shaped valleys. (3)
Vertical erosion results in the formation of a steep sided valley and the sides weakened overtime (weathering and further erosion).
Gradually materials move down the valley sides, creating the V-shape and loose material is then transported away by the river when there is enough energy to do so.
Discharge is low in upper course so there’s only energy to erode downwards.
Large scale landforms in a river - Rapids (3)
Stretches of fast flowing water tumbling over a rocky-shallow river bed, caused by different resistance among rocks.
Formed when the water goes from one hard rock that resists the waters erosion to a softer rock that is easier eroded.
For example, boulder rapids on the Avon Tryweryn in Bala, North Wales.
Large scale landforms in a river - Potholes (2)
A circular hollow in the riverbed, formed when a pebble becomes trapped, swirls and rotates around with the fast flowing river.
A hollow is formed which becomes deeper through the process of abrasion.
What is a meander?
As the course of the river approaches its middle and lower course it flows over the floor plain. The river winds its way through the floodplains in the form of large bends (meanders).
Meanders - migration, outside bend, inside bend.
Meanders migrate as water is mostly flung to the outside bend and so they constantly change their shape and position.
On the outside bend, the river flows quickly and has an increased energy. The water is deep so there is less friction and so less lateral erosion. This means a river cliff is formed.
On the inside bend, the river flows much more slowly, and has a reduced energy. The water is shallow and so there is a greater friction with the bed and banks and so deposition occurs, leading to the formation of a gently sloping slip off slope.
What is an oxbow lake?
An oxbow lake is a horse shaped lake that is isolated from the main river channel. It is where the meander bend has become disconnected from the main river because the processes of erosion and deposition. Over time this will dry up and vegetation will grow, leading to a meander scar.
4 steps of how an oxbow lake is formed?
As water travels around a meander loop, the outside bend is deeper and so has less friction. Erosion happens here and so forms a steep river cliff. On the inside bend deposition occurs and forms a slip-off slope.
Continuous lateral erosion of the outside bend leads to the meander neck becoming narrower.
Continuous deposition on the inside bend has led to the accumulation of sediment blocking some of the river channel.
Eventually, the river cuts through the meander neck often in times of flooding when energy levels are higher and erosion is greater. It eventually becomes isolated from the main river channel, and becomes the oxbow lake and eventually becomes a meander scar.
How are levee’s formed? (3)
By deposition in the time of a flood.
When a river floods, it deposits heaviest of its particles nearest to the channel which form the levees.
Every time the river floods deposition builds up the floodplain.
How are delta’s formed? (5)
When a river reaches the sea and material is deposited, it can at times block the main river channel.
The channel splits up into smaller channels (distributaries) to reach the sea.
Along the sides of the distributaries, sand and silt builds up to form a delta, where the amount of material transported is too great for sea currents to remove it.
The top of the delta is a fairly flat surface where the coarsest river load is dropped, and the finer particles are carried into deeper water.
For example, the Mississippi Delta.
Give 4 examples of distinctive landscapes - 4 areas with an example for each.
River landscape e.g. River Severn
Costal landscape e.g. Stair hole, Dorset
Upland landscape e.g. Snowdonia
Lowland landscapes e.g. Gwent Levels
Define ‘lowland’ and ‘upland’
Upland - A landscape that is hilly or mountainous.
Lowland - An area of land that is lower than the land around it.
Give a case study of a distinctive landscape and the 4 areas I need to discuss that make it distinctive.
Snowdonia
Geology
People and culture
Vegetation
Land use
What is a hydrograph?
A graph showing the discharge of a river at a given point. It displays a river regime and how the amount of water in the river changes over the year.
What is a flood hydrograph and its 3 features?
Shows how a river responds to one rainfall event
Lag time - period of time between the peak rainfall and the peak discharge.
Rising limb - increase in discharge.
Falling limb - excess water in channel begins to subside and river returns to its normal flow.
Why does river discharge vary over the year?
Its higher in winter due to a greater precipitation, colder temps and thus less evaporation and trees not having leaves reduces interception and transpiration. It’s the opposite for summer.
What makes a flood ‘flashy’ or ‘flat’.
Flashy - Short lag time, high peak, steep rising limb.
Flat - Long lag time, low peak, gentle rising limb.
Size of drainage basin and hydrographs. (2)
Larger drainage basins receive more rainwater, which makes it back to the channel, increasing the discharge.
There is a longer lag time in larger drainage basins as the water has further to travel to get back into the main channel.
Valley side steepness and hydrographs. (2)
Steeper gradients have a faster rising limb and shorter lap time, so water gets into the channel much faster, increasing flood risk.
It takes longer for water to get to the main channel on flatter slopes, meaning discharge never gets too high but water is present for longer.
Vegetation and hydrographs. (2)
Bare ground results in no interception or absorption of water meaning water gets back to the river quicker, increasing the flood risk.
Forested areas have a much-reduced discharge as much of the water is intercepted by and stored in the vegetation rather than flowing into the river.
Soil type and hydrographs. (2)
Impermeable areas have a much shorter lag time and a much greater discharge as water is unable to infiltrate into the soil and instead runs off over the surface, getting back into the channel quickly.
Permeable soils allow for infiltration and percolation thus slowing down the return of water back to the channel.
When does a flood occur?
When the discharge of a river is so great that it cannot be contained within the river channel and so as more water is added, the river will burst its banks and the water will flood its surrounding land.
Inputs, processes and outputs of the river and its drainage basin?
Inputs = precipitation
Processes = erosion, transportation, deposition and flooding
Outputs = water flowing out to sea
If the inputs are great and the outputs are small there will be a greater flood risk.
5 climatological factors causing flooding.
Heavy prolonged rainfall - causes the river to burst its banks and causes saturated soil, encouraging surface runoff, reducing lag time and thus increasing risk of flood.
Snowmelt - Causes an excess amount of melt water to enter the system where the river can’t cope.
Frozen ground - Impermeable layer so no rainwater can infiltrate, so surface runoff reduces lag time and increases the risk of flood.
Very dry soil - impermeable layer preventing precipitation from infiltrating into the soil.
Saturated soil - cannot allow anymore precipitation to infiltrate so water runs over the surface.
5 terrestrial factors causing flooding.
Steep slopes - The steeper the slope, the quicker water flows back to the channel because precipitation is more likely to run off with little time for infiltration.
Geology - If rocks are permeable (e.g. chalk is porous) water will infiltrate and percolate to groundwater which is a slow route. Granite is impermeable and so there will be lots of surface run off.
Soil type - Porous soil allow infiltration reducing lag time.
Vegetation amount - Can intercept huge quantities of water, reducing the amount in the system. Trees are deciduous however, so there is seasonal variation.
Drainage density - The denser the drainage (the more tributaries) the water gets into the main river channel quicker.
3 human factors causing flooding.
Urbanisation - buildings clear vegetation and use impermeable rocks like concrete. Drains flush precipitation straight to the river.
Deforestation - Reduces interception and there is less water uptake.
Agriculture - Pastoral farming causes compacted soil, reducing pore space and thus less infiltration.
Causes of the Boscastle Floods (2004)
Climatological - A month’s worth of rainfall fell in two hours and a very hot day.
Terrestrial - short river, rocks are impermeable, ground was already saturated and at the confluence.
Human - agriculture (trampled soil), buildings near river and Boscastle built on a flood plain.
Social, Economic and Environmental impacts of the Boscastle floods.
Social - 1000 residents affected, houses and shops flooded with possessions ruined and psychological effects.
Economic - homes, businesses and belongings were swept away, income from tourism lost, large number of insurance claims and cost of repairs.
Environmental - eroded river banks, and costal pollution.
Immediate response to the Boscastle floods.
Emergency services such as fire, police and ambulance.
150 airlifted to safety and many evacuated
Emergency centres opened in nearby villages.
3 P’s to manage floods.
Predict - Climate data and flood hydrographs
Protect - Flood prevention techniques
Prepare - flood plan
Define ‘hard engineering’ and ‘soft engineering’
Hard engineering - altering river channel, usually by building artificial structures to reduce impact of river processes.
Soft engineering - using natural features of a river and its drainage basin to reduce flood risk.
5 hard strategies to prevent floods.
Artificial leaves - embankment walls can be built either side of the river to increase the height of channel sides. Very effective, but very expensive and increases speed of river.
Straighten river channel - cutting through meander loops lets water flow more quickly, increasing river efficiency. River flow is faster so fish can’t lay eggs and causes problems downstream. Better for farmers.
Build dams - In the upper course to hold back floodwater and can be slowly released to regulate flow. Can generate electricity however they are extremely expensive and have a large impact on environment.
Widen channel - Allows river to hold more water, protects land and doesn’t spoil natural habitat, but can make rivers dangerously fast.
Line channel with concrete - Reduces friction so water travels faster, but impacts river ecosystems.
5 soft strategies to prevent floods.
Flood plans - Educated people on what to do in a flood.
Reforestation and afforestation - Intercept rain and store it to reduce chance of flooding, improves environment but private land makes it hard.
River restoration - Removing hard engineering.
Land use zoning - Dividing floodplain area into areas which experience different degrees of flood risk.
Improved flood warning system - allows evacuation and preparation.
Define:
Coast
Waves
Fetch
A narrow zone between the land and see rear is constantly changing due to the effects of land, air and marine processes.
Provide the force that shapes our coastline. They are created by friction between the wind and surface of the sea. Stronger wind makes bigger waves and larger waves have greater energy.
The distance the wind blows over open water and thus generating waves. The size of the wave depends on fetch and the greater the fetch, the larger the wave.
How does a wave form?
Waves have a circular orbit in open water which becomes more elliptical in movement, due to friction with the sea bed. Then, the top of the wave moves faster and so the wave begins to break.
Constructive waves (5)
Have limited energy as most of it is used by the swash to transport material up the beach.
Flat and low.
Large wavelength in relation to wave height.
Long wave period (6-8 waves a minute) and tend to occur in calm conditions and shelters locations.
Weak backwash and so little erosion.
Destructive waves (6)
Have much more energy and most of it is used by the backwash which pulls sand and shingle down the beach.
Waves are steep and high.
Wavelength is small in relation to wave height.
More frequent than constructive waves, and break approximately every 5 seconds.
Strength and power depends on windspeed and the fetch.
Weak swash, and so little beach building.
Define:
Marine processes
Subaerial processes.
(erosion) occur when the waves come into contact with the cliff face.
(weathering) occur on the cliff face above the wave contact zone.
5 processes of coastal weathering.
Freeze thaw or frost shattering - water enters joints and cracks in a rock. In the night, temperatures drop and water freezes and expands, causing cracks to widen.
Salt crystallisation - Salt crystals form in cracks and pore spaces when saline water evaporates, this causes rocks to disintegrate and break off.
Solution/carbonisation - Rainwater produces a weak carbonic acid which reacts with limestone and dissolving it.
Biological weathering - Plant roots pr narrowing animals may prise apart rocks and making it susceptible for other types of weathering. Causes cracks to widen and the rock eventually falls apart.
Chelation - decaying vegetation releasing humid acids chelates which decompose the minerals in the rocks.
4 processes of mass movement of coasts.
Soil creep - occur on gentle slopes of less than 5 degrees and it a continuous process.
Flows - on slops 5-15 degrees when materials become saturated with water.
Slides - occur on slopes 15-40 where weathered rocks move rapidly downhill causing rapid retreat.
Falls - Spontaneous but rare debris movement on slopes exceeding 40 degrees.
5 processes of coastal erosion.
Hydraulic action - Breaking waves create hydraulic pressure in cracks/joints. Air in cracks are compressed by the force of the waves, weakening the rock.
Solution - Weak acidic seawater chemically attacks certain rocks, dissolving minerals e.g. calcium carbonate in limestone.
Abrasion - Rock fragments wear away the coast as they scape over bare rock and wear it away and smooth it.
Corrosion - Waves hurl debris against the coast, causing pieces of the cliff face to break off.
Attrition - Sand and pebbles smash against each other and wear into smaller and more rounded pieces.
Concordant vs disconcordant coastlines.
Concordant coastline - Bands of differing rock types run parallel to the coast. Erosion still occurs here but it is very slow and is constant along the coastline.
Disconcordant coastline - occur where there are bands of differing rock type running perpendicular to the coast. the difference resistance to erosion leads to the formation of headlands and bays e.g. parts of the Dorset coastline.
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Flashcard (53)