What is the hydrological cycle?
The cycle of water from the sea, to rain, to over land and back to the sea.
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What is the input into the hydrological cycle?
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What are the processes in the hydrological cycle?
Overland flow, stem flow, infiltration, through flow, ground flow, percolation, ground water, surface water and soil water.
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What are the outputs in the hydrological cycle?
Overland/Surface flow, evaporation, transpiration and evapotranspiration.
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What is interception?
Where plants, trees, or buildings collect the precipitation.
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What is precipitation?
Water in any form that comes from the clouds (e.g. - snow, rain, sleet, hail).
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What is stem flow?
Where the precipitation flows along the stems of a plant to the ground, (going down the plant).
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What is through fall?
Where the precipitation is not intercepted but falls straight to the ground.
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What is percolation?
The movement down and into the soil, and storeage of water in soil.
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What is infiltration?
Where the water filters through the ground and the tiny pores in the soil.
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What is over land flow?
When either the soil is impermeable or saturated and the water flows over the top of it.
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What is ground water flow?
This is the movement of water sideways underground towards the streamflow.
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What is through flow?
The horizontal movement of water through soil.
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What is underground flow?
The slow movement of water through the ground.
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What is transpiration?
Where the water goes up through the plants and is released into the air through the leaves.
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What is evaporation?
Where water is heated up to become gas.
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What is condensation?
Where water is cooled from a gas to liquid.
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What is evapotranspiration?
Water evaporated off any plants (going up the plant).
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What do the bars and lines represent on a storm hydrograph?
The bars represent the rainfall during a storm event and the lines represents the storm runoff/discharge from a river and the normal flow.
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What is the tallest bar called on a storm hydrograph called?
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What is the tallest point on the line on a storm hydrograph called?
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What are the assending and dessending parts of the line on a storm hydrograph called?
Assending is the rising limb and dessending is the falling limb.
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What is the lag time on a storm hydrograph?
The time between the peak rainfall and the peak discharge.
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What is the water basin?
The area in which all precipitation will flow into one river or body of water back towards the sea.
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What is the source of a river?
The point at which the river starts.
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What is a tributary?
A tributary is a smaller river or body of water leading into the main river.
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What is a confluence?
The point at which a tributary meets the main river.
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What is the water shed?
The line at which all water within it will flow to a single river.
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What are the geological reasons that may cause a river to flood?
Bedrock of clay which is impermeable when wet or impermeable rock, for example granite. If the bedrock is of chalk then the river won't flood as chalk is permeable, the same is for other impermeable rocks.
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What are the physical reasons that may cause a river to flood?
A high drainage density (lots of streams), already saturated soil, steep slopes, thin layer of soil, less vegetation or other inteceptors and no storage in a lake, underground, in plants or in the soil.
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What types of land-use may cause a river to flood?
An urbanised area (as the concrete is impermeable) and a deforested area (as there are fewer inteceptors). Rural areas, a ploughed field and areas of dense woodland are less likely to flood.
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What are the climatical reasons that may cause a river to flood?
A heavy thunderstorn after a long-dry period, a rainstorm after a month of high rainfall and other high rainfall events. A heavy thunderstorm followed by sunshine, a gentle drizzle and a summer rainstorm wouldn't cause a river to flood.
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What human activities can cause a river to flood?
Urbanisation, reducing artificially the capacity of the river, deforestation, removing vegetation, building low bridges over rivers or other constructions which could act as a dam and building on flood plains.
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Where and when was the Boscastle flood?
North Cornwall, where River Valency and River Jordan meet, on the 16th August 2005
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How much rain fell causing the Boscaslte flood?
200mm fell during one afternoon, it was the remenants of Hurricane Alex.
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What were the physical causes of the Boscastle flood?
The area is mainly impermeable clays and shales, also the ground was already saturated from previous rainfall earlier in the week. The area also has steep slopes which led to high surface runoff and low infiltration. The confluence between two rivers
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What were the human causes of the Boscastle flood?
Natural channel has been walled, stopping the river running its natural cause. Building on the floodplain of the river. Artificially reducing the capacity of the river. Vegetation removed from valley sides. Low bridges and car park.
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What was the effect of the high rainfall on the river Valency during the Boscastle flood?
Estimated 20.1 tonnes of water flowed in the river. A 2m high wall of water. Peak discharge of 140 cumeces, compared to the normal of 0.5 cumeces.
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How many buildigs were destroyed by the Boscastle flood?
25 business properties destroyed, 4 footbridges washed away and 58 buildings damaged, including the Wellington Hotel and Museum of Witchcraft.
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How many cars were washed into the sea?
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What happened to the economy of the local area?
One man lost £10,000 to £15,000 of stock. The area relies on tourism for 90% of their income, and the floods came in mid August, peak tourist time. Some lost up to 60% of their income in 2004 and 2005.
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What is a cumecs?
Cubic metres per second.
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How much did insurance companies have to pay out after the Boscastle flood?
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How many casaulties during the Boscaste flood?
1, a broken thumb. Everyone else was air lifted to safety, 12/13 per helicopter.
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What was done after the Boscastle flood to reduce the risk of flooding?
£4.6 million flood defence scheme now in place. New culvert (buried pipe). Carpark raised and now made of permeabe rock. River Valency bed widened and lowered. Removed lower bridges. Remove sewer crossing. New defence wall. Monitering and warning.
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Which river flooded Boscastle?
River Valency (and River Jordan).
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Where and when were the South Asian floods?
South Asia, mainly bangladesh and India, the flooding of Brahmaputra and Ganges, in July and August 2007.
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What were the causes of the South Asian floods?
Heavy and continuous rainfall in July saturated the soil, in one region 900mm of rain fell. Melting snow from the Himalayan mountains increased the discharge of Brahmaputra river. Peak river discharge occured at the same time in both rivers.
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How many died in the South Asian floods?
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How many were made homeless from the South Asian floods?
Around 25 million.
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How many schools were affected in the South Asian floods?
Around 4000, with 44 being totally destroyed.
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What effect did the South Asian floods have on the industry of the area?
Many factories closed and lots of livestock were killed.
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How many houses were destroyed from the South Asian floods?
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How many roads were destroyed from the South Asian floods?
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What happened to the river after the South Asian floods?
They became polluted with rubbish and sewage.
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How many people caught water-borne diseases, like dysentery and diarrhoea, from the South Asian floods?
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What happened to the basmati rice after the South Asian floods?
The flooded fields reduced the yield of the rice fields so the prices rose by 10%.
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Who became unemployed after the South Asian floods?
Many farmers and factory workers.
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What flood warnings are in place for Bangladesh after the South Asian floods?
Flood Forecasting and Warning System (FFWS). Which has 85 flood monitoring stations. Flood warnings can be issued up to 72 hours before a flood occurs, but the warnings don't reach many rural commintees.
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What flood protection measures are in place after the South Asian floods?
Around 6000km of man-made levees, but they are easily eroded and aren't properly maintained so they are easily breached by flood waters. Instead of trying to stop flooding entirely flooding has been allowed in some areas under controlled conditions.
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What is physical weathering?
Freeze thaw. The continued freezing and thawing of moisture in rocks will eventually cause the rocks to break up.
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What is chemical weathering?
Solution. The slightly acidic water can dissolve calcium which breaks down rocks such as limestone.
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What is biological weathering?
The break down of rocks by the roots of plants, and burrrows of animals.
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What forms of erosion are there?
Hydraulic action, attrition, corrosion and abrasion.
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What is hydraulic action?
The power of moving water being forced against the cliffs and riverbanks causes them to collapse and be washed away.
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What is attrition?
Pebbles and rocks collide with eachother, reducing their size and making them increasingly smooth.
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What is corrosion?
Chemical reaction occurs when slightly acidic water dissolves calcium, breaking down rock such as limestone.
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What is abrasion?
Fragments of rock carried by a river wear away at the bed and banks of a river, and the cliffs by the sea. Increased flow will increase the amount of materials carried in the water and so increases the effect of abrasion.
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What is deposition?
Occurs when a river or flow of water does not have enough energy to carry the material any further.
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What types of transportation are there?
Bedload, suspended load, solution and long shore drift.
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What is bedload?
Larger fragments of rock are rolled along the riverbed (traction) or bounced along the river bed (saltration).
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What is suspended load?
Smaller fragments of rock carried in the flow of the river.
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What is solution?
Dissolved minerals carried along in the water.
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What is long shore drift?
Waves hit the shoreline at an angle and so move rocks that they pick up down the shore.
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What is mass movement?
The mass collapse of a cliff or shift of deposotion.
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What landforms are there in the upper course of a river?
Upper-course river features include steep-sided V-shaped valleys, interlocking spurs, river banks, waterfalls and gorges.
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What landforms are there in the middle course of a river?
Middle-course river features include wider, shallower valleys, river banks, meanders, and oxbow lakes.
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What landforms are there in the lower course of the river?
Lower-course river features include wide flat-bottomed valleys, river banks, floodplains and deltas.
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How do river banks form?
Hydraulic action, abrasion and, in certain areas, corrosion erode the edge of the river creating a bank. The meanders and bends of a river causes lateral erosion into the outside bank of the river.
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How does the speed of the water vary in a cross section of a river?
The outer edge of a river bend or meander is where the water is flowing the quickest, so more erosion occurs and the water is deeper. The inner edge of a river bend or meander is where the water is flowing the slowest, causing deposition.
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How do waterfalls form?
When a river flows from hard rock to soft rock the soft rock is eroded quicker creating a step in the river. After a while the step becomes a steep drop with a plunge pool at the bottom.
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How do meanders form?
Bends in the cause of a river, as lateral erosion becomes more significant than vertical erosion. The river is bending around obstacles, like hard rock.
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How do oxbow lakes form?
Cointinued erosion at the neck of a meander will cause the river to break through on a straight course, creating a river which flows in two directions. Deposition will eventually break off the meander, creating an oxbow lake.
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How do gorges form?
A waterfall, from the erosion of the plunge pool, will create an overhang in the hard rock which will eventually collapse, leaving the unaffected, steep, hard rock next to it. Over time this effect causes the waterfall to retreat upstream.
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How do deltas form?
Formed at the mouth of large rivers, where the river deposits materials faster than the sea can remove it.
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How do flood plains form?
Flood plains are the wide valley floor on either side of the river which will occasionally flood. High precipitation in the water shed and other factors will increase the rick of flooding.
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How do V-shaped valleys form?
Abrasion causes both lateral, but mostly, vertical erosion to the sides and bed of the river, creating a V shape.
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How do interlocking spurs form?
Most erosion is vertically downwards, so the river has to weave around hillsides, creating the interlockinig effect. The river doesn't erode laterally because of the hard rock taking longer to erode then the soft rock.
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How does the shape of the river vally change from the upper course to the lower course?
In the upper cause the river valley is steep-sided and narrow. In the middle cause it is a bit wider and shallower. In the lower course it is a wide, flat-bottomed shape.
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How can the effects of erosion and weathering be increases naturally?
Increased precipitation, extreme temperatures or temperature change, soft rocks, large amounts of sediment to be carried in the water and faster flowing water.
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Where is the River Clyde?
Southern Uplands region of Scotland. It flows north west though Motherwell and Glasgow.
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How long is the River Clyde?
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Where is the source of the River Clyde?
In the Loowther Hills, where two tributaries (Daer Water and Portail Water) come together.
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Where are interlocking spurs found on the River Clyde?
Crawford. The spurs are between 300 and 500m high.
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Where are waterfalls found on the River Clyde?
Lanark. There are four waterfalls near Lanark, the highest being Corra Linn which is 27m high.
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Where is a gorge found on the River Clyde?
Lanark. Where the waterfalls are retreating.
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Where is an oxbow lake forming on the River Clyde?
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Where are meanders on the River Clyde?
Between Motherwell and Glasgow.
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Where is the floodplain on the River Clyde?
Glasgow is buit on the floodplain. The land is about 5m above sea level on either side of the river.
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Where is the estuary on the River Clyde?
34km west of Glasgow, it joins the Firth of Clyde river and eventually goes into the Irish Sea.
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How can you define destructive and constructive waves?
More than 10 waves in a minute is a destructive coastline, less than 10 is a constructive coastline.
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How are cliffs formed?
The erosion of the sea against the land causes the land to break down and collapse, creating a cliff.
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What is a destructive wave?
One which has high wave energy, travelled over a long fetch, short wave length and steep, so has a tall and powerful break. The backwash is greater than the swash. They erode coastlines.
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What is a constructive wave?
One which has little wave energy, a long wave length, little height and little power. The swash is greater than the backwash. The deposit at coastlines.
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How are headlands formed?
Where hard rock is eroded slower than soft rock causing it to be left sticking out.
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How are bays formed?
When soft rock is eroded quicker than hard rock causing a dent to form in the coastline which is a bay.
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How are caves formed?
Continued erosion (abrasion and hydraulic action) at a crack in a cliff causes it to widen, and eventually expand to become a cave.
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How are gulleys formed?
When the roof of a cave collapses leaving part of a the headland, next to the cave, sticking out.
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How is an arch formed?
When a cave in a headland breaks through to the other side, due to erosion, or meets another cave from the other side, creating an arch in the headland.
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How is a stack formed?
When the roof of an arch collapses due to continued erosion and weathering.
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How is a stump formed?
When coninued weathering causes a stack to collapse leaving just the base, or stump.
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How is a raised beach formed?
When sea levels dropped.
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How are beaches formed?
The continued deposition of sediment in one area from the sea where it loses energy.
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How are spits formed?
When waves hit the beach at an angle causing long shore drift, this moves sediment along the beach and causes it to form a sand bar out to sea. Strong winds and waves can curve the end of the spit.
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How are bars and lagoons formed?
When a spit joins two headlands together.
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What is a tombolo?
A spit bar that connects the shore to an island.
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Where is there a headland at Westward Ho!?
Baggy Point (baggy sandstone, oldest rock in the area).
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Where is there a bay at Westward Ho!?
By the town and Northern Burrows (Westward Ho! formation of sandstone and shales, newest rock in the area).
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Where is there a raised beach at Westward Ho!?
Under Kipling Tors (pebbles stuck in the ground there).
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How is a wave-cut platform formed?
Continued erosion at the base of a cliff causes it to create an overhang which collapses, leaving just the base as a wave cut platform.
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Where is a wave-cut platform at Westward Ho!?
By the cliffs at Kipling Tors.
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Where is a cliff at Westward Ho!?
By Kipling Tors.
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Where are there caves at Westward Ho!?
In the cliff by Kipling Tors.
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Where is there a gulley at Westward Ho!?
On the edge of the raised beach at Kipling Tors.
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Where is there a beach at Westward Ho!?
By the town and along the spit.
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Where is there a spit at Westward Ho!?
Between the town and into the Taw-Torridge Estuary.
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What are the economic reasons to protect the coastline?
Loss of tourism, businesses near cliffs, coastal flooding damages agricultural land because of the salt in sea water, farmland being lost to the sea and property prices can fall if the house is at threat from the sea.
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What are the social reasons to protect the coastline?
Deaths as coastal floods have killed thousands, water supplies can be affected, Areas of Outstanding Natural Beaut destroyed, loss of housing, loss of jobs and damage to infilstructure.
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What are the environmental reasons to protect the coastline?
Ecosystems affected as the increased salt levels can damage or kill organisms, the force of the flood water can also uproot plants and destroy habitats and some Sites of Special Scientific Interest are threatened.
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What types of hard engineering are there to protect the coast?
Sea wall, rip rap, groynes, curved sea wall, revetments, gabions, breakwaters and bulkhead.
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What types of soft engineering are there to protect the coast?
Beach replenishment and managed retreat.
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What is a sea wall and how sustainable is it?
A sea wall is a barricade between the sea and land which prevents erosion and flooding and a curved one deflects some of the wave energy. However they create a strong backwash which erodes under the wall and are expensive to build and maintain.
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What is rip rap and how sustainable is it?
Boulder which are piled up to absorb wave energy and so reduce erosion and flooding. However they can be moved around by strong waves so need to be replaced.
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What are groynes and how sustainable are they?
Wooden or stone fences that are built at right anges to the coast to trap material transported by longshore drift. Groynes create wider beaches which slow the waves giving greater protection to the coast but they starve beaches of sand further down.
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What are revetments and how sustainable are they?
Slanted structures mad of wood or rocks built at the bottom of cliffs which absorb wave energy and so reduce erosion. However they are expensive to build and create a strong backwash which erodes under the barrier.
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What are gabions and how sustainable are they?
Rock filled cages, built at the foot of cliffs which absorb wave energy and reduce erosion. However they look ugly.
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What are breakwaters and how sustainable are they?
Concrete blocks or boulders deposited on the sea bed off the coast which force waves to break offshore so their erosive power is reduced by the time they reach shore. However they are expensive and can be damaged by storms.
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What is beach replenishment and how sustainable is it?
Sand or shingle from elsewhere is brought in to create wider beaches which slow the waves. However taking material from the sea bed can kill organisms, it is an expensive treatment and it has to be repeated.
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What is managed retreat and how sustainable is it?
Removing an existing defence and allowing the land behind it to flood which over time will create new marshland and habitats, the flooding and erosion will be reduced and it is cheap. However people disagree over where to flood.
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Where is there a bulkhead sea defence in Westward Ho!?
By Seafield House, however it has failed and the house has been left for ruins.
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Where is there a sea wall in Westward Ho!?
Along the sea front of the town and campsite to protect the businesses, homes and industry there.
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Where is there a combination of a curved sea wall and smaller rip rap in Westward Ho!?
At Nassau apartments to protect them, however the rip rap is being washed away.
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Where is there a combination of a sea wall and large rip rap in Westward Ho!?
By the arcade promenade next to the beach, to protect the tourist industry there.
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Where were there gabions in Westward Ho! and why were they removed?
Along the beach to tray and replenish the spit to protect Northern Burrows. They were removed because they were ugly and ineffective as the cages broke.
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Where are there wooden groynes in Westward Ho!?
Along the beach but they are broken, old and ineffective.
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What soft engineering is taking place at Westward Ho!?
Beach replenishment of taking the pebbles from the end of the spit to the start so that they are not lost to sea and maintain the spit.
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Why does Northern Burrows need to be protected?
It is a golf course, so attracts tourists, but mainly it covers a rubbish tip that would be environmentally dangerous if released into the sea. On the 18th of October 2012 it was on the news for it.
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Other cards in this set
What is the input into the hydrological cycle?
What are the processes in the hydrological cycle?
What are the outputs in the hydrological cycle?
What is interception?