Coastal zone
- Created by: C.P.
- Created on: 06-04-13 18:16
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- COASTAL ZONE
- LANDFORMS RESULTING FROM EROSION
- FLAMBOROUGH HEAD
- 1.Caves arches stacks and stumps form as a resultof erosion.
- 2.Headlans form where there is less resistant rock and there tends to be faults in the resulting headland.
- 3.Waves expose these weakness. There are 3 ways it does this.
- 1. HYDRAULIC ACTION (force of the waves themselves)
- 2. CORRASION (material flung against the cliff)
- 3.CORROSION (dissolving of the rock)
- 4.The continued erosion leads to a cave.
- 5. If the wave forms part of a narrow headland, the continued erosion may lead to the other side getting broken through causing an arch to form.
- E.G. Durdle Door.
- 6.Continued erosion will lead to the base being too wide and the roof of the arch will collapse.
- 7.When the roof collapses it will leave a stack.
- E.G. Old Harry
- 8. Eventually, the base of the stack will be undercut and a stump will form.
- E.G.Old harrys wife
- FLAMBOROUGH HEAD
- LANDFORMS RESULTING FROM DEPOSTION
- SPURN POINT
- 1. Eroded materials are transported along the coast by longshore drift
- LONGSHORE DRIFT
- 1. Longshore drift is when sand and pebbles are moved along a coastline by the sea
- 2. The material follows a zig-zag course.
- 3.The direction in which the materials travel is goverened by the previaling wind.
- 4.Groyned are built to stop long shore drift from hapening.
- LONGSHORE DRIFT
- 2.Where there is a bend in the coastline deoposition will occur.
- 3.The material builds up and forms a spit
- 4.Some spits extend part way across Estuaries
- E.G. Spurn Point
- 5.They cannot grow totally across because the river current is to strong.
- 4.Some spits extend part way across Estuaries
- 6.When winds blow from a different direction it causes the spit to become curved.
- 7. When the wind goes back to its normal direction the spit extends again.
- 8.Salt marshes devolop behing the spit. here, mud is deposited making the water shallower.
- 9.Spits become permanent when sand is blown on tothem causing sand dunes and locking them in place.
- 1. Eroded materials are transported along the coast by longshore drift
- SPURN POINT
- IMPACT OF COASTAL FLOODING
- EAST ANGLIA
- POLITICAL
- In 30 years time the Thames Barrier will have to be replaced.
- ENVIROMENTAL
- 20% of salt marshes will be lost by 2050 due to rising sea levels
- Low lying parts will become flooded
- SOCIAL
- Thames barrier being constructed -£80billion
- 1953 300 dead in East Anglia.
- ECONOMIC
- Destroying agriculture-The Fens
- Jobs will be lost in cities and other areas.
- POLITICAL
- MALDIVES
- SOCIAL
- Houses are damaged and destroyed
- Limited acces to freshwater means that if floods occur then the freshwater available will drop.
- POLITICAL
- Maldivian goverment ask Japan for $60million to build sea walls.
- They became carbon neutral.
- Buying land in Austrailia and India so they can move people when the islands become uninhabitable.
- ECONOMIC
- Loss of tourism. The Maldives has only one airport and if that becomes flooded then there will be no tourists.
- Disrupted fishing industry. Damageing fish processing plants will ruin their economy as fish is their biggest export.
- ENVIROMENTAL
- Loss of beaches will casue further land to flood as there is less of a buffer.
- Loss of soil as the soil is thin and floods can easily destroy it.
- SOCIAL
- EAST ANGLIA
- COAST EROSION- MAPPLETON ON HOLDERNESS COAST
- Cliff is constantly retreating due to erosion
- About 1.8m of land lost every year.
- WHY ITS ERODING QUICKLY.
- Easily eroded rock type
- Narrow beaches- less protection from waves.
- Groynes were built which stops sand being devoloped and this leads to less protection
- Powerful waves causes massive damage as they have a big fetch.
- IMPACTS ON PEOPLE
- Homes near cliffs are at risk of collapsing which means home insurance is impossible to get.
- Property prices have fallen
- Easlingtons Gas Terminal is 15m from cliff- 25% of britains gas.
- Roads have collapsed into the sea.
- IMPACTS ON ENVIROMENT
- Some sites of special scientific intrest sre threatened
- Lagoons near Easington may be destroyed as they are sepearated from the sea by a narrow bar, if the bar is eroded the lagoons will be destroyed.
- Some sites of special scientific intrest sre threatened
- COASTAL MANAGEMENT- HOLDERNESS COAST.
- HARD
- SEA WALL
- ADS
- Prevents erosion on the coast and acts like a barrier
- DIS-ADS
- Creates a strong back wash which erodes underneath
- Expensive.
- Creates a strong back wash which erodes underneath
- A wall that deflects waves
- ADS
- ROCK ARMOUR
- DIS-ADS
- Need to be replaced frequently
- ADS
- Absorb the wave energy
- Fairly cheap
- Absorb the wave energy
- Large boulders that are built along the coast.
- DIS-ADS
- GROYNES
- DIS-ADS
- Down the coast there is less sand deposited so there is less of a buffer from the sea for them- more damage.
- ADS
- Bigger beach-more absorbsion
- Fairly cheap
- Bigger beach-more absorbsion
- Wooden or stone fences that build up sand making beaches wider.
- DIS-ADS
- SEA WALL
- SOFT
- MANAGED RETREAT
- Removing a sea defence and letting the land behind flood on purpose-creating marshland.
- ADS
- Cheap
- Marshland stops flooding
- Cheap
- DIS-ADS
- People disagree on what land to flood
- ADS
- Removing a sea defence and letting the land behind flood on purpose-creating marshland.
- BEACH NOURISHMENT
- When sand and shingles that are added
to the beach from the sea.
- ADS
- Bigger beach- more protection
- DIS-ADS
- Exspensive
- Frequently managed
- Exspensive
- ADS
- When sand and shingles that are added
to the beach from the sea.
- SAND DUNES
- Adding sand and creating sand dunes
- ADS
- Effective barrier
- DIS-ADS
- Exspensive
- Protection area is limited
- Exspensive
- ADS
- Adding sand and creating sand dunes
- MANAGED RETREAT
- HARD
- KEY HAVEN MARSHES
- THE RESULTING HABITAT
- Due to rising sea levels (6mm) per year - the salt marsh retreats 6m a year under the water.
- Major storms mean the marsh is also under threat.
- 1989 a storm did just this and the open area was retreated in less than three months.
- The sea wall could break as a result and ruin the salt marsh.
- Tourism also effects the area badly.
- ENVIROMENTAL FEATURES
- Lots of wildlife
- Cordgrass
- Sea lavender plant-attracts wildlife
- Oystercathcer a bird
- It is beetween a sea wall and the sea
- WHATS BEING DONE TO PROTECT IT
- The sea walls were thickened and hightened- £5million.
- Tourism restricted
- Turned into SSSI- meaning that no devolopment and limited access.
- Nothing can be done about sea level.
- THE RESULTING HABITAT
- LANDFORMS RESULTING FROM EROSION
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