Coasts Flashcards
(277 cards)
1
Q
Input-What?
A
Material or energy moving into the system from outside the system
2
Q
Output-What?
A
Material or energy moving from inside the system to outside the system
3
Q
Energy-What?
A
A power or driving force
4
Q
Dynamic Equilibrium-What?
A
A state of balance within a constantly changing system
5
Q
Stores-What?
A
The individual elements or parts of a system
6
Q
Flows/Transfers-What?
A
The links or relationships between the components
7
Q
Positive Feedback-What?
A
When a flow/transfer leads to increase or growth
8
Q
Negative Feedback-What?
A
When a flow/transfer leads to decrease or decline
9
Q
Erosion-What?
A
The gradual destruction of the coasts by waves
10
Q
Landforms-What?
A
A naturally created thing on the coast
11
Q
Landscape-What?
A
The area as a whole
12
Q
Deposition-What?
A
When sediment is deposited on a beach
13
Q
Open System-What?
A
A system with inputs and outputs
14
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Coastal System-What?
A
The way the coast works
15
Q
Links between the coast and other systems-Urban Pollution
A
Pollution in towns and cities causes water pollution, which leads to animals dying
16
Q
Links between the coast and other systems-Farms near rivers
A
The fertilizers used runs into the water-causes water pollution and eutrophication
17
Q
Links between the coast and other systems-Global Warming
A
Causes sea levels to rise. Increase in coastal flooding
18
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Links between the coast and other systems-Marine Ecosystem
A
Small fish in river estuaries-more coastal biodiversity
19
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Links between the coast and other systems-Forests
A
They provide food for the coastline when they erode. Mangroves are known as the “nurseries of the sea”-provides habitat
20
Q
Energy Sources at Coast-Wind
A
Wind is the movement of air. Strong winds can create powerful winds
21
Q
Energy Sources at Coast-Wind-Prevailing Wind
A
The prevailing wind is the direction in which the wind consistently comes from. In the UK, it is the South West
22
Q
Energy Sources at Coast-Factors that influence wave height
A
- Fetch
- Wind Strength
- Seismic Movement-Tsunami
- Asteroids colliding with water
- Atmospheric Pressure
23
Q
Fetch-What?
A
The distance the wave has travelled. High fetch=more energy=Strong Wave
24
Q
Types of Atmospheric Pressure-High Pressure
A
- Dry
- No wind
- Low energy waves/No waves
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Types of Atmospheric Pressure-Low Pressure
- Storms
- Strong Winds
- Strong Waves
26
Wave Formation-How?
- The water becomes shallower and the circular orbit of the water particles change to a elliptical shape
- The wavelength and the velocity decreases, wave height increases-Causes water to back up behind and rise to a point where it starts to topple over
- Water rushes up the beach as Swash, and moved back down the beach as Backwash
27
Wavelength-What?
The distance between the crest (top) of two waves
28
Types of Wave
There are two different types of wave:
- Constructive
- Destructive
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Differences between Wave Types-Formation
- Constructive-Distant weather systems generate waves in the open ocean
- Destructive-Local storms create these waves
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Differences between Wave Types-Wave Form
- Constructive-Low,surging waves with a long wavelength
| - Destructive-High,plunging waves with a short wavelength
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Differences between Wave Types-Wave Break
- Constructive-Strong Swash, Weak Backwash
| - Destructive-Strong Backwash, Weak Swash
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Differences between Wave Types-Beach Gain/Loss
- Constructive-Beach gain
| - Destructive-Beach loss
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Differences between Wave Types-Beach Profile
- Constructive-Gentle beach that will over time will become steeper
- Destructive-Steep beach, over time it will become flatter
34
Sources of Energy at Coast-Tides-What
Tides are the periodic rise and fall of the ocean surface, caused by the gravitational pull of the Moon, and to an extent the Sun
35
Sources of Energy at the Coast-Tides
Tides affect the position at which waves break on the beach. The area between maximum high tide and minimum low tide is where most landforms are created and destroyed
36
Sources of Energy at the Coast-Currents-What?
The general flow of water in one direction.
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Sources of Energy at the Coast-Currents
Currents move materials along the coast
38
Types of Coastlines
There are two types of coastline:
- High Energy
- Low Energy
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Types of Coastlines-High Energy Coasts
- Has large powerful waves
- Sandy Coves
- Rocky Landforms
- High rate of erosion
- Low rate of deposition
40
Types of Coastlines-Low Energy Coasts
- Has small,gentle waves
- Has offshore reefs or islands
- Has saltmarshes and tidal mudflats
- High rate of deposition
- Low rate of erosion
41
Types of Coastline-Causes
On a local scale, the cause of high and low energy coastlines is Wave Refraction
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Wave Refraction-What?
Wave refraction is the distortion of wave fronts as they approach a indented coastline
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Wave Refraction-How?
Wave refraction causes energy to be concentrated at headlands (on high energy coasts) and dissipated in bays
44
Sediment-What?
Any material which can be eroded,transported or deposited. Sediment can vary in size from large boulders to microscopic particles
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Sources of Sediment-Rivers
Sediment that is transported in rivers often account for the majoirty of coastal sediment. The sediment will be deposited in river mouths and estuaries, where it will be reworked by waves, tides and currents
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Sources of Sediment-Cliff Erosion
Important in areas of relatively soft or unconsolidated rocks. Soft rock cliffs erode much quicker than hard rock cliffs
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Sources of Sediment-Longshore Drift
Sediment is transported from one stretch of coastline to another stretch of coastline
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Sources of Sediment-Wind
In glacial or hot environments,wind blown sands can be deposited in coastal erosion. Sand dunes are both a acclamation of sand and a potential source of sand
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Sources of Sediment-Glaciers
Ice Sheets break off and fall into the sea, depositing sediment trapped within the ice
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Sources of Sediment-Offshore
Offshore sediment can be transformed into the coast by waves,tides and currents. A rise in sea level means that a large amount of sediment being bulldozed to form landforms. Storm surges and Tsunami waves can also be responsible for inputs of sediment to the coastal system
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Sediment Cell-What?
A stretch of coastline, usually boarded by two prominent headlands, where the movement of sediment is more or less contained within the cell
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Sediment Cells in the UK-How many
There are eleven major sediment cells in the UK. These can be divided into smaller subcells
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Sediment Budget-What?
The difference between the amount of sediment that enters the system and the amount of sediment that leaves the system
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Sediment Budget-Positive Budget
Occurs when more sediment enters the system than leaves. This builds the coastline
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Sediment Budget-Negative Budget
Occurs when more sediment leaves than enters the system. This causes the coastline to retreat
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Weathering-What?
The breakdown or disintegration or rock in situ (original place) at or close to the ground
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Types of Weathering
There are three types of weathering:
- Physical (Mechanical) Weathering
- Biological Weathering
- Chemical Weathering
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Weathering-Physical-What?
The break down of rocks without any chemical changes taking place
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Weathering-Physical-Types-Frost Shattering
Occurs when water enters a crack or joint in the rock when it rains and then freezes. When water freezes, it expands. This expansion exert pressure on the rock, which makes the cracks widen. Once this process repeats,rock fragments break away
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Weathering-Physical-Types-Salt Crystallization
When salt water evaporates, it leaves salt crystals behind. These grow over time Nd exert pressure in the rock,causing it to break up. Salt can also corrode rocks
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Weathering-Physical-Types-Wetting and Drying
Frequent cycles of wetting and drying are common on the coast. Rocks rich in clay expand when wet and contract as they get dry. This can cause them to crack and break apart
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Weathering-Biological-What?
The breakdown of rocks by organic activity
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Weathering-Biological-Types-Plant Roots
Thin plant roots grow into small cracks in a cliff face. These cracks widen as the roots grow,causing rocks to be broken up
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Weathering-Biological-Types Water
Water running through decaying vegetation becomes acidic, leads in increased chemical vegetation
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Weathering-Biological-Types-Birds and Animals
Birds and animals dig burrows into cliffs
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Weathering-Biological-Types-Marine Organisms
They can also burrow into rocks and/or secreting acids
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Weathering-Chemical-What?
A chemical reaction where salts are dissolved and the rocks becomes easily erodeable
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Weathering-Chemical-Types-Carbonation
Rainwater absorbs carbon dioxide from the atmosphere to form a weak carbonic acid. This reacts with calcium carbonate in the rock to form calcium bicarbonate, which can easily dissolved
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Weathering-Chemical-Types-Oxidation
The reaction of rock minerals with oxygen to form a powder, leaving rocks vulnerable to erosion
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Weathering-Chemical-Types-Solution
The dissolving of rock minerals
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Mass Movement-What?
The downhill movement of material under the influence of gravity
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Mass Movements-Types-Soil Creep-Rate and Nature
Rate of movement:Imperceptible
| Nature of movement: Creep/Flow
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Mass Movements-Types-Soil Creep-How?
When sediment expands, individual particles are lifted up at right angles to the slope. Sediments can expand when they freeze, get wet or heated up. When sediment shrinks, the particles fall straight back down. Soil creep takes a long time because each participant might move a millimetre each time
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Mass Movements-Types-Soil Creep-Case Study
Launceston
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Mass Movements-Types-Mudflow-Nature and Rate
Nature of movement: Flow
| Rate of movement: Quite rapid
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Mass Movements-Types-Mudflow-How?
After a period of heavy rain, water gets trapped within the rock, increasing water pressure. This forces rock particles apart and leads to slope failure. Mudflows are often sudden and fast flowing
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Mass Movements-Types-Mudflow-Case Study
California
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Mass Movements-Types-Landslides-Nature and Rate
Nature of movement-Slide
| Rate of movement- Usually rapid
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Mass Movements-Types-Landslides-How?
A landslide involves a block or rock moving very rapidly down a slide plane. Landslides are frequently triggered by earthquakes or very heavy rainfall, when the slip surface becomes lubricated and friction is reduced. Landslides tend to be very rapid and pose a threat to people and property
80
Mass Movements-Types-Landslides-Case Study
Holbeck Hall
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Mass Movements-Types-Rockfall-Nature and Rate
Nature of movement-Fall
| Rate of movement-Rapid
82
Mass Movements-Types-Rockfall-How?
A rockfall involves the sudden collapse or breaking away of rock at cliff. They are associated with steep or vertical cliffs and resistant rocks. A rockfall is often triggered by freeze thaw or a earthquake. Once broken away from the source, rocks fall or bounce down the slope to form scree at the foot of the slope
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Scree-What?
Scree is a temporary store in the coastal system, with material being removed and transported. Scree is a store and a input into a sediment cell
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Mass Movements-Types-Rockfall-Case Study
Cornwall
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Mass Movements-Types-Landslide/Slope-Nature and Rate
Nature of movement-Slide
| Rate of movement-Rapid
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Mass Movements-Types-Landslide/Slump-How?
A landslide/Slump differs from a landslide in the the slide surface is curved rather than flat. Landslips occur in weak clays and sands, often when permeable rock overlays impermeable rock, which causes pore water pressure to build up. Landslips are characterized by a sharp break of slope and the formation of a scar
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Mass Movements-Types-Landslips/Slumps-Case Study
The Holderness Coastline
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Mass Movements-Types-Runoff-Nature and Rate
Nature of movement-Flow
| Rate of movement-Rapid
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Mass Movements-Types-Runoff-How?
When overland flow occurs down a slope/cliff face, small particles are moved downslope to enter the littoral zone. Runoff can be considered a type of flow that transfers both water and sediment from one store to another
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Mass Movements-Types-Runoff-Case Study
Any river
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Mass Movements-Types-Solification-Nature and Rate
Nature of movement-Creep
| Rate of movement-Imperceptible
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Mass Movements-Types-Solification-How?
Solification is similar to soil creep, but it only happens in cold periglacial environments. In the summer, the surface layer of soil thraws out and becomes extremely saturated because it lies on top of impermeable frozen ground called permafrost.
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Mass Movements-Types-Solification-Case Study
The Arctic
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Types of Movement-Slides
Material shifts in a straight line
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Types of Movement-Slumps
Materials shifts with a rotation
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Types of Movement-Flow
Materials flow downslope
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Transportation of Sediment
Coastal transportation plays a major role in the coast system as it transfers sediment from one store to another
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Transportation of Sediment-Types
There are 4 types of coastal transportation:
- Saltation
- Suspension
- Solution
- Traction
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Transportation of Sediment-Types-Traction
The rolling of course sediment along the seabed that is too heavy to be picked up and carried by the sea
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Transportation of Sediment-Types-Saltation
Sediment is "bounced" along the seabed. Sediments is light enough to be picked up or dislodged but too heavy to remain in the water flow
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Transportation of Sediment-Types-Suspension
Smaller (lighter) sediment is picked up and carried within the water flow
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Transportation of Sediment-Types-Solution
Chemicals dissolved in the water , transported and precipitated elsewhere
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Transportation of Sediment-Longshore Drift
Longshore drift is an important transfer mechanism as it is responsible for moving vast amounts of sediment along the coastline
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Transportation of Sediment-Longshore Drift-How?
The waves approach the beach at an angle, in the direction of the prevailing wind. The waves are refracted before reaching the beach. When the wave reaches the beach, it picks up sediment and advances up the beach. Backwash then carries the sediment down the beach at 90° to the swash. This is due to gravity. The sediment is either moved by traction, saltation or suspension. This repeats until the sediment has reached the end of the beach, or a curve in the beach, where a spit would be created
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Ways to erode the coast-Abrasion
Bits of rock and sediment transported by the waves smash and grind against rocks and cliffs, breaking bits off and smoothing surfaces
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Ways to erode the coast-Hydraulic Action
Air in cracks in the cliffs is compressed when waves crash in. The pressure exerted by the compressed air breaks off rock pieces
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Ways to erode the coast-Cavitation
As waves recede, the compressed air expands violently, again exerting pressure on the rock and causing pieces to break off
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Ways to erode the coast-Wave Quarrying
The energy of a wave as breaks against a cliff is enough to detach bits of rock
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Ways to erode the coast-Solution
Soluble rocks get gradually dissolved by the sea water
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Ways to erode the coast-Attrition
Bits of rock in the water smash against each other and break into smaller bits
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Factors affecting coastal erosion-Waves
The size and type of wave can affect the rate of coastal erosion on a stretch of coastline. Most erosion occurs during winter storms when destructive waves are at their largest and most powerful
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Factors affecting coastal erosion-Rock Type
Tough and resistant rock erode at very slow rates compared to weaker rocks
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Factors affecting coastal erosion-Geological Structure
Cracks, joints, bedding planes and faults create weaknesses in a cliff that can be exploited by erosion
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Factors affecting coastal erosion-Beach
Beaches absorb wave energy and reduce the impact of waves on a cliff. If a beach is not there, a cliff may experience increased erosion as it is more vulnerable to wave attack
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Factors affecting coastal erosion-Subaerial Processes
Weathering and mass movement will weaken cliffs and create piles of debris that are easily eroded by the sea, increasing the rate of erosion
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Factors affecting coastal erosion-Coastal Management
The presence of coastal management can affect erosion rates. When the sediment is trapped by groynes, beaches further down the coast are affected, as they will not have a beach. A sea wall may deflect wave energy elsewhere along the coast, exacerbating erosion in those localities
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Coastal Deposition-What?
When sediment is put down on to a beach by constructive waves
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Beach-What?
A accumulation of sand and shingle, known as a store. A beach is formed between high and low tide marks. They are a temporary store
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Erosion Based Landforms-Wave Cut Platform-Formation
At high tide, the waves attack the cliff. This is done by hydraulic action. This creates a wave cut notch between the high and low tide marks. As the notch gets bigger due to more erosion, the cliff is undercut and the rock above it becomes unstable, eventually collapsing due to gravity. This causes the cliff to move inland, leaving a gently sloping wave cut platform, which can only be seen at low tide
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Cliff Profile-Steep Cliffs
Steep cliffs occur when the rock is strong and resistant to erosion. They tend to have no beach, but a wave cut platform
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Cliff Profile-Gentle Cliffs
Gentle cliffs occur when the rock is weal or unconsolidated rocks that are prone to slumping. They are sloped towards the sea and tend to have a big beach
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Factors affecting the rate of retreat of cliffs
- Rate of weathering
- Geology-Rock Type
- Fetch
- Wave type
- Energy levels
- Size of Beach
- Rate of erosion
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Costal Morphology-What?
Not just the geology of the cliff, but also the cliffs lithology
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Lithology-What?
The geological structure
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Strata-What?
Layers of rock
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Costal Morphology-Strata
Horizontal strata produces steep cliffs
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Bedding Planes-What?
Horizontal, natural breaks in the strata, caused by gaps in time during periods of rock formation
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Joints-What?
Vertical fractures caused by either contraction as sediments dry out, or by earth movements during uplift
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Costal Morphology-Joints
Rocks dip gentle towards the sea with almost vertical joints. The joints are opened by weathering and pressure release
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Folds-What?
Formed by pressure during tectonic activity which makes rocks buckle and crumble
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Faults-What?
Formed when the stress or pressure to which a rock is subjected to exceeds its internal strength causing it to fracture. The faults then slip or move along fault planes
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Dip-What?
Refers to the angle at which rock strata lie
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Costal Morphology-Steep Dip
A steep dip towards the sea makes rocks slabs slides down the cliff along bedding planes
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Costal Morphology-Inland Dip
Rocks dip inland producing a stable steep cliff profile
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Costal Morphology-Inland dip with joint
Rocks dip inland but with a well developed joint at right angles to bedding planes. The joints act as slide planes
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Headland Erosion-How?
The erosion of rocks like limestone tends to exploit ant lines of weakness. Joints and faults are eroded by hydraulic action and abrasion to create caves. If two caves join up, or a single cave is eroded though a headland, an arc is formed. The gap is enlarged by erosion and weathering. The top of the arc then collapses due to gravity and erosion. This creates a stack. As the stack continues to be eroded by hydraulic action, the stack collapses to leave a stump, which may only appear above the surface at low tide
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Depositional Landforms-Beaches
Beaches are the most common landform of deposition and represent the accumulation of material. Beach material in the form of sand, shingle, pebbles and cobbles come from three sources
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Sources of Beach Material
- Cliffs
- Offshore
- Rivers
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Types of Beaches
There are two types of beaches. They are:
- Swash Aligned Beaches
- Drift Aligned Beaches
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Types of Beaches-Swash Aligned Beaches
Formed in low energy environments, this type of beach may consist of either sand or shingle, depending on factors like the nature of the sediment and the power of the waves. High energy waves will transport sand, leaving behind coarser shingles whereas low energy waves will deposit sand or mud
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Types of Beaches-Drift Aligned Beaches
Formed when the waves approach the coast at a angle. Long shore drift moves the sediment along the beach, Finer shingles are likely to be carried further and also become increasing rounder as they move
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Beach Profile-Beach Zones
- Backshore Zone
- Forshore Zone
- Nearshore Breaker Zone
- Offshore Zone
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Berm-What?
A ridge made of the biggest boulders thrown by large waves, found above the high tide mark
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Cusp-What?
Semi circular shaped depressions which form when waves break directly on thee beach
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Runnel-What?
Developed on the sand by wave action or tidal currents
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Spit-What?
A long narrow accumulation of sand or shingle with one end attached to land and the other projecting out to sea or to a river estuary
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Depositional Landforms-Spit-Formation
Long shore drift continues to deposit material across the river mouth, leaving a bank of sand and shingle sticking out into the sea. Occasional changes to the dominate wind and wave direction may lead to the spit having a curved end. Over time, the curved ends may be abandoned as they waves return to their original direction. The area behind the spit is sheltered from the waves and often develops into mudflats and saltmarshes
148
Offshore Bar-What?
Elongated ridges and mounds of sand or gravel deposited beyond a shoreline by currents and waves
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Tombolo-What?
Beaches formed between an islands and the sea
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Depositional Landforms-Offshore Bar-Formation
Bars are formed when a spit joints two headlands together. A lagoon formed behind the bar. Bars can also form off shore when material moves towards the coast
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Depositional Landforms-Tombolo-Formation
A bar is formed that connects the shore to an island
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Barrier Beach-What?
When a beach extends across an indentation in a coastline to join two headlands
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Depositional Landforms-Barrier Beach-Formation
We are not shore how they formed, but scientists think they formed after the ice age ended, when ice melted caused sea levels to rise. The rising waters flooded the land behind beaches and transported sediment offshore, where it was deposited in shallow waters, forming the barrier beaches
154
Salt Marshes-What?
A salt marsh is a coastal ecosystem in the upper coastal tidal zone between land and open salt water or slack water that is regularly flooded by tides
155
Factors associated with salt marsh development
- A sea shore with very little wave action
- Shelter from the waves
- A source of mud
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Depositional Landforms-Salt Marshes-Formation
The low energy coast allows the negatively charged mud particles to become neutral and stick together, to be transported. The shelter protects the area and allows the mud to build up, forming the salt marsh
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Sand Dunes-What?
Sand dunes are accumulations of sand shaped into mounds by the wind. They are dynamic ecosystems called Pasammoseres
158
Sand Dunes Equation
Wind+Sand+Water+Beach Grass (Marram Grass)=Sand Dunes
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Depositional Landforms-Sand Dunes-Formation
Sand trapped by driftwood or berms is colonised by plants and grasses. The vegetation stabilises the sand and encourages more sand to accumulate there. Over time, the oldest dunes migrate inland as newer dunes are formed
160
Wind Transportation Methods-Creep
Creep is similar to Traction
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Wind Transportation Methods-Saltation
Saltation is similar to saltation of sediment
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Wind Transportation Methods-Suspension
Suspension is similar to suspension of sediment
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Types of Sand Dunes-Embryo and Fore Dunes
- High water mark
- Poor water retention
- Sand builds up against pioneer plants
- Seaweed deposits humus
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Types of Sand Dunes-Yellow Dunes
- Above high tide
- Reduced water speed
- Surface continuously blown away, replaced with new sand
- More water retentive
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Types of Sand Dunes-Grey Dunes
- Shelter by higher dunes
- No longer gaining sand
- Has a closed vegetation community
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Types of Sand Dunes-Dune Slack
- Occurs in low lying hollows between dune ridges
- High water table
- Relief intersects the water table
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Types of Sand Dunes-Heath/Woodland
- Well sheltered from wind
- High organic soil
- Rich in nutrience
- Minimal maritime influence
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Types of Sea Level Change
There are two types of sea level change:
- Eustatic Change
- Isostatic Change
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Eustatic Change-What?
When the sea level rises or falls
170
Eustatic Change-Features
- A global change
- A lot of Ice in the water- Low sea levels
- Sea levels rise when Ice sheets melt- More water in sea
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Isostatic Change-What?
When the land rises or falls, relative to the sea
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Isostatic Change-Features?
- A local change
| - Caused by vertical movements of the land, due to uplift, depressions, drainage or tectonic plate movement
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Isostatic Change-Case Study-Isle of Arran
On the Isle of Arran, they have caves and a raised beach. This is caused by land rising
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Isostatic Change-Case Study-Turkakirae Head, New Zealand
In this place, there is multiple wave cut platforms
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Landforms Created by Sea Level change
There are two types of landforms created by sea level change:
- Emergent Landforms
- Submergent Landforms
176
Emergent Landforms-What?
Occurs when Isostatic change occurs more than Eustatic change. In simple terms, the land rises quicker than the sea does
177
Emergent Landforms-Types
- Raised Beaches
- Wave Cut Platforms
- Relic Stacks
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Raised Beach-What?
When a beach is above the current sea level
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Relic Stacks-What?
The remains of eroded cliffs lines
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Submergent Landforms-What?
Occurs when Eustatic change occurs more than Isostatic change. In simple terms, the sea rises quicker than the land does
181
Submergent Landforms-Types
- Fjords
- Rias
- Dalmatian Coasts
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Fjord-What?
A fjord is a flooded glacial valley
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Fjord-Case Study
Fjords can be seen in Norway
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Rias-What?
A ria is a flooded river valley
185
Rias-Case Study
A ria can be seen in Kingsbridge
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Dalmatian Coast-What?
A Dalmatian coast is a set of offshore islands. These islands are the tops of valleys, and run parallel to the coastline
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Dalmatian Coast-Case Study
A example of a Dalmatian Coast can be seen in Croatia
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Sea Level change and Tectonics-Japan
The earthquake caused the land to drop 2 metres. The sea level essentially rose 2 metres, flooding the area
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Sea Level change and Tectonics-Banda Ache
The earthquake caused the sea level to rise
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Sea Level change and Tectonics-The Indian Ocean
The rising of the sea bed caused the Indian ocean to have less water in it, causing a permanent rise in sea level by 0.1mm
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Sea Level change and Tectonics-Tsunamis
Tsunamis cause a short term increase in sea level
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Sea Level change and Tectonics-Fold Mountains
The creation of fold mountains causes sea levels to drop
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Sea Level change and Tectonics-Thermal Expansions
Causes more warm water in the sea
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Sea Level Rise-Case Study-Tuvalu
Tuvalu is a island that was created on a old coral reef. They are incredible vulnerable to sea level change
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Sea Level Rise-Case Study-Tuvalu -Why are they Vulnerable
- Waves have a large fetch-More powerful
- Width of land is thin
- Land is flat
- Ocean is on both sides of Island
- Everything is close to the sea
- Protected by a small beach
- No flood Defences
196
Sea Level Rise-Case Study-Tuvalu Responses
Tuvalu has sued the US and Australian Governments for producing a lot of Carbon dioxide, which help to cause sea level rise
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Coastal Management-Types
There are many types of Coastal Management:
- Hard Engineering
- Soft Engineering
- Shoreline Management Plan
- Integrated Coastal Zone Management Plans
198
Hard Engineering-What?
Hard engineering is man made structures that protect the coastline
199
Types of Hard Engineering
There are many types of Hard Engineering Techniques:
- Groynes
- Sea Walls
- Rip-Rap
- Reventments
- Offshore Breakwater
200
Types of Hard Engineering-Groynes-Description
Wood or rock structures at right angles to the coast. They trap sediment being moved by long shore drift
201
Types of Hard Engineering-Groynes-Cost
£10,000 each
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Types of Hard Engineering-Groynes-Advantages
+Works with natural processes to built up beaches-Leads to more tourists
+Protects land behind beach
+Not too expensive
203
Types of Hard Engineering-Groynes-Disadvantages
- Deny beaches of sediment-Causes increased erosion
- Unnatural
- Unattractive
204
Types of Hard Engineering-Sea Walls-Description
Stone or concrete walls that normally have a curved face which reflects waves back to the sea
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Types of Hard Engineering-Sea Walls-Cost
£6000 per metre
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Types of Hard Engineering-Sea Walls-Advantages
+Effective protection of erosion
| +Often have a promenade for people to walk across
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Types of Hard Engineering-Sea Walls-Disadvantages
- Does not absorb wave energy
- Intrusive
- Unnatural
- Very expensive to build and maintain
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Types of Hard Engineering-Rip-Rap-Description
Large rocks that form a permeable barrier to the sea-breaking up the waves, but allowing some water to pass
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Types of Hard Engineering-Rip-Rap-Cost
£100,000 to £300,00 per 100 metres
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Types of Hard Engineering-Rip-Rap-Advantages
+Relatively cheap
+Easy to construct and maintain
+Used for recreational activities
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Types of Hard Engineering-Rip-Rap-Disadvantages
- Rocks can look out of place with local geology
| - Can be dangerous for people clambering over them
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Types of Hard Engineering-Revetments-Description
Sloping wooden concrete or rock structures that break up the waves energy
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Types of Hard Engineering-Revetments-Cost
£4500 per metre
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Types of Hard Engineering-Revetments-Advantages
+Cheap
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Types of Hard Engineering-Revetments-Disadvantages
- Unnatural looking
| - Needs high levels of maintenance
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Types of Hard Engineering-Offshore Breakwater-Description
A partly submerged rock barrier, designed to break up the waves before they reach the coast
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Types of Hard Engineering-Offshore Breakwater-Cost
£100,000 to £300,000
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Types of Hard Engineering-Offshore Breakwater-Advantages
+Effective Permeable barrier
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Types of Hard Engineering-Offshore Breakwater-Disadvantages
- Visually unappealing
| - Potential navigation hazard
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Soft Engineering-What?
Techniques that use the natural environment
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Types of Soft Engineering
There are a few types of soft engineering:
- Beach Nourishment
- Cliff regrading and drainage
- Dune Stabilization
- Marsh Creation
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Types of Soft Engineering-Beach Nourishment-Description
The addition of sand or pebbles to an existing beach to make it higher or wider. The sediment is normally drained from the nearby seabed
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Types of Soft Engineering-Beach Nourishment-Cost
£300,000 per 100 metre
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Types of Soft Engineering-Beach Nourishment-Advantages
+Cheap
+Easy to maintain
+Natural looking
+Helps build bigger beach
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Types of Soft Engineering-Beach Nourishment-Disadvantages
-Needs constant maintenance
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Types of Soft Engineering-Cliff Regrading and Drainage-Description
Cliff regrading reduces the angle of the cliff to help stable it. Drainage removes water to prevent landslides and slumping
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Types of Soft Engineering-Cliff Regrading and Drainage-Cost
Variable
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Types of Soft Engineering-Cliff Regrading and Drainage-Advantages
+Effective on clay or loose rock cliffs
| +Drainage is cost effective
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Types of Soft Engineering-Cliff Regrading and Drainage-Disadvantages
- Causes cliff retreat
| - Drained cliffs can dry out, leading to rock fall
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Types of Soft Engineering-Dune Stabilization-Description
Marram grass can be planted to stableise dunes. Areas can be fenced in to keep people off the dunes
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Types of Soft Engineering-Dune Stabilization-Cost
£200 to £2000 per 100 metres
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Types of Soft Engineering-Dune Stabilization-Advantages
+Maintains natural environment
+Provides habitats for wildlife
+Cheap
+Sustainable
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Types of Soft Engineering-Dune Stabilization-Disadvantages
- Time consuming to plant Marram grass
| - People may respond negatively to being kept off areas
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Types of Soft Engineering-Marsh Creation-Description
A form of managed retreat, by allowing low lying coastal areas to be flooded by the sea. The land then becomes a salt marsh
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Types of Soft Engineering-Marsh Creation-Cost
Variable depending on the size of the area
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Types of Soft Engineering-Marsh Creation-Advantages
+Cheap
+Natural buffer created
+Habitat created
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Types of Soft Engineering-Marsh Creation-Disadvantages
- Agricultural land is lost
| - Farmers or landowners will need to be compensated
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Sustainable Coastal Management-Shoreline Management Plan
A SMP is a extremely detailed document that decides what to do with the sediment cell. There are 4 options:
- Hold the Line
- Advance the Line
- Managed Retreat
- Do Noting
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Shoreline Management Plan Options-Hold the Line
Maintain the current position of the coastline ,often using hard engineering
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Shoreline Management Plan Options-Advance the Line
Extending the coastline out to sea, by encouraging the build up of a wider beach
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Shoreline Management Plan Options-Managed Retreat
Allowing some areas to flood in a planned and manged way. Normally, this is low quality land
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Shoreline Management Plan Options-Do Noting
Let nature take its course, allowing sea to erode cliffs, flood the land and allow existing defenses to collapse
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Sustainable Coastal Management-Integrated Coastal Zone Management
This form of management involves splitting the area up into zone, which each zone for a certain purpose
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Integrated Coastal Zone Management-Case Study-St Lucia
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The coastline of St Lucia has been divided into zones
These zones are:
-Marine reserves
-Fishing priority area
-Recreational Areas
-Multi Use Areas
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Integrated Coastal Zone Management-Case Study-St Lucia-Economic Reasons
- Provides people with jobs
| - More income for people
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Integrated Coastal Zone Management-Case Study-St Lucia-Social Reasons
- Provides people with jobs
| - Increases tourism
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Integrated Coastal Zone Management-Case Study-St Lucia-Environmental Reasons
- Some areas are protected
- Allows area to be regenerated if damaged
- Protects wildlife
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Case Study-Holderness-Where?
The Holderness coast is on the east coast of England, close to Hull
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Case Study-Holderness-Rate of Erosion
Since Roman times, about 3.5 km has been eroded. It is the fastest eroding coastline in the UK
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Case Study-Holderness-Coastal Issues
- Landslides
- Slumping
- High Cliff Erosion-Due to boulder clay
- Houses Destroyed
- Roads Destroyed
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Case Study-Holderness-Fetch
The fetch is very long. This means that powerful waves hit the soft rocks, causing lots of erosion
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Case Study-Holderness-Coastal Features
- Flamborough Head-North of Holderness, eroded headland with a wave cut platform
- Spurn Head Spit-A spit on the south of Holderness
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Protection Methods on Holderness-Hornsea-Uses
The town of Hornsea is used for tourism
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Protection Methods on Holderness-Hornsea-Methods Used
- Wooden Groynes
| - Beach Nourishment
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Protection Methods on Holderness-Hornsea-Conflict and Issues
Mappleton did not receive any sediment. This lead to major cliff erosion there
The sand that was added can be removed in a year, it has to be replaced every year
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Protection Methods on Holderness-Mappleton-Uses
The village of Mappleton has a main road going through it
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Protection Methods on Holderness-Mappleton-Methods Used
- Rock Groynes-Groynes of Norwegian Granit laid out and work like wooden Groynes
- Re graded cliff face
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Protection Methods on Holderness-Mappleton-Conflicts and Issues
Erosion increased past the last groyne. Erosion rate increased from 2.5 metres a year a 3.8 metres a year
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Protection Methods on Holderness-Easington-Uses
Easington has a gas terminal, which provides gas for the north
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Protection Methods on Holderness-Easington-Methods Used
-Rock Revetments
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Protection Methods on Holderness-Easington-Conflicts and Issues
- Expensive but long lasting
| - Some people think they are unattractive
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Protection Methods on Holderness-Withernsea-Uses
Withernsea is one of the largest towns in the area, It has hospitals, lifeboat station and schools
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Protection Methods on Holderness-Withernsea-Methods Used
- Sea Wall
| - Rip Rap
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Protection Methods on Holderness-Withernsea-Conflicts and Issues
- Cost £6.3 million- justified using cost-benefit analysis
- Smaller Promenade
- Views from hotels have been damaged
- Rip Rap is expensive and unattractive
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Case Study-Odisha-Location
Odisha is a province on the east coast of India. It is on the eastern coastal plain of India
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Case Study-Odisha-Factors that make the area unique
- Between 0-1500 metres above sea level
- Mostly Depositional Landforms
- Six major deltas on the coast
- Has 1435km of Mangrove Forest
- Chillika Lake-Salty Lagoon-increases in area during monsoon season
- Beaches are important sediment stores
- Region is a significant sediment store
- Rivers transfer sediment from the Bay of Bengal
- Majority of inputs are rivers
- Coastal and River based landforms
- Relatively low energy coastline
- Concordant coastline
- A multi hazard area
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Case Study-Odisha-Factors that disrupt the sediment cell
- Storm surges that erode the sediment
- Tsunami Waves
- Sea Walls-Prevent transportation
- Mangroves-Natural defence,- if taken away, it affects the sediment cell
- Breakwaters
- Rock Armour
- Shoreline Change
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The Opportunities and Risk of the Odisha Coastline-Economic
- Offshore oil, natural gas and seabed mining
- Cultural and archaeological sites, drawing visitors from around the world-Money into area
- Tourism-Beaches, Wildlife sanctuaries
- 35% of the coast is laden with substantial sediment minerals and heavy metal deposits. They are important clay and limestone resources in the north of Odisha
- Huge potential for offshore wind, tidal and wave power
- Many local people are employed in coastal fishing and in aquaculture
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The Opportunities and Risk of the Odisha Coastline-Environmental
- Large stocks of fish, marine mammals, reptiles, sea grass meadows and seaweed
- Wide variety of marine and coastal flora and fauna including mangroves, sea grasses, salt marshes, sand dunes, estuaries and lagoons
- The Chilika Lake Bird Sanctuary has over 150 migratory and resident species of bird
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Risks of Coastal Development on Odisha
- Cyclones create storm surges-flooding
- Flooding causes erosion
- Flat land-easily flooded
- Rising sea levels-Flooding
- Locals are forced to adapt
- Could built on flood plains
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Risks of Coastal Development on Odisha -Types of Risk
There are both human and physical risks to developing the Odisha coast
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Risks of Coastal Development on Odisha -Types of Risks-Human
- Infrastructure Destroyed
- Homes destroyed
- Flooding of buildings
- Jobs lost due environmental destruction
- Economic loss
- Loss of life
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Risks of Coastal Development on Odisha -Types of Risk- Physical
- Storm Surges
- Tsunami
- Coastal erosion
- Disruption to sediment cells
- Areas destroyed
- Rising sea level
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Management of Odisha-Technique used
They used a ICZM project. This project is a joint venture between organisations
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Odisha- ICZM- Aims
- Establish sustainable levels of economic and social activity
- Resolve environmental, social and economic challenges and conflicts
- Protect coastal environment
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Odisha- ICZM- Issues Identified
- Coastal erosion
- Assessing vulnerability to disaster
- Biodiversity conservation
- Livelihood security
- Pollution and environmental quality management
- Conservation of cultural assets
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Odisha- ICZM- What have they done?
- Planted mangrove trees
| - Built cyclone shelters
