Crowded Coasts: Coastal Management Flashcards
What is SMP
Shoreline Management Plan
These encompass the various procedures that can be implemented to handle coastal erosion
What are the components of SMP
Advance the line
Hold the line
Managed Realignment
Do nothing
What is Advance the line?
building new defences on the seaward side of the original defences.
What is Holding the line
maintaining or changing the coastal defence that is currently in place.
What is managed realignment?
Removing coastal defences from an area so it is exposed to flooding by the sea
What is the ‘Do nothing’ approach?
there is no investment in coastal defences or operations
What is hard engineering management?
A man made structure being built that works against forces of nature.
What is soft engineering management?
Management that works with the forces of nature
What is coastal squeeze?
A process that describes when coastal habitats and natural features eventually become lost or drowned as they are caught between sea defences or rising sea levels.
What coastal defence were at Walton-on-the-Naze?
Groynes- Hard engineering Supergroynes Cragwalk- Hard Seawall - Hard Revetment Hard Cliff regarding- Hard
How successful were the defences at Walton on the Naze in terms of cost?
The groynes were the least successful in terms of cost as they were the most expensive at £7000/m
Seawall-
What is an embankment/levee and what does it do
An artificial bank built to prevent flooding inlow lying areas
Sloping hill next to river
What is a gabion and what does it look like?
Small rocks held in metal cages
What are the strengths of embankments
Simple
Cheap
What is a revetment?
A sloping ramp that takes the force of the wave energy to reduce erosion.
What is a sea wall
A massive wall that reflect wave energy preventing erosion and flooding.
What are the weaknesses of revetments?
Can’t cope well with strong storm waves
May damage coastal ecosystems
What are the weaknesses of sea walls
They are expensive to build and maintain
Foundation of wall can be weakened on beaches where longshore drift occurs
What are the weaknesses of gabions?
Metal cage may fail and spill contents
May move during storms
What are the strengths of revetments
Unlike sea walls have little risk of undermining and are cheaper.
Name three soft engineering techniques
Beach nourishment
Beach re-profiling
Developing natural defences of coral reefs and mangroves
What is Beach nourishment
Sand pumped from seabed to replace sand that has been eroded from the beach
What is Beach re-profiling
The shape of the beach is altered to reduce the effects of erosion.
What is the strength of Developing natural defences of coral reefs and mangroves
Its environmentally friendly.
What is the weakness of Developing natural defences of coral reefs and mangroves
can prevent economically beneficial developments.
What is the strength of beach nourishment
Its natural looking
What is the weakness of beach nourishment
Expensive
Never ending
Adverse ecological impacts
What is the strength of beach re-profiling
Cheap
Simple
What is the weakness of beach re-profiling
Only works in low energy environments
What is a tidal barrage?
A large wall that can use the tidal energy of a river eg the Severen Barrage, from Cardiff to Bristol
What are the environmental costs of the Severen Barrage
(Salt marsh , CO2, birds ,fish
Intertidal habitats such as salt marshes would be vulnerable to coastal squeeze
The barrage would be used for transport which would increase CO2 emissions this is especially bad as our government has set a target to reduce CO2 emissions by 60% by 2050
Cause loss of some organisms such as the ‘Honeycombe worm ‘ which is responsible for the forming of some reefs in the Severen Estuary meaning a reduction in the formation of reefs
Salt marshes expected to be reduced by 540 hectares
The Severen Estuary currently provides for 65 000 water birds with 10 that are of national importance and 5 that are international importance
Various fishe species (salmon already in shortage) migrate through the estuary the barrage would create a physical barrier for these fish and the turbines would be a danger to them
The barrage would cause a greater flood risk upstream due to drainage of the land.
What are the economic benefits of the Severen Barrage
(Salt marsh , CO2, birds ,fish
Improve enrgy security- Sources of non revewable energy such as oil and gas have become unstable so it’s beneficial for the Uk if we are self sufficient in energy production
The SW would become famous as a world leader in ‘barrage technology’ and highly skilled jobs may be developed in research developing and engineering , this would be beneficial as a large amount of the jobs (28.1% ) are in the production industry which is typically low paid
The Barrage would provide a much safer environment for water sports which have previously been unsafe due yo dangerous currents. Meaning a greater demand for sailing and waterskiing which would attract tourism , this is especially beneficial as tourism plays a very important role for the SW economy, in 2003 tourism contributed almost £5 to the regions economy
The improved transport links would mean regeneration for deprived areas such as Newport , Wales and Bridgewater,Somerset
It would produce 5% of the Uk’s electricity
What are the economic costs to the Severn barrage?
It would cost around 26 billion pounds and the UK government is already in a large deficit as it is which may mean more cuts and higher taxes are necessary, this could lead to people being made redundant which reduces economic growth (negative multiplier effect)
The barrage would be a physical barrier to shipping. This is because the barrage would be fitted with locks (further cost) which increases shipping time, as a result tradewill be reduced as firms/countries will trade where their are more efficient ports thus damaging our economy .
IT would also reduce trade as the depth of the water would be reduced this would prevent much existing shipping from being able to access docks in Wales and Bristol putting thousands of jobs at risk
What is the Severn Barrage
The possibility of a tidal barrage being built over the Severn Tidal Estuary (from the English Coast to the Welsh Coast)
What is a tidal barrage?
A large wall that uses the tidal energy from the estuary to create tidal power.
What are the environmental benefits to the use of tidal power form the barrage rather than non-renewable sources
It does not involve the combustion of fossil fuels meaning if the UK generate more energy this way will lower carbon emissions and help us meet our target of reducing carbon emissions by 60% (2050) under the Kyoto Protocol. And help us meet our target of having 20% of energy from renewable source by 2020 (currently 15%)
It would provide the Severn estuary with protection from flooding as storm surges would no longer be a threat.
State 2 alternatives to the Severn Barrage.
Tidal Lagoon
Tidal Stream Generators
What is a tidal stream system
Kinetic energy from the moving water is used to powerturbines
What are the benefits of tidal stream systems compared to barrages
They have a lower ecological impact
Lower cost
What is the advantage of a tidal lagoon
Lower construction cost
They can produce hydro electric power continuosly unlike barrages
Who are the key stakeholders in the Severn Barrage
Government (treasury and DEFRA)
Local residents -(Jobs , sea level)
RSPB
What are 2 factors that can lead to rising sea levels
Thermal Expansion
Melting of Polar Icecaps
What is Thermal Expansion?
When water heats up (as a result of climate change) it can expand by up to 50%
What is the melting of Polar Icecaps ?
Glaciers naturally melt a bit each summer , however the snow during winter is enough to balance this. Having said that the higher temperatures due to global warming have lead to higher rates of melting in the summer and less snow in the winter. The inbalance means higher sea levels
Give an example of a natural diaster that occurred due to rising sea levels in a densely populated area
The Asian Tsunami 2004
What were the social impacts of the Asian Tsunami?
230,000 deaths in 14 countries
1.7 million made homeless
The spread of diseases such as cholera and typhoid was significant.
What were the economic impacts of the Asian Tsunami?
In Sri Lanka a largely impacted country industrial fishery is the major economic activity, providing direct employment to about 250,000 people.Its estimated that 66% of the fishing equipment and vital infrastructure were destroyed.
Reduction in tourism as many tourists cancelled vacations and trips to that part of the world, even though their travel destinations may not have been affected. This ripple effect could especially be felt in Thailand
Thousands of rice, mango, and banana plantations in Sri Lanka were destroyed almost entirely and will take years to recover.
What were the economic impacts of the Asian Tsunami?
Severe damage has been inflicted on ecosystems such as mangroves, coral reefs, forests and sand dunes
the spread of solid and liquid waste and industrial chemicals has lead to high levels of water pollution
Thousands of rice, mango, and banana plantations in Sri Lanka were destroyed almost entirely and will take years to recover.
What is it called when sea level rises due to climate change?
Eustatic Change
What is Isostatic Change?
When a change in the height of the land causes a change in sea level.
When the height of the land rises sea levels fall and vice versa
What is the difference between Eustatic and Isostatic sea level changes in terms of impact
Eustatic is global
Isostatic is Local
What is compression?
During isostatic change eg during an ice age the ground becomes heavier causing the ground to sink and sea level to rise.
What is decompression (Isostatic rebound)
When the ground becomes lighter eg at the end of the ice age the ground is lighter so it slightly rises, thus causing sea level to fall
What is decompression AKA
Isostatic rebound
