Coastal Managements Flashcards
What are the different approaches to managing coastal areas
● Hold the line – Defences are built to try and keep the shore where it is.
● Managed realignment – Coastline moves inland naturally but managed.
● Advance the line – Defence are built to try and move the shore seawards.
● Do nothing – No defences are put in place and the coast is allowed to erode.
What factors are looked at when deciding what approach to use?
▪ Economic value of assets that could be protected is looked at, for example the important natural gas terminal at Easington would be protected however farmland and caravan parks wouldn’t
▪ The technical feasibility of engineering solutions, for example a sea wall may not be possible for a certain location.
▪ The ecological and cultural value of land. For example, it may be desirable to protect historic
sites or SSSI.
What contributes to coastal decision making?
CBA - Cost benefit analysis
ICZM - integrated coastal zone management
SMP’s - shoreline management plans
What is a cost benefit analysis?
This is an analysis that is carried out before any form of coastal management takes place. The cost involved include construction, demolition, maintenance etc. is then compared to the expected benefits like the value of land saved, homes and businesses protected. Costs and benefits include both tangible and intangible things. For a project to be given the go ahead, the expected benefits have to outweigh the costs
What is ICZM
▪ A coastal area (sediment cell) is managed as a whole. This often involves management between different political boundaries e.g in the UK different councils will have to work and manage coasts together.
▪ The ICZM recognises the importance of the coast for people’s livelihoods.
▪ The ICZM recognises that coastal management must be sustainable whereby economic
development is important but this should come at a cost for the environment.
The ICZM must involve all stakeholders, plan for the long term and try to work with natural process and not against them.
What is hard engineering?
Hard engineering is a very traditional and in many ways outdated approach to coastal management and it involves man made structures that aim to prevent erosion. They are often very effective at preventing erosion in the desired area, but are high cost and have a significant environmental impact due to the use of concrete and other man-made materials. By reducing erosion in one area of the coastline, they may act to exacerbate erosion elsewhere. Therefore their only impact is to change where erosion is occuring
What are the types of defences?
Offshore breakwater
Groynes
Sea walls
Rock armour
Revetments
Beach nourishment
Cliff regrading and drainage
Dune stabilisation
Marsh creation
What is offshore breakwater?
Rock barrier which forces waves to break before reaching the shore
👍🏼effective at reducing waves energy
👎🏼visually unappealing
👎🏼navigation hazard for boats
👎🏼can interfere with LSD
What are groynes?
They are timber or rock protrusions that trap sediment from LSD
👍🏼builds up beach, protecting cliff and increasing tourist potential
👍🏼cost effective
👎🏼visually unappealing
👎🏼deprives areas downwind of sediment, increasing erosion elsewhere
What is a sea wall?
Concrete structure that absorbs and reflects wave energy, with curved surface
👍🏼effective erosion prevention
👍🏼the walk on top attracts tourists
👎🏼visually unappealing
👎🏼expensive to construct and maintain
What is rock armour?
Large rocks that reduce wave energy, but allow water to flow through
👍🏼cost effective
👎🏼rocks are sourced from elsewhere so do not fit with local geology
👎🏼pose a health hazard if climbed on
Revetments
Wooden or concrete ramps that help absorb wave energy
👍🏼cost effective
👎🏼visually unappealing
👎🏼can need constant maintenance, which creates an additional cost
What is soft engineering?
Unlike hard engineering, soft engineering aims to work with and complement the physical environment by using natural methods of coastal defence. They are useful for protecting against sea-level change as well as coastal erosion.
What is beach nourishment?
Sediment is taken from offshore sources to build up the existing beach
👍🏼builds up beach, protecting cliff and increasing tourist potential
👍🏼cost effective and looks natural
👎🏼needs constant maintenance
👎🏼dredging may have consequences on local coastal habits
What is cliff regrading and drainage?
Reduces the angle of the cliff to help stabilise it. A steeper cliff would be more likely to collapse
👍🏼cost effective
👎🏼cliff may collapse suddenly as the cliff is drier leading to rock falls which poses a hazard
👎🏼may look unnatural
