Coasts: How can coastlines be managed? EQ4 Flashcards
What are the economic costs of coastal flooding & erosion? explain why for each one
- Housing - Cost of land + repairing/rebuilding homes
- Businesses - destruction/damage to business leads to loss of profits + cost of rebuilding
- Agricultural land - can lead to food shortages + loss of income from crop and livestock sales
- Infrastructure - Roads, power stations, power lines, water and energy= all costly to rebuild and repair after flooding
What are the social costs of coastal flooding & erosion?
- Loss of lives - affects family members & friends
- Relocation - people will properties at risk must relocate their homes
- Loss of livelihood - income for farmers lost due to loss of livestock and flooding of crops
- Amenity value - large areas of land with amenity value are coastal= at risk of coastal flooding
What does the extent of losses depend on?
Where the country is a developing or developed country
Why do developed countries face higher economic losses?
The homes, businesses & infrastructure are of higher value due to quality of materials and technology used
Why do developing countries losses tend to be of a greater magnitude in terms of deaths, injuries & loss of buildings?
Lower wealth
What does lower wealth lead to?
- Less preparation and planning
- Emergency services not as well trained
- lack of public education (e.g. how to protect themself + homes)
- poor building quality
Consequences in developed countries: UK
Economic
- what is an acre of residential land valued between?
- Average damages in the UK from coastal flooding is… a year?
Social
- what was estimated in 2007?
- what impacts to farmers have?
- what happens if businesses are affected?
Economic
- £300,000 (north) - £1 million (south)
- £120 million a year
Social
- £48 billion worth of land with amenity value= at risk of coastal flooding before 2050
- Income for farmers lost= loss of livestock + flooding of crops
- loss of jobs
Consequences in developed countries: Bangladesh
- what % of land is 8m above sea level
- how long is the coastline?
- what events are common in this area?
- what cyclone hit Bangladesh in 2007?
- how many deaths and injuries were their?
- what were the total economic losses?
- what things were significantly damaged?
- more than 50%
- over 600 km long
- tropical cyclones & storms
- Cyclone Sidr
- over 3,400 deaths, over 55,000 injuries
- total economic losses= US$ 2.31 billion
- roads, bridges + other infrastructure
What can climate change create? why
Environmental refugees in coastal areas
- many displaced from their homes due to natural hazards
In Bangladesh, the loss of land due to sea level rise + increased coastal erosion could lead to how many environmental refugees?
20 million
What are environmental refugees?
- what kind of problem will they soon be?
A person forced to move by environmental changes
- A global problem
Issues faced due to coastal flooding:
(5 things)
- Loss of land and a lack of money for coastal defences
- Coral reef bleaching= reduces the natural defences against storm surges
- Salt water incursion= reduces the freshwater supply
- Loss of tourism
- Limited space for relocation
Hard engineering:
- Is it generally effective?
- give two disadvantages
- Yes
- very expensive, ‘unattractive’
What must be carried out to decide the most appropriate hard engineering strategy?
A cross-benefit analysis (CBA)
Costs and benefits of CBA are of two types:
Tangible= costs and benefits are known and can be given a monetary value
Intangible= where costs may be difficult to assess but are important (e.g. visual impact)
Why may some areas be left with no protection in terms of coastal management?
Costs outweigh the benefits
What is hard engineering?
A man made coastal sea defence that is strong, costly and has lots of benefits
Groynes:
- what are they & how do they help?
- advantages
- disadvantages
- structure build at right angle to the shore which traps sediment that is transported by LSD allowing beach to build up and absorb wave energy
Advantages: - not as expensive as other hard engineering strategies
- builds up beach= improves tourist potential
Disadvantages: - causes sediment starvation further along coastline
- can be unattractive
- needs lots of maintenance to ensure no sediment is getting through any holes or cracks
Sea walls:
- what are they & how do they help?
- advantages
- disadvantages
- walls with a curved surface that absorb & reflect wave energy
Advantages: - highly effective
- can have tourism benefits as walkways are created
Disadvantages: - very expensive to build & maintain
- ugly & intrusive to the landscape
Rip Rap/Rock armour:
- what are they & how do they help?
- advantages
- disadvantages
- large concrete or granite boulders at the foot of a cliff. Spaces in between boulder cause waves to bounce between many surfaces reducing energy of wave.
Advantages: - cheaper than sea walls
- used for recreation such as fishing
Disadvantages: - Dangerous when people are on them
- Rocks from elsewhere are intrusive to local geology
Revetments:
- what are they & how do they help?
- advantages
- disadvantages
- Sloped structure that breaks up wave energy
Advantages: - cost effective compared to other hard engineering strategies
Disadvantages: - needs lots of maintenance
- unnatural looking
- slopes are dangerous
Offshore breakwater:
- what are they & how do they help?
- advantages
- disadvantages
- Rock barrier a little out to sea from the shoreline which breaks the waves and dissipates their energy before they reach the coast
Advantages: - Effective
- away from the beach so does not disrupt tourist potential
Disadvantages: - can create a navigation barrier in harbour areas
What is soft engineering?
A more natural type of coastal sea defence which costs less but are not as effective
What does soft engineering NOT do compared to hard engineering strategies?
- what does it do instead
Alter physical processes & systems
INSTEAD
It works with physical processes & systems to protect coasts and manage risks caused by changes in sea-level
Beach nourishment:
- what is it & how does it help?
- advantages
- disadvantages
- Adding sand or shingle to a beach to widen it creating more surface area to absorb wave energy
Advantages: - looks very natural
- bigger beaches better for tourism
- relatively inexpensive
Disadvantages: - material constantly subjective to erosion + LSD= lots of maintenance & monitoring needed
- dredging the seabed can have impacts on local ecosystems
Cliff regrading:
- what is it & how does it help?
- advantages
- disadvantages
- reducing the angle of the cliff to stabilise the slope. Drainage of water also stabilises the cliff against mass movement
Advantages: - cost effective
Disadvantages: - can look unnatural as cliff is unnaturally flatter
- creates cliff retreat
- dried out cliffs can collapse
Dune stabilisation:
- what is it & how does it help?
- advantages
- disadvantages
- Planting species like marram grass so that the roots bind the dunes. The dunes absorb wave energy & protect land behind it.
Advantages: - cheap and sustainable
- creates habitats for wildlife
- maintains a natural environment
Disadvantages: - people walk on dunes and damage them
- planting is time consuming
- takes time for plant species to become established
Marsh creation:
- what is it a form of?
- what is it & how does it help?
- advantages
- disadvantages
- Form of do-nothing or managed retreat
- land is allowed to be flooded by sea and then left to become a salt marsh= absorbs wave energy, creates a buffer to rising sea level & protects higher value land
Advantages: - A cheap option
- creates important and unique wildlife habitats
Disadvantages: - Agricultural land is lost= creates a need for compensation
What type of approach is sustainable management?
- what does it consider?
- what might this mean in some cases?
- what may this come into conflict with?
A long-term approach
- considers future threats such as sea-level rise & storm surges
- abandoning coastlines, low-land areas or those where coastal erosion may increase
- local people who may lose their land, home, job and sense of community
What does ICZM stand for & what idea is it based on?
- what type of strategy is it?
- what conflicts does it also seek to resolve?
Integrated coastal zone management
- based on the idea of sustainable coast management
- A holistic strategy
- Farmers may lose productive land due to managed retreat or do-nothing policies= bc their land has less value than that in towns
- People may lose their homes and have to relocate in areas where the cost-benefit analysis decides the areas cannot be protected
