- Created by: jodiewest_
- Created on: 08-04-14 17:43
We live in an increasing affluence (rich) society and more people are now starting to buy second homes. Many of these are at the coast. (Economic)
- Tourism - The pleasent climate and surroundings found in many coastal locations are a attraction for holiday makers, which also fuels development for these areas.
- Retirement - Coastal areas are popular for retirement. They are offered a good quality of life as its not as busy and it is relaxing. This boosts the areas reputation for attracting more people(Social).
- Recreation - Offer opportunities for sailing, surfing etc. Also hiking and bird watching. These will attract certain types of holday makers. This results in more caravan sites, camping sites, hotels and B & B's are needed to keep up with the amount of people in coastal areas.
Dubai has changed as it has grown outwards and since 1990 - 2003 there is now a high density of skyscrapper. Infrastructure has changed. More green space has been added.
Dubais Economy -
- The Dubai economy used to be based on oil - but the oil is runningout so they need to develop alternative industries instead.
- The government believe that the tourist industry has a huge potential.
- The UAE government sees the Dubai coast as an excellent location for the development of a range of business oppertunities that are based largely around tourism.
- Dubai is a tax free haven, making it very attracted to shoppers.
Tourism figures are expected to have doubled in the last ten years between 2000 - 2010 from 3,900,00 visitors per year to 8,400,000.
Palm Jumeirah = International hotel, shopping mall of 200 shops, yachting marina, 1,000 beach side villas.
What is the coastal system?
Rate of Erosion
Some factors that affect the rate of erosion along the way:
The type of rock -
- Less resistant rock e.g. clay = wide beach
- More resistant rock e.g. chalk = steep cliffs, narrow beaches, headlands.
Constructive waves - are long, low waves that spill onto the beach. They have a strong swash and limited backwash.
Destructive waves - are short, steep waves that plunge onto the beach with force. They have quite a strong swash but a much stronger backwash.
Factors that Effect the Coastline
1) Shape of the coastline:
Where there are rocky outcrops (headlands) these are exposed to the full force of the sea. Headlands also protect the surrounding bays from erosion.
2) Human Activities:
Through their activities humans can slow down or speed up the rate of erosion, e.g.
- Constructing groynes to trap sand and sediment will slow down erosion.
- Rise in sea level due to climate change can speed up erosion rates.
- By removing vegetation it is exposed and can be easily eroded by the sea.
- Destorying natural protective features such as dunes.
Old Harry Rocks
How Old Harry Rocks was formed:
What happens at Headlands and Bays:
Wave Cut Platform
A wave cut platform is formed when waves attack the base of the cliff through the process of marine erosion. Overtime a wave cut platform is formed. Eventually the cliff becomes unstable and collapses.
Coastal Deposition and Transportation
Coastal Transportation: is the movement of material in the sea along the coast by waves. The movement of material along the coast is called longshore drift.
Coastal Deposition: is when the sea drops or deposits material. This can include sand, sediment and shingle.
Beaches form in sheltered enviornments such as bays. When the swash is stronger than the backwash, deposition occurs. Constructive waves pick up and carry sediment to form beaches.
Swash aligned beaches:
- formed when waves approach parallel to the coastline.
- swash and backwash move sediment up and down the beach.
- this creates a wide beach with an even profile along the shoreline.
- during storm conditions ridges of sediment (berms) can form along the beach.
Drift aligned beaches:
- formed when waves approach the coastline at an angle.
- the swash moves sediment up the beach at the same angle.
- the backwash moves it back down the beach under the force of gravity.
- sediment is moved along the beach by longshore drift.
- creates a beach with an un even profile.
- longshore drift is slowed down by adding groynes. These trap the sediment to help preserve the beach).
Formation of a Spit
A spit is an accumulation of sand with one end attacthed to the land and the other reaching out across and estuary or onto the sea. They are features of coastal deposition.
They are formed where large amounts of sediment are transported by longshore drift and where the coastline suddenly changes direction to leave a sheltered, shallow area of water.
Due to an increase in friction more deposition can occur in the water sheltered by the headland and the spit slowly builds up to sea level and extends in length.
Formation of a Bar
- Lagoon - the area of water dammed by the bar will eventually be filled by deposition.
- a BAR is formed as a spit which grows across a bay, joining up the two headlines.
Formation of a Tombolo
A Tombolo is where a spit joins the main land to an island and a tombolo is created.
The longest best known tombolo in Britain is Chesic Beach.
- Prevailing wind
- Longshore drift direction
- Change in shape of headland results in a spit
- Old island now joined to the main land by a spit.
Hard and Soft Engineering
There are two kinds of coastal management -
- Aims to stop coastal erosion and flooding by either creating a barrier or forcing the wave to break before it reaches the land.
- Building large concrete structures.
- Expensive and Not Natural needing constant maintenance
- Not sustainable
- Example - Sea wall and Groynes
- Works with natural processes to protect the beach
- Doesnt need constant maintanence
- Example - Beach nourishment or Managed retreat
Coastal Management Strategies
- Rip Rap - Layers of hard rock with the largest on top. When the waves hit the rock it spreads out weakening the backwash. Its easy to repair and fairly natural. Its expensive - £100 per metre.
- Sea Wall - Concrete wall at the back of the beach. Stops erosion by providing a barrier. It reduces erosion but results in it eroding at the base of sea wall. Expensive - £800 - £5,000 per square meter.
- Gabions - Wire baskets filled with rocks placed at bottom of cliffs. Blocks the wave eroding at bottom of cliff as it absorbs the rocks energy. Lasts 5 - 10 years. Needs replacing regulary as it cant work with strong waves. Cheap at £350 per meter.
- Revetment - Parrellel walls on the beach. Stops waves going past the beach onto cliffs. There is no erosion but need replacing after storms. Cheap - £100 per meter.
- Groynes - Built at 90 degrees. Made of timber or concrete. Stops longshore drift and keeps the beach in place building it up but the beaches down the coast dont get enough sand and are easily eroded. Expensive ar £200,000 each.
- Managed Retreat - Low lying land which is flooded naturally. The water floods until it reaches high land then is stopped. There is no cost to it but people arent happy as it destroys homes.
What is a coral reef?
A coral reef is reffered to as 'garden of the sea'. There is an extreme range of plant and animal life which develop in warm, shallow seas. They are formed by colonies of tiny animals called polyps. When the polyps die they leave behind a skeleton made up of calcium and carbonate which accumulates and forms coral reefs with living coral on the top surface.
They are under threat due to:
- Coastal development
- Climate change
75% of coral reefs are affected by human activity; new analysis released by the World Resources Insitute.
Coral reefs will die in 40 years if no protection is made.
How is the coastline managed in England and Wales?
DEFRA (the Department for Enviornment, Food and Rural Affair) is responsible for protecting the coastline from flooding and erosion.
It is not possible to protect all parts of the coastline because:
- its too expensive
- would change the whole coastal enviornment
DEFRA has decided:
- which parts of the coastline should be protected
- which methods should be used