Hard Engineering - New Brighton, Wirral
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Background
History
Coastal Defences
- New Brighton, is located on the North West tip of Wirral, on the coast facing the Irish Sea.
- Waves that reach here can have much power, as a strong fetch across the Irish Sea of approximately 200 km allows the water to build up energy.
- New Brighton is also located around a common low pressure system, which results in storm surges becoming a regular occurrence.
- As well as this, the town is only a few metres above sea level meaning coastal flooding is a persistent issue.
History
- New Brighton is considered an important tourist destination, with many holiday makers visiting over the years.
- Although the town has faced much decline over the past 30 years, many areas are beginning to be rejuvenated and new structures are being built.
- In recent years, New Brighton has had has had the opportunity to bring in new visitors to the area in the form of the 'Floral Pavilion', a theatre.
- As well as using New Brighton for economic reason (tourism), the town is also used for residential purposes, with an approximate population of 14,000 people.
- It is for these reasons that coastal management and protection is important.
Coastal Defences
- Several sea defences have been employed to try to protect New Brighton.
- Constructed in the 1930s, a large sea wall was built, 4 metres tall and along 2.3 kilometres of coastline, known as the King's Parade Sea Wall.
- The wall was built with a curved front designed to reduce the impact of the waves, to protect from coastal flooding and increase the walls lifespan. With the waves being reflected backwards, the rate at which the wall is worn away is reduced.
- When the wall was built it was very expensive and continues to need attention and maintenance.
- Behind King's Parade Sea Wall 100 metres of 'new land' has been produced, with beach that was once submerged under the sea now accessible as the sea wall stop waves from reaching it.
- This has also saved the cliffs from erosion, with no cliff collapses occuring for many years.
- This reclaimed land has been left undeveloped, as should the wall be breeched heavy flooding would cause devastation.
Soft Engineering - Thurstaston, Wirral
![Picture](/uploads/3/8/3/4/38346663/4497369.jpeg?311)
Background
Coastal Defences
- Thurstaston is located in the west of Wirral, close to the river Dee.
- Although Thurstaston has had very little development, in terms of tourism and residential development, the area is in fact a Site of Special Scientific Interest (SSSI) with plenty of plant, wildlife and interesting sandstone landforms.
- Due to little human contact here, many people consider it to be of little importance and coastal erosion has been allowed to occur.
- The cliffs here are susceptible to much erosion, even with constructive waves being most common here.
- The reason this area is vulnerable to coastal erosion is due to the rock type and composition. The cliffs are primarily comprised of sandstone and clay and are not very stable.
- As well as wave action at the base of the cliff, sub-aerial processes and mass movement is common.
- What defences they do have here, are mostly soft engineered.
Coastal Defences
- Most techniques used here are soft engineered due to their low cost, as the land here is considered by some as low value and not worth the money.
- One exception is the gabions placed at the base of the cliff, designed to prevent undercutting. However, these are ineffective as the cliffs continue to collapse.
- A positive outcome of the gabions, however, is the newly formed habitat for plants and wildlife, which in turn makes the gabions more attractive.
- A soft engineered defence used includes a drainage pipe fixed into the cliffs. These are designed to drain away the water that inflitrates through the cliff to stop them from becoming saturated and then lubricated.
- These have also proved to be ineffective with mass movement still occurring.
- One final defence technique here that may protect the cliffs in the future, is the development of a salt marsh which has naturally begun to build. This should potentially grow to a reasonable size and become a defence for this coastline in the future.