Topic 4, EQ3 Part 1 Flashcards
How does coastal management affect coastlines down drift?
Coastal management can have a detrimental effect to coastlines further along the coast. Using Groynes as an example, the role of coastal groynes is too trap sediment from longshore drift (LSD) and to create a beach, this beach will dissipate wave energy. Since material and sediment has now been trapped it can no longer move along the coast. Areas further along are starved of material and as a result they suffer worse from erosion because there is no sediment (in the form of beaches) to dissipate their wave energy. Other forms of coastal engineering also have the sole purpose of reflecting wave energy and this can lead to other areas of coastlines being attacked by waves with much greater energy.
How does dredging affect the coastline?
Dredging can have a dangerous affect on coastlines if not administered or planned correctly. An example would be Hallsands in Devon in 1917, the extreme unplanned dredging of the coastline lead to the flooding and later evacuation of the village in 1917. The removal of large quantities of sediment from the coastline alters the sea level and can cause a change in currents. If a previously shallow area of coast becomes much deeper it is more likely to suffer from destructive more powerful waves which can damage the coastline. Dredging can also lead to parts of the beach collapsing into the dredged area and leaving the coast unprotected and at risk of coastal erosion. Dredging can also benefit the coastline, the increased material placed upon the beach can greatly reduce erosion to the coast, the material will dissipate the wave energy.
How does industry affect the coastline?
Industry can restrict the natural evolution of a coastline. When ports and harbours are built along the coast they are heavily protected and allow for no erosion whatsoever. Other companies that use the coastline for industrial purposes are oil companies, most notably Esso who have an oil refinery in Bacton, Norfolk. This movement of oil and petroleum from the North Sea oil rigs to various destinations around the UK is vital to the economy, this usually means the “Hold the Line” policy instated, the defences around these areas of coastlines allow for very little erosion and ensure this area of high valued coastline remains safe.
How does development (jobs/housing/building) affect the coastline?
20 million Britons live along the coast, all of which need protection. With the price of property increasing in London and cities many people (especially retirees who move to locations such as Blackpool, Bournemouth, Eastbourne and Scarborough) and companies, including JP Morgan, relocate to the coast. This increased building and increasing of the population means that more areas of coastline have to be protected, in Holderness alone the village has been affected by flooding 29 times in the last 1000 years. Councila are also now under more pressure to protect the areas of coast which are inhabited or risk paying a lot in compensation. Along the coast many plants, the roots of which stabilised the coast, have been removed to make way for promenades, increasing the risk of movement on the cliffs by coastal locations.
How is Swanage coastline affected by physical processes?
-Durlston Bay (at the end of the concordant coastline between Durlston Bay and Kimmeridge) consists of hard rock and since it is unprotected there are commonly mass movements along the coast and sone coastal erosion. At the very end of Durlston Bay coastal cave have been formed as a result of the coastal erosion.
-Swanage Bay South- This bay of soft rock along a discordant coastline suffers from coastal erosion, it consists of soft clays and sands but the emplacement of twenty Groynes means that coastal erosion has been reduced in the last century.
Swanage Bay North to Ballard’s Point- This headland consists of hard chalk but the emplacement of groynes further south has left this area of coastline starved of sediment and as a result it erodes.
How is the Swanage coastline being affected by human processes?
Durlston Bay- This headland contains hard limestone and also contains internationally important fossils and as a result has been granted the status of World Heritage Coastline, it is also a part of the Dorset Jurassic Coastline and attracts large amounts of tourists, although it is visited frequently conservationists and archaeologists work hard to protect this area of coastline and as a result it has a few coastal defences.
Swanage Bay South- A large residential and employment centre in South Dorset. It is also a very large tourist attraction (over 1 million visitors annually) because of its wide sandy beach. Tourism is vital to the local economy and the town must be kept safe, including houses and infrastructure, as a result groynes are emplaced around Swanage Bay South.
Swanage Bay North to Ballard’s Point- Again part of the World Heritage Coast but largely unprotected leading to coastal erosion of the limesotne cliffs.
