4.a. Human activity intentionally causes change within coastal landscape systems Flashcards
How does human activity cause change in coastal landscapes
- activities change transfers of energy and sediment
- human activity will always cause change in coastal landscapes
- humans deliberately change coastal landscape systems, to attempt to protect them from natural processes
What is hard engineering
the controlled disruption of natural processes by using man made structures e.g. sea walls
What is soft engineering
the deployment of natural, sustainable processes to protect the environment from erosion, flooding etc
Case study- Sandbanks, Dorset- where is it
The Sandbanks Peninsula separates Poole Harbour from Poole Bay. It is heavily managed and the strategies for this come fromthe Two Bays Shoreline Management Plan
What is the Two Bays Shoreline Management Plan
- a collectively designed and updated by the Poole Harbour commission, Poole Borough Council and the Environment Agency
- it is based on the movement of sediment withn the sediment cell covering Poole Bay and Christchurch Bay
Why does the Sandbanks peninsula need management
- it has a large number of high value commercial properties built on it e.g. Havan Hotel, which provides employment opportunities
- residential properties are in high demand and command premium prices. Luxury apartments and large detached houses (up to £10m)
- the beach is a major tourist attraction- it has a Blue Flag aware for water quality
- it provides protection and shelter from waves for Poole Harbour- popular for water sports
- at the end of the Peninsula is the entrance to the Poole Harbour, used by cross channel ferries as well as commercial ships. Longshore drift could cause the harbour entranve to become shallow
How have rock groynes been used to manage the coastal landscape
- constructed to minimize the movement of sediment along longshore drift and maintain a deep and wide beach
- stop sediment entering the harbour entrance, keeping it free for shipping
- groynes absorb wave energy- reducing erosion rates
- without groynes, erosion rates coule be 1.6m a year
How has beach recharge been used to manage the coastal landscape
- used to conserve the beach
- sand is dredged from offshore and sprayed onto the beach by processes called ‘rainbowing’
- adds to the size of the beach and costs about £20/m³
How has dredging sediment been used to manage the coastal landscape
- dredging sediment from Poole Harbour and dumping it offshore has lead to the natural maintenance of the beach
- natural currents transport the sediment onshore and it only costs £3/m³
- over 3.5 million m³ of sediment has been added to Poole Bay beaches
