CASE STUDY: Human Coastal Change (Intentional): Sandbanks

Question 1

Name of harbour and what

Answer 1

Poole harbour is heavily managed

Question 2

Where are the management strategies employed?

Answer 2

On the sediment cell covering Poole bay and Christ church bay

Question 3

Why managed?

Answer 3

• Residential properties in high demand (housing prices v exoensive as well (large detached house = 10 million)
• Beach is major tourist attraction - blue flag beach
• peninsula absorbs the wave energy + sheltering the other side from erosive waves allwing for protection for water-sports, etc (sailing)
• peninsula acts as entrance to Poole harbour and is used by cross channel ferries + commercial ships. Without management, LSD beach sediment makes it shallow
• climate change and rising sea levels (0.6m in the next 100years) could cause flooding without management and could destroy properties. Without management it is estimated that 18 million of damage would occur over the next 20 years.

Question 4

How managed?

Answer 4

• rock groynes are installed to maintain deep wide beach. This minimises movement of sediment along beach by LSD. This beach will absorb wave energy and reduce rate of erosion. W/out rock groynes erosion rates - 1.6m/year
• beach recharge is also used to preserve beach. Sand dredged from offshore reserves sprayed onto beach so cross section increased. In total over 3.5 million m^3 of sediment added to the beach
• management working w nature - sand is dredged + deposited out to sea. over time constructive waves move this sand inward, building up the buffer of the beach naturally

Question 5

why is the management strategy working w nature so effective?

Answer 5

• works w natural systems + is much cheaper

- £3/m cubed vs £20/m cubed for beach recharge

Question 6

What have been the consequences of this coastal management?

Answer 6

• In Barton Cliffs (eastwards of Sandbanks) - was once a 100m promenade has now suffered severe wave action + thus erosion
• this is bc much of the sediment that was destined for this area from the LSD has been stopped by coastal management in Sandbanks, so cliffs have no buffer zone to protect from erosive waves