4.a. Human activity intentionally causes change within coastal landscape systems.

Question 1

management strategies in Sandbanks and their intentional impacts and effects on the landscapes

Answer 1

Beach nourishment-
-> used to maintain the same amount of sediment on the beach -> ‘hold the line approach’
-> widening the beach -> means wave energy will be dispersed -> reducing erosion -> meaning the sediment budget will not go into a deficit as quickly

They are also dredging sediment from the harbour -> and dumping it offshore -> then letting the natural currents transport it onshore -> this is cheaper -> £3 per m3 vs £20 for ‘rain-bowing’

Rock + wooden groynes-
-> prevent LSD -> so sediment will not enter the harbour
-> absorb wave energy -> reducing erosion -> Without -> erosion rates would be 1.6m per year

-> allows sediment to accumulate -> encouraging further deposition -> increasing the width of the beach-> in the future -> this could ‘advance the line’ -> as sediment continues to builds up

-> rock groynes become colonised by plants + life -> such as algae + crabs -> showing ecological benefits

• less erosion + transportation
• more deposition

Question 2

unintentional impacts

Answer 2

groynes starving sediment cells further up the coastline of sediment -> putting them in a deficit -> e.g. Hengistbury Head experiencing high rates of erosion -> making it vulnerable to mass movement

Question 3

reasons for these strategies

Answer 3

• beach is a major tourist attraction -> blue flag award
• a lot of high value commercial properties -> providing employment opportunities and money
• residential properties are in high demand -> 4th most expensive area to live in the world -> most houses worth over £10mil
• LSD can block the entrance to pool harbour -> must be cleared -> for commercial ships + ferries
• Harbour is also popular for water sports

without-
- erosion rates would be 1.6m per year
- sea levels predicted to rise by 0.6m in the next 100 years -> this could cut the peninsula off from the mainland -> resulting in £18 mil in damages to residential properties alone

Question 4

effects of these strategies

Answer 4

positive-
- tourist industry worth £440 mil per year -> bigger beaches promote tourism
- shoreline management plan (SMP) protects 3,110 residential and 110 commercial properties at risk of coastal erosion
- maintenance of pool harbour ensures commercial ships + ferries can still use the area -> allowing for income through trade + ferrying

negative-
- due to maintenance -> climate change is likely to have little impact
- groynes ensure that waves remain low energy -> reducing rates of erosion + the risk of floodings