Dorset coastline - Hengistbury Head

Question 1

Why is Hengistbury Head a Site of Scientific Interest?

Answer 1

Because it supports a wide variety of wildlife and rare plant species

Question 2

Why is Hengistbury Head a Site of significant archaeological importance?

Answer 2

Contains the remnants of an Iron Age settlement with ramp and ditch defences called Double Dykes

Question 3

Why has the rate of erosion increased since the 1850’s?

Answer 3

Hengistbury Head mining company removed a great deal of hard iron ore boulders called doggers from the beach which had formed a natural defence against the sea

Question 4

An example of soft engineering

Answer 4

Beach replenishment - replacing cliff material/shingle instead of sand as less prone to longshore drift
Managed retreat - allowing erosion to occur but areas considered to be of low value

Question 5

Disadvantages of beach replenishment

Answer 5

Repeated every 10 years
Doesn’t replicate a beaches sandy nature
Causes disrupution

Question 6

How does beach replenishment work

Answer 6

50cm diameter pipeline from beach to dredger

Dredger pumps up sand from the seabed which is then transported to the beach

Question 7

Advantages and disadvantages of long groynes

Answer 7

cliff has gradually become more vegetated and sand dunes are accumulating in the area
groyne has reduced beach sediment which means more erosion to cliff faces

Question 8

What is a gabion revetment

Answer 8

A cage of rocks forming a defence against wave force

Question 9

How was Old Harry/Old Harry’s wife formed?

Answer 9

Cracks in the headland opened up to form a cave
Over time the cave eroded through creating an arch
The arch would have eventually collapsed resulting in a stack due to abrasion, hydraulic action, freeze thaw, chemical and biological weathering - Old Harry
The stack would continue to erode by weathering leaving Old Harry’s wife