2. Swanage
Decision Making Exercise

3. Where is Swanage?

4. Swanage
Beach narrows
Wide beach
Longshore drift from south to
north

5. Longshore Drift
Foreshore Pebbles and
sediment
moved onto
beach
Pebbles and
sediment
moved back
down the
beach
Pebbles and
sediment
moved onto
beach
Pebbles and
sediment
moved back
down the
beach
Pebbles and
sediment
moved onto
beach

6. Swanage
Longshore drift from south to
north
Sediment is moved from
south to north
Banjo Pier

7. Groynes
The groynes extend at right angles to the beach and act like arms to catch
sediment. These groynes are very old and run down.

8. The sea at work
The beach is hit by strong waves which have travelled across the Atlantic
Ocean. Groynes are designed to trap sand and sediment and to
encourage deposition.

9. Powerful waves

10. Swanage Banjo Pier
Makes people’s homes
safer and insurance
premiums lower.
Built at right angles to the
beach
Contains an outflow for the
River Swan.
Reduces the risk of flooding
in the town by moving run-
off into the sea very quickly.

11. Beach south of the Pier
Beach is wide and sandy.
Deposition is taking
place.
The beach is hit by strong waves which have travelled across the Atlantic
Ocean.
Wide variety of tourist
services and attractions.

12. Beach South of the Pier facing
the NorthBeach is wide and sandy.
Deposition is taking
place.
Sand and pebbles are building up against the pier
Less sand and sediment
is carried past the pier.

13. Beach north of the pier
Sea wall to protect houses
and road from flooding and
erosion.
Old groynes which were to
trap sediment and sand.
Beach is narrower north of
the pier.
The pier is stopping as
much sand and sediment
getting to this part of the
beach.

14. Where the sea meets the cliff
Top layers of cliff are
permeable
Beach huts and other
tourist facilities are very
close to the edge of the
beach.

15. Cliff erosion
Top layers of cliff are
permeable
Lower layers of cliff are
impermeable
Rotational Landslips
Erosion and landslipping
has become worse since
the Banjo Pier was built

16. Landslip Hazard
Erosion and landslipping has become
worse since the Banjo Pier was built
Landslips are
threatening
human
activities such
as this path.
The Banjo Pier is blocking the sand and sediment
that used to be deposited here.

17. Landslip Hazard
Permeable
layers at top of
cliff.
Impermeable
layers at bottom
of cliff.
Most recent landslip blocking the
path.

18. Managing the Landslips
Steel piling is inserted into
lower cliff.
Pipes put into cliff to drain
off water.
Concrete reinforcements to
help stabilise the cliff (stop
it from slipping).

19. Groynes at work

20. Beach north of the pier