Environmental Engineering Reference
In-Depth Information
blocks (Fig.
4.16
), and to cover this with quartzite gravel brought by lorries from
an inland quarry at Woodford, 12 km away: the natural beach had included sedi-
ment originating from coastal outcrops of this formation. The renourished beach
was shaped as a terrace with a steep seaward slope. Two angled offshore break-
waters were then built to protect it from prevailing SW waves and storms, and a
terminal groyne (East Pier) to prevent it being lost by longshore drift to the east
(Fig.
4.17
). The gravelly fill consisted of well-rounded but poorly sorted pebbles
and cobbles, and initially had a pink colour from the earthy Triassic matrix. The
beach was hosed down by the local fire brigade in an attempt to get rid of the pink
stain, but it was more effectively removed by waves reworking the seaward slope,
and did not last long. The beach restoration was completed in 1995.
The use of coarse sediment as a basis for a renourished sandy beach was
also illustrated between Monte Circeo and Terracina, on the west coast of Italy.
Fig. 4.16
The sea wall at
Sidmouth in South Devon
was reinforced by dumping
stone blocks after the
bordering beach was depleted
by erosion. Shingle was then
added to restore the beach,
which now looks similar to
that at Seaford (Fig.
4.15
).
© Geostudies
Fig. 4.17
When the shingle
beach at Sidmouth in South
Devon had been renourished,
offshore breakwaters (
A
,
B
)
were built to protect it from
the prevailing SW waves and
groynes (
G
) were inserted to
retain it. © Geostudies
