Environmental Engineering Reference
In-Depth Information
Fig. 2.7
Cleeland Bight on Phillip Island, Australia, showing the northward drift of sand
towards Newhaven. When dunes were spilling on to the shore the beach was built upward and
outward, but after the dunes were stabilised in the 1980s by planting marram grass this supply
was reduced, and beach erosion ensued. © Geostudies
establishment of a vegetation cover on formerly drifting dunes, or the extinction
of the dunes that had been drifting to the coast. On Phillip Island, Australia, partial
stabilisation of dunes that had been spilling eastward across the Woolamai isthmus
to renourish the beach in Cleeland Bight (Fig.
2.7
) was followed by beach erosion
(Fig.
2.8
).
On Balneario Camboriu Beach in southern Brazil intensive urbanization of the
coastal zone since the 1960s has resulted in the building of a sea wall, a road and
several tall buildings. This process has reduced the amount of sediment exchange
between the beach and dune and resulted in erosion during storms and a reduction
in beach width (Temme et al.
1997
). To minimise the loss of beach area 50,000 m
3
of sand was dredged from the sea floor and placed on an 800 m stretch of the
beach in 2002 (Pezzuto et al.
2006
). Periodic beach replenishment is required to
widen the dry-beach and add height to the berm (Finkl and Walker
2004
).
