Environmental Engineering Reference
In-Depth Information
Fig. 2.15
Sequence where a beach fed with sediment from a receding cliff which is stabilised
by building a basal sea wall. Waves reflected from the sea wall then withdraw sediment from the
beach, which is lowered by reflection scour. © Geostudies
and gun emplacements, and massive sea walls were then constructed. These
resulted in reflection scour, eroding the remaining beach, which is now completely
submerged at high tide in St Ouen's Bay, Jersey (Fig.
2.18
).
Calcareous beaches on the coast of Cornwall have been depleted by the extrac-
tion of shell sand and gravel for agricultural use as lime on farmland. Such
extraction has traditionally been on a small scale (50-100 t/year) from several
beaches, notably at Bude, where Summerleaze Beach has been depleted. Again,
