Assessment of the Movement of Material Along Deal's Beach

932 Words2 Pages

Assessment of the Movement of Material Along Deal's Beach

This was carried out at site 3 because there are groynes at site 3

which created an area within 2 groynes called a groyne box which I

could study in order to look at the movement of pebbles within a

confined area.

Diagram of a Groyne Box:

Sea Wall

[IMAGE]

1 2

3

4 5

[IMAGE]

[IMAGE]

Groyne 1

Groyne 2

Sea

The purpose of this aim is to see the effects of Longshore Drift over

a longer period of time.

Theory Work

Groynes are structures that extend finger like, perpendicularly from

the shore. Usually constructed in groups called groin fields, their

primary purpose is to trap and retain sand, nourishing the beach

compartments between them. Groynes initially interrupt the longshore

transport of littoral drift. They are most effective where longshore

transport is predominantly in one direction, and where their action

will not cause unacceptable erosion of the down drift shore. When a

well designed groin field fills to capacity with sand, longshore

transport continues at about the same rate as before the groins were

built, and a stable beach is maintained.

Groynes are suitable erosion control measures where a beach is

desirable, and they are compatible with most recreational activities.

The beach fed by the sand trapped between the groins acts as a buffer

between the incoming waves and the backshore and inland areas: the

waves break on the beach and expend most of their energy there. Filled

groins provide this protection during normal weather conditions but

offer only limited protection against storm-driven waves. Groynes can

be found a t Deal.

[IMAGE]

Seawalls are solid structures built parallel to the beach for two main

reasons. One reason for building seawalls is to protect homes on the

coastline from the destruction of large storms such as hurricanes or

from the large waves they can create. Another reason they may be

Open Document