Groynes are concrete or wooden walls or fences that are built out into the sea at right angles to the coast. They work to reduce longshore drift by trapping the sediment carried by waves. They trap the sand, which then builds up the level of the beach.
An example can be seen at Rosslare, Co. Wexford. How are groynes helping to build up this beach?
Why is the top of a sea wall curved, such as you can see here?
Sea Walls
Sea walls are built to break the power of the incoming waves. They are curved at the top to push the waves back out to sea.
An example can be seen at Bray, Co. Wicklow.
Why do you think the stones are put in cages rather than being built as a stone wall?
Gabions
Gabions are steel wire cages filled with stones. They are then stacked on top of each other where they act like a sea wall. They are used to slow down or prevent erosion by breaking the power of the waves.
An example can be seen at Lahinch, Co. Clare.
11.6 People and the Sea –
Managing Surface Processes Humans have put many measures in place to protect their coasts from the powerful processes of sea erosion. The following are methods used to defend our coasts against the sea.
