Question 21 of 21: Question 7, Part 3: Shoreline Protection Methods

Question 7, Part 3: Shoreline Protection Methods (4 marks)

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

Hard engineering – seawalls / groins / breakwaters. Rigid concrete or rock structures are built directly on the shoreline (seawalls, parallel to shore) or projecting into the surf zone (groins, perpendicular to shore; breakwaters, offshore) to physically absorb or deflect incoming wave energy and trap longshore-drifting sand; effective locally but often starves down-drift beaches of sediment, causing erosion to migrate elsewhere along the coast.

Soft engineering – beach nourishment (and dune/vegetation stabilization). Sand dredged or trucked in from elsewhere is periodically added to a beach to replace what longshore drift and storms remove, artificially widening the buffer between waves and infrastructure; often paired with planting dune-stabilizing vegetation (e.g. marram grass) to trap wind-blown sand and hold the beach/dune system in place. This approach works WITH natural sediment transport rather than blocking it, but requires ongoing (and costly) re-nourishment.