(iv) Self-closing flood barriers are flood barriers that use the hydrostatic pressure of the rising floodwater to activate and raise the barrier into position. No external power or intervention is required, making them ideal for unmanned locations, especially alongside rivers.
C. Coastal Management What is it? These are strategies that can be applied on the coast to help with defending against flooding. There are “hard engineering methods” and “soft engineering methods” . Hard Engineering Methods (i) Groynes is a rigid hydraulic structure built from an ocean shore or from a bank (in rivers) that interrupts water flow and limits the movement of sediment.
Benefits • Uses the floodwater itself to operate the barrier - no manual intervention required. • No storage required - the barriers recesses fully into the ground when not in use. • Fast action - with a fast flood the barrier will close within a minute. • Easy to test - the pit can be filled with water, which automatically lifts the barrier ready for inspection. • Unlimited lengths - from 1m to 1km or more. Uses The Self Closing Flood Barrier can be used to protect areas such as: • Underground garages • Riverside defences • Coastal defences
(ii) Seawalls is a form of coastal defense constructed where the sea, and associated coastal processes, affect directly upon the landforms of the coast.