What is the role of coastal defences in protecting settlements?

Coastal defences protect settlements by reducing the impact of erosion, flooding, and storm surges on coastal areas.

Coastal defences are crucial in safeguarding communities situated near the sea. These defences come in various forms, such as sea walls, groynes, and breakwaters, each designed to address specific coastal challenges. Sea walls, for instance, are solid structures built parallel to the shore to absorb and reflect the energy of incoming waves, thereby preventing the sea from encroaching onto the land. This helps to protect homes, businesses, and infrastructure from being damaged or destroyed by the relentless force of the ocean.

Groynes are another type of coastal defence, typically constructed from wood, stone, or concrete, and extend perpendicularly from the shore into the sea. Their primary function is to interrupt the process of longshore drift, which is the movement of sediment along the coast by wave action. By trapping sand and shingle on one side, groynes help to build up the beach, which acts as a natural barrier against wave energy. This not only protects the coastline but also maintains the beach for recreational use and tourism, which can be vital for local economies.

Breakwaters are offshore structures designed to break the force of incoming waves before they reach the shore. By creating calmer waters behind them, breakwaters reduce the rate of coastal erosion and provide a safe harbour for boats and ships. This is particularly important for fishing communities and ports, where the economy relies heavily on maritime activities.

In addition to these hard engineering solutions, there are also soft engineering approaches like beach nourishment and managed retreat. Beach nourishment involves adding sand or shingle to a beach to replace material lost through erosion, while managed retreat allows certain areas to flood naturally, creating new habitats and reducing pressure on other parts of the coast.

Overall, coastal defences play a vital role in protecting settlements from the dynamic and often destructive forces of the sea, ensuring the safety and sustainability of coastal communities.