Large waves hit rocks with lots of force. The energy in waves can break apart rocks. Over time waves make small cracks bigger. Eventually the wave causes the rock to chip off.

A plunging wave breaks with more energy than a significantly larger spilling wave. The wave can trap and compress the air under the lip, which creates the “crashing” sound associated with waves. With large waves, this crash can be felt by beachgoers on land. Offshore wind conditions can make plungers more likely.

Crashing waves can break solid rock and throw the pieces back toward the shore. Cliffs made of hard rock, such as granite, erode slowly. Cliffs made of soft rock, such as shale, erode more quickly. During storms, large, high-energy waves can erode the shore very quickly.

Fudai

Saemangeum (pronounced “say-man-gum”) is a 40 100 ha ongoing “reclamation” project in South Korea, entailing damming the estuaries of the Mangyeung and Dongjin Rivers, replacing vast bird-rich tidal-flats and sea-shallows with land and a huge freshwater reservoir, both still lacking any clear end use.

Seawalls can also lead to a loss of habitat on the beaches above higher water level, which can adversely affect a range of animals including invertebrates, turtles and shore birds. The type of structure built can influence the nature of marine and estuarine communities that develop on it.

Environmentally friendly erosion protection: seawalls (Fish Friendly Marine Infrastructure) Seawalls are commonly used to armour estuarine and coastal foreshores against erosion and to prevent the inundation of low-lying areas. This habitat loss can greatly impact upon fish and other marine life.

Floridians now have the chance to build environmentally friendly seawalls to enhance and soften our shorelines. Additionally, living seawalls manage wave energy so well that they require less material in their construction which is both good for the environment, and a less expensive solution for waterfront land owners.

Seawalls are expensive to design and construct. Seawalls interrupt natural sediment transport: Such as by stopping sediment from cliff erosion nourishing a beach, reflecting waves, or blocking movement of sediment alongshore. In this way, seawalls can increase erosion in surrounding areas.

A seawall provides a high degree of protection against coastal flooding and erosion. It fixes the boundary between the sea and land which can be beneficial if important infrastructure or buildings are located on the shoreline. Seawalls have a lower space requirement than other coastal defences such as dikes.

Hard engineering – sea walls, groynes, rock armour Hard engineering involves the building of entirely ARTIFICIAL structures using various materials such as rock, concrete and steel to reduce or stop the impact of coastal processes.

Sea Walls. These are the most obvious defensive methods. Sea walls are exactly that. Giant walls that span entire coastlines and attempt to reduce erosion and prevent flooding in the process.

You can probably think of many more reasons why coasts need to be protected. It is not possible to completely stop the power of natural forces from changing the coast. People try to protect some areas from erosion but this can have negative impacts as well as positive. The way the coast is managed can cause conflict.

Contents

• 3.1 Groynes.
• 3.2 Sea wall.
• 3.3 Revetments.
• 3.4 Breakwaters.
• 3.5 Gabions.

Sea wall