Degradation of breakwaters
Introduction
Coastal erosion is the loss or displacement of land, or the long-term removal of sediments and rocks along the coast due to the action of waves, currents, tides, wind-driven water, water-borne ice, or other storm surge impacts.[1][2][3] Coastal retreat toward land can be measured and described on a time scale of tides, seasons, and other short-term cyclical processes. term.[4] Coastal erosion can be caused by hydraulic action, abrasion, impact and corrosion by wind and water, and other forces, natural or unnatural.
On non-rocky coasts, coastal erosion results in rock formations in areas where the coastline contains rock layers or fracture zones with varying resistance to erosion. Softer areas erode much faster than harder ones, usually resulting in landforms such as tunnels, bridges, natural "Column (architecture)" columns, and pillars. Over time, the coastline generally levels out. Softer areas are filled with sediment eroded from hard areas and rock formations are eroded.[5] Additionally, abrasion commonly occurs in areas where there are high winds, loose sand, and soft rocks. The blowing of millions of sharp sand grains creates a sandblasting effect. This effect helps to erode, smooth and polish rocks.
According to the IPCC, sea level rise caused by climate change will increase coastal erosion worldwide, significantly changing low-lying coastlines and coastal zones.[6].
Coastal processes
hydraulic action
Hydraulic action occurs when waves hitting a cliff compress air in the cracks in the cliff. This puts pressure on the surrounding rock and can progressively splinter and remove pieces. Over time, cracks can grow, sometimes forming a cave. The chips fall to the seabed, where they are subjected to the action of the waves.
Wear
Weathering occurs when waves cause loose pieces of rock debris (scree "Talus (geology)") to collide with each other, crushing and splintering each other, becoming progressively smaller, smoother, and rounder. The scree also collides with the base of the cliff, chipping small pieces of rock from the cliff or has a corrosion (abrasion) effect, similar to sandpaper.