Answer:
The are important as to protect the landscape and getting destroyed by the action of the sea waves.
Step-by-step explanation:
- Coastal management is the defense against flooding and erosion, as the coastal lands occupy about 15% of the earth's land area and 45% of the world population. With about 3/4 of the world population expected to rise in the coastal zones by the year 2025 coastal management is essential.
- Groins are walls that are perpendicular to the coastlines and often are made of concrete, rock, or wood. As the sand material filter and absorb the waves energy. They are cost-effective, but needs maintenance and don't protect the beaches against the storm.
- Revetments are upright blockages that are built parallel to the coast and are paced sat the back of the beach to protect the area. They allow the water to filter through the wave's energy. Most of them get eroded by the progressive surfs thus maintenance is necessary.
- The Gabions are boulders and rocks that are wired into a mesh and placed in areas that vulnerable to erosion. They need to be securely tied to the protect the structures.
- Sea walls are walls or frass or paper that are usually done to protect the settlement from flooding or erosion. And are 4 to 5 meters. They tend to reduce the most turbulence. They often cause the beaches to dissipate and their presence also alters the landscape they tend to protect.