Coastal erosion is the removal of coastal material such as cliffs and marshes by sea waves or human activities causing seawater to encroach into the land. This is a huge problem because approximately 23% of the world population lives within 100 km distance of the coast. All these inhabitants are exposed to the risk of flooding and losing their property.
1800 km of the 4500 km of the English coast is at risk of erosion particularly the east coast. For hundreds of years, the North Sea has been eating up roads, fields and even villages of the East Yorkshire coast. More than 200 homes are expected to be devoured by the ocean before the end of the century!
The rate of erosion seems to have speeded up. Cliffs are eroding as much as 0.7m per year. The solution, therefore, needs to be found soon. It’s not possible to completely eliminate the danger of flooding but action can be taken to lessen the impact on the communities surrounding the sea.
Soft Structural Engineering
This approach includes making use of the natural processes and features to break wave impact. The methods are as follows:
Beach nourishment
Beach nourishment involves widening the beach area by adding sediment where it has been eroded.The sediment could be outsourced or it could be dredged offshore.The aim here is to achieve what natural beaches do by dissipating the wave impact. It also serves to restore the aesthetic value of beaches. This method, however, requires constant maintenance.
Revegetation
Coastal vegetation is instrumental in holding together sediment, stabilising beach slopes and reducing wave impact. Planting vegetation will, therefore, reduce coastal erosion. Establishing which type of vegetation grows in the given coast will give you an idea of which plants are suitable.
Dune reconstruction
Constitutes the building of sand fences, mesh matting in conjunction with vegetation which keep the sand dunes in place due to their root systems. Wind also plays an important role of depositing sand onto the sand dunes. During a storm, waves can draw sand onto the beach extending its surface so waves are easily dissipated.
Coastal realignment
This involves letting the sea make its way into a defence and trapping it in the land behind it. This creates a marshland which will eventually have vegetation that will prevent coastal erosion.
Cliff stabilisation
This is achieved through reducing the angle of the cliffs so that whenever it’s hit by a wave, not much is eroded away. A gentle slope does not experience as much erosion as a steep one. Cliffs can be stabilised through planting vegetation on it. This is especially done on soft unstable cliffs. Another method is by placing sand or pebbles at the bottom of the cliff.
References:
https://www.groundsure.com/news/the-importance-of-coastal-defence-to-prevent-flood-risk/
https://www.fao.org/docrep/010/ag127e/AG127E09.htm
