Coastal erosion is the wearing away of land and the removal of beach or dune sediments by wave action, tidal currents, wave currents, or drainage.Erosion is also sporadic. All areas are not eroded at the same rate during a storm. Some areas have severe erosion during an event. Other areas have mush less erosion.
What could possibly cause it?
It can be caused by natural and human forces:-
Natural
- the rising sea levels globally
- constant waves that generated by storms, wind, or fast moving motor craft, cause coastal erosion, which may take the form of long-term losses of sediment and rocks, or merely the temporary redistribution of coastal sediments; erosion in one location may result in accretion nearby.
- It may be caused by hydraulic action, abrasion, impact and corrosion.
Human forces
- Removing sand and other materials from beaches and dunes for construction purposes causes erosion and the loss of beaches and coastal lands, destroying the natural heritage of the coast and reducing the vibrancy of the tourism industry.
- Building too close to the beach interferes with the natural sand movement and may impede beach recovery after a serious storm or hurricane.
- Badly planned sea defences may cause the loss of the beach, and of neighbouring beaches.
- Pollution from human activities on the land may damage coral reefs and seagrass beds; these biological systems protect, and provide sand to the beaches.
- Removing vegetation from coastal areas destabilises beaches; and clearing sites inland results in increased soil and dirt particles being washed offshore and smothering coral reef systems.
Sand and Coral Mining, and Maintenance Dredging
The mining of sand and gravel along beaches and in the surf-zone will cause erosion by depleting the shore of its sediment resources.
Coral mining and other means of spoiling the protective coral reefs, for example, fishing by the use of explosives or pollution, will also cause coastal erosion and beach degradation. The protective function of the reef disappears and the production of carbonate sand stops
Maintenance dredging of tidal inlets, harbours, and navigation channels, sand is very often lost from the littoral budget because the sand, unless otherwise regulated by legislation, is normally dumped at deep water.
What can we do about it?
The state of the beach affects everyone’s lives. So there's large involvements from the communt.There are no simple or universal solutions to shoreline erosion, since there are often several factors, both human and natural, contributing to the problem at a particular beach.
Each beach behaves differently, so it is advisable to find out as much information as possible about a particular beach before taking any corrective action.
Though there is little we can do to stop them, there are ways we can help to slow down the rate of erosion:
- Resorting to ‘hard’ engineering structures such as seawalls, revetments and bulkheads, only when there is a need to protect beachfront property from wave action. Such structures, even with careful design, result in the loss or narrowing of the beach over time.
-
Considering all other beach enhancement measures such as offshore breakwaters, groynes and beach nourishment (placing sand from the offshore zone or from an inland source on the beach) at a particular site.
- Planning new development so that it is a ‘safe’ distance behind the beach will reduce the need for expensive sea defence measures in the future.
-
Revegetating beach areas beyond the reach of storm waves, and sand dunes, with native vegetation, e.g. grasses, vines and salt resistant, deep-rooting trees, such as sea-grape