Why is it essential to prevent coastal erosion?
Anyone who lives or owns a business on the coast is at risk because decay can eventually cause the ground beneath your home to collapse.Coast erosion is gradually destroying it.
Beach erosion can pose severe dangers to the environment and human health. If it is not controlled or prevented, it can lead to:
- Property and lives are at risk
- Losing your home and business
- Financial loss
- Eorosion can cause water damage to property and documents.
- Eorosion-related issues can cause costly repairs
- Trade sector losses, particularly in fisheries
- Water can pool around your foundation due to erosion
How to prevent coastal Erosion
The force of waves can cause erosion on the coast. It is the gradual wearing down of beaches, dunes, and gullies. Officials can decrease erosion risk by implementing policy and strategic planning to increase awareness and take action.
There are many ways to reduce or protect the economic effects of coastal erosion. We can use those methods to minimize erosion risks, such as nourishment (by adding sand to the beach to act as an erosion buffer) or shoreline “hardening.” dikes, and similar structures may be used to help. These impacts can be avoided by strategically placing infrastructure and buildings in coastal communities and cities.
There are following main two types of solutions to prevent coastal erosion. i.e., Hard structural and soft structural options.
1) Hard structural options
Rigid structural options are used onshore or offshore to avoid erosion. These are engineering options and take time to build. These are the following;
i.Groyne /breakwaters/Jetty
Groynes are rigid hydraulic structures perpendicularly built to an ocean shoreline or river. It interrupts the flow of water and limits the movement of sediments. It is made from wood, concrete, or steel.
A breakwater is a structure that protects a beach or harbor from the forces of the waves. There are three main types of breakwater: rubble pile, vertical wall and floating wall.
These breakwaters attach to the mainland and deflect waves. These breakwaters trap the sand pushed into the rock structure by wind and waves.
A Jetty is a long, narrow structure that protects the coast from waves and currents. It is composed of concrete or wooden poles embedded in the water to preserve a navigation channel and allow ships to dock.
Downsides:
- Coast erosion occurs when sand accumulates in the rock structure.
- Building a breakwater can be costly and time-consuming.
- The drive along the coast can be disturbed by a jetty and lead to downward erosion.
- The coastal transport of sediments, along with ecological processes, will be affected by the jetty.
ii.Sea walls
Seawalls are a type of coast defence built where the sea and associated coastal processes directly impact the landforms alongside its coastline.They can trap and hold the sand and protect plateau property.
Seawalls are made from concrete, stones and sheet piles. They are constructed side-by-side along the corridor between the beach, mainland and dune. They can withstand large amounts of wave energy.
Downsides:
The coastal environment can be affected by artificial structures like piers and dams.
- Seawalls can often disrupt natural processes like habitat migration and cause intertidal ecosystems to shrink.
- It is common for the beach to disappear before a seawall. Often, after a few decades, it will be necessary to reinforce the seawall base with a layer of crushed stone.
- Seawalls are expensive to construct and require permits. For years, exposure to salt water, wind, and waves can lead to cracking, rubbing, and deterioration.
2. Soft structural options
Soft armor options prevents erosion by replicating and strengthening nature’s coastline.
i.Beach nourishment
Beach nourishment (or beach backfilling) is adding large quantities of sand and sediment to beaches to reduce erosion and increase beach width.
The waves that break off a fed beach naturally move away from sediments, weakening their energy and causing them to reach the shore.
Nature-based protection measures, or “green infrastructure,” are not structural projects. They enhance the natural ability of coastal areas to absorb and dissipate energy from storms without interfering with coastal biological processes.
This “soft structural” response allows sand to move and transfer with currents and waves.
The Corps was authorized in 1956 to conduct nourishment activities for coast protection. The Corps has been involved in nourishment projects along approximately 350 miles of coastline, mainly along the Atlantic and Gulf coasts.
Downsides:
Beach erosion is not solved by nutrition. The waves will continue “chewing” the sand and, eventually, eroding.
- The new sand may have a different grain size and chemical composition than natural sand. It can affect the environment on which beach animals depend
- Feeding beaches can also be costly in dealing with/combating coast erosion. Some communities bring in large quantities of sand often, only for it to wash into the ocean in the next season’s storms.
- Pismo clam is an example of a long-lived species that does not reproduce often and can take years to recover.
ii.Reconstruction and dune building
“sea level rise is a slow-moving tsunami threatening coastal development.”
Dr. Mick O’Leary
The best line of defense against erosion is the dunes. Coastal dunes protect against coastal hazards like wind erosion, wave overshooting, and tidal flooding during severe storms.
Because the roots of the plants can bind sediment and allow wind baffles to build up residue, vegetation is essential for dunes’ survival.
Downsides:
- Storms can cause the sand to be eroded by the waves. It creates a scar and forces the sand towards the sea.
- If the beach is not restored to its original condition, and if too much of the sand is lost to the sea, and there is not enough sand entering the system to replace it, then the coast will retreat toward the land and could endanger coastal property.
iii.Coastal revegetation
Coastal plants are a great source of sand for beach replenishment during periods of erosion.
The coastal native flora plays an essential part in stabilizing the surface and providing a habitat for wildlife.
Because of its specificity, the revegetation site can thrive in low-energy environments but not high-energy open ocean environments.
Coastal vegetation includes mangroves, salt marshes, macroalgae, beaches, and dunes.
Downsides;
- Broken trees can also cause floating debris, damaging nearby buildings and injuring people.
- The vegetation covering provided little protection for the coast if the wave height was less than 3 meters.
- Fisheries activities will be affected by the establishment of a biofield within a new region.
- Establishing a solid biological barrier against rising sea waves can be challenging. It could lead to an overall negative response.
Last words:
Experts agree that nourishment is the best way to prevent coastal erosion. However, both hard and soft solutions can have adverse consequences.
Although soft options can be effective, raising awareness is the biggest problem. They take time to produce results.
The long-term effectiveness of coastal structures could be more satisfactory. It is also an expensive option.
However, the overall guideline is to balance the benefits and costs of all options.
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