Coastal Erosion

Soft engineering is working with nature by using natural materials or allowing nature to take back areas. some examples of this is beach nourishment is the process of dumping or pumping sand from elsewhere onto an eroding shoreline which is to create a new beach or to widen the existing beach,this technique is natural and makes the waves lose power travelling across it,However it dosen’t last very long and It does not stop erosion,it simply gives the erosional forces (usually waves) something else to erode for awhile,another type of soft engineering is managed retreat which is where Areas of the coast are allowed to erode and flood naturally,this makes the land become an marsh,slowing waves and reducing ersoion,however land is lost. Another type of coastal management is hard engineering involves building structures to protect the coast. Some examples of this is a sea wall,which is a wall set up to prevent the sea eroding an area of land,thishelps prevent flooding,however waves bounce off the wall and scour the beach removing

Seawalls are also strategies that Cronulla and Collaroy implement on their beaches. However, the seawalls in Collaroy are buried under the sand and are only visible after large-scale erosion events. Whereas Cronulla beach’s seawalls are visible and reduce the scenic

The prevailing wind that hits the coast is the main concern as it causes long-shore drift, which depletes sand levels at the south of Adelaide's coast. The way to combat this is by implementing groynes into a beach, which has been done at Glenelg and slightly north at the boat ramp. From an economical perspective, groynes are simply expensive to maintain. In the case of the ones along the coast, they are mainly made from large rocks, which means that they do gradually erode and collapse with time. A social impact of groynes would be that they are not pleasing to look at and ruin the recreational value of the beach. Like breakwaters, there are no immediate alternatives to groynes apart from removal. The removal of groynes would instigate more maintainable for the beaches. More work would need to be made in order to keep the sand evenly displaced across the

At Nudgee Beach, erosion was found to have occurred on the edges of the mangrove forest and along the mudflat shorelines. Erosion is typically influenced by natural factors and occurs when pieces of weathered rock or soil are moved – typically by wind and water – from one place to another. Shorelines with lots of sediment and sand are more inclined to be effected by erosional progression. Erosion may also be provoked and accelerated by human interference. For example, if the decision to clear trees and plants from an area is made, erosion is likely to occur as the root systems of plants work to hold the soil in place. If these root systems are removed and erosion does occur, environmental conditions – such as; landslides and flooding – are more likely to take place. Erosion may also cause other plants to tip over, have their underground roots exposed and damaged and contribute to the pollution of local waters; as a result of mud and soil runoff [26]. Erosion at Nudgee Beach was likely to have been influenced by natural factors; however, the development and extension of the Kedron Brook golfing course may contribute to the acceleration of erosional processes and further damage the mangrove

Natural disasters are considered harmful in terms of coastal management and can often cause years of work to be wiped out. It can take large amounts of sand from the beach and remove plant life. Collaroy Beach has been a victim of such natural disasters. A large storm back in 1945 caused Collaroy Beach to empty out a large percentage of its sand and damaged many structures. Collaroy Beach’s local council, Warringah Council, has taken action to prevent storm damage in the future. A revetment wall has been established on the sand dunes so waves do not cause as much damage to the dunes behind. Warringah has also purchased properties that were residential and cleared them, so that a storm will not damage as many structures.

Erosion is unfortuanately present at Cronulla beach, the local government have tried to tackle this problem with solution such as dune stabilization and rip rap

How effective are the coastal management strategies used at present in your local beach area?

The erosion of shorelines is a natural process that can have beneficial or adverse impacts on the creation and maintenance of habitats. Sands and gravels eroded from the shores of coastal bays maintain the beach as a natural barrier between the open water and coastal wetlands. Beaches move back and forth onshore, offshore and along shore with changing wave conditions. The finer-grained silts and clays derived from the erosion of shorelines are sorted and carried as far as the waters of wetlands or tidal flats, where benefits are derived from addition of the new material. However, excessively high sediment loads can smother submerged aquatic vegetation beds, cover shellfish beds and tidal flats, fill in riffle

The more coastal erosion there is, the higher the chance is for saltwater contaminating freshwater resources and the salt from the ocean can cause soil to be uninhabitable to plants (Again this can affect agriculture). Coastal erosion is not only an issue for water resources, it’s also a direct issue for the communities. The communities on islands lay very close to the coast and important infrastructures are one of them. Islands cannot get all of their resources from the local farmers, so they import it via plane or boat. The problem with that is the airports and ports are all on the coast. Coastal erosion has the power to ruin airport runways and docks of the harbors and ports; this means that eventually communities will be starved of basic necessities and there will be no way of getting in basic needs. Not only will airports be ruined, so will our tourism industry. Coastal erosion will eventually ruin the beaches that attract tourists. Island communities depend on the tourism industry because that industry brings in a lot of money every year. Without tourists, communities will struggle financially. Lastly, the ecosystem of the islands will suffer the

There are many different types of coasts that exist throughout the United States. The south shore of Long Island has a unique types of coast known as a barrier beach. Barrier beaches are long narrow land forms that are composed of sand and other lose sediments. These sediments are brought together by the actions of waves, currents and storm surges. Barrier beaches are subject to constant changes by the same forces. Sand is constantly eroded in one area an deposited in another. Barrier coasts are important for a number of reasons; they protect the mainland of Long Island from the open ocean and flooding during storms, for recreational use and the unique ecosystems which exist on barrier

There are 2 types of beaches. One is erosion dominant and the other is deposition

Wind and waves affect Glenelg as they set up a northward drift of sand along the coast and this type of sand movement is known as littoral drift. During coastal storms, huge quantities of sand are eroded and this does damage to near shore, beach and sand dune areas. Glenelg is not considered to be a stable as beach as many others are. Seagrass loss and seabed instability that affect Glenelg is that a third of seagrass meadows along the coasts of Glenelg has died since 1950 and poor water quality resulting from the stormwater runoff and effluent disposal has most likely been the initial cause. When there are gaps in the seagrass meadows the sand below the meadow edge can be eroded by the waves and this will in turn increase the rate of seagrass loss and make it difficult for plants to recolonise the seafloor, even though the water quality has been improved. Sea levels affect Glenelg as parts of Glenelg are being subsided as a result of climate change and a relative sea level rise of one to two millimetres per year has been recorded for Glenelg. “As a result of the loss of sand from the seabed, the level of the seabed has steadily become up to one metre deeper and the wave energy reaching our beaches has increased.” (Adelaide’s Living Beaches Strategies,

In New Jersey alone state, local and federal agencies have spent 1.2 billion dollars over the last thirty years to dump 120 million cubic yards of sand over the state’s coastline. This high price tag is in part due to the fact that the sand that is placed on the coastline quickly erodes and a new project must be undertaken. In fact, sand used to nourish beaches erodes at a rate that is often two to three times faster than natural sand.This creates a cycle in which beaches are constantly needing to be renourished and does nothing to actually prevent the process of erosion.

It has become common for sand dunes to be bulldozed to improve the views to the sea. However this destroys the natural protection of the coast. Human activities such as water transport also can cause problems for coastal areas. The dredging of navigation channels and the discharging of the material in deep water to enable larger ships to travel though water channels removes sediment from the coastal system leaving the area susceptible to erosion and will also interfere with longshore drift which will prevent the coastal beach landforms from being maintained such as the development of a spit. It is likely that a spit will be eroded and start to regress in conditions such as these.

Wave cut platforms are another feature of an erosional coastline. Along coastlines with cliff edges that sit about the shore these features are apparent they look like gently sloping areas of landnear the shore just above sea level. (Chambers, 2007) These benches and marine terraces are the product of wave action eroding the rock at the base of the cliff until the cliff cannot support itself on its new foundation and crumbles into the sea. Over time the collapsed land will have much of the smaller debris eroded away and much of the remaining rock or earth will be somewhat smoothed over to create a gentle slope to the water. (Chambers, 2007)