Advantages And Disadvantages Of Coastal Management

Are these strategies used in the coastline within Randwick city council boundaries and how effective are these management strategies?

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,

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

Sand nourishment refers to the replacement of sediment on beaches that has previously been lost, generally through natural processes. It is a commonly used practice in coastal management. Collaroy Beach uses sand nourishment as longshore drift has moved sand, which cannot be replenished as there are rock formations preventing sediment from refilling the beach. Collaroy Beach also does not have an established dune system, and cannot trap sand.

The Year 10 geography field trip was an insightful experience into the workings and functioning of metropolitan coastlines here in South Australia. The day consisted of visiting various beaches in Adelaide that were influenced by some form of hard or soft engineering techniques that changed the natural processes of the beaches. What was evident from this trip was how much these beaches have been changed to an extent where it is unlikely that they will ever go back to the way they were prior to human settlement.

Newhaven is well known for having a harbour arm built in 1890 and is 700m wide. The harbour stops any sediment from moving further and protects river Estuary from any longshore drift damage. The harbour also allows boats to preserve their acess to the river Ouse. Longshore drift occurs when waves approach the coastline at an angle of 45°. The sediment is then carried up the beach (Swash) at the same angle. The wave then moves back down (Backwash) at 90°. This results in a zigzag motion along the beach which transports and deposits sediment along the coastline. The formation of the cliff depends on erosion or weathering, the three main types of marine erosion include abrasion, attrition and hydraulic action. The two significant types of weathering in coastal areas are corrosion and wetting/drying. As a result of longshore drift, the sediments and shingle is transported from the sea and tends to be depostited on the oppersite side of the harbour arm. The beach is used mainly by locals of pleasure and lesuire. predict that the cliff will be

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

Thusly, chronic coastal erosion is beginning to become a huge problem along a majority of the U.S. coast, exclusively on Hawaiian Islands (Romine and Fletcher, 2013). “Kona” storms, with southerly winds and waves, can trigger momentary erosional events to south and west exposed beaches on the coast (Romine and Fletcher, 2013). Erosional events are undoubtedly proving to control most shoreline changes throughout the state Hawaii, let alone Kauai. Romine and Fletcher’s studies of historical shorelines on major Hawaiian Islands, including Kauai, have proven that shoreline changes on the islands are displaying a dominant trend of being caused by erosion (2013) on the leeward and windward sides of the

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

* The sand dunes on the beaches. This area is affected by wind erosion as well as the tides if adequate vegetative cover is not present. The main type of erosion, from the sea, takes the sand from the sand dunes as well as the rest of the beach in a rip. The sand is then pulled out to sea where it forms a sand bar. On calmer days, the sand is brought back to the beach.

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

be due to the fact that on either side of the headland are two bays or

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

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

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