Coastal Dune Systems Serve As A Natural Alternative For Hard Engineering Defence Methods

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

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,

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.

This investigation will be exploring whether the movement of pebbles, shingle, shells and other materials found on the beach have impacted on the shape and structure of Newhaven beach and Castlehead Cliff. One of the key processes this investigation will focus on is that of long shore drift caused by strong prevailing winds, prevailing wind is the direction from which the wind usually blows. Cliffs are made from mainly two materials, chalk which is at the bottom and sand and clay at the top. If cliffs are facing the direction of prevailing wind it may lead in high rates of cliff

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

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

This is not just an architectural design and the fashion, but because of the fact that the developers know that the land is being swallowed by the sea. More and more houses, hotels, shops and restaurants have decks and some piers that lead into and over the water. The Florida Department of Environmental Protection even has courses for those in construction to acknowledge the erosion and increase the proper design, construction and maintenance of erosion and sediment control. The beaches, whether sandy or rocky are the buffers that keep the sea at bay from the land behind enemy lines. They are nature’s way of saving all the people and their livelihoods from being swept away into the deep blue yonder. When waves crash into the beach it carries sediment with it and deposits such sediment. The alternative is that when a wave recedes back into the ocean it carries that sediment back to sea. This is usually done at an unequal rate, and leads to coastal erosion. In fact, coastal erosion is one of the reasons we have so many beautiful beaches around the world due to their unique shape. Long shore currents move water in a parallel direction of the shoreline, carrying the sand with it. But as we continue to build piers, docks, sea walls, and jetties

A healthy dune system contains a primary and secondary dune defined by the start of vegetation as you progress from the swash and berm. The vegetation helps stabilise the landform helping to protect it from erosion, it also helps the soil in the secondary dune to become more stable and erosion resistant. The decaying plant material creates humus which makes the soil more nutrient allowing greater plant diversity.

* 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.

walkways to prevent human interference. The main reason of dune stabilization is to slow down the speed of erosion. In 1974 the Cronulla beaches were at an all time low and

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)

Long Island is famous for its sandy ocean beaches. Between the barrier beach and the main coast is the Great South Bay. The beaches and dunes have very different characteristics. The sandy beach is the junction of land and ocean. The sandy beach consists of two zones, the swash zone and the drift line. The swash zone is the area of wet sand, caused by the incoming wave. The drift line is formed by the dead seaweed and other aquatic plants. Behind the sandy beach is the primary dune. The primary dune's main function is to absorb the force of the ocean and protect the great south bay and the island's main coast. In some cases secondary dunes form. These dunes are behind the primary dune and are therefor protected from the ocean. This provides the stability necessary for plant growth. Many time a maritime forests will form on secondary dunes.

Humans have adversely affected the South Port sand dunes particularly the biophysical processes occurring in the accretion cycle and on the flora and fauna in the biosphere. People, especially boot campers, are walking or running in the wrong areas causing cliff faces to gradually collapse. There are also people camping in areas that there should not be campers, council has had to remove tents and mattresses as a consequence. (Jock Conlon, 2017)

Barrier Island is a low edge of sand that is parallel to the mainland with a distance of 2 to 19 miles’ off the shoreline, 300 barrier islands border the shore of Cape Cod, Massachusetts, to Padre Island, Texas. The barrier island defends the coast from the full power of storm waves. In the central of the barrier island and the mainland is a peaceful lagoon or a bay. Mainly most of these barrier island are 0.6-3 miles wide and amid from 9-18 miles long. The highest structures example of barrier island are sand dunes with the height of 16-33 feet; however, in some places the dunes can reach the height of 100 feet. Few barrier islands are initiated as spits that were then detached from the inland by upsurge corrosion, rising of sea level resulting

Some amount of natural erosion is necessary to provide the sediment for beaches in estuaries and coastal bays. However, excessive erosion has occurred in the past due to development. Industrial and private development along the world’s coastlines has increased dramatically since the 1970s (Nepf). Developers and builders completed much of this construction without taking into account the effects of coastal erosion. New buildings were often placed too close to the existing shoreline so that