As the coastal management expert of Southerland Shire I have come up with the most appropriate way to manage this problem. Storm surges are effects of severe storm systems due to a rise in sea level, if a storm surge and a tide meet when reaching the coast line severe damage can occur; resulting in extreme flooding in coastal areas, leading to damaging buildings surrounding the coastline. To prevent this problem and minimize storm surges having such a large impact and causing severe damage to the coastline, rock revetments can be placed on South Cronulla beach (parallel to the beach and the coastline and in front of the dune system). Behind the rock revetments sand bags can also be placed, as sand bags absorb the water and they will act like a line of final defense when extreme waves are in action. Rock revetments are designed to reduce the impact on erosive power coming from the waves by absorbing the physically powerful forces approaching from storm surges and increases run-up and wave reflection. Rock revetments also encourage upper beach stability. The gaps between the rocks trap the water coming from waves allowing the flow of water to be slowed down, and minimising the effect of the soil or any structures on the beach to erode. The reason why I have recommended rock revetments as the best possible solution is because they do not have a large impact to the natural environment and do not damage the structures behind the beach or any structures surrounding the coastline. Rock revetments are required to have long-term security and are also not of a high maintenance; hence this coastal management structure will not be too costly for the council and the ratepayers of Southerland Shire. The rock revetments will be placed on a flat angle on the sand and parallel to the beach and the shoreline. Materials which will be used in the process of constructing rock revetments are rock types- commonly granite or limestone, concrete and vinyl sheet piling for shoreline...
...Sea Walls are an example of Happisburgh’s coastal defences. They reflect the energy of the waves back into the sea and work best at high tide. But as the wave backwashes; it erodes the base of the wall. This area weakens and could eventually collapse A sea wall will be necessary at a large beach, as the sea wall will come into actions during high tides and storm surges Cost= £2000-£5000 per metre
Timber Groynes are mainly used to act against long-shore drift. They do this by interrupting the sediment’s course with perpendicular dividers. They also can help to build up the beach as they encourage to backwash to flow parallel to the groyne, lengthening it Impermeable groynes do not allow any material to pass through them and this deprives parts of the beach of sediment. Permeable groynes allow some sediment to pass through them and build up down-drift sides Cost = £1000 per metre Found in Cromer, Overstrand, Trimingham and Sheringham
It should last for 100 years, but if it gets damaged it needs to be repaired every 20 years
Sea Walls are found in Sheringham, Cromer, Cart Gap and Mundesley
North Norfolk Coastal Defences Revision Guide Side 1
Rock armour absorbs the energy of the waves like revetments but use hard igneous and metamorphic rocks to last longer and resist erosion better. Rock is also used to build groynes known as Rip-Rap The wave hits the rocks and pass around them with less energy to erode the coastline. This means that...
...The Issue Coastalmanagement is the dealings surrounding the management of development along the coastline with sustainability- being able to meet the needs of future generalizations while capitalizing the use of desired areas of the coasts for residential and commercial purposes.
My written report on coastalmanagement will revolve around the main issue explored in our field trip which is the gradual erosion of the foredune on Collaroy beach, and its effects on stakeholders (incl. residents, developers, specialist groups). This report will also include the decision making processes considered by the management (both local and state), as well as the descriptions of their actions/strategies, and thus the results of their policies.
The LocationOur site of interest, Collaroy beach is located in the suburbs of Northern Sydney, in the state of New South Wales, Australia. Collaroy is part of the local government area of Warringah Council and part of the Northern Beaches region. Collaroy is well known for its excellent surf beach which joins with Narrabeen Beach in the north and Long Reef and Dee Why Beach in the south. Also in close proximity is the Dee Why Lagoon as well as the Long Reef Head.
Collaroy beach is the most highly capitalized shoreline in the Warringah local government area, featuring beachfront houses and apartments built on the edge of the sand including the famous Flight Deck...
...Gerald Tan (7) Secondary 3D 27 July 2010
Raffles Academy: Geography - Essay (Coastal Protection)
Q1. Examine the success of coastal protection measures in Singapore.
Singapore, as a small island nation, has been experiencing continued coastal erosion for the longest time ever. As such, some coastal protection measures have been undertaken to ensure that land-scarce Singapore does not lose anymore of its precious land, which it needs to combat the burgeoning population as well as for various industries for economical growth, not to mention for recreational activities that Singaporeans caught up in the rat race desperately need. In my essay today, I shall be examining the success of coastal protection measures in Singapore.
Let us now look at different areas of Singapore where coastal protection measures have been implemented and to what degree of success.
Firstly, on the island of Pulau Tekong, the largest of Singapore's outlying islands and used exclusively for army training, more than 1,000 mangrove trees on its north-eastern coastline are at risk of falling due to coastal erosion. Deputy director of National Parks' National Biodiversity Centre, Dr Lena Chan, has said that the erosion, with mud being scraped out, is due to movements of ships and strong waves in the area. The...
...recreational activities and minimising it will defeat the purpose of the Changi spit. Another possible costal protection for the Jetty side might be mangrove trees. The mangrove trees have prop roots or kneed roots that anchor the trees firmly. These roots also bind the loose soil, and protect it from erosion. However, the mangrove trees can be an eyesore to the people coming there and it also reduces accessibility. The last coastal protection will be the ripraps. Riprap works by absorbing and deflecting the energy of waves before they reach the defended structure. The gaps between the rocks trap and slow the flow of water, lessening its ability to erode soil or structures on the coast. Even though ripraps are the most feasible coastal measure for the Jetty side they are an eyesore and limit the accessibility for people visiting the Chamgi Spit. Now moving on to the end of spit. Even though the end of spit has a longer fetch, building a breakwater is not feasible since it obstructs the path of the boats. Hence, stabilising coastal dunes will be the only convenient coastal measure. The seaward side of the beach has pretty long fetch and thus we can build breakwaters. Breakwaters are relatively cheap as compared to sea walls and are easier to maintain. The breakwaters absorb the impact and effects of ocean waves, creating a calm, quiet waterway behind it thus reducing erosional rates. However, erosion will still occur...
The geographical processes that are occurring at the Terrigal beach area are:
* Erosion, which is effecting:
* The Skillion, mainly the headland and rock platform, which is part of a preserved area of land known as “the Haven” which also contains the rugby oval. The man type of erosion that affects this is from the sea.
* 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.
* Storm damage can affect coastal properties. This is especially made obvious when buildings are constructed on sand dunes. When the sand is taken, the result on the houses is catastrophic.
* Lagoons, which are formed where sand deposits to form a baymouth barrier at the entrance to a bay, either partially or fully, blocking it off. Here, either the lagoon can access the sea during high tide or it can be closed for the majority of time, only accessing the sea when a tidal inlet forms.
The main human activities that are impacting the Terrigal beach area are:
* Building on sand dunes - when the dangers of building on sand dunes were not known, the council sold the land and allowed people to build on it. This lead to the destruction of a large...
...against the seawall, the curved sea walls reflect the energy of the waves which is redirected downwards, to the base of the seawall, resulting in a strong backwash. The backwash wears away the base of the seawall, causing it to weaken and eventually collapse. Hence, seawalls have to be carefully maintained. the probable collapse of the seawall may also affect access to the beach by people and tourists. It is expensive to build seawalls. In England, it can cost 1 million pounds ($3 million) to build 1 kilometre stretch of seawall.
Advantages A seawall provides excellent defence where wave energy is high, reassures the public and has a long life span. It protects the base of cliffs, land and buildings against erosion. and can prevent coastal flooding in some areas. Breakwaters How it is designed to overcome the problem An offshore breakwater is a structure that parallels the shore (in the nearshore zone) and serves as a wave absorber. It reduces wave energy in its lee and creates a salient or tombolo behind the structure that influences longshore transport of sediment. More recently, most offshore breakwaters have been of the submerged type; they become multipurpose artificial reefs where fish habitats develop and enhance surf breaking for water sport activities. These structures are appropriate for all coastlines. Challenges /Limitations /Disadvantages They are unable to provide complete protection as they still leave areas of the coast...
Coastal Erosion is a huge problem today and is causing our beaches to get smaller and smaller every year. Coastal erosion is also causing the coast lines to recede and therefore taking away space for which people build on. Even though coastal erosion causes issues it is also the effect of something, Humans! Nature has a way of keeping the world in balance, it creates things such as barrier islands and sand dunes to help protect against costal erosion. However, humans play a big part in messing up that balance by creating man-made structures that actually increase the damage of coastal erosion rather than preventing it. Some of these structures such as groins, jetties, breakwaters and seawalls, when used properly can help. Unfortunately, in most cases they are used improperly and cause more damage than they do to help. With this being said, there needs to be laws or guidelines put in place to implement the proper use of these structures to reduce the effects they have on coastal erosion.
Groins are man-made structures designed to trap sand as it is moved down the beach by the longshore drift. As the longshore drift current reaches the groin it is forced to not only slow down but also change direction. As stated by Carla Montgomery, a professor Emerita at the Northern Illinois University, in her book Environmental Geology Ninth Edition, the shoreline eventually...
Mrs Sandra Burrows
Date: November 4, 2008
The Human Impact on Coastal Landscape
The relationship between humans and their environment is a topic that engenders much debate. Humans are intellectual. They can think, reason, feel and make deductions or hypothesis and seek to solve or prove their deductions or theories. The environment on the other hand is inanimate and exists by means of natural laws and principles that govern the universe. It cannot prevent man’s exploitations; it cannot take up arms and fight. However, in its own way, by natural laws, it makes efforts to purge and renew itself from the effects of man’s endeavors. Mangor (2002) argues that like the ocean that shapes coastal landforms, the coasts are dynamic aspects of the environment that are in constant change. Thus, by means of its natural processes such as sea level rise, waves and various phenomenon, erosion, accretion and reshaping of coasts, flooding and the creation of continental shelves it defends itself against man. A specific aspect of the environment that engenders conversation is the coastal landscape: its beauty, its purpose, its abuse, and its future.
Other aspects of the coastal landscape that engender discussion are those animate expressions of nature such as fossils and vegetations, birds and crustaceans, fishes and other wild life that depend on it for survival. Humans are the guardians of...