Observations On The Effect Of Pumping Jetty On The Southport Mouth

Over the last 30 years, sand has been needed to replenish the beaches at Brighton and Glenelg North in particular, and this has been taken mostly from Glenelg, the Torrens Outlet, Grange and Semaphore. Sand has also been dredged offshore from North Haven. In all, the average quantity of sand moved along the Adelaide coast has been over 100,000 cubic metres each year.

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 leaves the sand dunes more susceptible to erosion causing blowouts and disrupting the succession of vegetation in the area. This has been a problem at Studland Bay in Dorset on the south coast of England. Persistent human leisure activities on the dunes has led to substantial erosion in some parts of these dunes which has meant that Management programs have had to been introduced by English Nature. Sand dunes help absorb the pounding of high waves and reduce overwash flooding in storms.

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.

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

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.

tides. There are also many programs which help to ensure the stabilization of dunes, these include the planting of new vegetation to combat erosion, fencing and designated

Barrier beaches are not static, they are constantly being changed (Coastal Change ) by the forces that formed them; waves and wind. One change effecting barrier beaches is they are moving closer to the main coast. This movement is caused by the rise in sea level. As the sea level rises waves crash higher and higher upon the beach, as they do this the dunes are pushed back. There are also seasonal changes in the barrier beaches. During stormy seasons sand is removed from the beach and deposited off shore on the longshore bar. During calm season waves redeposit sand upon the beach and the beach grows.

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)

The Southport Spit has many geographical features; natural and built. It is home to many natural beaches, sand dunes and islands. There are also many shops, hotels, houses, parks, roads, buildings, resorts and The Sand Bypass System which are all built in the area. The Spit is a product of long shore drift and erosion from Stradbroke Island. It was formed between 1897 and 1898 when high seas broke on Stradbroke Island and divided the island into two. In 1983, the government decided to create rock walls in the mouth of the Gold coast seaway to prevent it becoming a baymouth bar. This opening provided easy access to the harbour for vessels and boating. The Sand Bypass System was built along beside the wall to stabilize the entrance to the Broadwater

1. Consider Exhibit 10 on page 22 of the case; does it include the factors you consider most important in the selection process? Which factors would you be inclined to weight most heavily?

1. Brief description of the context and of the decision which has to be made.

Below are the criteria that will inform her decision on which alternatives satisfies her objective:

1. Comparison of the decision factors created with the criteria established to arrive at a decision