Page 167 Questions

1. Why did it become necessary to extend the Tweed Riverbreakwaters?

originally, the breakwaters were constructed to stabilise the river entrance and help keep it clear of sand, however the continual build up of sand on the southern side of the breakwater eventually eventually caused the river mouth to once again silt up, therefore the breakwaters needed to be extended

2 What impact would the construction of the breakwaters have had on the replenishment of sand to the Gold Coast beaches after severe storm erosion?

At the time of the construction of the breakwaters, the long term effect on the supply of sand to beaches north (gold coast) was not considered. Gold coast beaches were being deprived of there natural source for sand because of these breakwaters. This is because the breakwater trapped sand that would normally move in a northerly direction.

3 Why did the Tweed River become unsafe to shipping? Explain the natural process that caused sandbars to form over theWhat impact would the construction of the breakwaters have had on the replenishment of sand to the Gold Coast beaches after severe storm erosion?

During the 1950's Tweed river became a hazard for shipping because of sandbars that were forming across the river mouth. Longshore drift was the cause of this continual build up of sand.
Why was the dredging of the Tweed River and the associated beach nourishment program only a short-term solution to
A more efficient long-term solution was required for this problem because the dredging of sand for nourishment in northen beaches is extremely expensive and would need to occur continously in order to solve the problem

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Describe the way the TRESBP replaces the natural process
This project is an example of how people can implement strategies that re-creates a natural process that is operating along the coast. The project aims to replicate the natural process of longshore drift. Sand is pumped from where it accumulates on the southern side of the Tweed River, via a system of pipes, across the Tweed River to one of four outlets where sand is released onto the beach. The beaches of the area are monitored in order to determine which beach will be supplied with sand from the pumping scheme. It has ensured a continual supply of sand to the beaches of the southern Gold Coast and solved the problem of the Tweed River silting up.

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6 Write a paragraph that explains your opinion of the TRESBP.Why do you think the project is regarded as one of the most
successful coastal management schemes in Australia?

In my opinion, TRESBP is one of the most effective, if not the most effective, coastal strategies in the World. I feel this way because of the way that the natural proceccess that are being re-created artificially, long-shore drift is mimicked by a simple pumping of sand. This strategy is put head and shoulders above the rest because of the way it is minimising apparent human impact, instead of dredging sand and using it for nourishments in a northerly direction. It is also very cost effective, which is a massive advantage




Draw an annotated map to explain the operation of

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the TRESBP.

 .Look at the aerial photographs in 7.28. Describe the changes that have occurred to the mouth of the Tweed

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River since 1962.

the banks of sand have slowly crept further and further out into the water. This would be a result of sand building up and up.

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 Approximately 100 metres wide

Using the topographic map in 7.25 on page 164, estimate the length of the breakwater along the Tweed River entrance in 1962 and in 1994.