Geography Notes: Coastal Management
1. What is a waste zone?
The coastal hinterland and the inner continental shelf and everything in-between.
2. What is sustainable management?
Using resources in a way that will meet the needs of the present population without endangering
the ability of future generation’s needs.
3. What altered the ways Australian’s though about coastal management?
When Sydney’s Bilgola beach was severely eroded.
4. How are waves formed?
By wind blowing over an open stretch of water called a fetch.
5. Explain all the spheres:
Atmosphere: affects the weather
Hydrosphere: contributes the major energy sources
Lithosphere: determines how easily the coast is eroded and what types of landforms occur.
Biosphere: includes all the terrestrial and marine flora and fauna.
6. What is a swash?
The movement of waves up the beach caused by the increase of the wave’s height and the
spilling over of the crest causing it to break up onto the beach.
7. What is a backwash?
The movement of wash returning back to the sea.
8. What is the longshore drift?
The movement of sand particles along the beach caused by a swash and backwash. They move
parallel to the beach.
9. What is the longshore current?
The movement of water parallel to the shoreline cause by swash and backwash.
10. What is a rip?
A localized, rapidly-flowing current moving out to sea. They depend on the heights and durations
of the waves.
11. What do the size of waves depend on?
- Wind velocity
- The fetch
- duration of time that the wind blows
12. When do spilling waves occur?
When the sea bed rises gently and the waves rise and break gently.
13. When do plunging waves occur?
They occur where the sea bed rises steeply causing the waves to rise and break within a few
metres. These waves are dangerous.
14. When do surging waves occur?
When waves run up a steep slope without appearing to break.
15. How are constructive waves made?
When the swash is more powerful than the backwash and material transported by the waves will
be deposited on the beach. During winter they break more frequently and have higher energy.
16. How are destructive waves made?
When the backwash is more powerful than the swash and able to erode beach material.
17. How can the direction of the long shore drift alter?
When winds blow in a certain direction during one season.
18. What are rip currents?
Currents of water which move out from the beach below the surface of the water. They are
caused by water moving back from the beach and out to sea again.
19. What is a storm surge and how can they cause damage?
A rise in the sea levels resulting from the effects of intense storm systems. When they coincide
with a flooded river it results in damage.
20. Define abrasion and corrasion.
The wearing away of rock from the movement of rock particles along the surface.
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21. Define Attrition.
The breaking up of material caused by the bumping together of rocks.
22. Define Corrosion.
Rock being chemically eaten away by salt.
23. Define Hydraulic Action.
Waves wearing away rock through sheer power of the wave itself.
24. Define Quarrying
Waves pulling away large, loose rocks.
25. What is the sea bee wall? What is its purpose?
It is a well, 34 meters long on a slope and filled with hexagonal shapes to absorb the energy of a
wave during a storm. This reduces the dire consequence of strong storms damaging and eroding
material.
26. Why is beach nourishment necessary at Cronulla?
The original sand has eroded away and they need to replace it.
27. Outline 4 possible changes that could impact on Cronulla and Kurnell.
Sandmining, building of resorts and apartments, building of a film studio and redevelopment of
the Cronulla Sharks Leagues Club.
28. What is Research Action Plan (RAP)?
Fieldwork outside of the classroom and doing some research in the field.
29. What is primary research?
Photographs, surveys, observations, mapping, measuring and recording data.
30. What is secondary research?
Collecting information that someone else has already collected and interpreted such as from the
Australian Bureau of Statistics and the local council.
31. What are the 8 steps involved when doing a RAP?
1. Identify the aim or purpose of the investigation
2. Generate a number of focus questions
3. Decide which primary and secondary data is needed
4. Identify the techniques that will be used to collect data
5. Collect primary and secondary data
6. Process and analyse the data collected
7. Select presentation methods
8. Propose individual response.
32. What was the problem at Kurnell?
Longshore drift carrying sand to one end of Botany Bay. It impacted on the beach as some had a
lot of sand, others only had a little.
33. What was the solution and result?
Building 20 groynes along the southern side of Botany Bay at Silver Beach. Yes it worked.
34. What was the problem at Wanda Beach?
They were trying to manage the sand dunes by using wire fences to protect them and their
vegetation from human impact.
35. What was the result?
Reasonably successful, there were some areas that were covered with marron grass (up the
back) and there were some areas that were exposed to erosion (blowouts). Re-vegetation is
needed.
36. What was the problem at North Cronulla?
The beach suffered severe erosion and the property behind the beach was under threat.
37. What was the solution and result?
Building of the sea bee walls and yes it does work, albeit gives it an ugly look.
38. What is beach nourishment?
The placement of artificial sand onto a beach. The disadvantage is that it may have an
environmental impact on the beach from which the sand was taken from and the ad is it has a
low environmental impact on the present beach.
39. What are groynes?
An artificial structure designed to trap sand being moved by longshore drift. The ad is that it
traps the sand on the beach and the dis is that it is a visual eyesore. xD
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40. What is an offshore breakwater?
A possible solution of reduce erosion in which a structure parallel to the shore is placed in water.
The ad is that the waves break in the deeper water reducing their energy at the shore and this
dis is that it would cost extremely high.
41. Define purchase property.
To buy buildings and to remove structures which are threatened by erosion. The ad is that it
allows easier management of the dune area and the di si that it does not solve sand loss.
42. What are the main factors that affect coasts?
-Weather
-Wind
-Currents
43. What is an example of the four spheres interacting?
The occurrence of an onshore sea breeze and an offshore breeze.
44. What is an onshore sea breeze and offshore sea breeze?
Onshore: a wind that blows form a body of water towards land. It helps waves to erode.
Offshore: a wind that blows from the land to the water.
45. How can the height of a wave increase?
If the wind blows strongly for several hours.
46. How can a wave become steep?
When a wind is very strong, but when the wind abates, the height decreases and the wave
length increases.
47. What is a swell?
When the height decreases and the wave becomes more undulating and regular in size and
direction.
48. What is a tide?
The alternating rise and fall in sea level with respect to the land produced by the gravitational
attraction of the moon and the sun.
49. What are lunar tides?
Tides that the periodic rise and falling of large bodies of water.
50. What is hydraulic action?
A form of erosion, that is, the sheer force of waves hitting the shore.
51. How is a wave cut notch formed?
When waves erode the base of cliffs by hydraulic action. Caves can be formed from these.
52. What is a geo?
A narrow steep sided inlet.
53. How are sand dunes formed?
They are formed at the interface between sea and land and are formed from sand which is
eroded and ground rock. Marram grass is used to protect the sand dunes.
54. Why are sand dunes important?
Sand dunes filter water; enhance coastal water quality and gives protection to the land behind.
55. What are incipient foredunes?
They are not permanent features and are newly developing dunes.
56. How is tombola formed?
Spit + Stack = Tombola. It is when a spit lines an island or stack to the coast.
57. What is a spit?
Continuations of beaches.
58. What is a rock platform?
When a cliff is worn back.
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