Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
The Shifting Sands of
Noosa
Estuaries & Coasts
Did we manage in the past?
Are we managing now?
Can we manage in the future...
OUTLINE
 Geologic and historic timeline of Noosa
coasts and estuaries
 Geo 100 – Understanding coastal and
estuary proce...
The Story Line
Apologies to Jules Verne
3
YEARS
Mixing the Metaphor
Captain Nemo Lost Nemo
4
20 000 years Over the Sea
5
The oldest dated evidence of occupation in South East
Queensland comes from Stradbroke Island ...
Geologic Sea Level Rise
6
Aboriginal Use of Coast
7
 There is evidence of aboriginal
occupation in the Great Sandy Region
for at least the past 5,5...
1871 Map
8
1876 Harbour
Map
9
 River mouth
appears to be
closer to First
Point
1920s
10
1920 map
11
1930s Sea is Beyond First Point
12
1935 Hastings St
13
1938
14
15
1940s ORIGINAL NOOSA SPIT
Large sand bars shifted up
and down the coast with the
channel.
Main Beach, Noosa Woods
and N...
Before 1947 Cyclone
16
1947- 48 Cyclone Major Erosion
17
1960s
18
60s early 70s
19
1971 Map
20
1971 at High Tide
21
August 1977
22
August 1977
23
May 1978
24
1979
3 metre sea
cliff
25
August 1977
26
Coastal Observation
Programme (COPE) 1977-80
27
COPE Report
28
High Seas in 1988
29
February 1989 (after pumping)
30
GEOGRAPHY 100
31
Sediment Plume-Burdekin River (CSIRO)
Erosion Alexandra Headlands and
Maroochydore (Sunshine Coast Daily)
Estuaries
 Include deltas, tidal marshes and mangrove swamps
 Partially enclosed
 Mixing of fresh and salt water
 High...
Typical Beach System
33
Processes in the Coastal Zone
© 2012 John Wiley & Sons, Inc.
All rights reserved.
Wind Waves
Friction between air and wate...
© 2012 John Wiley & Sons, Inc.
All rights reserved.
Waves
• Swash – forward surge of wave
• Backwash – return flow of wave...
Coastal Dune Systems
 Dunes are part of the active beach system that helps
protect against storm events
Cross-section of ...
Beach Profile Dynamics
37
© 2012 John Wiley &
Sons, Inc. All rights
reserved.
Processes in the Coastal Zone
Littoral Drift
• Littoral drift = The tr...
39
Evidence of
Longshore
Drift
Kirra
1933 and 1973
after the first
groyne was built
Source:
http://www.tweedsandbypa
ss.ns...
40
Tweed Sand Bypass
41
Post Bypass 2004
42
Coastal Morphodynamics
43
44
Dunes and Beach Erosion
 Clearing and development
on coastal dunes
 Coastal engineering –
groynes, retaining walls
inter...
© 2012 John Wiley &
Sons, Inc. All rights
reserved.
Processes in the Coastal Zone
Wave Refraction
• Headlands - Wave energ...
© 2012 John Wiley &
Sons, Inc. All rights
reserved.
Human Interactions with Coastal
Processes
Coastal Engineering
• Rip-ra...
1960s
48
The First Rock Wall
 Following cyclones in 1967–68, panicked
beachfront property owners began dumping
rock in front of th...
Noosa Buffer 40m,
North Shore 150m
50
Straight Sea Wall 1970
51
3. Hays Island becomes Noosa Sound.
52
In 1972, Noosa Council
approved an application to
develop Hays Island as a
canal es...
The Sound
Sand was pumped from
the river to raise the
land by one metre and
natural channels were
widened to create
artifi...
1977 study Flood
Discharge
Volume
54
1978 Estimates
Longshore Transport
55
Beach Protection Scheme
1978
56
Works in Progress
57
Before and After Relocation
58
The Spit Extended
In 1977 a scheme for the
“protection” of Hays Island
and “restoration” of Noosa
Beach surfaced, jointly
...
New Groyne in 1988
60
Softer Beach Nourishment
61
1999 Study
62
63
2001
Study
64
Wave Conditions
with and without artificial reef
65
Modelled Reef Designs
66
Wave Heights
with different
Reef Designs
67
New Coastal Management
Option in 2001
68
Why wasn’t the Reef Built?
69
Sand Pumping
 Trials with a submerged sand-pump began in
December 2004 while plans were developed for
a permanent install...
Pumping Statistics
 Approx 1000 cubic metres per day ( 100
truckloads)
 Cost $3.50per cu m ( alternate $15-20 cu
m) (Has...
72
73
74
Spit ‘Dog’ Beach Erosion and
Management 2010
75
Doggy Beach Reclaimed
Even though the hydrologists had not modelled their
proposal beyond the Noosa Spit area, council cho...
Before and After
77
Munna Point Erosion 2012
78
79
80
NOW & INTO FUTURE
81
Ocean acidification
Tracking an Ocean of Carbon FEB 2012 4:02min
Acid Test: The Global Challenge of Ocean Acidification 21...
OCEAN ACIDIFICATION
 the name given to the ongoing decrease in the pH and
increase in acidity of the Earth's oceans, caus...
Coral Reefs
 A rock like accumulation of
carbonates secreted by corals and
algae along marine shorelines
 Largest variet...
Mixing the Metaphor
Captain Nemo Lost Nemo
85
Sea Level
Rise
Projections
86
Figure: Estimated
increases in the
frequency of extreme sea
level events (indicated by
the d...
1990 - Baseline Summer
Maximum Temperature
2100 – Summer
Maximum Temperature A2
CHANGES TO CONDITIONS IN
SEQ
Most Likely Scenario
More frequent and severe droughts.
Increased intensity of storm events...
Increase Nutrient & Temp
driving Algal Blooms?
89
The Story Line
Apologies to Jules Verne
90
YEARS
91
Upcoming SlideShare
Loading in …5
×

The Shifting Sands of Noosa

690 views

Published on

A brief pictorial history of Noosa Main Beach and Estuary reviewing coastal management from first nations through first settlement to current day - with a brief overview of coastal management theory.
Sources include Nancy Cato's Noosa Story and other publications featured in slides.

Published in: Environment
  • Be the first to comment

  • Be the first to like this

The Shifting Sands of Noosa

  1. 1. The Shifting Sands of Noosa Estuaries & Coasts Did we manage in the past? Are we managing now? Can we manage in the future? 1
  2. 2. OUTLINE  Geologic and historic timeline of Noosa coasts and estuaries  Geo 100 – Understanding coastal and estuary processes  The past and present of coastal ‘management’ interventions  The future challenges for Noosa coasts and estuaries 2
  3. 3. The Story Line Apologies to Jules Verne 3 YEARS
  4. 4. Mixing the Metaphor Captain Nemo Lost Nemo 4
  5. 5. 20 000 years Over the Sea 5 The oldest dated evidence of occupation in South East Queensland comes from Stradbroke Island 20,560 +/-250 BP – Pleistocene, when this area was part of the mainland;
  6. 6. Geologic Sea Level Rise 6
  7. 7. Aboriginal Use of Coast 7  There is evidence of aboriginal occupation in the Great Sandy Region for at least the past 5,500 years.  Transformed around 3000 BP with climate induced changes in rainforest resources  Demographic and technological changes occurring approximately 1500 BP may have been triggered by key areas such as SEQ  Semi-sedentary aboriginal villages and huge gatherings of several thousand of people being supported by migratory fish runs
  8. 8. 1871 Map 8
  9. 9. 1876 Harbour Map 9  River mouth appears to be closer to First Point
  10. 10. 1920s 10
  11. 11. 1920 map 11
  12. 12. 1930s Sea is Beyond First Point 12
  13. 13. 1935 Hastings St 13
  14. 14. 1938 14
  15. 15. 15 1940s ORIGINAL NOOSA SPIT Large sand bars shifted up and down the coast with the channel. Main Beach, Noosa Woods and Noosa Spit in the 1940s show a very different landscape to that of today. The promontory of the Spit was less than half its current size.
  16. 16. Before 1947 Cyclone 16
  17. 17. 1947- 48 Cyclone Major Erosion 17
  18. 18. 1960s 18
  19. 19. 60s early 70s 19
  20. 20. 1971 Map 20
  21. 21. 1971 at High Tide 21
  22. 22. August 1977 22
  23. 23. August 1977 23
  24. 24. May 1978 24
  25. 25. 1979 3 metre sea cliff 25
  26. 26. August 1977 26
  27. 27. Coastal Observation Programme (COPE) 1977-80 27
  28. 28. COPE Report 28
  29. 29. High Seas in 1988 29
  30. 30. February 1989 (after pumping) 30
  31. 31. GEOGRAPHY 100 31 Sediment Plume-Burdekin River (CSIRO) Erosion Alexandra Headlands and Maroochydore (Sunshine Coast Daily)
  32. 32. Estuaries  Include deltas, tidal marshes and mangrove swamps  Partially enclosed  Mixing of fresh and salt water  Highly productive  Strongly affected by tides and flows from catchments MacroalgaeGroundwater Mangroves Seagrass Meadow Phytoplankton Terrestrial Vegetation Salt marsh Estuary conceptual model - http://www.ozcoasts.gov.au
  33. 33. Typical Beach System 33
  34. 34. Processes in the Coastal Zone © 2012 John Wiley & Sons, Inc. All rights reserved. Wind Waves Friction between air and water and wind pressure transfers energy to water – form wave • Fetch-length of water exposed to the wind • Wavelength – distance between wave crests • Wave trough - depression between crests
  35. 35. © 2012 John Wiley & Sons, Inc. All rights reserved. Waves • Swash – forward surge of wave • Backwash – return flow of wave • Undercurrent (undertow) – force of the backwash carries both material and people Processes in the Coastal Zone
  36. 36. Coastal Dune Systems  Dunes are part of the active beach system that helps protect against storm events Cross-section of a sandy beach showing the significant difference in the volume of sediment eroded in high- magnitude storms (1:100 year) compared to seasonal erosional events. http://www.ozcoasts.gov.au
  37. 37. Beach Profile Dynamics 37
  38. 38. © 2012 John Wiley & Sons, Inc. All rights reserved. Processes in the Coastal Zone Littoral Drift • Littoral drift = The transport of sediment parallel with the shoreline by the combined action of beach drift and longshore current transport Longshore drift Beach drift – waves reach beach on an angle the swash pushes sand up the beach sand - backwash is perpendicular to beach carrying material back out Long shore Drift - zigzag path that transports sediment long distances along the beach
  39. 39. 39 Evidence of Longshore Drift Kirra 1933 and 1973 after the first groyne was built Source: http://www.tweedsandbypa ss.nsw.gov.au
  40. 40. 40
  41. 41. Tweed Sand Bypass 41
  42. 42. Post Bypass 2004 42
  43. 43. Coastal Morphodynamics 43
  44. 44. 44
  45. 45. Dunes and Beach Erosion  Clearing and development on coastal dunes  Coastal engineering – groynes, retaining walls interrupt natural sediment transport  Loss dune vegetation  results in beach erosion and loss of property 45
  46. 46. © 2012 John Wiley & Sons, Inc. All rights reserved. Processes in the Coastal Zone Wave Refraction • Headlands - Wave energy concentrated at Headlands where sediment is eroded • Wave refraction- Wave fronts slow at headlands and wrap around headlands • Pocket beaches – Sediment carried by littoral drift deposits at head of the bay – crescent shaped beach – long term straightening of the shore
  47. 47. © 2012 John Wiley & Sons, Inc. All rights reserved. Human Interactions with Coastal Processes Coastal Engineering • Rip-rap • Artificial beach nourishment
  48. 48. 1960s 48
  49. 49. The First Rock Wall  Following cyclones in 1967–68, panicked beachfront property owners began dumping rock in front of their properties to hold back the sea. With approval from the state government’s Department of Harbours and Marine, Noosa Council constructed a boulder wall that permanently fixed the shape of the bay. The wall broke up during subsequent storms, thus requiring further work. 49
  50. 50. Noosa Buffer 40m, North Shore 150m 50
  51. 51. Straight Sea Wall 1970 51
  52. 52. 3. Hays Island becomes Noosa Sound. 52 In 1972, Noosa Council approved an application to develop Hays Island as a canal estate. It was habitat for inestimable numbers of crabs, birds and reptiles, and its mangroves provided essential shelter for fish fingerlings.  The 144-acre development, called Noosa Sound, stretched from the bridge behind what is now the Sheraton Resort all the way to Munna Point.
  53. 53. The Sound Sand was pumped from the river to raise the land by one metre and natural channels were widened to create artificial waterways. 53 Following the cyclones of 1974 and 1976, there was panic about the possible consequences of a cyclonic event combined with high tide and river surge. At the time some of Noosa Sound was in direct line of sight to the open ocean.
  54. 54. 1977 study Flood Discharge Volume 54
  55. 55. 1978 Estimates Longshore Transport 55
  56. 56. Beach Protection Scheme 1978 56
  57. 57. Works in Progress 57
  58. 58. Before and After Relocation 58
  59. 59. The Spit Extended In 1977 a scheme for the “protection” of Hays Island and “restoration” of Noosa Beach surfaced, jointly funded by state and local governments plus Noosa Sound’s developers. The design provided for a relocation of the river mouth further northwards 59 The Spit Scheme was completed in December 1978. Significant erosion appeared at the southern end of Noosa Main Beach only a few months later.
  60. 60. New Groyne in 1988 60
  61. 61. Softer Beach Nourishment 61
  62. 62. 1999 Study 62
  63. 63. 63
  64. 64. 2001 Study 64
  65. 65. Wave Conditions with and without artificial reef 65
  66. 66. Modelled Reef Designs 66
  67. 67. Wave Heights with different Reef Designs 67
  68. 68. New Coastal Management Option in 2001 68
  69. 69. Why wasn’t the Reef Built? 69
  70. 70. Sand Pumping  Trials with a submerged sand-pump began in December 2004 while plans were developed for a permanent installation. 70
  71. 71. Pumping Statistics  Approx 1000 cubic metres per day ( 100 truckloads)  Cost $3.50per cu m ( alternate $15-20 cu m) (Hastings Street Business levey)  Aims to achieve a 1:7 gradient to dissipate wave energy  On average only need to pump a couple of times a year , if profile is OK no need to pump 71
  72. 72. 72
  73. 73. 73
  74. 74. 74
  75. 75. Spit ‘Dog’ Beach Erosion and Management 2010 75
  76. 76. Doggy Beach Reclaimed Even though the hydrologists had not modelled their proposal beyond the Noosa Spit area, council chose to proceed with the project at an estimated total cost of $3.6 million. Due to concerns about stream power some of the planned submerged geotextile bags were substituted with rocks. 76
  77. 77. Before and After 77
  78. 78. Munna Point Erosion 2012 78
  79. 79. 79
  80. 80. 80
  81. 81. NOW & INTO FUTURE 81
  82. 82. Ocean acidification Tracking an Ocean of Carbon FEB 2012 4:02min Acid Test: The Global Challenge of Ocean Acidification 21:35min 82
  83. 83. OCEAN ACIDIFICATION  the name given to the ongoing decrease in the pH and increase in acidity of the Earth's oceans, caused by the uptake of anthropogenic carbon dioxide (CO2) from the atmosphere.  About a quarter of the carbon dioxide in the atmosphere goes into the oceans, where it forms carbonic acid.  As the amount of carbon has risen in the atmosphere there has been a corresponding rise of carbon going into the ocean  Between 1751 and 1994 surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14, representing an increase of almost 30% in "acidity" (H+ ion concentration) in the world's oceans.  This ongoing acidification of the oceans poses a threat to the food chains connected with the oceans. 83
  84. 84. Coral Reefs  A rock like accumulation of carbonates secreted by corals and algae along marine shorelines  Largest variety of species of marine life in a very tiny area  Produce more living biomass than any other marine ecosystem  Remove CO2  Protect against wave action  Very important to fisheries and tourism industries  Problems: very slow growing and easily damaged Great Barrier Reef GBRMPA
  85. 85. Mixing the Metaphor Captain Nemo Lost Nemo 85
  86. 86. Sea Level Rise Projections 86 Figure: Estimated increases in the frequency of extreme sea level events (indicated by the diameters of the circles), caused by sea level rises of 10 centimetres (left) and 50 centimetres (right).
  87. 87. 1990 - Baseline Summer Maximum Temperature 2100 – Summer Maximum Temperature A2
  88. 88. CHANGES TO CONDITIONS IN SEQ Most Likely Scenario More frequent and severe droughts. Increased intensity of storm events 3-5% decrease in rainfall Increased flooding and erosion
  89. 89. Increase Nutrient & Temp driving Algal Blooms? 89
  90. 90. The Story Line Apologies to Jules Verne 90 YEARS
  91. 91. 91

×