Mitchell Harley (2273773). PhD Thesis. March 2009. Supervisor: Dr. ..... These include Wendy, Ross, Joan, Martin, James, Will,. Bruce, Ron, Monika, Anna, Chin, ...
The University of New South Wales School of Civil and Environmental Engineering
Daily to decadal embayed beach response to wave and climate forcing Mitchell Harley (2273773) PhD Thesis March 2009
Supervisor: Dr. Ian Turner Co-supervisor: Prof. Andrew Short
to Nan
ORIGINALITY STATEMENT ‘I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project’s design and conception or in style, presentation and linguistic expression is acknowledged.’
Signed . . . . . .
Date . . . . . .
COPYRIGHT STATEMENT ‘I hereby grant the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. I also authorise University Microfilms to use the three hundred and fifty word abstract of my thesis in Dissertation Abstract International (this is applicabable to doctoral theses only). I have either used no substantial portions of copyright material in my thesis or I have obtained permission to use copyright material’
Signed . . . . . .
Date . . . . . .
AUTHENTICITY STATEMENT ‘I certify that the Library deposit digital copy is a direct equivalent of the final oficially approved version of my thesis. No emendation of content has occurred and if there are any minor variations in formatting, they are the result of the conversion to digital format’
Signed . . . . . .
Date . . . . . .
Abstract A multi-decadal survey program undertaken at the Collaroy-Narrabeen embayment in SE Australia identifies medium-term (∼ 2-7 year) cycles of both erosion and accretion across the entire embayment (‘beach oscillation’) and at its two extremities (‘beach rotation’). These cycles have been observed to respond to phase shifts in the El Ni˜ no/Southern Oscillation (ENSO). To investigate wave and climate controls of embayment variability in finer detail, this study combines historical surveys with 45 years of wave data from the ERA-40 reanalysis and four years of high-resolution beach measurements using RTK-GPS and image-derived survey techniques. ENSO and Southern Annular Mode (SAM) controls of wave variability in the Sydney region are first explored. In general, wave heights increase/decrease and wave directions become more easterly/southerly during La Ni˜ na/El Ni˜ no phases. A positive correlation is observed between the SAM and summer wave heights, and a negative correlation between the SAM and winter wave directions. Storm variability is observed to be modified by the ENSO, but not the SAM. In particular, La Ni˜ na phases are generally associated with longer duration, higher energy events from a more easterly direction when compared to those during El Ni˜ no phases. Wave controls of embayment variability are subsequently investigated. In the short-term (days – months), beach oscillation/rotation is observed to be the most dominant process, accounting for approx. 60%/20% of overall embayment variability. Beach oscillation is related to changes in wave height and storms, whereas beach rotation is related to changes in wave direction and/or wave period. An empirical model that estimates the beach response to individual storm events is developed. In the longer-term (months – years), beach rotation is observed to respond to both wave heights and directions. Larger waves are sheltered somewhat at the southern end,
v
creating an apparent clockwise rotation under energetic wave conditions. Clockwise/anticlockwise rotations are also observed to follow southerly/easterly wave shifts at lags of up to 12 months. Comparisons between the ENSO and beach oscillation/rotation agree with previous observations that El Ni˜ no/La Ni˜ na phases are associated with an overall accretion/erosion and clockwise/anticlockwise rotation of the embayment. In general, the SAM shows little influence on embayment variability. While it is clear that beach oscillation is driven by cross-shore processes, to what extent beach rotation is a longshore and/or cross-shore phenomena requires further investigation.
vi
Contents Abstract
v
Acknowledgements
xiii
Relevant publications
xvi
1 Introduction 1.1 Motivation . . . . . . . . . . . . . . . . . . . 1.2 Study site . . . . . . . . . . . . . . . . . . . 1.2.1 The south-east Australian coastline . 1.2.2 The Collaroy-Narrabeen embayment 1.3 Thesis objectives and outline . . . . . . . . .
. . . . .
. . . . .
. . . . .
. . . . .
1 2 5 5 7 10
2 Relative uncertainties of beach survey methods 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Collaroy-Narrabeen Beach Survey Program . . . . . . . . . . . . 2.2.1 Conventional Surveys . . . . . . . . . . . . . . . . . . . . 2.2.2 RTK-GPS Surveys . . . . . . . . . . . . . . . . . . . . . 2.2.3 Image-derived Surveys . . . . . . . . . . . . . . . . . . . 2.3 Validation of survey methods . . . . . . . . . . . . . . . . . . . 2.3.1 Validation of conventional survey method . . . . . . . . . 2.3.2 Validation of image-derived method . . . . . . . . . . . . 2.4 Assessment of survey uncertainty in relation to beach variability 2.4.1 Magnitude of beach variability: 1976 – 2008 . . . . . . . 2.4.2 Semivariogram and signal-to-noise ratio analysis . . . . . 2.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . .
. . . . . . . . . . . . .
. . . . . . . . . . . . .
13 14 16 16 18 19 25 25 27 32 33 36 38 39
. . . . . . . . .
41 42 44 44 45 50 50 52 56 56
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
3 Inter-annual variability of the Sydney wave climate 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Wave data description and verification . . . . . . . . . . . . 3.2.1 The ERA-40 wave dataset . . . . . . . . . . . . . . . 3.2.2 Validation for the Sydney region . . . . . . . . . . . . 3.3 Wave climate of the Sydney region: 1957 – 2002 . . . . . . . 3.3.1 Inter-annual wave height and direction variability . . 3.3.2 Inter-annual variability of storm events . . . . . . . . 3.4 Climate controls of the inter-annual Sydney wave climate . . 3.4.1 Mean sea-level pressure and the Sydney wave climate vii
. . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
CONTENTS
3.5 3.6
3.4.2 ENSO and temporally-averaged values 3.4.3 SAM and temporally-averaged values . 3.4.4 ENSO/SAM and storm events . . . . . Discussion . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
59 60 62 63 64
4 Uniform/non-uniform response to waves and storms 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Data processing and analysis methods . . . . . . . . . . . . . 4.2.1 Topographic surveys . . . . . . . . . . . . . . . . . . . 4.2.2 Image-derived shorelines . . . . . . . . . . . . . . . . . 4.2.3 Wave data . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Survey results . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3.1 Total subaerial beach volume . . . . . . . . . . . . . . 4.3.2 Beach mobility and beach envelope . . . . . . . . . . . 4.3.3 EOF analysis . . . . . . . . . . . . . . . . . . . . . . . 4.3.4 High-frequency (daily) beach variability . . . . . . . . 4.4 Wave forcing of embayment dynamics . . . . . . . . . . . . . . 4.4.1 Wave forcing of EOFs . . . . . . . . . . . . . . . . . . 4.4.2 Individual storm events . . . . . . . . . . . . . . . . . . 4.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5.1 Role of the nearshore wave climate . . . . . . . . . . . 4.5.2 Empirical model of embayment response to storms . . 4.5.3 Beach rotation – an alongshore or cross-shore process? 4.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
66 67 69 70 73 74 76 76 79 80 83 86 86 88 93 93 94 96 97
5 Wave/climate controls of oscillation and rotation 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Beach profile data . . . . . . . . . . . . . . . . . . . . . . . 5.2.1 Beach width time-series . . . . . . . . . . . . . . . 5.2.2 Beach oscillation and rotation time-series . . . . . . 5.3 Wave controls of profile variability . . . . . . . . . . . . . . 5.3.1 Wave data . . . . . . . . . . . . . . . . . . . . . . . 5.3.2 Time-series analysis . . . . . . . . . . . . . . . . . . 5.4 Climate controls of oscillation and rotation . . . . . . . . . 5.4.1 SOI and SAM time-series . . . . . . . . . . . . . . 5.4.2 Time-series analysis . . . . . . . . . . . . . . . . . . 5.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5.1 SOI, wave climate and beach response: 1985 – 2000 5.5.2 On the mechanisms driving beach rotation . . . . . 5.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . .
. . . . . . . . . . . . . .
. . . . . . . . . . . . . .
. . . . . . . . . . . . . .
99 100 101 102 105 108 108 110 113 113 114 116 116 120 121
. . . . . . . . . . . . . .
. . . . . . . . . . . . . .
6 Concluding remarks
122
Bibliography
125
A Survey data transform technique
139
viii
CONTENTS B AutoIBM algorithm 146 B.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 B.2 Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 B.3 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 C Collaroy-Narrabeen SWAN Model
ix
152
List of Figures 1.1 Map of the Collaroy-Narrabeen embayment . . . . . . . . . . . . . . . 1.2 Wave rose for the Sydney wave climate . . . . . . . . . . . . . . . . . 1.3 Examples of erosion on the Collaroy-Narrabeen embayment . . . . . . 2.1 2.2 2.3 2.4 2.5 2.6
Diagram of the Emery method . . . . . . . . . . . . . . . . . . . . . Topographic surveying of the entire subaerial beach . . . . . . . . . Argus coastal imaging stations at Collaroy-Narrabeen . . . . . . . Timex images from the Collaroy-South Narrabeen cameras . . . . . Variance and timex images from the North Narrabeen camera . . . Frequency distributions of deviations between RTK-GPS and conventional survey measurements . . . . . . . . . . . . . . . . . . . . . . 2.7 Calibration of elevation models for the Collaroy-South Narrabeen cameras . . . . . . . . . . . . . . . . . . . . . . . .√. . . . . . . . . 2.8 Comparison between elevation model residuals and H0 L0 . . . . . 2.9 Alongshore variability of vertical and cross-shore deviations at the Collaroy-South Narrabeen station . . . . . . . . . . . . . . . . . . . 2.10 Calibration of elevation models for the North Narrabeen camera . . 2.11 Time-series of beach width at Profile 6 . . . . . . . . . . . . . . . . 2.12 The empirical semivariogram of beach width at Profile 6 . . . . . . 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 4.1 4.2 4.3
. . . . .
6 8 9 17 18 19 20 21
. 26 . 29 . 30 . . . .
Locations of ERA-40 and C-ERA-40 grid cells . . . . . . . . . . . . . Comparisons between ERA-40/C-ERA-40 and measured wave data . Hsig error as a function of predicted wave direction . . . . . . . . . . Validation of mean annual cycles . . . . . . . . . . . . . . . . . . . . Validation of temporally-averaged anomalies . . . . . . . . . . . . . . Validation of data during storm conditions . . . . . . . . . . . . . . . HCERA40 from 1957 to 2002 . . . . . . . . . . . . . . . . . . . . . . . . T h0ERA40 from 1957 to 2002 . . . . . . . . . . . . . . . . . . . . . . . Example of the peak-over-threshold method . . . . . . . . . . . . . . Variability of storm events from 1957 - 2002 . . . . . . . . . . . . . . Spatial correlations between monthly-averaged amended Hsig and MSLP Spatial correlations between monthly-averaged amended T h0ERA40 and MSLP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31 33 34 37 44 46 47 47 48 50 53 54 55 55 57 58
A time history of the survey data collection program . . . . . . . . . 70 Distances along the Collaroy-Narrabeen embayment . . . . . . . . . . 71 Wave data between July 2005 and August 2008 . . . . . . . . . . . . 75
x
LIST OF FIGURES 4.4 Significant wave heights during the seven storm events in June-July 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Total subaerial volume between 2005 and 2008 from the 36 topographic surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 Beach width and volume mobility and envelopes from the 36 topographic surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 The first three spatial and temporal EOFs for beach width data from topographic surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 The first three spatial and temporal EOFs for beach volume data from topographic surveys . . . . . . . . . . . . . . . . . . . . . . . . 4.9 Time-series of daily beach width from the northern and southern ends of the embayment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.10 Correlations between averaged offshore wave conditions and ∆ck (t) 4.11 Examples of barless and barred morphology from the three cameras 4.12 Relationships between ∆W and ∆V at the three regions used for individual wave event analysis . . . . . . . . . . . . . . . . . . . . . 4.13 Relationships between storm energy E and beach response ∆W and ∆V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.14 Alongshore gradients of breaking wave height derived from SWAN wave modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.15 Empirical model of the embayment response to storms . . . . . . . 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11
. 76 . 77 . 79 . 81 . 82 . 83 . 85 . 89 . 90 . 91 . 93 . 95
Time-series of beach width (1976 – 2008) at the five profile locations . 103 Time-series of beach oscillation between 1976 and 2008 . . . . . . . . 106 Time-series of beach rotation between 1976 and 2008 . . . . . . . . . 107 Monthly-averaged Hsig and T h0 anomalies between 1977 and 2008 . . 108 Lagged cross-correlations between beach oscillation and wave data . . 111 Lagged cross-correlations between beach rotation and wave data . . . 112 SOI and SAM time-series between 1976 and 2008 . . . . . . . . . . . 113 Lagged cross-correlations between oscillation and the SOI/SAM . . . 114 Lagged cross-correlations between rotation and the SOI/SAM . . . . 115 Overview of beach, wave and ENSO variability between 1985 and 2000117 Aerial photographs of the Collaroy-Narrabeen embayment in both 1990 and 1995 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
B.1 Algorithm for the AutoIBM technique . . . . . . . . . . . . . . . . . 147 B.2 Example of an AutoIBM shoreline from a plan-view image at CSN5 . 150 B.3 An AutoIBM shoreline detected using an automatically-generated ROI151 C.1 Higher resolution bathymetry of the Collaroy-Narrabeen embayment used for SWAN modelling . . . . . . . . . . . . . . . . . . . . . . . . 153
xi
List of Tables 1.1 List of sites with extensive beach survey programs . . . . . . . . . . . 1.2 General parameter summary of study site . . . . . . . . . . . . . . . . 2.1 2.2 2.3 2.4
Comparisons between benchmark elevations . . . . . . . . . . . . . Statistics of environmental conditions during shoreline calibrations . Correlation coefficients between various beach variability definitions Basic beach-width statistics at the five profile locations . . . . . . .
3.1
Correlations between predicted and measured anomalies for both amended and unamended data . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Temporally-averaged wave height statistics from 1958 – 2002 . . . . . 51 Temporally-averaged wave direction statistics from 1957 – 2002 . . . 52 The ten largest storm events between 1957 and 2002 . . . . . . . . . 56 Correlation coefficients between HCERA40 /T h0ERA40 and the SOI . . . 60 Correlation coefficients between amended HCERA40 /T h0ERA40 and the SAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Correlation coefficients between the SOI/SAM and annual storm statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
3.2 3.3 3.4 3.5 3.6 3.7 4.1 4.2 5.1 5.2 5.3
. . . .
3 7 25 28 33 35
Statistics of the cluster of storm events in June-July 2007. Periods coincide with the peak Hsig . . . . . . . . . . . . . . . . . . . . . . . . 76 List of the four periods that charactise subaerial beach volume variability beteen 2005 and 2008 . . . . . . . . . . . . . . . . . . . . . . . 78 Cross-correlation coefficients between the beach width time-series . . 102 Cross-correlation coefficients between the five beach rotation time-series106 Averages of monthly-averaged values of Hsig and T h0 . . . . . . . . . 110
xii
Acknowledgements The idea of spending several years of my life cruising up and down the beach, on a quad bike listening to bossa nova music, was sold to me in 2004, when my supervisor Ian Turner approached me in my final year of undergraduate studies. He neglected to mention the fact that the quad bike might break down, the GPS batteries might die inexplicably, a thunderstorm might suddenly arrive and all the other things that Murphy’s Law requires, but I am glad that he didn’t because I might have missed out on this wonderful experience. I could not have asked for more from him as a supervisor and he was always there to help whenever required. So for that I am extremely grateful and I look forward to working with him in years ahead. While I write about this project here in 2009, it was in fact born many years before this – in fact several years before I was even born myself. It began when Andy Short first threw his tape measure and red-and-white survey poles into the back of his van in April 1976 and started measuring the movements of what effectively was his backyard. His dedication to the pursuit of understanding how and why this region continually contorts itself into a multitude of shapes has been inspiring and I thank him for giving some of his time to share his extensive knowledge with me. Although my first beach survey with him may have caused a few shakes of the head (having forgotten my swimming gear and ending up wading around the surf zone in jeans) I eventually learnt the ropes of beach surveying and here I am, forty-two surveys later. Here’s to another three hundred! I would like to acknowledge the efforts of my other, but unofficial, co-supervisor, Rosh Ranasinghe. Although I must admit emails arrived from him with a degree of angst, his comments were always thoughtful with a strong attention to detail that improved the manuscript immensely. It’s a pity the same attention to detail hasn’t been shown in the batting performances of the Sri Lankan cricket team. xiii
0. Acknowledgements Of course it would have been very difficult without the strong support received from my family. I would really like to thank Mum and Dad for their continued support and kindness, for giving me a bed to sleep in when my scholarship money ran out and for looking interested when I was trying to explain EOF analysis. My two brothers Luke and Tristan also helped out when they could. Luke went through and scrutinised every word of the thesis, which for a poetry and language scholar must have been an arduous and incredibly banal task. Tristan slept for three months in a makeshift bedroom in the hallway while I occupied his room trying to finish writing the manuscript. I promised my grandmother Ngaira that I would have my thesis finished for her 84th birthday, but I hope that she can forgive me for taking a few more months. I would also like to thank my girlfriend Natalia for her support and understanding. Muchos gracias parce. Over the course of these four years I was fortunate enough to have had two amazing experiences overseas. The first was a month spent at Delft Hydraulics in the Netherlands working on the automated shoreline technique. This trip would not have been possible without Stefan Aarninkhof. Nor would it have been as fun if it were not for Robin Morelissen, Antonio Cerezo and Anna Cohen keeping me company. The second trip was an incredible week spent with Paul Komar giving me a personal tour of the Oregon coastline, perfectly accompanied by the music of Philip Glass. It is a week that I cherish immensely for opening my eyes to all the coastal processes in action, from tiny grains arranging themselves into individual colours, to huge sea stacks formed over thousands of years. The atmosphere and tranquility of the Water Research Laboratory provided a perfect environment for undertaking a thesis and I would like to thank everyone there that made it so. These include Wendy, Ross, Joan, Martin, James, Will, Bruce, Ron, Monika, Anna, Chin, Libby, Hamish, Gabriel, John, Caroline, Duncan and many more... A special thanks is reserved for Doug Anderson who dedicated a great deal of time to helping me over the years. I hope the water dragons don’t miss their daily feed too much. I also received a lot of encouragement from Warringah Council, in particular Daylan Cameron. It was always refreshing to hear that people may actually be
xiv
0. Acknowledgements interested in your work and Daylan was always discussing it with me, whether it was in a council meeting or in a chance encounter on the beach. Another unexpected contribution was made by a man named Thomas Vietch. Having observed my laptop and hard drives (containing all my thesis files) being stolen from the back of my car, he proceded to run after the thief and confront him. Unfazed by the thief threatening him at knife-point, he somehow managed to retrieve the bag. Let me just say that I was quite relieved that he did so. Lastly I would like to give a special mention to Brad Morris, who accompanied me throughout most facets of this project. He was always willing to help out without question and it would have been a long and lonely struggle if he wasn’t there to share the joys and frustrations with me. Mitchell Harley March 2009
This research was supported by the Australian Research Council (grant number LP0455157), NSW Department of Environment and Climate Change, Warringah Council and Deltares (the Netherlands). Wave and tide measurements were kindly supplied by the Manly Hydraulics Laboratory (NSW Department of Commerce) on behalf of the NSW Department of Environment and Climate Change. Wave reanalysis data were supplied by the European Centre for Medium-Range Weather Forecasts, with corrected wave height reanalysis provided by Andreas Sterl at KNMI. Beach measurements at Collaroy-Narrabeen would not have been possible without the numerous volunteers who have generously assisted over the last three decades.
xv
Relevant publications Journal publications Harley, M. D., Turner, I. L., 2008. A simple data transformation technique for pre-processing survey data at embayed beaches. Coastal Engineering 55 (1), 63–68. Harley, M. D., Turner, I. L., Short, A. D., Ranasinghe, R., in press. Interannual variability and controls of the Sydney wave climate. International Journal of Climatology. Harley, M. D., Turner, I. L., Short, A. D., Ranasinghe, R., submitted. Relative uncertainties of conventional and image-derived survey methods. Coastal Engineering. Harley, M. D., Turner, I. L., Short, A. D., Ranasinghe, R., in prep. Empirical model of embayed beach response to storms. Geophysical Research Letters. Harley, M. D., Turner, I. L., Short, A. D., Ranasinghe, R., in prep. Alongshore uniform and non-uniform embayed beach response to energetic wave forcing. Marine Geology Harley, M. D., Turner, I. L., Short, A. D., Ranasinghe, R., in prep. Wave and climate controls of beach oscillation and rotation. Marine Geology. Conference Proceedings Harley, M. D., Turner I. L., Short, A. D., Ranasinghe, R., submitted. An empirical model of beach response to storms – SE Australia. 19th Australasian Coastal and Ocean Engineering Conference, Wellington, New Zealand. Harley M. D., Turner I. L., Short A. D., Ranasinghe R., 2009. Rotation and oscillation of an embayed beach. In: 31st International Conference on Coastal Engineering. Hamburg, pp. 865–875. Harley, M. D., Turner I. L., Morris B. D., Short, A. D., Ranasinghe, R., 2007. Nearshore wave climate and localised erosion during storm events. 18th Australasian Coastal and Ocean Engineering Conference, No. 89 [published on CD], IEAust, Melbourne, Australia, pp. 1–6. xvi
0. Relevant publications Harley M. D., Turner I. L., Short A. D., Ranasinghe R., 2007. Assessing the accuracy and applicability of a multi-decadal beach survey dataset. In: 30th International Conference on Coastal Engineering. AASCE, San Diego, pp. 4000–4008. Harley M. D., Turner I. L., Short A. D., Ranasinghe R., 2006. Monitoring beach processes using conventional, RTK-GPS and video image-derived survey methods: Narrabeen Beach, Australia. In: GIS for the Coastal Zone: A Selection of papers from CoastGIS 2006, Wollongong, Australia, pp. 152–163. Harley M. D., Turner I. L., Short A. D., Ranasinghe R., 2005. Comparison of image-derived, RTK-GPS and conventional beach survey methods. In: 17th Australasian Coastal and Ocean Engineering Conference, IEAust, Adelaide, Australia, pp. 465-470.
xvii
0. Relevant publications
xviii
