Beach Protection Authority Queensland

ISSN 0158-7757

WAVE DATA RECORDING PROGRAMME WAVE DATA RECORDING PROGRAMME

CAIRNS REGION

REPORT NO. WOl.2

• Prepared by the Beach Protection Authority

March 1986 All reasonable care and attention has been exercised in the collection, processing and compilation of the wave data included in this report. However, the accuracy and reliability of this information is not guaranteed in any way by the Beach Protection Authority and the Authority accepts no responsibility for the use of this information in any way whatsoever. DOCUMENTATION PAGE

REPORT NO.:- WOl.2

TITLE:- Report - Wave Data Recording Programme - Cairns Region

DATE:- March 1986

TYPE OF REPORT:- Technical Memorandum

JSSUING ORGANISATION:- Beach Protection Authority G.P.O. BOX 2195 BRISBANE QLD 4001 AUSTRALIA

DISTRIBUTION:- Public Distribution

ABSTRACT:-

This is the second report to provide summaries of primary analysis of raw wave data recorded in 18 metres of water offshore near Cairns in north Queensland. Data were recorded using a Datawell "Waverider" buoy, and covers the period May 2, 1975 to June 11, 1985. The data is divided into seasonal groupings for analysis. Directional wave data as used in the Mulgrave Shire Northern Beaches report are also included within this report. This report supersedes Wave Data Recording Programme, Cairns Region (Report No. WOl.1).

OTHERS AVAILABLE IN THIS SERIES:-

Wave Data Recording Programme, Cairns Region (Report No. WOl.1) Wave Data Recording Programme, Mackay Region (Report No. W02.1) Wave Data Recording Programme, Townsville Region (Report No. W .03.1) Wave Data Recording Program, Sunshine Coast Region (Report No. W04.1) Wave Data Recording Program, Burnett Heads Region (Report. No. W05.l) Wave Data Recording Program, Abbot Point Region (Report No. W06.1) Wave Data Recording Program, Weipa Region (Report No. W07.l) Wave Data Recording Program, Gladstone Region (Report No. W08.l) Wave Data Recording Program, Brisbane Region (Report No. W09.1) Wave Data Recording Programme, Bowen Region (Report No. Wl0.1)

REFERENCES:

Beach Protection Authority, 1984: Mulgrave Shire Northern Beaches: A Detailed Study of Coastline Behaviour in north Queensland, Australia.

B.P.A. Queensland •

• INDEX

1. Introduction

2. Recording Equipment

3. Wave Recording and Analysis Procedures

4. Data Losses

5. Wave Climate

6. Data Presentation

7. Attachments

{a) Summary Sheet 1: Details of Wave Recorder Installation.

{b) Summary Sheet 2: Major Meteorological Events.

{c) Table 1: Wave Statistics; Wave Period/Wave Height Occurrences, All Data, All Directions.

(d) Table 2: Wave Statistics; Wave Period/Wave Height Occurrences, Summer Data, All Directions.

{e) Table 3: Wave Statistics; Wave Period/Wave Height Occurrences, Winter Data, All Directions.

{f) Figure 1: Locality Map.

{g) Figure 2.1: Percentage {of time) Exceedance of Wave Heights (Hsig) for All Wave Periods {Tp).

Figure 2.2: Percentage (of time) Exceedance of Wave Heights (Hsig) for All Wave Periods {Tp) and Directions.

{h) Figure 3.1: Histogram Percentage {of time) Occurrence of Wave Heights (Hsig) for All Wave Periods {Tp).

Figure 3.2: Histogram Percentage (of time) Occurrence of Swell Wave Heights (Hsig) by Periods (Tp)

Figure 3.3: Histogram Percentage (of time) Occurrence of Sea Wave Heights {Hsig)

by Periods (Tp) and Directions •

• (i) Figure 4.1: Histogram Percentage (of time) Occurrence of Wave Periods (Tp) for All Wave Heights (Hsig).

Figure 4.2: Histogram Percentage (of time) Occurrence of Wave Periods (Tp) for All Wave Heights (Hsig), and Directions.

(j) Figure 5: Wave Parameter Relationships.

(k) Figure 6: Average Duration of Exceedance of Wave Heights (Hsig).

(1) Figure 7 .1 to 7.11: Daily Wave Heights (Hsig), Periods (Tp) and Directions.

(m) Figure 8: Wave Height (Hsig) Recurrence Interval. WAVE DATA RECORDING PROGRAMME

CAIRNS REGION

REPORT NO. WOl.2

1.0 INTRODUCTION

The Beach Protection Authority as part of its long term programme of investigating erosion problems along Queensland's coastline has been recording wave characteristics through a network of wave recording stations since 1968.

This report summarizes the primary analysis of wave data collected in the Cairns region. In addition brief details of the recording equipment, the method of handling raw data and the type of analysis employed are provided.

2.0 RECORDING EQUIPMENT

All wave recording installations operated by the Authority employ the "Waverider" system developed by Datawell b.v. of the Netherlands.

Initially the installation comprised a Waverider 6000 series buoy transmitting to a shore based W AREP Mark II receiver which in turn is coupled to an ANMA analogue recording unit. From January 5, 1985 the ANMA analogue recording unit was replaced with a DIMA digital recording unit while the remainder of the wave recording equipment for this installation was retained.

This system utilises a buoy mounted accelerometer to follow the water surface movements and transmits a frequency modulated analogue signal of these water level movements to a shore based receiver (W AREP). The . W AREP receiver provides a paper chart of the record and relays the analogue signal to tape on the ANMA recorder or DIMA recorder.

3.0 WAVE RECORDING AND ANALYSIS PROCEDURF.S

In general between May 2, 1975 and March 17, 1981 two recordings of water levels each of 20 minutes duration were made each day with the timing of the recordings set at 0300 hours and 1500 hours respectively.

During cyclonic events or other periods of severe wave action the recording frequency may have been increased to 4 times daily. Twenty minute records are still maintained at such times.

From March 18, 1981 there have been 4 recordings per day each of 20 minutes duration at 0300 hours, 0900 hours, 1500 hours and 2100 hours.

Digitization of the analogue data tapes was carried out at the Brisbane Office and the digital records held on 9 track digital tapes compatible with the computing facilities available to the Authority. In this process the analogue tapes produced in the field were sampled electronically at half second intervals and this information together with necessary administration information was transferred to the digital tape by a digitizer which was specifically developed for this purpose. 2.

The DIMA recorder provides digital data on cassette sampled at half second intervals with the necessary administration information included at the beginning of each record. Digital wave data can be transferred directly from the cassette to the Authoritys computer facilities by a digital cassette reader.

Routine and spectral analysis of digital wave data was performed by a computer program to obtain the following parameters.

1. Energy Density Spectrum A representation of the distribution of wave energy over the component wave frequencies.

2. Significant Wave Height (Hsig) The average height of the highest one third of waves in the record.

3. Root Mean Square Wave Height The root mean square of the (Hrms) wave heights from the record.

4. Maximum Wave Height (Hmax) The highest individual wave in the record. (Zero upward crossing).

5. Peak Energy Period (Tp) The wave period corresponding to the peak of the energy density spectrum.

6. Significant Period (Tsig) The average period of the highest one third of waves in the record.

7. Zero Crossing Period (Tz) The average period of all waves in the record based on upward zero crossings.

8. Crest Period (Tc) The average period of all the waves in the record based on successive crests.

These parameters are the basis for the summary plots and tables attached to this report.

4.0 DATA LOSSES

Data losses can be divided into three categories - losses due to recording equipment failure, losses during routine processing and losses as a result of spurious data produced by twisted accelerometer cables within the Waverider buoy.

Losses in the first two categories are usually non-recoverable. Data produced when accelerometer cables are twisted, however, are generally recoverable. The twisting of the cables causes a low frequency component to be added to the analogue wave data at the recording stage. When analysis is carried out, the component is easily detected and may be eliminated during data editing following the completion of routine processing and spectral analysis of data.

Details of data losses in the Cairns region are included in Summary Sheet 1, "Details of Wave Recorder Installation". 3.

5.0 WAVE CLIMATE

S.l General The wave climate presented in this report is based on statistical analyses of the parameters obtained from the recorded wave data.

Computer programs developed by the Authority provide statistical information on percentage of time occurrence and exceedance for wave heights and periods. The results of these analyses are presented in Tables 1, 2 and 3 and Figures 2.1, 2.2, 3.1, 3.2, 3.3, 4.1 and 4.2. In addition, similar analyses are carried out on the relationships between the various wave parameters and these are presented in Figure 5.

5.2 Wave Persistence

Wave height persistence is the duration for which any given wave height is exceeded in any single event. Persistence information has been calculated from the recorded data by linearly interpolating the times of exceedance of various wave heights. Wave height persistence data is presented in Figure 6.

5.3 Retum Intervals

The percentage of time of exceedance data for various wave heights (Figures 2.1 and 2.2) are combined with the persistence data (Figure 6) to determine the average wave height recurrence intervals.

The technique used to calculate the return intervals presented in Figure 8 is given below:-

No. of hours per year of exceedance H = Pe x 8760 hrs of a given wave height 100

= 87.6 Pe hrs where Pe is the percentage of time of exceedance from Figure 2.

Average No. of events per year in = 87.6 Pe which H is exceeded p where P is the average persistence (hours) of events of exceedance of the given wave height H.

However, of this number of events, a certain percentage Pn will persist for at least the specified duration. i.e. No. of events per year in which H is exceeded for at least the specified duration = 87 .6 Pe x Pn p 100

= 0.876 Pe x Pn p where Pn may be determined from Figure 6. 4.

By inverting this, the average return interval of the occurrence of an event in which H is exceeded for the given duration is given by -

Return Interval = 1 Ave. No. of occurrences per year

= p 0.876 Pe x Pn

It should be noted that the data presented in Figure 8 are for the average wave height recurrence interval and include all exceedance events of the given wave height without regard for duration of the event. In these calculations Pn was taken as 100 percent.

5.4 Wave Directions

The Mu1grave Shire Northern Beaches report was published by the Authority in October 1984. This report contains wave data from the Cairns offshore buoy recorded between May 2, 1975 and December 20, 1981. This wave data has been assigned directions and a directional wave analysis has been carried out for The Mulgrave Shire Northern Beaches report. Directionally analysed wave data for The Mulgrave Shire Northern Beaches report is included in this report.

Due to the presence of the Great Barrier Reef, the waves recorded at the Cairns buoy are a combination of sea waves generated within the reef and swell waves penetrating gaps in the reef. Usually, the sea waves and swell waves approach the buoy from different directions with different heights and different periods.

For the Mulgrave Shire Northern Beaches report, sea waves are defined as waves with peak energy periods less than 5 seconds and waves with peak energy periods greater than 5 seconds and wave steepness (wave height divided by wavelength) not less than 0.0175 metre. The report also defined swell waves as those with peak energy periods greater than 5 seconds and wave steepness less than 0.0175 metre.

Sea wave and swell wave components are evident from the spectral analysis of the wave record, as the occurrence of multi-peaked spectra. In the Cairns region, multi-peaked spectra are predominantly bi-modal. Single peaked spectra occur approximately 4% of the time.

For the abovementioned recording period, bi-modal wave spectra were decomposed using a spectral splitting method, into representative sea and swell components. The majority of decomposed bi-modal wave spectra observed the following first order linear theory of energy summation.

2 2 1'2 Hsig (Routine) = (Hsea + Hswell) Wave directions were assigned to the sea wave components by using wind data recorded at Low Isles by the Bureau of Meteorology. It appears the majority of swell at the Cairns offshore buoy comes from the north-east through Trinity Opening. Sea wave directions were grouped into sectors to enable convenient analysis of the directional sea wave data. 5.

The sectors are

Sector Degrees relative to true north

North 327° to 11° North-East 12° to 78° East-south-east 79° to 146°

All wave data were used to produce sea and swell components. Statistical analyses of significant wave heights and peak energy periods of all components were carried out to produce percentage occurrence and percentage exceedance diagrams. Directional analyses were performed on sea wave data. Daily sea wave direction plots are also provided.

For more details on the methods used to determine the directional wave climate for the Cairns offshore region, the reader should consult the Mulgrave Shire Northern Beaches report.

6.0 DATA PRESENTATION

No attempt has been made to interpret the recorded data for design purposes or to apply corrections for refraction, diffraction and shoaling to obtain equivalent deep water waves. Before any use is made of this data it is therefore necessary to note the exact location of the buoy and the water depth in which the buoy was moored. This data is shown on Summary Sheet 1, "Details of the Wave Recorder Installation". The "Waverider" recording system which is utilised by the Authority is designed to record vertical movements of the water surface only and any wave directions must be assigned to the individual wave records by other means.

Wherever major meteorological events such as cyclones have occurred during the recording period, these were noted and are summarized together with the maximum wave height recorded and any other relevant comments in Summary Sheet 2, "Major Meteorological Events".

In addition to the above Summary Sheets the following tables and figures are presented to complete this report.

Table 1: Wave Statistics; Wave Period/Wave Height Occurrences, All Data, All Directions.

Table 2: Wave Statistics; Wave Period/Wave Height Occurrences, Summer Data, All Directions.

Table 3: Wave Statistics; Wave Period/Wave Height Occurrences, Winter Data, All Directions.

Figure 1: Locality Map.

Figure 2.1: Percentage (of time) Exceedance of Wave Heights (Hsig) for All Wave Periods (Tp).

Figure 2.2: Percentage (of time) Exceedance of Wave Heights (Hsig) for

All Wave Periods and Directions • • (Tp)

Figu�e 3.1: Histogram Percentage (of time) Occurrence of Wave Heights (Hsig) for All Wave Periods (Tp). 6.

Figure 3.2: Histogram Percentage (of time) Occurrence of Swell Wave Heights (Hsig) by Periods (Tp).

Figure 3.3: Histogram Percentage (of time) Occurrence of Sea Wave Heights (Hsig) by Period (Tp) and Directions.

Figure 4.1: Histogram Percentage (of time) Occurrence of Wave Periods (Tp) for All Wave Heights (Hsig).

Figure 4.2: Histogram Percentage (of time) Occurrence of Wave Periods (Tp) for All Wave Heights (Hsig) and Directions.

Figure 5: Wave Parameter Relationships.

Figure 6: Average Duration of Exceedance of Wave Heights (Hsig).

Figures 7.1 to 7.11: Daily Wave Heights (Hsig), Periods (Tp) and Directions.

Figure 8: Wave Height (Hsig) Recurrence Interval.

The above tables refer to data recorded in Summer and Winter. For the purposes of analysis, Summer has been taken as the period from November 1 to April 30 in the following year. Winter covers the period May 1 to October 31 in any one year. SUMMARY SHEET 1

DETAILS OF WAVE RECORDER INSTALLATION

Region:- Cairns Region

Buoy Location:-

Co-ordinates:- 145°42' East 16° 42'33" South

Description:- 3 kms NE of Double Island. (See Figure 1)

Water Depth at Buoy:- 18 metres relative to Australian Height Datum

Location of Recording Station:- Yorkeys Knob - near water tank on Mulgrave Shire Council Reserve.

Period of Data Collection:- May 2, 1975 to June 11, 1985.

Normal Recording Interval:- Two twenty minute records daily at 0300 hours and 1500 hours between May 2, 1975 and March 17, 1981.

Four twenty minute records daily at 0300 hours and 0900 hours, 1500 hours and 2100 hours between March 18, 1981 and June 11, 1985.

Total No. of Recorm Analysed:- 8039

Number of Recorm Lost Due to:-

Losses during Analysis 12 8 Damaged Accelerometer Cables 110

Number of Days Lost Due to:-

Field equipment not operating 845

Periods during which four recordings per day were taken:

March 4-5 1976

January 31 - February 1, 1977 January 30-31, 1978 October 16 - November 6, 1978 January 2 - February 19, 1979 February 10-11, 1981 February 26-27, 1981 March 18, 1981 to June 11, 1985 SUMMARY SHEET 2

MAJOR METEOROLOGICAL EVENTS

Meteorological *Central Date *Estimated Maximum Maximum Tp Event Presmire Position Hsig Hmax of Cyclone Recorded Recorded Relative to Buoy (mb) (km) (metres) (metres) (secs) High pressure 1032 7.9. 75 1.32 2.17 4.80 system over New South Wales

Cyclone Alan 994 1.2.76 120 NNE 1.54 2.77 4.95

Cyclone Wat ore a 970 27.4.76 170 ENE # # # Cyclone Keith 993 31.1.77 50 NE 1.91 3.21 5.44

Cyclone Nancy 998 13.2. 77 140 NE 1.31 2.34 5.03

Cyclone Otto 998 8.3. 77 130 NW 1.33 2.62 5.51

Low pressure system over Tasman Sea 1008 12.4. 77 1.42 2.22 5.03

Cyclone Hal 995 8.4. 78 160 NNW 1.18 2.11 5.03

Cyclone Peter 997 3.1.79 140 NNW 1.80 3.32 5.30

Cyclone Greta 997 12.1.79 310 WNW 1.14 1.91 4.88

Low pressure system over northern Queensland 1000 26.1.79 1.43 2. 70 5.31

Cyclone Stan 1002 14.4.79 440 NE 1.11 1.73 4.49

Cyclone Ruth 999 11.2.80 410 SE # # # Cyclone Eddie 987 10.2.81 230 N 1.37 2.19 4.59

Cyclone Freda 997 26.2.81 330 NW 1.17 2.04 3.69

High pressure system off New South Wales Coast 1032 6.9.81 1.30 2.13 4. 72

Cyclone 0 Dominic 1000 9.4.82 180 NE 1.38 2.60 5.10

Cyclone Elinore 989 19.2.83 350 NE 0.98 1.79 4.06 2.

Meteorological *Central Date *Estimated Maximum Maximum Tp Event Pressure Position Hsig Hmax of Cyclone Recorded Recorded Relative to Buoy (mb) (km) (metres) (metres) (secs) Cyclone Fritz 1000 10.12.83 340 NE 1.16 2.15 4.45

Cyclone Ingrid 991 22.2.84 460 E 0.96 1.48 3.91

Cyclone Jim 1003 7.3.84 510 NE 0.98 1.67 4.30

Cyclone Kathy 990 19.4.84 420 N 1.09 2.01 4.44

Cyclone Lance 998 4.4.84 540 ENE 1.16 2.15 4.45

Cyclone Monica 990 26.12.84 410 E 1.17 2.21 4.23

Cyclone Odette 998 17.1.85 310 NE 1.11 1.69 4.59

Cyclone Tanya 980 31.3.85 270 N # # #

High Pressure system off New South Wales coast 1024 17.2.85 1.42 21.3 3.33

Highest Significant Wave Height (Hsig) recorded was 1.91 m on January 31, 1977 due to Cyclone Keith.

Highest Maximum Wave Height (Hmax) recorded was 3.32 m on January 3, 1979 due to Cyclone Peter.

Meteorological information obtained from the "Monthly Weather Review" published by the Bureau of Meteorology.

*Central pressure and position of cyclone at time of maximum wave conditions.

# Field Equipment not operating. TABLE 1

WAVE STATISTICS

WAVE PERIOD/WAVE HEIGHT OCCURRENCES

ALL DATA, ALL DIRECTIONS

Significant Peak Energy Wave Period (Seconds) Wave Height Totals (metres)

0 - 2.99 3 -4.99 5 -6.99 7 -8.99 9 -10.99 11 -12.99 13 -14.99 > 14.99

.00 - .20 37.38 29. 77 41.13 17.85 6.75 2.50 0.50 * 135.88 .20 - .40 267.18 180.44 329.49 128.96 21.43 2.23 * * 929.73 .40 - .60 91.56 379.27 214.66 118. 75 12.13 2. 75 * * 819.12 .60 - .80 2. 75 454.59 38.75 69.84 3. 75 1.25 * * 570.93 .80 - 1.00 * 294.46 6.38 13.75 3.00 0.50 * * 318.09 1.00 - 1.20 * 93.64 2.00 0.50 0.50 * * * 96.64 1.20 - 1.40 * 8.98 1. 75 * * * * * 10. 73 1.40 - 1.60 * 1.50 1.25 * * * * * 2. 75 1.60 - 1.80 * 0.75 1.38 * * * * * 2.13 1.80 - 2.00 * * 0.25 * * * * * 0.25 2.00 - 2.20 * * * * * * * * 0.00

TOTALS 398.87 1443.40 637.04 349.65 47.56 9.23 0.50 o.oo 2886.25

Values in the above tables are durations in days and have been rounded to the second decimal place.

0 TABLE 2

WAVE STATISTICS

WAVE PERIOD/WAVE HEIGHT OCCURRENCES

SUMMER DATA, ALL DIRECTIONS

Significant Peak Energy Wave Periods (Seconds) Wave Height Totals (metres) 0 - 2.99 3 - 4.99 5 - 6.99 7 - 8.99 9 -10.99 11 - 12.99 13 - 14.99 > 14.99

.00 - .20 30.50 23.27 35.13 14.60 5.50 2.50 0.50 * 112.00 .20 - .40 201.56 131.69 171.58 59.20 17 .93 2.23 * * 584.19 .40 - .60 65.29 221.86 76.95 21.14 8.63 2. 75 * * 396.62 .60 - .80 2. 75 207. 70 14.14 9.25 2.25 1.25 * * 237 .34 .80 - 1.00 * 110.65 3.25 2.25 * 0.50 * * 116.65 1.00 - 1.20 * 39.08 1.75 0.50 * * * * 41.33 1.20 - 1.40 * 5.00 1. 75 * * * * * 6. 75 1.40 - 1.60 * 1.50 1.25 * * * * * 2. 75 1.60 - 1.80 * 0. 75 1.38 * * * * * 2.13 1.80 - 2.00 * * 0.25 * * * * * 0.25 2.00 - 2.20 * * * * * * * * 0.00

TOTALS 300.10 741.50 307 .43 106.94 34.31 9.23 0.50 0.00 1500.01

Values in the above table are durations in days and have been rounded to the second decimal place. TABLE 3

WAVE STATISTICS

WAVE PERIOD/WAVE HEIGHT OCCURRENCES

WINTER DATA, ALL DIRECTIONS

Significant Peak EnergyWave Period (Seconds) Wave Height Totals (metres)

0 - 2.99 3 - 4.99 5 - 6.99 7 - 8.99 9 - 10.99 11 - 12.99 13 - 14.99 > 14.99

.00 - .20 6.88 6.50 6.00 3.25 1.25 * * * 23.88

.20 - .40 65.62 48.74 157 .92 69.76 3.50 * * * 345.54 .40 - .60 26.27 157 .42 137.71 97.61 3.50 * * * 422.51 .60 - .80 * 246.89 24.60 60.59 1.50 * * * 333.58 .80 - 1.00 * 183.81 3.13 11.50 3.00 * * * 201.44 1.00 - 1.20 * 54.56 0.25 * 0.50 * * * 55.31 1.20 - 1.40 * 3.98 * * * * * * 3.98 1.40 - 1.60 * * * * * * * * o.oo

1.60 - 1.80 * * * * * * * * 0.00 1.80 - 2.00 * * * * * * * * 0.00 2.00 - 2.20 * * * * * * * * 0.00

TOTALS 98. 77 701.90 329.61 242. 71 13.25 0.00 0.00 0.00 1386.24

Values in the above table are durations in days and have been rounded to the second decimal place.

I · Tribulation rt• 'SOUTH PACIFIC

OCEAN

;:;-;:::;:::. . :.. . :-: · ::::M;o$$fr.i�n \

5: . lo.. >15 20:. 25 ,,,,,, .::-·§P.,�:::r�, ,5-09qw · . .,, ,,., . AHO· Depths:·iitme-ties: on

17°00'

Wave Data Recording Program me.

• Cairns Region

LOCALITY MAP ,.. Figure 1

Beach Protection Authority W01:2 17;? r77 /:7 I 11 l'/ /j !1 / ,I/ ·b/ /// /Jv !1/�{I / (}/ /1/I I I I 11r: I I;�ti •J J 11J 'J I �II J

I c( ) I a: I- w c( a:w ·O � I- ..J � z ' ..J :::> - c( en 3: � I l � nJ,.. fa,z /J � """j

PERCENTAGE (OF TIME) Wav e Data Recording Programme. Ca rns R egion EXCEEDANCE OF WAV E HEIGHTS (HSI ) i G �- - - - - ...... FOR ALL WAV E PERIODS (Tp) ,. ,., Figure 2· 1 W01:2 Beach Protection Authority 2nd May 1975 to 11th June 1985 ... 2 Percentage occurrence of � each Sector r-.::::: N 54% �� NE 18.8% � ESE 75.8o/c 1 ...... _,� - ...... 0.9 " ...... r-...._ (ii 0.8 ...... � 0.7 ... " I'-." Q) ' E o.6 r-... �... !'\"""" S2 " :-"" 0.5 �-...... (/) " "...... J: 0.4 ...... _ r..... � -...."" -!'.. ' ....' .... 0.3 '" "r-...."' �<� ' ' �)� '\ ' 0.2 '� � '- i\. NE I� �SE

0.1 0.01 0.05 0.1 0.2 0.5 1 10 20 30 40 50 60 70 80 90 95 98 99 99.8 99.9 99.99 Percentage of Time Exceedance of sea waves ALL DATA and N, NE & ESE SECTORS (' 2nd May 1975 to 20th December 1981 r'' 2 (�� .2 "-..� � 0 0 2/5175 - 20/12/81 � ,.____ � 2/5175 - 11 16/85 1 �"""" 0.9 � 0.8 ...... ::� ...... , .. (/) i"""-o.. """"" 0.7 ...... " � ...... Q) 0.6 !'... 1'._ � E o.5 �.... '"' � ...... " �� r. <.'.) .... c:n o.• ...... 1' <:t-� J: �1'.. I"\ ""�(,/'c5fy · ·bv 0.3 !'... r\. "'� r, ....� ....�� ...... ;; r� �- �'1� "'v,�•• '\ �:,y$�< '( � '>. 0.2 , I\.� �� ...... R ...... "'� r--...: ...... r-....r-.....: ..._ 0.1 0.01 0.05 0.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.8 99.9 99.99 Percentage of Time Exceedance of sea waves ALL DIRECTIONS

PERCE_NTAGE (of time) EXCEEDANCE Wav e Data Recording Programme. Cairns Region OF WAV E HEIGHTS (H· SIG ) FOR ALL PERIODS (Tp) AND DIRECTIONS ,.. Figure 2.2 W01:2 Beach Protection Authority 2nd May 1975 to 11th June 1985 40 40

(I) (I) E ·;:; - 30 30 -·� 0 .3 Q) Q) 0 0 c: c: Q) Q)...... � � 0 0 0 20. 0 20 0 0 Q) Q) a a al ..al c: i Q) ....0 0... Q) 10' Q) 10 Q. Q.

O· 2 0·4 0·6 0·8 ·0 1-2 1-4 J.6 1·8 0.2 0·4 0·6 0·8 1·0 J.2 J.6 0 0 H 1 metres) (metres) HSIG ( H SIG ALL DATA SUMMER DATA

Q) g Q) t: 211 ;:, CJ 0 0 Q) a al c Q) 10 ....0 G> Q.

().6 O·B 1·0 1·2 ().2 ().4 H etres) H SIG (m WINTER DATA

HISTOGRAM PERCENTAGE (OF TIME) Wav e Data Recording Program me. OCCURRENCE OF WAV E Cairns Region HEIGHTS (H51G) FOR ALL WAVE PERIODS (T P) Figure 3· 1 Beach Protection Authority 2nd May 1975 to 11th June 1985 WQ1:2 WAVE PERIOD Tp (5-7 secs) WAVE PERIOD Tp (7-9 secs) WAVE PERIOD Tp (>9 secs) 30 30 30

28 28 28

26 26 26

24 24 24

22 22 Qi 22 Qi Qi ·E .§ 20 .§ 20 ;::; 20 0 '§ Q) 18 � 18 � 18 c(,) c c � 16 16 16 �::J ::J� :s u (,) (,) 0(,) 14 8 14 8 14 Q) Q) Q) en en en 12 12 "' 12 "' "' c cQ) cQ) Q) u 10 10 (,) 10 (,) Q; Cl.Q; Cl.Q; Cl. 8 8 8

6 6 6

4 4 4

2 2

0.2 0.4 0.6 0.8 1.0 0.2 0.4 0.6 0.8 1.0 0.2 0.4 0.6 0.8 1.0 Hs1G1m1 Hs1G1m1 H SIGiml

34 ALL WAVE PERIODS 32

Qi 26 ·;::;E 24 '§ � 22 c � :s 20 (,) 0(,) 18 enQ) E 16 Q) 14 Q)� 0.. 12

2 o ��'LLL�::..ll:l��==.,,__� 0 0.2 0.4 0.6 0.8 1.0 Hs1G1m1

Wav e Data Recording Programm e. HISTOGRAM PERCENTAG E (OF TIME) Cairns Region OCCURRENCE OF SWELL ...... �,...--- � WAV E HEIGHTS (H51G) BY PERIODS (TP) Figure 3·2 W01:2 Beach Protection Authority 2nd May 1975 to 20th December 1981 NORTH WAVES NORTH-EAST WAVES EAST-SOUTH-EAST WAVES Qi Qi 14 Qi 14 14 E E E ·;:; 12 ·;:; 12 ·;:; 12 :§ 10 :§ 10 :§ 10 Q) Q) Q) (.) 8 (.) 8 (.) 8 c: c: c: e 6 e 6 e 6 (.)5 4 (.)5 4 (.)5 4 (.) (.) (.) 0 2 0 2 0 2 *- 0 *- *- 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 i.6 1.8 2.0 Hs1G1m1 Hs1G1m> Hs1G1m1 WAVE PERIOD Tp (0-3 secs) 16 16 16 Qi Qi Qi E 14 14 14 · .g .g ;:; 12 12 12 :§ 0 0 Q) 10 -; 10 -; 10 (.) (.) (.) c: 8 c: 8 c: 8 e 6 e 6 e 6 (.)5 (.)5 (.)5 (.) (,) (,) 0 4 0 4 0 4 2 2 2 *- *- *- 0 0 Q2 0.4 Q6 Q8 1� 1.4 1.6 1.8 0.2 1.4 1.6 1.8 1.8 12 2.0 0.4 0.6 0.8 1.0 1.2 2.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 2.0 Hs1G1m1 Hs1G1m1 Hs1G1m1 WAVE PERIOD Tp (3-5 secs) � j � 1 �1 I I I I 1 I I I I I I I j I I 0 0.2I 0.4 I 0.6 I 0.8 I 1 I .0 1.2 1.4I 1.6 1.8 2.0 0 0.2 0.4I 0.6 I 0.8 I 1.0 I 1 I.2 1 I .4 1.6 I 1.8 I 2.0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1 .B 2.0 Hs1G1m> Hs1G1m1 Hs1G1m1 WAVE PERIOD Tp (:>5 secs) 24 24 24 Qi 22 Qi 22 22 Qi .g 20 .g 20 .g 20 :§ 18 18 18 Q) :§ :§ (.) 16 � 16 �- 16 c: c: c: 14 14 14 e e e (.):; 12 12 12 (.) (.)3 (.)3 0 10 0 10 10 Q) 0 Cl 8 � 8 � 8 "' "' 6 �c: 6 6 cQ) Q) cQ) (.) 4 4 4 a..iii � � 2 a.. 2 a.. 2 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1 .8 2.0 Hs1G1m1 Hs1G1m1 Hs1G1m1 ALL WAVE PERIODS 32 I 28 :§ 24 Q) � 20 e 16 3(.) 12 �Cl "' 8 cQ) (.) 4 a..iii

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.8 2.0 1.6 Hs1G1m1 ALL WAVE PERIODS AND DIRECTIONS

Wav e Data Recordin� Programme. HISTOGRAM PERCENTI/-\AG E (OF TIM E) Cairns Region OCCURRENCE OF SEA WAV E HEIGHTS �,..---,� (H51G) BY PERIOD (TP ) AND DIRECTION Figure 3.3 W01:2 Beach Protection Authority 2nd May 1975 to 20th December 1981 50

3 9 11 13 Wave Periods TP (Secs) ALL DATA

50 50

40 Qi 40 E - <%> .§ CD a ll g 30 CD (J �... c: CD � (J t:: 0 20 (JB Cl) 0 :l CD c a Cl) ca (J... 10 1 cCD :. (J CD... A.

3 5 9 11 13 7 5 11 Wave Periods Tp Secs Wave Periods T Secs ( ) P ( ) SUMMER DATA WINTER DATA

HISTOGRAM PERCENTAGE (OF TIME)· Wav e Data Recording Programm e. ·OCCURRENCE OF WAV E Cairns Region PERIODS (T p) FOR ALL WAV E ,.. HEIGHTS (H51G) Figure 4· 1 Beach Protection Authority 2nd May 1975 to 11th June 1985 W01 :2 SEA-ALL DIRECTIONS SWELL

40 40 Qj Q) E E ·;::; ·;::; 0 :§Ql Ql u u c: 30 c e e 30

u:; u:; u u 0 0 Ql Ql CJ) CJ) "' �c 20 20 Ql cQl u u

a..Qi a..Qi

10 10

CD 5 7 9 11 Wave Period Tp (secs) Wave Period Tp (secs)

EAST-SOUTH-EAST SEA WAVES

Q) ·;::;E 0 � 30 c e :; u NORTH SEA WAVES NORTH-EAST SEA WAVES u 0 Ql Q) Ql 20 g> 20 .g ·� :§ cQl Ql Ql � u Ql u a.. c c: e e 10 10 10 au au 0 0 Ql Ql CJ) CJ) "' �c Ql cQl u u

a..Qi 0 1 3 5 CD 0 1 3 5 CD 0 1 3 CD � 5 Wave Period Tp (secs) Wave Period Tp (secs) Wave Period Tp (secs)

HISTOGRAM PERCENTAGE (OF TIME) Wave Data Recording Program me. OCCURRENCE OF WAV E Cairns Region PERIODS (T P) FOR ALL WAV E HEIGHTS (H51G) AND DIRECTIONS Figure4.2 W01 :2 Beach Protection Authority 2nd May 1975 to 20th December 1981 � _.....i,.. !, ...... ___ _ Q) 0 E 14 � a:: ] 12 ,,.,. ,.. l!> � 10 \. Iu; 1·9 8 ...... � I \ x ...... a:: """'- �,,- gs 6 I \ �H u ' I u 4 � 0 ' z 2 j ... � 1·5 ...... � "' 0 _v � · 0 0·5 1·0 1·5 2·0 2·5 3·0 1 2 H 1-6 T·B 2·0 2·4 H MAX I H SIG RATIO Hs1G (m)

Q) 0 E 70 :;:: � 0 60 a::: - (/) 5 � 50 a:�1' � 40 � a:: l!> gs 30 u;H I 8 20 z 0 10 J � 1·3 ' I � "' 0 � 1-0 1·2 1-4 1-6 1·8 2-0 2·2 0 0·5 1-0 1-5 2·0 2·5 3·0

HsiG / HRMS RATIO Hs1G (m)

- Q) E :;:: 14 -0 12 � 10 "' I � 8 ' � �� a:: gs 6 I �v 8 4 I .J11' 0 v 2 �..,,,,,,.. '- - --� "' 0 J ....._ l/ 2-2 2·6 1-0 1·4 1-8 3·0 0 2 4 8 10 12 Tp /Tz RATIO T p (Secs)

- CD

.5 14 04·0 - -0 12 � UJ u 10 a:: 3·0 l!> UJz 8 a:: .§ a:: 6 '2·0 J :::> � """"" u ' -� u .. ' z � 0 ' � 2 � 1·0 !'-...... - "' 0 _/ :!: ,/ 1·0 1·8 2-2 2·6 3·0 0·6 H 1 2 4 6 8 10 12 Tp / TsiG RATIO T p (Secs)

Wave Data Recording Programme.

Cairns Region WAV E PA RAMETER ,. RELATIONSHIPS Figure 5·0 W01:2 Beach Protection Authority ... 1 ?nrl Mriv 1q7F) tn 11th .11 ini:i Q�� 1.8

1.6

1.4

....a> .... � 1.2 I !!? � 1.0 ·a; :::r:: _, "'� 0.8 �

0.6 -----�.:.111!'_9!.�1.:.___

0.4

0.2

- 0· 1 0.2 0.3 0.4 0.5 0.60.7 0.91 .0 2 3 4 5 6 7 8 9 10 WAVE HEIGHT PERSISTENCE !DAYS)

Note 1. Wave height persistence is the duration for which a given significant wave height is continuously exceeded. As an example, given a 0.6 metre significant wave height, there is a 40% probability that this wave height or greater will persist for more than one day. 2. The mean persistence line plotted represents the average persistence of all events having a given � significant wave height or greater.

Wave Data Recording Programme. AV ERAGE DURATION OF EXCEEDANCE Cairns Region

OF WAV E HEIGHTS (H ) 51G FigureS·O W01:2 Beach Protection Authority 2nd May 1975 to 11th June 1985 2.0 "' 1.8 � e 1.61.4 "' 1.2 v; :c 1.0 0.8 .E·""o; :c 0.6 0.4 � 0.2 � � JI 0.0 JAN FEB MAR APR MAY JUNE

:'.l., 10 "' 8 Q...... 6 .S! a..lii 4 �.. 2 3: ~ 0 JAN FEB MAR APR MAY JUNE

270 i .. O> .. 31? Q 450 c .S! 90 u fl � 135 i:5 180 ..� 225 3: 270 JAN FEB MAR APR MAY JUNE·

2.0 .. 1.8 � 1.6 e 1.4 1.2 "' v; 1.0 :c 0.8 .E.!? .. 0.6 :c 0.4 �.. 0.2 ti 3: 0.0 JUL AUG SEP OCT NOV DEC

:'.l• 10 � 8 Q...... 6 .S! a..lii 4 flt �.. 3: 2 0 JUL AUG SEP OCT NOV DEC

270 "' "" .. 315 Q 0

c 45 90 -�.. 135 a .. 180 ,. .. 225 3: 270 JUL AUG SEP OCT NOV DEC

Wav e Data Recording Program me.

Cairns Region DAILY WAV E HEIGHTS, (H5,G) PERIODS (T p) AND DIRECTION Figure 7· 1 W0 1:2 Beach Protection Aut�ority 1975 2.0 1.8 1.6 Cyclone Allan 1.4 1.2 1.0 .E 0.8 o.s I.. > .. 0.4 ;!:: 0.2 o.o ��---��----��-��---��-��---��--��---��-__�---e MAR APR MA Y JUNE

12 ., � 10 8 Q...... 6 4 2

o --��-��-+��--��--��--��-+-��--��--.-��--��-+-��-__�-- JAN FEB MAR APR MAY JUNE

270 ., 315 ;g 0 � 45 .S! 90 135 a�

>.. 180 � 225 27o --��-��--��--��-+-��--��---+-��--��-+-��--��---+-��-__�---c JAN FEB MAR _ A� MAY JU NE

2.0 1.8 1.6 1.4 "' 1.2 ;;; ::c 1.0 -i 0.8 ·a; ::i:: 0.6 .. 0.4 � 0.2 o.o --���---���--���--���--���--���- JUL AUG SEP OCT NOV DEC

l'.l 10 � 8

Q...... 6 ... . S! .E 4 .. � 2 o ��-��-+��--��--��--��--.��--��--��--��--.��--��- JUL AU G SEP OCT N0V DEC

270 g. 315 Q 0

c 45 ·� 90 � 135 __,...._.."'-.JV 180 . �� 225 210 --���---���--���--���--���--���- JUL AUG SEP OCT NOV DEC

Wav e Data Recording Programm e.

Cairns Region DAILY WAVE HEIGHTS, (H51G) ·.. PERIODS (T p) AND DIRECTION Figure 7·2 W01:2 Beach Protection Authority 1976 2.0 1.8 Cyclone Keith 1.6 1.4 Cyclone Nancy Cyclone Otto 1.2 1.0 0.8 0.6 0.4 0.2 O.O+----______-- JAN FEB MAR MAY JUNE

12 10 8 6 4 2

O +------+------

.. 270 :il' 315 c 0 45 90 �-� 135 "' 180 225 � +- 27o ---__ ___,__ ---+-----..,.��---+------+------+------< JAN __FEB MAR APR MAY JUNE

2.0 �.. 1.8 a; E 1.6 1.4 1.2 1.0 � 0.8 a.s I.. > '" 0.4 3:: 0.2 o.o +------______-___ JUL A P D UG S E OC T NOV EC

12 .. � 10 8 6 4 2 0 +------4 JUL AUG SEP OCT NOV DEC

JUL AUG OCT NOV DEC

. ------

Wave Data Recording Programme.

Cairns Region DAILY WAV E HEIGHTS, (H5 ) 1G ,.. PERIODS (T p) AND DIRECTION Figure 7·3 W01:2 Beach Protection Authority 1977 .. 12 �.. 10 8 0. ,_ .,, 6 ·� � ., 4 j ,; 2

.. 270 go 315 � 0 c: 45 .g 90 � 135 "" 180 225 270 ��--��---�� - -�� ---�� -�--�� 1 JAN FEB :::-:-=MAR -;-;;;;APR ";;AiMAY, :iiiNi�J UNE

2.0 1.8 1.6

I 1.4 "' 1.2 o; :c 1.0 -§, 0.8 � 0.6 ., > 0.4 � 0.2 o.o L------==------::-::: ------JUL AUG SEP OCT;-- -..m.NOV ----n�OEC 12

8 6 4 2

o ��-��--��---��---��--�---;�:;-�---t�� - L... JUL AUG SEP OCT NOV -+-��DE�C��

270 g. 315 c 0 I c: 45 .g 90 af;l 135 � 180 225 � 270 � ��--��---t>--� �--�� --

Wave Data Recording Programme: . Cairns Region DAILY WAV E HEIGHTS, (H51G)

PERIODS (T P) AND DIRECTION Figure 7·4 Beach Protection Authority 1978 ..._ W01:2 ....i 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 � o.o �� -�� ------�--�� ---�� --�� --�� --�� ---��---��--��-�7�-- JAN FEB MAR APR MAY JUNE

12 :'.: 10 e: 8 ;= 6 ... 4 "--� 2 3:� O +-�� -�� ----�� -�� +-��--��--�� --�� -+-�� --�� -__�----< JAN FE8 MAR APR MAY JUNE

270 � 315 � 0

c 45 -� 90 � 135 i5 1 BO ..� 225 3: 270 +-���--���---���---���---+��--��---< JAN FEB MAR APR MAY JUNE

2.0 1.8 1.6 1.4 "' l.2 :i::;;; 1.0 0.8 0.6 0.4 0.2 .._ o.o �� --��--�� --�� --��---�� --�� --�� --��-��--�� --�� ----- JU L AUG SEP OCT NOV 0EC

12 g 10 B

Cl...... 6 ... 4 "-·� "' � 2 O +-��--�� -+-�� --�� --��--�� --o--�� -�� --�� -��--�� --�� ----t JUL AUG SEP OCT NOV 0EC

JUL AUG OCT NOV DEC

Wav e Data Recording Programme.

Cairns Region DAILY WAV E HEIGHTS, (H51G) PERIODS (T p) AND DIRECTION Figure 7·5

Beach Protection Authority ... W01:2 ....i 1979 2.0 "' � 1.8 E 1.6 1.4 "' in 1.2 ::c 1.0

.E"" 0.8 ·a; ::c 0.6 0.4 � A 3:.. 0.2 "" a.a JAN FEB MAR APR MAY JUNE

12 "' ...,u 10 8 """ ,_ 6 .,,,.5! lil a.. 4 � .,> �.. 2 Ni a JAN FEB MAR APR MAY JUNE

270 """' 315 Q., a 45 c: 90 fl ·� e 135 [ a 180 .,> 225 3:.. 270 JAN FEB MAR APR MAY JUNE

2.0 "' e 1.8 1.6 . .,E '1 1.4 1.2 "':! ::c 1.0 . 0.8 .E= ·a; 0.6 ::c .,> 0.4 � 3:.. 0.2 � a.a JUL AUG SEP OCT NOV DEC

12 � 10 8 """ ,_ 6 .,,,.5!

a..lil 4 .,> 1J 2 �.. ~ a JUL AUG SEP OCT NOV DEC

270 .."" 315 Q., a c: 45 .5! t; 90 e 135 a J0 180 .,> �.. 225 270 JUL AUG SEP OCT NOV DEC

Wave Data Recording Programm e.

Cairns Region DAILY WAV E HEIGHTS, (H51G)

PERIODS (T p) AND DIRECTION Figure 7·6 W01:2 Beach Protection Authority 1980 2.0 1.8 1.6 1.4 Cyclone Eddie 1.2 Cyclone Freda 1.0

;:CD 0.8 ·o; 0.6 :r. ., 0.4 . � 0.2 o.o --��--�� --��--��--��---��-...��-��--��---�� --��---��-- JAN FEB MAR APR MAY J UNE

12 10 8 6 4 2 o --���----���----��--���----��--���-- JAN FEB MAR APR MAY JUNE

270 g. 315 � 0 c 45 -� 90 I!! 135 � 180 � 225 270 +--��-...��-...��--��---��--�� ...... JAN FEB MAR APR MAY JUNE

2.0 1.8 1.6 1.4 <.O in 1.2 ::c 1.0 ;: "" 0.8 ·o; ::c 0.6 ., > .. 0.4 3::: 0.2 o . o --���---��...... -���---��...... -���--���--- AUG JUL SEP OCT NOV OEC

l'.l 10 :ll 8 6 4 2

�� O +-- -��..-..��...... ,...��--+��-��-+-��---��--+��-��--+-��-��.__, JUL AUG SEP 0CT NOV DEC

JUL AUG SEP OCT NOV DEC

Wav e Data Recording Programm e.

Cairns Region DAILY WAV E HEIGHTS, (H51G) PERIODS (Tp) AND DIRECTION Figure 7. 7 W01:2 Beach Protection Authority 1981 Cyclone Dominic

12 .. : 10 " " 8 ...... 6 ] 4 ;f

�• 2 • (} MAY JUNE

270 � 315 .! 0 I 46 No Wave Directions are Available .� u 13590 � 100 .. ,; 270225 1------�------� -- �------��:;------�8 ------M� ----;;JW.NU E;----

12 i 10 I 8.

� 6

� 4 cf 2 •! oi---...,....�------�------"'."::"'"------::=------=-:------;m:-----... JUI. AUG , SEfl OCT NOV DEC

270 i;. 315 .! 0 Directions I 45 No Wave are Available 00 .j 135 � ;! 1111 t 225 � 210L------�---:-�----....---�;""------""'-::::::------�:;;;;;------��--...... JUI. AUG SEP OCT NOV DEC ------�------=:,______....;:;:.. ______� ------...;,;;.;.--��-=-�------:::;---- Wav e Data Recording Programme. DAILY WAV E HEIGHTS, (H51G) Cairns Region PERIODS (T p) AND DIRECTION ,...... Figure 7·8 W01:2 Beach Protection Authority 1982 ... Cvclone Elonore

FEB APR MAY

12 .. !: lO 8 6 4

270� i 31 45 No Wave Directions are Available -� 00 i 135 i5 1111

..• 2;0

jI Cyclone Fritz

i ::!.

JUL SEP OCT NOV OEC

!i lO 8 i : �1� 1 • j 2 O+-��--��---o��--��--��--��---. JUL SEP OCT NOV DEC

.. 270 g 315 I 0 4& .j 00 No Wave Directions are Available ¥ 135 � 1111 : 225 � m .._�------��----1��----�-..���--��--�--��---4 JUL AUG SEP OCT NOV DEC

Wave Data Recording Programm e. DAILY WAV E HEIGHTS, (H51G) Cairns Region PERIODS (T p) AND DIRECTION ,.. ,Figure 7·9 W01:2 Beach Protection Authority 1983 .... Cyclone Lance j ��

JAN FE& APR MAY JUNE

. FEB MAR MAY JUNE

No Wave Directions are Available

MAY JUNE

Cyclone Monica

JtJl SEP ·ocr NOV DEC

SEP oct DEC

No Wave Diretlona are Available

JUI. AUG SEP OCT NOV DEC

Wave Data Recording Programm e. D�ILY WAV E HEIGHTS, (H ) 51G Cairns Region �

,.. PERIODS (T AND DIRECTION p) Figure 7·10 W0 1:2 Beach Protection Authority 1984 .. 2-0 e 1· i 1·6 1·4 Cyclone Odette 1-2 ·! ::c 1·0 .E IJ.8 .S!' 0·6 � :! 0·4 � '\. .. 02 ,. O·O JAH FE& MAR APR MAY JUNE

..... 10 = 8 ...... 6 ] 4 �ii .,.. 2 v ,.. 0 JAM FEB MAR APR MAY JUNE

.. 270 l 315 I 0 .� � No Wave Directions are Available ;:; !II � 135 ..� li.J ,. 225 2711 FEB MAR APR MAY JUNE

DAILY WAV E HEIGHTS, (H51G) Wave Data Re cording Programme. Cairns Region

PERIODS (T p) AND DIRECTION ,... -, Figure7 .11 1985 W01:2 Beach Protection Authority ... 0 0 ID

0 0 N

0 0 . .--

(./) 0 a: <( ID UJ >- 0 0 a: UJ Cl. z a: :J f- UJ 0 a: N

0 \\ .--

\ ID \ 0 "<;t 0 \ _...., 0

\ N 0

\ 0 ID \ 0 ID N .- .... 6 (S9Jl9W) 1Hrn3H 3/\VM "(

Wav e Data Recording Programme.

Cairns Region WAV E HEIGHT (H 51G) ,... � RECURRENCE INTERVALS Figure 8 Beach Protection Authority 2nd May 1975 to 11th June 1985 ......