i

LONGSHORE SEDIMENT TRANSPORT IN THE SWASH ZONE AT DESARU

BEACH

MARIAHTI BTE BERAHIM

A project report submitted in partial fulfilment of the

requirements for the award of the degree of

Master of Engineering (Civil – Hydraulics & Hydrology)

Faculty of Civil Engineering

Universiti Teknologi Malaysia

JANUARY 2014

iii

Specially dedicated to my beloved father, mother, sisters and brother

iv

ACKNOWLEDGEMENTS

First of all, I am grateful to Allah s.w.t. for all His guidance and blessing

through all the hardship encountered when completing this project.

I would like to express my sincere appreciation to my supervisor, Dr.

Mohamad Hidayat bin Jamal and Assoc. Prof. Dr. Mushairry bin Mustaffar who

helped me a lot in the progress of my project by giving me guidance, encouragement

and details explanation.

I would like to thank the Department of Irrigation and Drainage (DID)

Malaysia and Malaysian Meteorological Department for the data and valuable

information that have been used in this project.

Thanks also to Mr. Radzuan Sa’ari, Mr. Md Ridzuan Makhtar, Mr. Norasman

Othman and Mr. Suhaimi for the help in this project. I appreciate very much.

A very special thanks to Izyan, Ling and Suhaila who helped me regarding

this project.

And last but not least, thank you very much to my beloved family who

always encourage me and their loving bless.

v

ABSTRACT

This study examined the processes of longshore sediment transport in the

swash zone at Desaru beach, Johor. It focused the suitability of sediment trap on

sandy beach and beach profile’s survey to determine the direction of longshore

transport. Field measurements were carried out by using sediment trap, Global

Positioning System (GPS) kit and water level logger. Data collected are sediment

samples, beach profile and tides. Laboratory sediment analysis also conducted to

determine the size, density and porosity at the area. It was found that the sediment

trap is unsuitable to be used at Desaru beach. This could be due to highly turbulent

waves and sediment transport from the cross-shore direction that had fully covered

the trap with sediment. The beach profile survey shows that the direction of the

longshore transport is coming from northwest to southeast of the beach. From the

analysis of sediment samples, it was found that the sediment size ranges from 0.33

mm to 0.35 mm with median diameter of 0.34 mm. From the experiment, the average

porosity is approximately 0.43, whereas the average density is about 2635 kg/m3. As

conclusions, the sediment trap is unsuitable to be used at sandy Desaru beach. The

direction of the longshore transport is from northwest to southeast of the area during

Northeast monsoon.

vi

ABSTRAK

Kajian ini mengenai proses pengangkutan sedimen pesisiran pantai di dalam

zon swash di pantai Desaru, Johor. Ia memberi tumpuan untuk menguji kesesuaian

perangkap sedimen di pantai berpasir dan profil pantai diukur untuk menentukan

arah pengangkutan pesisiran pantai. Kajian dijalankan dengan menggunakan

perangkap sedimen, alat GPS dan pengukur kedalaman air. Data yang diambil adalah

sampel sedimen, profil pantai dan air pasang surut. Analisis sedimen dijalankan di

makmal untuk mengenal pasti saiz, ketumpatan dan keliangan sedimen di kawasan

kajian. Hasil kajian mendapati bahawa perangkap sedimen tidak sesuai digunakan di

pantai Desaru. Ini mungkin disebabkan oleh gelombang yang bergelora dan

pengangkutan sedimen dari arah merentasi pantai yang telah menimbus sepenuhnya

perangkap sedimen. Hasil keputusan juga menunjukkan bahawa arah pengangkutan

pesisiran pantai itu dari arah barat laut ke tenggara di kawasan kajian. Daripada

analisis sedimen mendapati bahawa saiz sedimen adalah daripada 0.33 mm ke 0.35

mm dengan diameter median ialah 0.34 mm. Hasil ujikaji yang dijalankan, keliangan

purata sedimen adalah kira-kira 0.43 manakala ketumpatan purata adalah kira-kira

2635 kg/m3. Kesimpulannya, perangkap sedimen tidak sesuai digunakan di pantai

berpasir. Arah pengangkutan pesisiran pantai adalah dari arah barat laut ke tenggara

di kawasan kajian semasa monsun timur laut.

vii

TABLE OF CONTENTS

CHAPTER TITLE PAGE

DECLARATION ii

DEDICATION iii

ACKNOWLEDGEMENTS iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES x

LIST OF FIGURES xi

LIST OF ABBREVIATIONS xiv

LIST OF SYMBOLS

LIST OF APPENDICES

xv

xvii

1 INTRODUCTION 1

1.1 Introduction 1

1.2 Statement of Problem 2

1.3 Importance of the Study 3

1.4 Objective of the Study 4

1.5 Scope of the Study 4

2 LITERATURE REVIEW 5

2.1 General 5

2.2 Beach Sediment 6

2.3 Beach States 8

2.4 Wave Transformation 9

viii

2.4.1 Wave Refraction 10

2.4.2 Wave Diffraction 11

2.4.3 Wave Reflection

2.5 Sediment Transport

12

13

2.5.1 Longshore Sediment Transport 13

2.5.2 Cross-shore Sediment Transport 15

2.5.3 Sediment Transport Modes 15

2.6 Measurement of Longshore Sediment Transport 16

2.6.1 Tracers 16

2.6.2 Traps 17

2.6.3 Rates of Accumulation 17

2.7 Prediction of Longshore Sediment Transport Rates 18

2.7.1 CERC Formula 18

2.7.2 KAMPHUIS Formula 20

2.8 Swash Zone 21

2.8.1 Sediment Transport in the Swash Zone 22

2.9 Tides 25

2.9.1 Spring and Neap Tide 25

2.9.2 Tide Range 27

2.10 Beach Profile Change 28

2.10.1 Mechanisms Causing Beach Profile Change 30

2.10.2 Beach Measurement 31

3 METHODOLOGY 33

3.1 General 33

3.2 Sediment Trap 34

3.3 GPS Setup 37

3.4 Beach Profile Survey 39

3.5 Tidal Data Measurement 40

3.6 Sampling and Analysis of Samples 43

3.6.1 Sieve Analysis 43

3.6.2 Porosity Test 44

3.6.3 Density Test 45

ix

4 RESULTS AND DISCUSSION 46

4.1 Sediment Trap 46

4.2 Wave and Wind Rose Analysis 48

4.3 Beach Profile Results 51

4.3.1 Beach Profile Change for 1 Day 53

4.3.2 Beach Profile Change for 2 Days 54

4.3.3 Beach Profile Changes for 1 Week 57

4.3.4 Beach Profile Change for 3 Weeks 59

4.4 Tidal Analysis 61

4.5 Sediment Samples 62

5 CONCLUSIONS AND RECOMMENDATIONS 65

5.1 Conclusions 65

5.2 Recommendations for Future Study 66

REFERENCES 67

Appendices 70

Appendix A 70

Appendix B 71

x

LIST OF TABLES

TABLE NO. TITLE PAGE

2.1 Wentworth scale of sediment size classification 6

4.1 Tides with specified date 52

4.2 Erosion and accretion value for 1 day 54

4.3 Erosion and accretion value for 2 days 56

4.4 Erosion and accretion value for 1 week 58

4.5 Erosion and accretion value for 3 weeks 60

4.6 Sediment properties of sediment sample 63

xi

LIST OF FIGURES

FIGURE NO. TITLE PAGE

1.1 Location of Desaru beach 3

2.1 Type of wave breaking 9

2.2 Wave refraction pattern 10

2.3 Definition sketch for wave diffraction in the lee of a

barrier

12

2.4 Wave reflection analysis 12

2.5 Beach drifting – Schematic process of longshore

transport on the swash slope

14

2.6 Definition sketch for the nearshore littoral zone 22

2.7 Sediment transport processes during a swash cycle 24

2.8 Relative positions of the sun, moon and earth during

spring tides

26

2.9 Relative positions of the sun, moon and earth during

neap tides

26

2.10 Tidal curves, tide ranges and shore zones 28

2.11 Typical beach profiles and terminology 29

3.1 Desaru beach, Johor 33

3.2 Sediment trap with size of 15 cm by 9 cm for first

measurement

34

3.3 Location of sediment trap for first measurement 34

3.4 Sediment trap with size of 7.6 cm by 7.6 cm for second

measurement

35

3.5 Location of sediment trap for second measurement 35

xii

3.6

Sediment trap with size of 7.6 cm by 7.6 cm for third

measurement

36

3.7 Location of sediment trap for third measurement 36

3.8 Installation of sediment trap 36

3.9 Arrangement of sediment trap along the shore 37

3.10 RTK base receiver 38

3.11 RTK GPS setup 38

3.12 Beach survey location 39

3.13 Measurement of beach profile change by using RTK

rover receiver

40

3.14 Bench mark J4299 from JUPEM 40

3.15 Bench mark 5008J from Royal Malaysian Navy 41

3.16 Tide gauge at Jetty Tanjung Balau 41

3.17 Conversion from ACD to LSD 42

3.18 Beach profile (MSL is elevation of 0.41 m) 42

3.19 The equipment used to determine grain-size

classification

44

4.1 Observation of sediment trap 47

4.2 Sketch of wave effect to the sediment trap 48

4.3 Wave rose in October from 1984 to 2013 49

4.4 Wave rose in November from 1984 to 2013 49

4.5 Wind rose at station Mersing from 1968 to 2012 50

4.6 Beach profile change at location NW260 51

4.7 Beach profile change at location C0 52

4.8 Beach profile change at location SE290 52

4.9 Beach profile change for 1 day at location NW260 –

Profile 1

53

4.10 Beach profile change for 1 day at location C0 – Profile 2 53

4.11 Beach profile change for 1 day at location SE290 –

Profile 3

54

4.12 Beach profile change for 2 days at location NW260 –

Profile 4

55

xiii

4.13 Beach profile change for 2 days at location C0 – Profile

5

55

4.14 Beach profile change for 2 days at location SE290 –

Profile 6

56

4.15 Beach profile change for 1 week at location NW260 –

Profile 7

57

4.16 Beach profile change for 1 week at location C0 – Profile

8

58

4.17 Beach profile change for 1 week at location SE290 –

Profile 9

58

4.18 Beach profile change for 3 weeks at location NW260 –

Profile 10

59

4.19 Beach profile change for 3 weeks at location C0 –

Profile 11

60

4.20 Beach profile change for 3 weeks at location SE290 –

Profile 12

60

4.21 Tide data at Tanjung Balau, Johor 62

4.22 Grain size distribution of Sample A 63

4.23 Grain size distribution of Sample B 63

xiv

LIST OF ABBREVIATIONS

ACD - Admiralty Chart Datum

LSD - Land Survey Datum

MHHW - Mean Higher High Water

MLHW - Mean Lower High Water

MSL - Mean Sea Level

MHLW - Mean Higher Low Water

MLLW - Mean Lower Low Water

GPS - Global Positioning System

RTK - Real Time Kinematic

xv

LIST OF SYMBOLS

β - Beach slope

H0 - Deep water wave height

L0 - Deep water wave length

ζ0 - Iribarren number

I - Immersed weight longshore transport rate

E - Wave energy at breaker line

Hrms,br - rms wave height at breaker line

cg,br - Wave group celerity at breaker line

θbr - Wave angle at breaker line

K - Coefficient

Qt,vol - Longshore sediment transport by volume including pores

Qt,mass - Sediment transport by dry mass

Hs,br - Significant wave height at the breaker line

cbr - Phase velocity of the waves at the breaker line

nbr - Coefficient at breaker line

θbr - Wave angle at the breaker line

hbr - Water depth at the breaker line

p - Porosity factor

ρs - Sediment density

Qt,im - Immersed mass longshore sediment transport

Qt,mass - Dry mass

d50 - Median particle size in surfzone

Tp - Peak wave period

Vs - Volume of loose sand

Vw - Volume of water

VT - Total volume

xvi

Vsw - Volume of sand and water

Ws - Weight of sand

n - Porosity

D50 - Median size of sediment distribution

xvii

LIST OF APPENDICES

APPENDIX TITLE PAGE

A Tide table at Tanjung Sedili, Johor 70

B Value above chart datum at Tanjung Balau 71

1

CHAPTER 1

INTRODUCTION

1.1 Introduction

The study of sediment transport processes is fundamental to the

understanding of coastal evolution, which is necessary for effective coastal

engineering design. Generally, sediment transport can be divided into longshore

sediment transport and cross-shore sediment transport. Longshore sediment transport

is primarily driven by an alongshore wave-induced current produced by waves

approaching at an angle to the shore, whereas cross-shore sediment transport is

considerably generated during storm (Won and In, 2008). Longshore transport plays

a large role in the evolution of shoreline. If there are slight changes in sediment

supply, wind direction or coastal influence, the formation and evolution of beach

profile will be effected. The present study is focused on the longshore sediment

transport.

The swash zone has been considered as an important role in shaping natural

beaches. Thus, the understanding of processes in this zone is very important for the

estimating of coastal erosion and accretion. Elfrink and Baldock (2002) stated that

littoral sediment transport often occurs in the swash zone as sediment concentrations

are often high in the swash zone. The swash zone is the most dynamic part of the

nearshore region and characterised by large flow velocities, high turbulence levels

and large suspended sediment concentrations (Elfrink and Baldock, 2002).

2

Beach monitoring provides a way of understanding beach dynamics and the

factors that influence the volumetric gains and losses along the coast (Morton et al.,

1993). Changes in cross-shore beach profiles are controlled by many factors, which

include waves, tidal flows and sediment characteristics (Karunarathna et al., 2012).

By measuring the dimensions of a particular beach repeatedly, the amounts of

erosion or accretion can be determined over the period of the surveys, as well as

some indications of where the material may be going. Details about the behaviour of

the particular beach can be provided when measured the beach profiles at the same

location over a period of time.

People utilise the coast for many purposes such as commercial fishing,

tourism and recreation. The coastal environment is dynamic and it is one of the most

rapidly changing physical environments on earth. Due to the strong link between

society and coastal changes, it is advisable that we understand this environment and

what causes it to change its state. Although natural processes are shaping the earth’s

natural coastal landscape, but these processes can give trouble to people that live

along the coasts, where their homes are built right on or near the beaches. This is

because of the process that carries sediments away from the shore can lead to

erosion. Therefore, we should make every effort to control this from happening.

1.2 Statement of Problem

Johor is one of the coastal states in Malaysia with the longest coastline facing

the South China Sea in the east, the Strait of Malacca in the west and the Strait of

Johor in the south. Coastal resources are the main source of income towards

industrialisation and economic development in Johor especially along the coastal

area. Tourism plays an important role in the state’s economy. In Johor, Desaru beach

is most popular beach and situated on the southeast coast of the district. It is located

approximately 88 kilometres east of Johor Bahru and very close to the developing

country, Singapore. Figure 1.1 shows the location of Desaru beach in Peninsular

Malaysia.

3

The National Coastal Erosion Study (NCES) reported cases of coastal erosion

and established for three categories (ASEAN/US CRMP, 1991). First category is

critical erosion, second category is significant erosion and third category is

acceptable erosion. Thus, Desaru is in category one which is critical erosion. Desaru

beach also can be categorised as a steep beach slope. In coastal area, waves mobilise

and currents transport coastal sediments. Erosion occurs when the amount of

sediment transported away from an area exceeds the amount transported to it.

Therefore, further investigation in this area is needed to predict accurately coastal

erosion trends along Johor’s coast.

Figure 1.1: Location of Desaru beach

1.3 Importance of the Study

Desaru beach is a resort located at east of Johor. It is a very famous spot for

tourists mostly from Singapore and the locals. This study is conducted to examine

the suitability of the sediment trap on sandy beach by using different size of sediment

trap. The sediment trap is used to collect moving sediment so that the transport rate

4

can be measured. The analysis of sample also is conducted in the laboratory to

determine the size, density and porosity of sediment at the area. Beach profile change

is measured to determine the erosion and accretion of the study area and also to

analyse the direction of longshore sediment transport. Thus, the coastal erosion

trends can be predicted at Desaru beach.

1.4 Objective of the Study

The objectives of the study are to:

1. Examine the suitability of sediment trap on sandy beach.

2. Analyse the sediment properties on the beach.

3. Analyse the direction of longshore transport by measuring beach profile.

1.5 Scope of the Study

Field work is conducted in order to achieve all the objectives of the study of

longshore sediment transport in the swash zone at Desaru beach. The scopes of this

study are:

1. Tide table is referred to determine the neap and spring in order to conduct

beach profile measurement and to install the sediment trap.

2. Sediment trap is used to examine the suitability of the trap on sandy beach

with different size and duration of study.

3. Analyse the sample to determine the grain size, porosity and density of the

sediment.

4. Wind and wave rose are obtained from Malaysian Meteorological Department

for analysis of the effect of wave to beach profile change.

67

REFERENCES

ASEAN/US CRMP (Association of Southeast Asian Nations/United States of

Coastal Resources Management Project). (1991). The Coastal Environment

Profile of South Johore, Malaysia. ICLARM Technical Report. 24:65.

Baba, Y. and Camenen, B. (2007). Importance of the Swash Longshore Sediment

Transport in Morphodynamics Models. Coastal Sediments ’07.

Bird, E. (2008). Coastal Geomorphology: An Introduction. (2nd

ed.) . England: John

Wiley & Sons Ltd.

CEM (Coastal Engineering Manual). (2002). Lonngshore Transport. Part III Chapter

2.

Davidson-Arnott, R. (2010). An Introduction to Coastal Processes and

Geomorphology. United States of America: Cambridge University Press.

Dean, R. G. and Dalrymple, R. A. (2004). Coastal Processes with Engineering

Applications. Cambridge, United Kingdom: Cambridge University Press.

Elfrink, B. and Baldock, T. (2002). Hydrodynamics and Sediment Transport in the

Swash Zone: A Review and Perspectives. Coastal Engineering. 45, 149-169.

FredsØe, J. and Deigaard, R. (1992). Mechanics of Coastal Sediment Transport.

Singapore: World Scientific Publishing Co. Pte. Ltd.

Horn, D. P. and Mason, T. (1994). Swash Zone Sediment Transport Modes. Marine

Geology. 120, 309-325.

Hughes, M. G., Masselink, G., Brander, R. W. (1997). Flow Velocity and Sediment

Transport in the Swash Zone of a Steep Beach. Marine Geology. 138, 91-103.

Husain, M. L., Yaakob, R., Shahbudin, S. (1995). Beach Erosion Variability during a

Northeast Monsoon: The Kuala Setiu Coastline, Terengganu, Malaysia. Journal

Science and Technology. 3(2), 337-348.

Kamphuis, J. W. (1991). Alongshore Sediment Transport Rate. Journal of Waterway,

Port, Coastal and Ocean Engineering. 117(6).

68

Karambas, T. V. (2006). Prediction of Sediment Trasnport in the Swash Zone by

Using a Nonlinear Wave Model. Continental Shelf Research.

Karunarathna, H., Horrillo-Caraballo, J. M., Ranasinghe, R., Short, A. D., Reeve, D.

E. (2012). An analysis of the Cross-Shore Beach Morphodynamics of a Sandy

and a Composite Gravel Beach. Marine Geology. 299-3012, 33-42.

Larson, M., Kubota, S., Erikson, Li. (2004). Swash Zone Sediment Transport and

Foreshore Evolution: Field Experiments and Mathematical Modeling. Marine

Geology. 212, 61-79.

Liu, Z. (2001). Sediment Transport. (3rd

ed.). Aalborg.

Morton, R. A., Leach, M. P., Paine, J. G., Cardoza, M. A. (1993). Monitoring Beach

Changes Using GPS Surveying Techniques. Journal of Coastal Research. 9(3),

702-720.

Pedrozo-Acuña, A., Simmonds, D. J., Otta, A. K., Chadwick, A. J. (2005). On the

Cross-Shore Profile Change of Gravel Beaches. Coastal Engineering. 53, 335-

347.

Pieterse, J. J. (2009). The Influence of an Ecobeach PEM on Beach Development.

Msc. Thesis. Technical University Delft.

Puleo, J. A., Beach, R. A., Holman, R. A., Allen, J. S. (2000). Swash Zone Sediment

Suspension and Transport and the Importance of Bore Generated Turbulence.

Journal of Geophysical Research. 105.

Reeve, D., Chadwick, A., Fleming, C. (2004). Coastal Engineering: Processes,

Theory and Design Practice. Oxon: Spon Press.

Rosati, J. D. and Kraus, N. C. (1988). Hydraulic Test of Streamer Sediment Trap.

Journal of Hydraulic Engineering. 14(12).

Shore Protection Manual (1984). Coastal Engineering Research Center. U.S. Army

Corps of Engineers.

Sorensen, R. M. (2006). Basic Coastal Engineering. (3rd

ed.). New York, USA:

Springer Science + Business Media.

Trim, L. K., She, K., Pope, D. J. (2002). Tidal Effects on Cross-shore Sediment

Transport on a Shingle Beach. Journal of Coastal Research. 36, 708-715.

Van Rijn, L. C. (2001). Longshore Sediment Transport. Report Z3054.20. Delft, The

Netherlands.

69

Van Wellen, E., Chadwick, A. J., Lee, M., Baily, B., Morfett, J. (1998). Evaluation

of Longshore Sediment Transport Models on Coarse Grained Beaches Using

Field Data: A Preliminary Investigation. Coastal Engineering. 2640 – 2653.

Wang, P., Davis, R. A., Jr., Kraus, N. C. (1998). Cross-Shore Distribution of

Sediment Texture Under Breaking Waves Along Low-Wave Energy Coasts.

Journal of Sedimentary Research. 68(3), 497-506.

Won, C. C. and In, H. K. (2008). Cross-Shore Change of Beach Profile in Two

Shapes of Beach Slopes Breakdown. Proceedings of the Eighteenth (2008)

International Offshore and Polar Engineering Conference. July 6-18, 2008.

Vancouver, Canada.

Wright, L. D. and Short, A. D. (1984). Morphodynamic Variability of Surf Zones

and Beaches: A Synthesis. Marine Geology. 56, 93-118.