Hydrodynamic assessment of a new master plan for tam quan port binh dinh province

MINISTRY OF EDUCATION AND TRAINING MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT THUYLOI UNIVERSITY ------ PHAM PHU HYDRODYNAMIC ASSESSMENT OF A NEW MASTER PLAN FOR TAM QUAN PO

MINISTRY OF EDUCATION

AND TRAINING

MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT THUYLOI UNIVERSITY

- -

PHAM PHU

HYDRODYNAMIC ASSESSMENT OF A NEW MASTER

PLAN FOR TAM QUAN PORT - BINH DINH PROVINCE

MASTER THESIS

Ha Noi – 2016

MINISTRY OF EDUCATION

AND TRAINING

MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT THUY LOI UNIVERSITY

- -

PHAM PHU

HYDRODYNAMIC ASSESSMENT OF A NEW MASTER

PLAN FOR TAM QUAN PORT - BINH DINH PROVINCE

Field : Coastal Engineering and Management Field code : 62580203

MASTER THESIS

Supervisor : Assoc Prof Dr Mai Van Cong

Ha Noi – 2016

DECLARATION

I hereby certify that the work which is being presented in this thesis entitled,

“Hydrodynamic assessment of a new master plan for Tam Quan port – Binh

Dinh province” in partial fulfillment of the requirement for the award of the Master of

Science in Coastal Engineering and Management, is an authentic record of my own work carried out under supervision of Assoc Prof Dr Mai Van Cong The matter embodied in this thesis has not been submitted by me for the award of any other degree or diploma

Ha Noi, December 15, 2016

Pham Phu

ACKNOWLEDGEMENT

Implementing thesis study on hydrodynamic regime and sediment transport was a challenge but also an interesting and meaningful work to me From bottom of my heart, I gratefully acknowledge and give thanks to all individuals who gave me the possibility to complete this master thesis

First of all, I would like to express my hearty and deepest gratitude to my supervisor Assoc Prof Dr Mai Van Cong for his patience, timely advices, encouragement and valuable supports I would gratefully thanks to MSc Nguyen Quang Duc Anh from VINWATER for his constructive comments, providing data, guidance and practical suggestions to help me to accomplish this study successfully

I would like to thank to Assoc Prof Dr Tran Thanh Tung and Prof Dr Thieu Quang Tuan who are main co-ordinators of this master program, making value contributions

to success in Master course I am very thankful to all lecturers in Thuyloi University as well as Delft University of Technology who imparted their valuable knowledge which support me a lot in doing my thesis

I would like to thank sincerely to Assoc Prof Dr Do Van Luong – Director and MSc

Do Canh Hao, vice – Director of Institute of Education and Applied Sciences central Vietnam who gave me a chance to study this master course

I would like to thank all my classmates of this MSc course, all of them gave me the wonderful time during the course

Last but never least, I wish to express my thanks to my organization, my colleagues, special thank and love go to my family and my dear parents for their support and encouragements when I studied I dedicate this thesis to my family for their inspiration and support throughout my life; this research is simply impossible without you

TABLE OF CONTENTS

DECLARATION i

ACKNOWLEDGEMENT ii

TABLE OF CONTENTS iii

LIST OF FIGURES vi

LIST OF TABLES ix

LIST OF ABBREVIATIONS x

CHAPTER 1 INTRODUCTION 1

1.1 Background 1

1.2 Objectives of the study 3

1.3 Scope of the study 3

1.4 Methods of the study 3

1.5 Expected outcomes 3

1.6 Chapters outline 4

CHAPTER 2 LITERATURE REVIEW 5

2.1 Overview of fishing ports 5

2.1.1 Concept of fishing ports 5

2.1.2 Classification of fishing ports 6

2.1.3 Highlighted fishing ports in the world and Vietnam 7

2.1.4 Current status of fishery of Binh Dinh province 10

2.2 Overview of hydrodynamics of tidal inlets 15

2.2.1 Difference between tidal inlets and estuaries 15

2.2.2 Behaviour and hydrodynamics of a tidal inlet 18

2.3 Overview of deposition on tidal flats 22

2.3.1 Density currents at estuary areas and deposition in rivers (Cat, 2002) 22

2.3.2 Sediment transport and deposition on tidal flats (Verhagen, 1999) 23

2.4 Overview of the study area 24

2.4.1 Previous studies in the study area 24

2.4.2 General information on the existing Tam Quan fishing port 26

2.4.3 General information on the new master plan of Tam Quan fishing port

(IEAS, 2016) 29

2.4.4 Focus of this study 34

2.5 Overview of numerical models and the selection model 35

2.5.1 Introduction of numerical models 35

2.5.2 Numerical model selection 35

2.5.3 Introduction of MIKE 21/3 Coupled Model FM (DHI, 2012) 36

CHAPTER 3 FORMULATION OF PORT DESIGN AND PLANNING CRITERIA & MODEL SET-UP 41

3.1 Formulation of port planning and design criteria 41

3.1.1 General principles of planning anchorage area for boats and ships 41

3.1.2 Applied design standards, parameters for Tam Quan port and anchorage areas and its navigation channels 42

3.1.3 Formulation of port planning and design criteria according to hydrodynamic aspects 43

3.2 Natural conditions of Tam Quan fishing port area 46

3.2.1 Geographical location 46

3.2.2 Topographical characteristics 48

3.2.3 Geological characteristics 49

3.2.4 Hydrogeological conditions 50

3.2.5 Geology and geomorphology conditions 50

3.2.6 Climatic conditions 51

3.2.7 Oceanographic factors 53

3.3 Model set-up 56

3.3.1 Steps to set-up the model 56

3.3.2 Basic model input data 57

3.3.3 Model domain, computational mesh and boundaries 63

3.3.4 Hydrodynamic model parameters 64

3.3.5 Spectral wave model parameters 66

3.3.6 Sand transport model parameters 68

3.4 Model calibration and validation 68

3.4.1 Measured data 69

3.4.2 Model calibration and validation 70

3.4.3 Calibration results 70

3.4.4 Validation results 72

3.4.5 Discussion 75

CHAPTER 4 HYDRODYNAMIC ASSESSMENTS OF THE NEW MASTER PLAN FOR TAM QUAN PORT 76

4.1 Formulated modeling scenarios for hydrodynamic assessment of Tam Quan port area 76

4.1.1 For the existing situation 76

4.1.2 For the new master plan 77

4.1.3 Model extracted locations 77

4.2 Hydrodynamic assessments of Tam Quan port area based on criteria 79

4.2.1 Criterion 1 Avoid flooding in the port land area 79

4.2.2 Criterion 2 To ensure calm wave condition in the port 84

4.2.3 Criterion 3 To ensure permissible currents for ship maneuvering 87

4.2.4 Criterion 4 Avoid deposition to maintain channel depths 94

4.2.5 Discussion 104

4.3 Proposal of adjusted measure of the port entrance in order to fulfill port design criteria 105

4.3.1 Proposal of adjusted measure 105

4.3.2 Analysing the results of the adjusted measure 107

4.4 Discussion 116

CONCLUSIONS AND RECOMMENDATION 118

1 Conclusions 118

2 Existing weakness 118

3 Further researches 119

REFERENCES 120

APPENDICES 124

APPENDIX A – Master plans of Tam Quan fishing port 124

APPENDIX B – Results of the simulated scenarios for the existing situation 127

APPENDIX C – Results of the simulated scenarios for the new master plan 131 APPENDIX D – Results of the simulated scenarios for the adjusted master plan 135

LIST OF FIGURES

Figure 2.1 Some pictures of Chimbote fishing port in Peru (Google Earth) 8

Figure 2.2 Some pictures of Vladivostok Sea Fishing Port in Russia (Google Earth) 9

Figure 2.3 The quantity and capacity of ships and boats in the whole province through each year (IEAS, 2016) 12

Figure 2.4 The quantity and capacity of ships in Hoai Nhon district through the years (IEAS, 2016) 13

Figure 2.5 Some pictures of Quy Nhon fishing port in Binh Dinh province (photographed in November 2015) 14

Figure 2.6 Some pictures of De Gi fishing port in Binh Dinh province (photographed in March 2015) 15

Figure 2.7 Morphodynamics of seasonally closed coastal inlets at the central coast of Vietnam (Tung, 2015) 18

Figure 2.8 Ebb (E) and flood (F) tidal channels During flood the water might overshoot the bend leading to flood chutes, this process is schematized by the arrows (Van Veen, 1950) 20

Figure 2.9 Some pictures of Tam Quan fishing port (photographed in November 2012) 27

Figure 2.10 Digitizing the channel route for planned ships (IEAS, 2016) 32

Figure 2.11 The location of Thien Chanh and Go Dai fishing ports 33

Figure 3.1 The altitudes and depths, heights in front of the pier (Giap et al., 2010b) 44

Figure 3.2 The location of the study area 47

Figure 3.3 Wave roses in the nearshore and offshore of Tam Quan area 54

Figure 3.4 Wave height in the offshore of Tam Quan area from 1988÷2013 55

Figure 3.5 Wave period in the offshore of Tam Quan area from 1988÷2013 55

Figure 3.6 Wave direction in the offshore of Tam Quan area from 1988÷2013 56

Figure 3.7 The topographic map of surveyed area (Duc et al., 2015) 58

Figure 3.8 The bathymetry of study area used to simulate in MIKE 21 model 58

Figure 3.9 Locations and design flood discharge hydrograph (P=5%) at Tam Quan

area (Duc et al., 2015) 59

Figure 3.10 Design flood discharge hydrograph (P=5%) at Xuan Thanh bridge and the upstream of Thien Chanh bridge 60

Figure 3.11 Wave roses at the border point of deep water wave of Tam Quan area 61

Figure 3.12 Model domain and computational mesh included triangular and quadrangular elements 64

Figure 3.13 The location of observation stations (background map sourced by Google Earth) 69

Figure 3.14 Comparison between calculated and measured water level at P1 71

Figure 3.15 Comparison between calculated and measured water level at P2 71

Figure 3.16 Comparison between calculated and measured wave height at P4 72

Figure 3.17 Comparison between calculated and measured wave period at P4 72

Figure 3.18 Comparison between calculated and measured mean wave characteristic at P4 72

Figure 3.19 Comparison between calculated and measured water level at P1 73

Figure 3.20 Comparison between calculated and measured water level at P2 73

Figure 3.21 Comparison between calculated and measured wave height at P3 74

Figure 3.22 Comparison between calculated and measured wave period at P3 74

Figure 3.23 Comparison between calculated and measured mean wave characteristic at P3 75

Figure 4.1 The bathymetry of new master plan and the extracted locations of the results from Mike 21/3 FM model 78

Figure 4.2 Water level in the port area during the flood peak period (at 0:00 AM October 11th, 2013) with the existing master plan (T) and the new master plan (B) 80

Figure 4.3 Comparison of water level between SC3_PL0 and SC6_PL1 at 10 points 82 Figure 4.4 Significant wave height field in the Southwest monsoon period with the existing master plan (L) and the new master plan (R) 85

Figure 4.5 Significant wave height field in the Northeast monsoon period with the existing master plan (L) and the new master plan (R) 86

Figure 4.6 Spring current field (T) and ebb current field (B) in the Southwest monsoon period with the existing master plan 88

Figure 4.7 Spring current field (T) and ebb current field (B) in the Southwest monsoon period with the new master plan 89 Figure 4.8 Spring current field (T) and ebb current field (B) in the Northeast monsoon period with the existing master plan 91 Figure 4.9 Spring current field (T) and ebb current field (B) in the Northeast monsoon period with the new master plan 92 Figure 4.10 Total bed level change in a month in the Southwest monsoon period with the existing master plan 94 Figure 4.11 Total bed level change in a month in the Southwest monsoon period with the new master plan 95 Figure 4.12 Total bed level change in a month in the Northeast monsoon period with the existing master plan 97 Figure 4.13 Total bed level change in a month in the Northeast monsoon period with the new master plan 98 Figure 4.14 Total bed level change in the flood season with the existing master plan 99 Figure 4.15 Total bed level change in the flood season with the new master plan 100 Figure 4.16 Comparison of bed level change between the existing master plan and the new master plan at 10 cross-sections along the channel routes 103 Figure 4.17 The adjusting plan ground and the main current directions 106 Figure 4.18 Water level in the port area during the flood peak period (at 0:00 AM October 11th, 2013) with the adjusted master plan 107 Figure 4.19 Significant wave height field in the Southwest (L) and Northeast (R) monsoon periods with the adjusted master plan 109 Figure 4.20 Spring current field (T) and ebb current field (B) in the Southwest monsoon period with the adjusted master plan 110 Figure 4.21 Spring current field (T) and ebb current field (B) in the Northeast monsoon period with the adjusted master plan 111 Figure 4.22 Total bed level change in a month in the Southwest (T) and Northeast (M) monsoon periods and in the flood season (B) with the adjusted master plan 113 Figure 4.23 Comparison of bed level change between the new master plan and the adjusted master plan at 03 cross-sections along the AB channel route 114

LIST OF TABLES

Table 2.1 The current status of changing ships and boats in the whole province through

each year (IEAS, 2016) 11

Table 2.2 The current status of boats and ships in Hoai Nhon district through the years (IEAS, 2016) 12

Table 2.3 The calculated ship parameters 30

Table 3.1 Requirements for calm wave condition in the port basin under Japanese regulations (OCDI, 2002) 45

Table 3.2 The statistic table of the wave parameters in calculating the sediment transport 62

Table 3.3 The location of observation stations, times and contents of observation 69

Table 3.4 The error assessment results of the model calibration 71

Table 3.5 The error assessment results of the model validation 73

Table 4.1 The extracted co-ordinates of the results from Mike 21/3 FM model 78

Table 4.2 The summarized result of the flooded area of the plans 81

Table 4.3 Results of water level at locations in the flood season (SC3_PL0&SC6_PL1) 83

Table 4.4 The summarized results of the wave height in Tam Quan port area 86

Table 4.5 Results of water level at locations in the flood season (SC6_PL1&SC9_PL2) 108

MARD Ministry of Agriculture and Rural Development

MOT Ministry of Transport

CHAPTER 1 INTRODUCTION

1.1 Background

Binh Dinh is a coastal province of the South Central Vietnam Its natural area is 6,050.58 km2 and its population is of about 1.5 million people With 134 km along its coastlines, and tens of thousands of hectares of the lagoon and reservoirs, these are favourable conditions for the development of the local fisheries sector There are five out of eleven districts of the province (Hoai Nhon, Phu My, Phu Cat, Tuy Phuoc districts) and Quy Nhon city having marine economy activities The fisheries sector has an important role in socio-economic development of the province In recent years, fishery production has gained remarkable achievements

Hoai Nhon district is located in the North Pole of Binh Dinh province, with a coastline

of 23 km, a population of 206,000, among which 72,721 are in coastal communes, longstanding experience of fishing, aquaculture and seafood processing, and fishery logistics services To exploit the advantages of the sea, the local government has determined that marine economy is the key advantages of the district in the near future

The advantages of geographical location, workforce and a long tradition of fishing and aquatic resource exploitation, Binh Dinh province in general and Hoai Nhon district in particular have identified marine economic development to be a priority for speeding

up socio-economic development in the local, increasing income for local people and contributing to the protection of the sovereignty and security of the country's islands Decision No 1976/QĐ-TTg, dated November 12, 2015 of the Prime Minister on the planning system of fishing port, storm shelters for fishing ships until 2020 and orientations to 2030 also identified as Tam Quan port as a level-2 fishing port with a capacity of 200 ships, 400 CV each per day and this was a dedicated tuna fishing port, combined with storm shelters for fishing ships in 1,200 regional scale ships up to 400

CV

However, the construction of infrastructure serving the maritime economy is not commensurate with the potential of the district Today, Tam Quan Bac is a fishing port where boats anchoring and fishing logistics services only Hoai Nhon district and during the rainy season was received by 200-300 ships of Quang Ngai province and Phu My, Phu Cat districts The existing port can only receive 800-1,000 ships The access channel is often filled with about 50,000-100,000 m3 sediment yearly, causing difficulties for boats and ships to move in and out the port The infrastructure for fishery is still limited for accommodating big ships

During the long development of this fishing port, fishing docks have been attached to the riverside fishing village, crowded residential, tight space; facilities procurement, processing and supply of oil and necessities are interspersed in residential areas causing environmental pollution, lack of safety guarantee for people and fishing ships; travel conditions, narrow roads that prevent from producing flow, and reduction of traction in attracting investment from society

Considering the above factors, People’s Committee of Binh Dinh province has advocated for having a detailed planning of fishing port, anchorages and storm shelters, fishing logistics services of Tam Quan (in Document No 237/TB-UBND, dated October 20, 2015) The project’s main aim is to facilitate economic development

of the region, but not yet for a second focus on national security in terms of providing shelter for warships

Moreover, to implement the national objectives to 2020 and vision to 2030 concerning the sea-based economy development, it should be focused on strengthening infrastructure of sea ports to serve better military aims and to ensure safety for ships in all weather conditions Thus, a study on master plan of Tam Quan port - Binh Dinh province is urgent This has been implemented recently by Binh Dinh province under a feasibility study project

This study focuses on assessments of a proposal master plan on the following aspects: sediment deposition in the port area and the port entrance; hydrodynamic condition in and around the port area and to check if these conditions are committed to port design operation criteria

1.2 Objectives of the study

- Analysis of hydrodynamic conditions by modelling interactions of waves and currents with the existing proposal of port infrastructures

- Assessment of hydrodynamic conditions (currents, waves, sedimentation) in the port areas and port entrance to see if these are met basic port design criteria

- Proposal of measures or adjustment of the existing master plan in order to fulfill port design criteria

1.3 Scope of the study

This study is to focus on assessment of hydrodynamic condition for the situation of having the existing port master plan with a direct concern to waves, currents conditions and deposition possibilities in and around the port area Other aspects such

as erosion or change of coastal morphology condition of the port vicinity, environmental condition are not within scope of this study

1.4 Methods of the study

The following methods have been applied to this study:

- Analytical method: formulation of port design criteria to estimate sediment volume exchange due to waves and tides

- Modeling method: using 2D hydrodynamic model (Mike, Delft3D, Swan, etc.) to analyze, assess the interactions between waves and currents with the proposal port infrastructures

1.6 Chapters outline

This thesis is structured in 5 chapters, includes:

Chapter 1: Introduction

Chapter 2: Literature review

Chapter 3: Formulation of port design and planning criteria & model set-up Chapter 4: Hydrodynamic assessments of the new master plan for Tam Quan port Conclusions and Recommendation

CHAPTER 2 LITERATURE REVIEW

2.1 Overview of fishing ports

2.1.1 Concept of fishing ports

According to Scheffczyk (2008), the importance of the application of clearly formulated definitions for the purpose of policy setting and management planning is widely acknowledged Therefore, most essential definitions are given below

- On systematic approach, a fishing port is a system combining infrastructure facilities, human resources, and management concepts, dedicated to the purpose

of servicing the fishing fleet, the requirements of the fish industry and the development of the fisheries sector as a whole

- On operational approach, the definition of port operations considers that a fishing port serves as an industrial zone for unloading, processing, storage and marketing of fish, as well as for maintaining and servicing the fishing fleet In consequence, a fishing port is an integral part of the national fishing industry,

an important element in promoting the fish industry, and an operation base for the viable and sustainable conduct of the fishing business

- On functional approach, the term port functions include all activities carried out

by the port for operation and maintenance of the infrastructure facilities, for organization and conduct of port services required by vessels, fish processors and buyers, collection of port and service fees, and administration

According to document from Wikipedia page, a fishing port is a port or harbor for landing and distributing fish It may be a recreational facility, but usually commercial

A fishing port is the only port that depends on an ocean product, and depletion of fish may cause a fishing port to be uneconomical In recent decades, regulations to save fishing stock may limit the use of a fishing port, perhaps effectively closing it

2.1.2 Classification of fishing ports

According to Pham Van Giap et al (2010a), the system of fishing ports and landing sites are classified into 03 categories: central territory fishing port, local fishing port and landing sites according to the following criteria:

- The building location;

- The function of the port;

- The nature of the port;

- The infrastructure;

- The equipment of the port;

- The attractive zone of the port;

- The transport to go to the port;

- The amount of designed seafood through the port;

- The port’s largest ships;

- Numbers of vessels go in and out the port per year

Under the current regulations, fishing ports are divided into 02 categories: level-1 fishing port and level-2 fishing port, according to the following criteria (Decree No 80/2012/NĐ-CP, 2012):

- The building location and the function of the port;

- The equipment and the chain of cargo handling of the port;

- The area of the port and logistics base for fishing;

- The amount of designed seafood through the port

Therefore, the classification of Tam Quan fishing port also based upon two viewpoints According to Pham Van Giap et al (2010a), Tam Quan fishing port is the local fishing port, until 2015 it has the capacity scale of 80 times/day with the largest sized ships of 400 CV and the amount of seafood products through the port of 18,000 tons/year Classification according to the decree No 80/2012/NĐ-CP which namely by decision No 1976/QĐ-TTg on November 12, 2015 of the Prime Minister approving to

adjust the planning of the system of fishing port and storm shelters for the fishing ships until 2020, vision to 2030 identified: “Tam Quan sea port is the level-2 fishing port with the capacity scale to response for 200 times of 400 CV ships and the amount

of seafood products through the port of 20,000 tons/year; simultaneously, Tam Quan storm shelter is also the regional storm shelter for fishing ships with the scale of 1,200 ships/400 CV”

2.1.3 Highlighted fishing ports in the world and Vietnam

2.1.3.1 In the world

Huntington et al (2015) made a list of the world’s busiest and most important fishing ports The database developed as part of that work provides port/province-specific fish landing data for 47 countries, with entries corresponding to 948 individual ports and

107 state provinces, which provide the most specific data when individual port data could not be obtained The proportion of landings for the key species group per port, the type of landings, and the level of data robustness are also listed At an aggregated national level, the largest level of total landings occurs in China, with 13.9 million metric tons, followed by Indonesia (5.7 million metric tons), U.S (5.1 million metric tons), Peru (4.9 million metric tons), and Russia (4 million metric tons)

Here is some information about typical fishing ports in the world

1 Chimbote fishing port in Peru

Chimbote fishing port is located on the coast in Chimbote Bay, south of Trujillo and

422 km north of Lima This is the largest fishing port in Peru and also is ranked the first in the world about fish landings by the study of Huntington et al in 2015 Some recent shots of the port for an overview are presented in Figure 2.1

Chimbote has more than 30 fish factories, and has some of the world's finest packing equipment More than 75% of Peru's fishing industry occurs in Chimbote The Chimbote – Huallanca rail line, built in 1922, serves as a railway for coal and iron mines on the interior and a railway for the river valley by transporting rice, cotton, sugarcane, and bananas (Chimbote – Peru, 2015)

fish-Figure 2.1 Some pictures of Chimbote fishing port in Peru (Google Earth)

2 Vladivostok Sea Fishing Port in Russia

Vladivostok sea fishing port is located on the southern shore of the Golden Horn bay This is the largest fishing port in Russia and also is ranked the second in the world about fish landings by the study of Huntington et al in 2015 Some recent shots of the port for an overview are presented in Figure 2.2

The port is locating on 10 berths (of depths from 9.8 up to 12.4 m.) on southern coast

of a nonfreezing Gold Horn Bay The extent of moorings is 2,020 m The general area

of port consists of more than 323,700 m2 (Vladivostok fishing port, 2015)

The Vladivostok Sea Fishing Port is the universal reloading complex that is capable apart from fish products handling to carry out cargo operations with such cargo classes

as a timber, metal, fertilizers, cellulose, combustive-lubricating materials, etc There are three covered warehouses for products, cellulose, cardboard, packages, fertilizers and other dry cargoes Their useful storage space makes more than 58,000 m2 All utilities are heated and supplied with effective system of ventilation that maintain temperature inside them from 0 up to 20 Celsius degrees at any time of the year It is possible to place up to 400 thousand tons of various cargoes at the open storage spaces

on the berths (Vladivostok fishing port, 2015)

Capacity of port makes more than 5 million tons of cargoes and 200 thousand containers of the international class per year (Vladivostok fishing port, 2015)

Figure 2.2 Some pictures of Vladivostok Sea Fishing Port in Russia (Google Earth)

2.1.3.2 In Vietnam (Giap et al., 2010a)

Detailed planning of the system of fishing ports, fishing markets and landing sites in Vietnam to 2015, identified 206 structures of fishing port and landing site, the total seafood products through the system of fishing port and landing site nationwide by 2,401,155 tons/year In which:

- 19 structures of central territory fishing port with the total seafood products through by 750,000 tons/year;

- 85 structures of local fishing port with the total seafood products through by 1,094,155 tons/year;

- And 101 structures of landing site with the total seafood products through by 557,000 tons/year

Among of 206 structures of fishing port and landing sites above, there are 179 structures located in coastal and 27 structures located in offshore islands and archipelagos

Considering overall the planning of the system of fishing ports, fishing markets and

landing sites to 2015 and the adjusted planning of storm shelters for fishing vessels until 2010 and vision to 2020 approved by the Prime Minister that there are 69 structures of fishing port and 31 structures of landing site can be combined with storm shelters for fishing vessels when construction investment

2.1.4 Current status of fishery of Binh Dinh province

Coastal districts of Binh Dinh province mostly rely on fishery from the Vietnam East Sea With a long coastal lines and high populated density along the coasts, thus Binh Dinh is known as of the most sea food exploitation and production in Vietnam Number of fishing family and thus fishing ships (boats) has been increasing rapidly during the last 10 years Tables 2.1 & 2.2 demonstrate the trend of development based

on number of ships

Along the coast of Binh Dinh province has 03 large inlets and 03 spots of fisheries: Tam Quan, De Gi and Quy Nhon Besides, there are also 7 small landing sites with 26 fisheries villages formed on capes, along lagoons and Nhon Chau Island commune Formerly, the fishing ports and fishing wharfs of Binh Dinh province in generally are all spontaneously formed, the fishing wharf is closely connected with the fishing village; there have not been any works of wharfs or piers and any rear service bases The phase from 2002 to 2006, supported from the Central and the provincial capital sources, the fishing ports of Quy Nhon, Tam Quan, De Gi and Nhon Chau island were alternatively invested on upgrading, dredging to open the channels, bayous, to construct the jetties, the anchorage pillars, piers, the yard systems, the warehouses, the electric supplying system, the fresh water supply, simultaneously and attracted socialization from the powers of investing and constructing the cold storage, the petrol supplying station, the necessities and the newly ships and boats building and fixing foundations

However, because the quick growth speed of the ships and boats quantity, especially the ships with high capacity so the fishing ports are overload, averagely each fishing port can only receive from 60-100 ships/day, when the demand goes up 150/200 ships/day at the peak On the other hand, due to not constantly being dredged, the channels or bayous are deposited, and the big ships are difficult to go in and out or

have accidents of crash, shipwreck, strand, causing many losses of human beings and properties of the fishermen The anchorage is narrow, not enough necessary deep whereas the sizes of ships are bigger and bigger and the depth of waterlines is higher and higher under the weight of the ships Therefore, a significant numbers of fishing ships in the province do not return the home fishing port but approach at the ports of Nha Trang, Ninh Thuan, Phan Thiet and Vung Tau to sell fish and receive petrol, ice, necessities, which causes difficulties for fish catching activities and reduces the aquatic product yield of the port, decreases the motivation of developing the activities

of fishery logistic services and aquatic product process in the province

The fishing ships of Binh Dinh province concentrates mainly in the coastal five districts of Hoai Nhon, Phu My, Phu Cat, Tuy Phuoc and Quy Nhon, in which Hoai Nhon is the district with the most powerful ship team with 2,458 ships, taking the rate

of 36% of the provincial ships total (6,909 ships) and gathers many ships with the great capacity for fishing offshore with the engine installing capacity of 816,386 CV equal to 63% of the provincial ships and boats total (1,301,587 CV)

Table 2.1 The current status of changing ships and boats in the whole province

through each year (IEAS, 2016)

a from 2005 to 2015 b in 2015

Figure 2.3 The quantity and capacity of ships and boats in the whole province through

each year (IEAS, 2016) Table 2.2 The current status of boats and ships in Hoai Nhon district through the years

Figure 2.4 The quantity and capacity of ships in Hoai Nhon district through the years

(IEAS, 2016)

Here is some information about typical fishing ports in Binh Dinh province

1 Quy Nhon fishing port

Quy Nhon fishing port belongs to Quy Nhon port system which is located in the gulf

of Quy Nhon and shielded by Phuong Mai Peninsula, extremely convenient for vessels

to anchor all the year round Quy Nhon fishing port has long-term development process, in 2002, Ham Tu wharf was invested in upgrading to become Quy Nhon fishing port Some recent shots of the port for an overview are presented in Figure 2.5 Main feature: providing key facilities for fishing ships mooring and creating shelter area for fishing boats which are operating in the surrounding sea during storm

Capacity: Quy Nhon fishing port is a national focal port (type 1) of the South Central

of Vietnam The port has the ability to provide storm shelters for about 2,000 ships and

it has the capacity scale of 150 times/day and the largest sized ships of 600 CV The amount of seafood products through the port is 41,482 tons/year

Figure 2.5 Some pictures of Quy Nhon fishing port in Binh Dinh province

(photographed in November 2015)

2 De Gi fishing port

De Gi fishing port is located in De Gi estuary, belongs to Cat Khanh commune, Phu Cat district, Binh Dinh province Some recent shots of the port for an overview are presented in Figure 2.6

Main feature: providing key facilities for fishing ships mooring and creating shelter area for fishing boats which are operating in the surrounding sea during storm

Capacity: De Gi fishing port is a local fishing port The port has the capacity scale of

120 times/day and the largest sized ships of 300 CV The amount of seafood products through the port is 17,000 tons/year (Giap et al., 2010a)

Figure 2.6 Some pictures of De Gi fishing port in Binh Dinh province (photographed

in March 2015)

2.2 Overview of hydrodynamics of tidal inlets

2.2.1 Difference between tidal inlets and estuaries

Estuaries

There are many ways in which estuaries have been defined, but by their very nature as places of transition between land and sea, no simple definition readily fits all types of estuarine system Perhaps the most widely used is that proposed by Pritchard Pritchard (1967) defines an estuary as a semi-enclosed coastal body of water which has a free connection with the open sea and within which sea water is measurably diluted with fresh water derived from land drainage

However, due to the shortcomings of the definition of Pritchard, many scientists have proposed of using a more proper definition than that of Fairbridge which was stated in

1980 Fairbridge (1980) defines “An estuary is an inlet of the sea reaching into a river

valley as far as the upper limit of tidal rise, usually divided into 3 various parts: (a) the

low sea part or the estuary part connecting with the ocean; (b) the medium river

estuary part, where the main mixture of sea water and fresh water are taken place; and

(c) the high river estuary part, dominated by the fresh water but still with the impact of

tide The limit among these parts are not fixed and oscillated under the fresh water amount poured from the river”

Due to the connection with the sea, the water level in an estuary is affected by discharges from upstream rivers and tides Estuaries can be considered as dynamic areas as changes in morphology can be seen at different time and spatial scales Variations in tidal prism, river discharges, relative sea level rise and the availability of sediment result in various characteristic types of estuaries (Julien, 2015)

In real estuaries the influence of river runoff is considerable, and a major contribution

to the morphology of the area Estuaries consist very often of mud, although also sand can be found Because of geological features, estuaries may have very particular shapes The Western Scheldt in the south of the Netherlands and the Elbe estuary in Germany are rather standard, but for example the Tagus estuary in Portugal is fully governed by a rock-formation near the mouth Therefore, this estuary has a narrow mouth and a much wider basin inside (Verhagen, 1999)

In Vietnam, the estuaries at Hong and Cuu Long river mouths are lobate-shaped, whereas the estuaries in the central are diversified For instance, the area in the south central Vietnam, where the mountains extend close to the sea, the estuaries change only little and flow on the igneous rock beds, whereas the estuaries in the north (from Thanh Hoa to Quang Tri) and in the south central Vietnam from Phu Yen to Binh Thuan, the estuaries develop on the sedimentary floor of the sea or the sea river and the estuaries are shut or opened under the circle of the flooding season-exhausting season (Cat, 2002)

Tidal inlets

According to Kee d'Angremond and E.T.J.M Pluim-Van der Velden (2001), a tidal inlet is a short, narrow waterway connecting a bay, lagoon or similar body of water with a large parent body of water Tidal inlets often exist at places where there are breaks in a barrier coast According to Verhagen, H.J (1999), an estuary is a more or

less wide mouth of a river, while a tidal inlet is a connection to the sea where river discharge is zero So, in case of a tidal inlet there are no effects of density currents, there is no variation of discharge due to high river runoff In general one may distinguish two types of tidal inlets, the barrier-island inlets and the lagoons

At a coast with barrier-island inlets there are gaps between the islands, through which the water flows in and out to fill the intertidal area between the islands and the mainland Usually in this case the environment of the inlet consists mainly of sand, although in the tidal flats behind the barrier-island often a lot of mud can be found In case of a lagoon (or a bay) the environment can be either sandy or muddy Because in these case the landward extend of the lagoon is considerable, these lagoons and bays show often resemblance to estuaries

Wherever wave power is relatively low (so behind barrier islands or inside an estuary) and the tidal range is moderate to large, then tidal flats, rather than beaches, are likely

to develop Tidal flats usually have very low gradients, in the order of 1:1,000 at the landwards edge, and are composed predominantly of silts and clays, instead of sands The large tidal range and shallow gradients mean that the waves do not break on any one part of the flats for a long time and, consequently, the flood and ebb tidal currents are more effective at sediment transport that is the wave action

There are some exceptions where tidal flats occur on coasts facing the open sea, e.g Surinam on the north-east coast of South America, or Tam Giang lagoon area of Vietnam In such cases, tidal-flat development is encouraged by a combination of exceptionally high concentrations of fine-grained, suspended sediments in the coastal waters and a very gentle offshore slope Elsewhere, tidal flats are usually restricted to regions in the shelter of features such as spits, barrier islands, and coastal embayments

or estuaries Figure 2.7 below is typical example about morphodynamic of seasonally closed coastal inlets at the central coast of Vietnam

According to the above features, Tam Quan estuary area has the nature of both a river estuary and a tidal inlet However, according to the study of Duc et al (2015) defined:

“Because Tam Quan channel connects the sea to the inside lagoon, Tam Quan estuary should be seen as a tidal inlet”

Figure 2.7 Morphodynamics of seasonally closed coastal inlets at the central coast of

Tidal asymmetry (Julien, 2015)

When describing a tidal wave, a distinction can be made between movements in horizontal and vertical direction A horizontal tide refers to the tidal currents or discharges and a vertical tide to the rise and fall of the water level The relationship between the horizontal and vertical tide depends on the shape of the cross-section (hypsometric effect) In a rectangular cross-section, a two times larger vertical tide results in a two times larger horizontal tide However, in an area with deep channels and large intertidal storage areas, the relationship between water level and flow velocity is not linear

As a tidal wave propagates into an estuary, it is affected by the friction from the bed and the narrowing width Due to the decreasing water depths and narrowing of the estuary, the tidal wave slows down and the amplitude increases The friction of the bed causes a decrease in tidal amplitude The net effect differs per situation

Neglecting friction and assuming a prismatic channel, the propagation velocity of a tidal wave is given by c= gh = g(h0 +η) This means that the speed of the tidal wave is larger during high tides than during low tides The tidal wave is deformed and differs from a sinusoidal curve The resulting saw-tooth-shape profile can mathematically be described by the inclusion of higher harmonics or so-called overtides The higher harmonics are generated by the interaction of basic tidal components causing non-linear effects These effects grow in shallow water where the ratio amplitude over water depth increases

Due to faster propagation of the tidal wave during high water with respect to the propagation during low water, the rising period is shorter than the falling period In this case, larger flood velocities occur because the same amount of water is moved in and out of the system during a tidal cycle This system, in which the period of the water level rise is shorter than the falling period, is called flood-dominant For deep channels and large intertidal storage areas, the opposite occurs Due to the low water depths in the intertidal areas, the propagation of the high tide is slowed down The situation where the ebb velocities are larger than the flood velocities is referred to as

an ebb-dominant system

Special types of (tidal) waves are progressive waves or standing waves where the phase difference between the surface elevations and the velocity is 00 and 900respectively Because the tidal wave is affected by friction, a phase difference of approximately 450 (corresponding to approximately 3 hours) is mainly found in estuaries This means that the mean water level during flood is higher than the mean water level during ebb

Flood and ebb channels

Like in a river, the channels are meandering This means that they have the tendency

to erode in the outer bends, and to accrete in the inner bends Also the outer side of the bend is much deeper than the inner side At those places where one bend meets the following bend the deep part has to move from left to right (or vice versa) and consequently there is no deep part This place is called a saddle or threshold in the estuary, and cause often problems for navigation These are the places which have to

be dredged periodically to allow ships to sail into the estuary (Verhagen, 1999)

Considering a straight channel connected to the sea, during each tidal cycle water flows in and out of the channel A small deviation in a straight channel triggers a positive feedback mechanism called meandering Due to curvature-induced secondary flow the outer bend will erode and deposition will occur at the inner bend Especially the ebb channels are subjected to this meandering process During flood the water enters the channel and might overshoot the bend due to inertia (see Figure 2.8)

Figure 2.8 Ebb (E) and flood (F) tidal channels During flood the water might overshoot the bend leading to flood chutes, this process is schematized by the arrows

(Van Veen, 1950)

The same phenomenon can occur during ebb Due to the tidal flats that are above water during low tide, during ebb the water will flow particularly through the ebb channels Because of this flow concentration, the ebb channels will be deeper and more curved than the flood channels (Van Veen, 1950) The resulting landscape of meandering channels and tidal flats is characteristic for an estuary basin

2.2.2.2 Waves

In order to describe the motion of a wave in a mathematical way, it is common use to simplify it into a sinusoidal wave Linear wave theory (Airy, 1845) is, among others, based on the assumption that the surface displacement is relatively small and the wave

is only affected by gravity According to Airy, a wave can be described using a

sinusoidal expression (as in equation 2-1) and travels by the phase velocity c (as

indicated in equation 2-2) This propagation speed is defined as the ratio between wave

length L and wave period T The instantaneous water level η is a function of the

amplitude a=H/2, the radian frequency ω=2π/T and wave number k=2π/L

)sin(

.)

g k T

as the average wave height of the highest one third of the waves Another way to determine the significant wave height is using the wave spectrum

/ 1

3 /

1 N i i

N H

2.2.2.3 Tidal prisms and the stability of the inlet (Verhagen, 1999)

In a tidal inlet there is usually a balance between the transport of sediment along the coast by the longshore transport, and the flushing capacity of the inlet If the flushing capacity is too low, the longshore transport will eventually close the inlet If the flushing capacity is very large, the sediment coming from the coast will all be transported into the intertidal areal between the barrier islands and the coastline

Bruun (1978) has investigated this stability factor in detail, and he came to the conclusion that the inlet stability is defined by the relation P/Mtotal In this relation, P is the tidal prism (in m3) and Mtotal is the total longshore transport (in m3/year) Mtotal is the transport from both directions of the inlet added up Be aware that this stability number is not dimensionless

However, one should realize that in case of significant river runoff (thus in fact an estuary instead of a tidal inlet) the effect of the river runoff has to be added to the tidal prism Numerically this is not so easy

In case of an estuary where during part of the year the discharge of the river is considerable, while during the rest of the year the discharge is negligible, one has to determine two different stability numbers The conclusion can be that during the dry season the inlet is unconditionally unstable, and will certainly close, while during the wet season the inlet is unconditionally stable This happens in areas with a clear monsoon climate, like in India and Sri-Lanka

2.3 Overview of deposition on tidal flats

2.3.1 Density currents at estuary areas and deposition in rivers (Cat, 2002)

A reviewed point is an upper limit of the tidal current when entering the estuary Because the salt and fresh water has a mixture at various levels, various locations, which is the cause for generating the density current The current is created by the difference from the density is called the density current

The water level oscillation in a tidal period is the cause which makes a salt wedge move up and down The most direct consequence of the salt wedge movement into the river is the sedimentation process at the estuary The current close to the bottom

changes strongly by the appearance of the salt wedge The top part of the salt wedge, the current has a direction towards the sea, whereas in the salt wedge the current has a direction to run into the river with the fairly small speed Because the bed velocity at the top wedge must to equal zero, the sedimentation process will occur at this area At the estuaries which have small tidal effects with the stable wedge existence, the sedimentation can make the river bed rise up significantly It is the role of the salt wedge that there is change of water density here, which is the major cause for the sedimentation phenomenon

There are very few technical measures with the high economic significance aiming at controlling the salt wedge situation to invade into the river Majority of the technical measures only concentrate on the small areas with the high economic significance such

as the channel and port area Be able to recognize that being able to limit the invading process of the salt wedge if there is a reduction of salt water depth or an increase of fresh water amount which runs out from the river

2.3.2 Sediment transport and deposition on tidal flats (Verhagen, 1999)

Tidal flats are flat and almost featureless areas which occur along some stretches of coastline and within estuaries They are often backed by areas of slat-marsh and dissected by a network of tidal channels Seawater enters the tidal channels on the flood tide, gradually filling them and the tide risus until the water spills over and floods the adjacent flats After the slack water of high tide, the water drains back off the flats and through the tidal channels until the entire tidal flat is exposed once more This pattern of water movement, and the interaction between tidal currents and wave action, has important consequences for the transport and distribution of sediment on the tidal flat

In the simplest situation, there is a seaward progression in grain-size from dominated sediments at the landwards end to sand-dominated sediments at the seawards end The low tidal flats are submerged for most of the tidal cycle and are subjected to strong tidal currents and minor wave action during this period Even at the slack water of low and high tide, there is some sediment disturbance by waves Consequently, muds are kept in suspension and sediments are deposited only from the bed load

mud-The mid-flats are submerged and exposed for roughly similar periods mud-They are usually submerged during the mid-tidal cycle when tidal currents may reach their maximum speeds and so the sediment may be affected by these strong tidal currents, although wave action is very weak Bed load transport and deposition of sands are again dominant, accompanied by the development of current-formed ripples However, during the period of slack high water, fine muds held in suspension are able to settle out, forming characteristic mud drapes over the surfaces of the previously formed ripples

The high tidal flats are submerged only at high tide when current speeds fall to zero

No bed load transport or deposition occurs but during the slack water period muds settle out of suspension to form the mud-flats When the tide turns, these muds will be eroded only if the ebb current generates a shear stress at the bed which is greater than the critical shear stress required to erode the sediment Because muds are cohesive sediments, there are difficult to erode after deposition

2.4 Overview of the study area

2.4.1 Previous studies in the study area

In 2010, an author group of Pham Ba Trung, Le Dinh Mau and Le Phuoc Trinh had an article for studying on “Sedimentation issue at the estuaries of Sa Huynh (Quang Ngai province), Tam Quan and De Gi (Binh Dinh province) due to the impact of jetty types” The article was published in Journal of Marine Science and Technology in October 2010, No 2, pages of 01÷13 The contents of the article supplied some information of present condition and impact for sedimentation of protective embankments at the estuaries of Sa Huynh, Tam Quan and De Gi via the field survey data The study result showed that the sediment impacts of the jetties at these three estuaries were the same The longshore current which had the direction from the south

to the north played a decisive role in the process of transportation and accumulation of bed material caused the estuary sedimentation, and it converged enough natures of a coastal hydrodynamic structure The measure for constructing the jetties in front of river mouth which barrier the South-North currents to prevent the estuary sedimentation, in consideration of science, was a proper one However, this measure

led to some changes in the hydrodynamic regime at the estuary area, dragging the process of transporting up sediment materials from the south, in which there was a large amount which deposited at the front surface of the jetty and another significant amount was put into for depositing the estuary and channel Particularly, at Tam Quan estuary, constructing lasted the jetty to about 850 m, at that time there was not anything to guarantee the effect on preventing the estuary sedimentation, but the hydrodynamic regime showed the opposite

Trinh Viet An (2012) had a study topic for the issue of some estuaries into fishing ports and storm shelter areas for fishing ships in the Central which were being seriously deposited, causing the significant impact to activities of fishery exploitation, activities of fishing logistic business, fisherman’s life and political security of locality This study showed obviously that the sedimentation phenomenon and concerned issues could be very obviously seen at some typical river estuaries such as Tam Quan (Binh Dinh province), My A and Sa Huynh (Quang Ngai province), Da Rang (Phu Yen province), Tung (Quang Tri province) and a series of the other Central Vietnam estuaries such as Dong Hai, La Gi, Phan Thiet, Nhat Le, etc This study gave the preliminary comments of the major elements and the causes for the estuary sedimentation, as well as some existences of the constructed coastal training structures, on this base the author petitioned some trends for solution Whereby, the concrete study results to Tam Quan estuary as follows:

- The phenomenon of the port entrance which was frequently seriously deposited making the boats and ships easily to be thrown into the jetty and broken by big waves, making the boats and ships not dare to go into the port and the anchorage area Despite many structural measures with the big expense, this phenomenon has not been overcome A temporary solution that was applied was frequent dredging the channel

- The basic causes and elements for causing sedimentation at Tam Quan estuary

in particularly as well as the Central Vietnam estuaries in generally include: (i) the wave and longshore current due to the wave, (ii) the tidal regime, and (iii) the situation of typhoons and floods

- Analyzing and giving the comments on arranging the coastal training structures

at Tam Quan estuary has not been proper

In 2015, Do Minh Duc implemented the topic “Study on scientific and technological solutions to improve sedimentation phenomenon at estuaries where go in and out storm shelter areas for boats and ships - applied for Tam Quan estuary, Binh Dinh province” The study took out the basic causes and factors for causing sedimentation at the Central Vietnam estuaries; evaluated the present conditions and the causes of sedimentation at Tam Quan estuary under the viewpoint of geology, geomorphology and sediment, and under the viewpoint of the hydro-fossil dynamics; and gave the solutions to prevent the sedimentation at Tam Quan estuary Whereby, the Mike 21 model was applied to calculate the wave fields, the current fields, the water levels and the morphological changes under the scenarios of without the jetty, within the 450 m jetty and within the 850 m jetty The results took out five main causes for causing the morphological changes at Tam Quan estuary including: (i) asymmetrical shape of the estuary topography, (ii) the wave field with prevailing direction was the northeastern direction; (iii) the wave refraction picture was rather uniform at the estuary despite following the various wave directions; (iv) part of river discharge was stopped at the upstream reservoirs and (v) the jetty construction was improper The solutions were proposed on the base of ensuring the channel normality to serve the flood drainage and waterway traffic and to be suitable for the local economic condition, including 2 groups: the first is to dredge and maintain periodically the channel routes; the second

is to arrange the works to prevent sands from both two sides (in which, the northern side is dominant because the longshore current has a trend of going from the north to the south), and to direct the flow and push the longshore current from the north away The distance between the two heads of works took the waterway traffic requirements and flood drainage at the estuary area

2.4.2 General information on the existing Tam Quan fishing port

This is one of the ancient fishing ports in the north of the province The port was spontaneously formed along Thien Chanh, Tan Thanh fishing villages of Tam Quan Bac commune Tam Quan port is an advantage of wide estuary with anchorage water