MINISTRY OF EDUCATION AND MINISTRY OF ARGICULTURE TRAINING AND RURAL DEVELOPMENT THUY LOI UNIVERSITY VU VAN LAN STUDY ON INUNDATION DUE TO STORM SURGE FOR PHU QUOC ISLANDS THESIS OF MASTER DEGREE MINISTRY OF EDUCATION AND MINISTRY OFARGICULTUREÍ ‘TRAINING AND RURAL DEVELOPMENT ‘THUY LOI UNIVERSITY VU VAN LAN STUDY ON INUNDATION DUE TO STORM SURGE FOR PHU QUOC ISLANDS. No: Supervisor: Ass. Vu Minh Cat HA NOI, 2016 Declaration hereby certify the work which is being presented inthis thesis entitled, “Study on storm surge due to inundated for Phu Quoc island” in partial fulfillment of the requirement for the award of the Master of Coastal Engineering Management, isan authentic record of my own work cartied out undersupervision of Ass. Vu Minh Cat.
The matter ‘embodied inthis thesis has not been submitted by me for the award of any other degree or diploma. Date: May 30, 2016 Vu Van Lan Acknowledgements 1 would like to express my sincere gratitude to my advisor Ass. PhD Vu Minh Cat for his guidance, suggestion and inspiration, 1 would like to acknowledge Ass. PhD Nghiem Tien Lam for his comments and suggestion.
[also want to show deep thanks to Ass. Tran Thanh Tung who is main co-ordinator, making value contributions to success in Master course, In addition, please allow me to send my bestgratitude to the KC09.16/11-15 subject, which support a lot of valuable data for my thesis. 1 would like to thank faculty of Marine and Coastal Engineering of Thuy Loi University and Faculty Marine Science & Island, Ha Noi University for Natural Resources and Environment for enabling me thesis before the deadline. Finally, I would like to express my special appreciation to my friends and colleagues for their support, encourage and advices.
The deepest thanks are expressed to my family member for their unconditional loves. TABLE OF CONTENS LIST OF FIGURES LIST OF TABLES INTRODUCTION 10 1. The necessity ofthe study 10 2. Objects and scope of the study " 4, Study approaches and methodology.
Structure of the thesis CHAPTER 1: OVERVIEWS ON STORM SURGE STUDY AND STUDY AREA 11, Literature reviews 1.1, International researches on storm surges. Storm surge researches in Viet Nam 1. Brief description on study area 1.2 Climatic and oceanographic characteristics 1.3, Hydrological and oceanographic characteristics, 1.4, Social and economic features. CHAPTER 2: APPLICATION OF DELFT3D TO STUDY STORM SURGE 2.1, Data used for he simulation 2.
Statistical typhoon data 2.3, On land and seabed topography 2. Set up the hydrodynamic model 2. 33 CHAPTER 3: SIMULATION OF STORM SURGE IN PHU QUOC ISLANDS. Typhoon zoning along the coastlines of Viet Nam 59 3.2, Generation of typhoon scenarios for Phu Quoc areas ¬ 3.3, Extraction of water level around Phu Quoc islands 6.
Scenario1: Simulation of typhoon namely Linda (later is called Linda typhoon) that approached to the study area in November, 1997 6 3.2 Scenario 2: Scenario 1 in case of the typhoon Linda coming at the same time offlood tide at the study area, 66 3.3, Scenario 3: Simulation of typhoons according scenarios approved by Ministry of Natural Resources and Environment (MoNRE), but wind velocity changes with the time V= f0. 69 CHAPTER IV: BUILDING INUNDATED MAPS CAUSED BY STORM SURGE FOR PHU QUOC ISLANDS 72 4. Introduction on application of GIS. Application of ArcGIS software to build up inundated map, 14 4.3, Building up inundation maps.
The inundation map of scenario Ì T8 4. The inundation map of scenario 2 82 4. Inundation of Phu Quoe island according scenario 03. 85 CONCLUSION AND RECOMMENDATION 89 Conclusion 89 Recommendation 90 References 92 LIST OF FIGURES Figure 1.
Flowchart to illustrate the study approach 12 1D model with experimental data of Bowen (1986) Figure 3 .Location of Phu Quoe islands on satellite image Figure 4 Statistical storm paths approaching to Viet Nam coasts Figure 5. Grid calculated in the study area Figure 6:Topography in Phu Quoc area Figure 7.The model grid and boundaries Figure 8. Phu Quoc oceanographic station 55 Figure 9. Observed and computed water level at Phu Quoc (C=55) Figure 10, Observed and computed water level at Phu Quoc (C=60) 36 Figure 11.
Observed and computed water level at Phu Quoc (C=65) Figure 12. Observed and computed water levels for model verification Figure 13, Observed and computed water levels in verification step Figure 14.Typhoon zoning along the Vietnam coasts Figure 15.Basie characteristics and storm risk in Viet Nam Coasts Figure 16, Extracted points of simulated water level Figure 17.The track of Linda typhoon in the study area Figure 18, Water level field around Phu Quoc islands in seenario | Figure 19, Storm surge at 8 points around islands in scenario 1 Figure 20-Tidal series at Phu Quoc during Linda typhoon Figure 21. Storm surge at 8 points around islands in scenario 2 Figure 22. Storm surge at 8 points around islands in scenario 3 Figure 23.Topographie data layer of Phu Quoc island Figure 24.
Vegetation cover layer on the Phu Quoc island Figure 25,Cadastral data layer of Phu Quoc island Figure 26 Hydrological data layer around Phu Quoc island Figure 27.Simulated water level and topography in coast of Duong Dong and Ham Ninh 78 Figure 28. Inundated mapping Phu Quoc with seenario 1 80 7 Figure 29. Inundation maps of the Cua Duong, Duong Dong, Duong To communes 81 Figure 30. Inundation mapping at the Ham Ninh commune se Figure 31, Inundated map in scenario2 sa Figure 32.
Inundated mapping of Duong To, Cua Duong and Duong Đông communes, _ Figure 33. Inundated mapping of Duong To, Cua Duong and Duong Đông communes.Spatial disribution of flooded areas in the Phu Quoc island in scenario 3 86 Figure 35, Inundated mapping of Duong Dong and Cua Duong commune 87 Figure 36 Inundated mapping of Ham Ninh commune 87 Figure 37. Inundated mapping of Dương To commune 88 LIST OF TABLES Table 1 Coordinate of Phu Quoc area shown in map scale of 50/0) Table 2. Monthly and yearly average temperature in Phu Quoe and Rach Gia Table 3 Monthly and yearly average and minimum humidity (%) at Phu Quoc ‘Table 4.Monthly and yearly average and minimum humidity (%6) at Phu Quoe Table 5.
Monthly wind velocity and main direction at Phu Quốc ‘Table 6.The statistical result of wave height and its period at Phu Quoc ‘Table 7.Water level at Phu Quoc (103958 E ~ 1013 N) station (1990-2008) Table 8 Stat ics on typhoon hitting to Phu Quoc and surrounding areas Table 9 Characteristics of typical typhoons approaching to the southern coasts.Tidal constituents at 3 boundaries.The locations where water level is extracted Table 13.Linda typhoon’s parameters 63 ‘Table 14.Highest storm surge and appearance time at the extracted points 65 ‘Table 15.Adjustment of Linda typhoon time to fit to spring tide.Highest water level and appearance time at 8 points in scenario 2. Typhoon parameters used to simulate in scenario 3 6 ‘Table 18, Highest water level and appearance time at 8 points in seenario 3. The maximum storm surge at the point around Phu Quoc islands mỊ ‘Table 20,Clasification of inundated depth T8 ‘Table 21. Flooded area for Phu Quoc island in scenario 1 ‘Table 22.
Flooded area for Phu Quoc island in scenario 2. Flooded area of Phu Quoe island in scenario 3 In recent years due to the impact of global climate change, natural disasters become more complex, especially storms, accompanied by rising sea levels caused flooding of coastal estuaries. The sea level rise due to storm caused flooding of coastal areas and break dike, especially storm occur during high tides. So the study, calculated and forecasting extreme storm surge in coastal area and flooding risk due to storm are positive tasks to find appropriate solutions for prevention and reduction of damages in coastal areas.
The components cause extreme water level during storm including tides, storm surge, and wave surge, in which the storm surge is an important one. ‘Storm surge is a dangerous natural phenomenon which causes lost lives, destruction of socio-economic infrastructures and valuable resources when typhoon attacking to coastal areas. Worldwide, storm surge has caused major damages such as the typhoon in 1970 and 1990 with water surge more than 7 m, generated large wave, inundated to delta of Bangladesh and over 400,000 people were killed. On the Caribbean, highest water surge of typhoon Flora is 8 meter, it had cause flood and over 5000 people were killed, Coastal of the United States had been affected by historic storm surge of up to 7.
The countries on the Northern coasts of Europe had been affected serious of storm surge in 1916, 1953, 1962, 1976, in which the storm occurred in 1953 in Netherland caused large inundation and over 1400 people killed ‘Storm surges may be defined as high sea water level above mean sea level which is caused by strong winds and low atmospheric pressures ofa storm, Winds which blow towards land exert a shearing stress on the surface, causes an increase in the sea water level near the coastlines. Low atmospheric pressure also produces high elevation due to the so-called inverted barometer effect. The highest surges have generated by strong tropical cyclones. The surge belongs to the same class of phenomena as tide waves and tsunamis, Its horizontal scale depends on the parameters of the storm.
In general the storm surge oceurs in duration of several hours, but it ean sometimes last fora few days Itis obvious that prediction of surges is a very urgent issue to be addressed, especially in coastal regions which are affected by tropical eyclones. There have also been many lo atempts to develop methods for forecasting storm surges in Vietnam, At present, all kinds of activities are inereased in number and almost marine constructions need sea level data for designing, Sometimes they need the values of sea level rise which happen at rare frequencies, while the observed stations located along coasts and islands are scarce. That’s why in this study numerical models are used to simulate storm surge based con the data of bathymetry, figure of coastlines, climate characteristics of typhoons and ‘oceanic data at sea and coastal stations. Objectives ‘The general objective of the present work, therefore, is to develop a method based on hydrodynamic models to determine maximum surface water elevation generated by typhoons.
The computed results of model produce an atlas of pre-computed surges and 4a collection of several possible typhoon conditions from many potential surges. It is straightforward to determine the highest possible surge at all vulnerable coastal locations from a particular family of tracks and simulated storm surges as input data for preparation of potential map of inundation in Phu Quoc island. Objects and scope of the study + Objects of the study: The extreme water level during storm at the shorelines and potential inundation caused by storm surge. + Scope of the study: Phu Quoc islands and surrounding areas 4.
Study approaches and methodology ‘The simulation of storm surge and land inundation by using Delft3d is shown in figure 1, of which the following steps are conducted. Flowchart to illustrate the study approach Step1: Collection ofdata ‘These data are used as input for calibration and verification of models and simulation of storm surge. These are included: + Hydro-meteorological data such as water level series atthe sea and observed stations, atmospheric pressure, water temperature, wind, wave, currents etc. + Topography including sea bathymetry and land elevation surrounding the study islands + Socio-economic data: including infrastructures around the coasts, lands, forests, ecosystem and all socio-economic activities that will be damaged if coastal strip of island is inundated by typhoon water.
‘Step 2: Set up computational model It includes computation network, meshes, defined boundaries such as tide series, seabed topography and typhoon information including central typhoon pressure, typhoon radius, wind velocity and so on.