MINISTRY OF FOREIGN AFFAIRS, ENVIRONMENT, TRADE, LABOUR AND TOURISM, GOVERNMENT OF TUVALU THE STUDY FOR ASSESSMENT OF ECOSYSTEM, COASTAL EROSION AND PROTECTION/REHABILITATION OF DAMAGED AREA IN TUVALU FINAL REPORT [Volume II : Main Report] JANUARY 2011 JAPAN INTERNATIONAL COOPERATION AGENCY KOKUSAI KOGYO CO., LTD. and FISHERIES ENGINEERING CO.,LTD. GED JR 11-094 < Structure of Report > Volume I Summary Report Volume II Main Report Volume III Supporting Report 1 FJ$ = 48.9 Yen (As of November 2010) ASSESSMENT OF ECOSYSTEM, COASTAL EROSION AND PROTECTION / REHABILITATION OF DAMAGED AREA IN TUVALU Location Map of Study Area Tuvalu JAPAN INTERNATIONAL COOPERATION AGENCY (JICA) MINISTRY OF FOREIGN AFFAIRS, ENVIRONMENT, TRADE, LABOUR AND TOURISM, GOVERNMENT OF TUVALU THE STUDY FOR ASSESSMENT OF ECOSYSTEM, COASTAL EROSION AND PROTECTION/REHABILITATION OF DAMAGED AREA IN TUVALU <FINAL REPORT> Volume II: Main Report Table of Contents Location Map Table of Contents List of Tables List of Figures Abbreviations Page: CHAPTER 1 BACKGROUND OF THE STUDY....................................................... 1-1 CHAPTER 2 OBJECTIVES OF THE STUDY AND STUDY AREA ...................... 2-1 2.1 Objectives of the Study.......................................................................................... 2-1 2.2 Study Area ............................................................................................................. 2-1 CHAPTER 3 SOCIAL AND ECONOMIC CONDITIONS....................................... 3-1 3.1 Social Conditions................................................................................................... 3-1 3.1.1 Laws and Acts in Coastal Zone ................................................................ 3-1 3.1.2 Standards................................................................................................... 3-1 3.1.3 Governance System .................................................................................. 3-2 3.1.4 Village Boundary...................................................................................... 3-5 i 3.1.5 Population Structure ................................................................................. 3-6 3.1.6 Gender....................................................................................................... 3-8 3.1.7 Tourism................................................................................................... 3-11 3.1.8 History .................................................................................................... 3-12 3.1.9 Development Plans related to Littoral Regions ...................................... 3-15 3.1.10 Tuvalu's Efforts on Climate Change and Donor Trends......................... 3-16 3.2 Economic Conditions........................................................................................... 3-19 3.2.1 Industrial Structure ................................................................................. 3-19 3.2.2 Transportation......................................................................................... 3-20 3.2.3 Economic Indicators such as Income...................................................... 3-22 3.2.4 Land Use................................................................................................. 3-22 3.2.5 Land Tenure System ............................................................................... 3-24 3.2.6 Rent of Land ........................................................................................... 3-25 3.3 Other Data related to Environmental and Social Considerations ........................ 3-26 3.3.1 Water Supply and Sewerage................................................................... 3-26 3.3.2 Waste ...................................................................................................... 3-30 3.3.3 Borrow Pits ............................................................................................. 3-36 CHAPTER 4 PRESENT SITUATION OF NATURAL AND ENVIRONMENTAL CONDITIONS IN STUDY AREA ..................................................................... 4-1 4.1 Meteorological Phenomena ................................................................................... 4-1 4.1.1 Winds........................................................................................................ 4-2 4.1.2 Precipitations ............................................................................................ 4-9 4.1.3 Air and Water Temperatures, and Atmospheric Pressures ..................... 4-10 4.1.4 Tropical Cyclones and El Niño - Southern Oscillation........................... 4-14 4.2 Oceanographic Phenomena ................................................................................. 4-19 4.2.1 Sea Levels and Tides .............................................................................. 4-19 4.2.2 Waves ..................................................................................................... 4-25 4.2.3 Currents................................................................................................... 4-30 4.3 Topographic and Geological Characteristics....................................................... 4-36 4.3.1 Topographic Feature............................................................................... 4-36 4.3.2 Bathymetric Feature................................................................................ 4-41 4.3.3 Geological Characteristics ...................................................................... 4-50 4.4 Water Quality and Bottom Sediments ................................................................. 4-52 4.4.1 Water Quality.......................................................................................... 4-52 4.4.2 Sea Bottom and Shoreline Sediments..................................................... 4-57 4.5 Coastal Ecosystem Survey................................................................................... 4-65 ii 4.5.1 Distribution of Foraminifera................................................................... 4-65 4.5.2 Distribution Conditions of Coral, etc...................................................... 4-75 CHAPTER 5 PRESENT SITUATION OF COAST ................................................... 5-1 5.1 Existing Coastal Structures.................................................................................... 5-1 5.1.1 Lagoon Side.............................................................................................. 5-1 5.1.2 Ocean Side.............................................................................................. 5-16 5.2 Causeway, Coastal Borrow Pit, Breaching.......................................................... 5-19 5.2.1 Causeway................................................................................................ 5-19 5.2.2 Coastal Borrow Pit.................................................................................. 5-20 5.2.3 Breaching................................................................................................ 5-22 5.3 Interview Survey.................................................................................................. 5-24 5.3.1 Justification............................................................................................. 5-24 5.3.2 Purposes.................................................................................................. 5-24 5.3.3 Method of Acquiring Information and the Contents of Questionnaire... 5-24 5.3.4 Implementation of Survey ...................................................................... 5-27 5.3.5 Data Processing and Summary ............................................................... 5-28 5.3.6 Results of Survey.................................................................................... 5-29 5.4 Wave Overtopping Field Survey ......................................................................... 5-39 5.5 Findings on Coastal Vulnerability....................................................................... 5-41 5.5.1 Lagoon Side............................................................................................ 5-41 5.5.2 Ocean Side.............................................................................................. 5-42 CHAPTER 6 BEACH DEFORMATION MECHANISM.......................................... 6-1 6.1 Changes in Coastal Lines....................................................................................... 6-1 6.1.1 Central part of Fongafale Islet .................................................................. 6-1 6.1.2 Northernmost Tip of Tenkago Islet........................................................... 6-3 6.1.3 Southernmost Tip of Fongafale Islet......................................................... 6-5 6.1.4 Near the Structures.................................................................................... 6-7 6.2 Beach Deformation Mechanism .......................................................................... 6-14 6.2.1 Ocean Side.............................................................................................. 6-14 6.2.2 Lagoon Side............................................................................................ 6-17 6.3 Amount of Littoral Drift ...................................................................................... 6-20 6.3.1 Lagoon Side............................................................................................ 6-20 6.3.2 Ocean Side.............................................................................................