Tài liệu Vulnerability assessment of freshwater resources in island to environment change a case study in phu quoc island kien giang province

1 CHAPTER 1: INTRODUCTION 1.1. Problem statement Water is our most precious resource. However, in recent years, water has become degraded in both quantity and quality. This situation is placing challenges and requires a worldwide effort in the use and sustainable management of water resources. The provision of water supply and sanitation has improved living conditions; in addition, the implementation of social justice and educational approaches, especially for women and children, are also contributing to the success of the enactment of the Millennium Development Goals (MDG). The development status of the Island, the isolation characteristic, the distance between neighboring islands, between islands and the mainland, the change of the environment, climate change, changes in rainfall, etc. are the challenges of water resources management. The Island, located in the lower floor of the Southwestern area, is a vulnerable area to climate change and sea level rise. Furthermore, the island is affected by the early phase of the El Nino and La Ninas. The Island is a key economic zone with typical activities, such as: fishing, oil and gas exploitation, maritime services, tourism as well as it is adjacent to the other countries in the region. Especially, Phu Quoc Island is the largest island in the coastal island system in Vietnam. The current status of the economic development has created a significant social pressure on the island regarding both system resources and the environmental management. There is no rational planning and efficient use of natural resources, although the extraction (water, oil, gas...) has been carried out for a long time. Therefore, freshwater resources in Phu Quoc Island are vitally important, and have a direct impact on daily life, and the development of the island. The assessment of freshwater resource vulnerability in Vietnam is still very limited, particularly in the Island. A vulnerability assessment of freshwater resources in Phu 2 Quoc Island will be essential to identify potential risks for fresh water resources on the island and to support decision making; Therefore, detecting early threats to gain insight sustainable solutions to the management of freshwater resources on an island, where the exploitation of freshwater resources management is still problematic. Understanding the vulnerability of freshwater resources of the Islands, therefore, is important to ensure sustainable water management in the region. Uses of water have an intimate relationship with land use and impact on ecosystems dealing with integrated water resource management. The integrated water resources management will help to use and to protect natural resources. In order to effectively implement integrated water resource management, the necessity of understanding and the ability to assess the vulnerability of water resources are highlighted. Performing a vulnerability assessment of freshwater will highlight gaps in information and identify the most influential factors affecting vulnerability, in addition to raising public awareness. The availability of such an evaluation would provide decision-makers with the option to evaluate and modify existing policies and to implement measures to improve the management of water resources. Different approaches to vulnerability assessment of water resources and hydrological systems have been developed for a long time with both advantages and disadvantages. One of the most effective responses, vulnerability assessment has recently been developed by the United Nations Environment Program and by Packing University. This approach is based on the available resources to meet the production, use, environmental pressures mitigation and capacity development and management. It highlights the vulnerability factors such as climate change, population growth, economic development, and management, etc. of vulnerable freshwater resources. Currently, this method is implemented in the Pacific Islands, in West and South Asia, in the Mekong River basin, and in several other river basins in Vietnam. However, the vulnerability assessment of freshwater resources on islands in Vietnam is very limited and this method is still not an application 3 option. Hence, this study can be considered as a the first application of this approach assessing freshwater vulnerability on islands in Vietnam. 1.2. Objectives and Research questions 1.2.1. Objective of study The main objectives of the study include: - Piloting a method in terms of assessing the freshwater vulnerability in the southwestern area of Vietnams: applied specifically on Phu Quoc – Kien Giang Province; - Assessing vulnerability of freshwater resources on the Island of Phu Quoc – Kien Giang and potential agents; - Providing scientifically-based evidence to support policy development of water resources management, to support the decision-making process; - Proposing measures to reduce the vulnerability of freshwater resources on the Phu Quoc Island. 1.2.2. Research questions - What methods and tools are appropriate to assess the vulnerability of freshwater resources on the Island? - Which elements are vulnerable to freshwater resources? - What are the opportunities and challenges regarding to freshwater resources management in the Island? - What are solutions that should be done to improve the freshwater resources in the Island? 1.3. The Assessment Process Water is essential for life. All activities of humans, animals and plants on earth need water. However, freshwater resources are vulnerable and a reliable assessment of vulnerability is essential. The vulnerability assessment of freshwater resources, newly developed by UNEP (United Nations Environment Program) and by Peking University is the methodology of the thesis. Firstly, relevant data in the study area are collected, including: relevant documents such as natural conditions, hydrology, environment, geology, etc. The statistical analysis results are collected 4 directly from the local agencies. The data processing is necessary to investigate additional fieldwork and to update the latest data content research serving as the current status and characteristics of water resources on the island and the control system influence of the current vulnerability of freshwater resources. This study will provide an overview of the evaluation method to assess the vulnerability of water resources; the preferred method will be the approach developed by UNEP (United Nations Environment Program) and Packing University. The evaluation of data will serve an analytical framework DPSIR (Driver, pressure, state, impact and response) to analyze quantitative and qualitative features, and a description of the vulnerability of freshwater resources on the island. Then, an integrated vulnerability index (VI) is calculated based on possible vulnerable parameters; the results will assess the vulnerability of freshwater resources on the island, followed by a proposal for solutions to reduce the vulnerability of freshwater resources on the Phu Quoc Island. 1.4. Structure of the thesis This report is divided into six chapters. The first chapter introduces the research to answer three main questions: Why is a vulnerability assessment is important? How can we assess the vulnerability of the island? And, what are the main objectives of a vulnerability assessment in this study? The chapter two reviews several studies about the concept of vulnerability, vulnerability assessment methods and some previous researches relate to study area. The chapter three presents an overview of freshwater resources, which describe the geographical context of natural, socio-economics, freshwater resources. Especially, we focus on the present status and the challenges dealing with the management of fresh water resources in the island. This chapter also discusses the importance of the influence of climate change and the pressures of environmental change to freshwater resources on the island. Chapter four identifies methods to assess the vulnerability of freshwater resources, summarizes the specific assessment method of UNEP, including, such as: 5 methods, diagnosis of issues, and DPSIR analytical framework to understand the vulnerability index (VI). Data used in the thesis. Chapter five is an important chapter of the report. This chapter continues to assess the vulnerability of freshwater resources on the island of Phu Quoc – Kien Giang Province. These assessments determine the importance and the interrelationship of social-economics, the environment, climate, geographical factors and management resources with vulnerable island freshwater resources. The study of assessment indicators and injury parameters such as water stress, development pressure, the insecurity of the ecosystem and management challenges, is necessary to calculate the vulnerability index. In addition, this chapter will provide proposed measures to reduce the vulnerability of freshwater resources on the Island. Chapter six: Finally, the last chapter concludes the findings of this thesis, discusses the limitations of this work and provides an outlook by giving recommendation for future areas of research. 6 CHAPTER 2: LITERATURE REWIEW 2.1. Concepts of vulnerability The concepts of vulnerability have been changed over time. According to Jörn Birkmann (2006) statistics, the current literature encompass more than 25 different definitions, concepts and methods to systematize vulnerability (for example, Chambers, 1989; Bohle, 2001; Wisner et al., 2004; Downing et al., 2006; UN/ISDR, 2004; Pelling, 2003; Luers, 2005; Green, 2004; UN-Habitat, 2003; Schneiderbauer and Ehrlich, 2004; van Dillen, 2004; Turner et al., 2003; Cardona, 2004b). According to Downing (2006), the vulnerability includes the expression, sensitivity and resilience of the system to combat the dangers posed by the effects of the agent. Researchers in the field of natural sciences often focus on the concept of risk, while researchers in the field of social sciences often refer to the term vulnerability. Concept of vulnerability is the social scientists associated with the group of socioeconomic factors and the community's ability to cope with natural disasters, but scientists about climate usually consider the concept of vulnerability as a function of the likelihood of occurrence and the potential impact of weather and climate related. According to Jörn Birkmann (2006) statistics, one of the best-known definitions were formulated by the International Strategy for Disaster Reduction (UN/ISDR), which defines vulnerability as: - The conditions determined by physical, social, economic and environmental factors or processes, which increase the susceptibility of a community to the impact of hazards. (UN/ISDR, 2004). - In contrast, the United National Development Programme (UNDP) defines vulnerability as: a human condition or process resulting from physical, social, economic and environmental factors, which determine the likelihood and scale of damage from the impact of a given hazard. (UNDP, 2004: 11) 7 Develop policies of integrated water resources management will require a comprehensive knowledge, the understanding of the vulnerability of water resources is a key element for this purpose. Vulnerability is a term used to describe a weakness or flaw exists in the system, the sensitivity of the system with a threat or a particular disadvantage, and/or challenges systems faced when dealing with the threat. In view of water resource management, the vulnerability can be defined as the characteristic weaknesses and flaws of the system of water resources makes it difficult to respond to changing economic and social and the environment. Thus, the vulnerability can look through (i) the pressure of the water resources in the study area; and (ii) the ability of ecosystems and society in the fight against the agents acting on the healthy function of water resource systems. 2.2. Vulnerability assessment Water, "blood" of natural ecosystems, have a role indispensable for almost all functions of ecosystems. Water is also one of the important resources needed to support the socioeconomic development of human. The result of the excessive population growth, rapid economic development, mismanaged of water resources, leading to dwindling water resources. Therefore, sustainable water resources management has become a priority concern of many national agendas. Vulnerability assessment is a process of investigation and analysis to assess the sensitivity of the system before the potential threat, and to identify the main challenges for the system in reducing or minimize the risks associated with, the negative consequences of the opposition activists. Assessment of water resources will be calculated based on the water balance between water supply and water demand, system policies and ownership to support the conservation and management of water resources, as well as regime change hydrology under the impact of climate change and other environmental factors. Besides, It needs to consider the risks that may occur from the surrounding areas can affect water resources. The vulnerability assessment can be used to orient the rational use of water resources through the provision of a priority plan for upgrades, adjusted operating 8 procedures, and/or change the policies to reduce risks and vulnerabilities to achieve the most efficient use. Vulnerability assessment will provide the basic framework for the development of options to reduce the risks and costs involved. In fact, every problem is identified, vulnerability assessment to delimit the main control factor; estimate the pressure; understand the current situation and development trend; impact analysis; and determine the response to deal with vulnerability of water resources systems. 2.3. Previous studies in study area Phu Quoc Island is the largest island in the system of the coastal islands of Vietnam. Phu Quoc Island in the Gulf of Thailand, the Southwestern of Vietnam. The studies related to the Island's water resources are very limited. The coastal islands Southwestern systems have a very important position on national security and economic development. Some typical projects in the Phu Quoc Island area are: - In 2006, Dr. Dao Manh Tien and Dr. Pham Van Thanh to implement the project "Investigation assesses the current state of the marine environment of Phu Quoc Island from 0 - 20m". The results were evaluated of marine resources Phu Quoc island, the environmental status of sediments and seawater. - Dr. Dao Manh Tien (2008) to implement the project "Investigation of environmental geology and geohazards coast of Phu Quoc - Ha Tien rate 1/100,000". - Within the scope of Phu Quoc Island and especially the National Park, this area has had plenty of the study of biological diversity. The survey results synthetic, fauna and flora of the area by the Institute of Forest Inventory and Planning II performed (1996, 2002). This is the basis of the results are to assess, comment on diversity and biological resources of Phu Quoc National Park. - NAWAPI - National Center for Water Resources Planning and Investigation (2010), Project “Water Resources Planning on the Phu Quoc Island”. Planning is approved as the basis for the management agency of water resources 9 Kien Giang Province implementation of management measures, protection and exploitation and use of water resources on the Phu Quoc Island. - Vietnam Academy for Water resources (2010), Project “ Research, evaluate the potential exploitation of surface water sources serving water supply on Phu Quoc Island”. The previous studies in Vietnam, not to mention much of each object on the Island are harmed by the activities of socioeconomic development, or the natural environment changes. In Vietnam, Vulnerability assessment of freshwater resources is limited, especially object is the island, where the water resources are very vulnerable. 2.4. Overview of assessment methods An approach to assess the vulnerability of water resources and hydrological system has been developed for a long time, with many different methods. Such as Water Poverty Index (WPI) – (Lawrence and others 2002; Sullivan and others 2003), with the aim is to provide an interdisciplinary measure, including the benefits associated with household water and indicate the level of water availability affect humans, the index takes into account the physical and social - economic factors related to water scarcity. Water Stress Indicator WSI description available water resources in a country, the water stress index developed by Swedish Falkenmark expert 1989. This index is often used in the evaluation on a national scale which data are available and provided intuitive results and understanding. However, the use of average annual water of the country should tend to obscure information water scarcity on a smaller scale. Meigh and others (2004) have developed a water availability index Water Availability Index (WAI). The index includes surface water, groundwater and compared to the total water demand of all sectors such as industry, agriculture, etc. Or water stress (Gleick 1996) at the regional level. The index uses measurements of input, output, and based on the water balance equation. 10 Or The South Pacific Applied Geoscience Commission (SOPAC) has developed an Environmental Vulnerability Index (EVI) 2005 to develop a vulnerability index to demonstrate the disadvantages, which the small islands are incurring. This index focuses on the vulnerability of the environment from the risks of natural and human. Including the effects on physical and biological aspects of the ecology, habitat, biodiversity, ecological resilience etc. There are many different evaluation methods to be studied and applied, with both advantages and disadvantages. For the vulnerability assessment of water resources in recent years, Method of water resources vulnerability assessment, developed by UNEP and Peking University (2009) emerged a way to evaluate the effectiveness and advantages. With the approach depending on the resources available to meet the production, use, environmental pressures and capacity development and management. It highlights the vulnerability factors such as climate change, population growth, economic development, and management, etc. of freshwater resource vulnerability. Currently, this method has been used to assess the vulnerability of water resources in the Pacific Islands, West Asia Region, and South Asia and some river basin as Mekong river basin, Amu Darya river basin,etc. The research on sea environmental resource vulnerability assessment in Vietnam has just begun in the late twentieth century. To date, there are many studies following different approaches, such as regions/areas, natural systems and social, community, resources in different areas. The study is based on general principles of a vulnerability assessment is to determine the ability of a compromised system (natural, social and economic) to meet natural disasters and man-made, one determine the resilience and recovery of systems; thereby, proposing vulnerability mitigation measures. From 2001, the team of Prof. Dr. Mai Trong Nhuan conducted studies assessing coastal vulnerability (Mai Trong Nhuan 2005). Thereby, the research team has identified the ability of the vulnerable segments of society, nature, previous works. The combined effects of natural and man-made disasters as well as vulnerability maps propose mitigation measures for many coastal localities 11 in our country. For the method to assess the vulnerability of water resources had initially applied research project to assess the vulnerability of water resources to river resources as Vulnerability Assessment of Water Resources Systems in Thach Han basin, Nhue Day basin by Trinh Minh Ngoc and others, 2013 - Faculty of Hydro-Meteorology and Oceanography, VNU University of Science used Methodologies Guidelines of UNEP and Peking University (Trinh Minh Ngoc 2013). However, this approach on the Island is still not applied. For Southwestern areas, the densely populated island group also has studied. As the evaluation of Prof. Le Duc An (1995), this area is much variation in natural conditions, natural resources. The project "Research on natural conditions and Southwestern areas of environmental, economic development serves to protect the security and sovereignty " KC09 02/06-10 of Prof. Do Ngoc Quynh mentioned the major motivating factors in the forms of sea disasters, environmental impacts of climate change in the current trend. Overall, the southwestern areas, especially in the island system have not been fully studied with the latest data on natural conditions, resources and environment. In which, freshwater resources is most vulnerable. 12 CHAPTER 3: DESCRIPTION OF THE STUDY AREA 3.1. Geography and Socioeconomics 3.1.1. Geography and Biodiversity a) Geography Phu Quoc, also known as Pearl Island, is the largest island of Vietnam, located in the Thailand Gulf. The total area of the Island is 567,55 km² (National land statistics, 2005), approximately the size of Singapore. Phu Quoc District has a total area is 589,23 km2, perimeter about 150km, includes 2 towns and 8 communes (NAWAPI 2010). Duong Dong Town, located in the northwest is the administrative town of the Island. Phu Quoc is located 120 km from Rach Gia and Ha Tien town by 45 km. Phu Quoc Island lies in the Gulf of Thailand in Southwest of Vietnam, Phu Quoc stretches from latitude 9°53' to 10°28' and longitude from 103°49'to 104°05'. \ Figure 3.1: Location of Phu Quoc Island on satellite images (Source: Google Earth) 13 b) Topography The topography here is quite diverse, but the main type is still hilly terrain. Topography can be divided into two areas of Phu Quoc Island with the following characteristics (NAWAPI 2010): North Island has an area of about 400km2 with over 70% of mountains - (average slope of 25-30%), less than 30% of the low hills and flat land. Overall, topography elevation is lower from the north to south and from east to west. South Island has an area of about 1672km2, including many low mountains - alternating strips of land fairly low and gradually in the direction from Northeast to Southwest with a slope less than 15%. Currently, it is being used or capable of use for agricultural production. Follwing are the results of the natural distribution according to altitude and slop. Table 3.1: Distribution by altitude and degree slope Altitude (m) Slope <5m <8% 5-40m <15% >40m >15% Current status and potential use Agriculture, construction, tourism Agriculture, construction, tourism Forest, ecotourism Total Area (km2) Percentage (%) 69 12,17 143,8 25,36 354,2 62,47 567 100 Source: National Center for Water Resources Planning and Investigation (NAWAPI) c) Meteorology Phu Quoc Island has one meteorological station was set up in 1957 in Duong Dong town, observation of meteorological factors: temperature, humidity, evaporation, wind, sun, and rain. Until 1995 on Phu Quoc island has two water levels stations at White bridge locations on Cua Can river and at Tram station on 14 Duong Dong river. Oceanographic stations are located in the estuarine areas of Duong Dong. The specific datas on temperature, humidity, wind, etc of Phu Quoac were provided by Kien Giang Hydrometeorology Center. Phu Quoc Island area characterized by tropical monsoon climate. High temperatures during the year, an average of 27.10C. Evaporation (Piche) annual average is 1,210 mm (3.3 mm / day). Average annual humidity is 82.6%. October, the highest average humidity (87.8%). February, the average humidity is lowest (75.5%) (NAWAPI 2010). Annual rainfall is abundant here, annual average 2902 mm and is relatively stable over the years (coefficients of variation Cv = 0.176) (NAWAPI 2010), pretty standard distribution. Rainfall in large stable with mountainous terrain conditions are ideal conditions for the development, management and operation of small and medium reservoirs on the island of Phu Quoc. 15 Table 3.2: Temperature characteristics (0C) at Phu Quoc Station (1984-2011) Characteristics I II III IV V VI VII VIII IX X XI XII Year Average 26.1 26.7 27.8 28.6 28.6 28.2 27.7 27.6 27.2 26.9 27.0 26.4 27.4 Highest 34.3 34.3 35.8 35.8 37.0 35.5 34.4 33.8 33.8 33.7 33.3 33.8 37.0 Lowest 17.3 17.1 18.5 22.0 22.1 22.5 21.7 21.8 22.1 21.4 19.9 17.6 17.3 Average lowest 30.7 31.3 31.0 32.6 31.6 30.6 30.0 29.7 29.5 30.3 30.7 30.5 30.7 Average highest 23.3 23.9 24.1 25.7 25.9 25.7 25.3 25.3 25.1 24.7 24.6 23.8 24.8 Table 3.3: Average humidity by months – year (%) Month I II III IV V VI VII VIII IX X XI XII Year Tho Chu 79 79 79 79 83 85 86 87 87 87 83 79 83 Rach Gia 79 78 75 78 82 84 85 85 85 84 81 79 81 Phu Quoc 74 77 77 80 83 85 86 87 87 86 79 73 81 (Source: Kien Giang Hydrometeorology Center) 16 Table 3.4. Lowest humidity by months – year (%) Month I II III IV V VI VII VIII IX X XI XII Year Tho Chu 54 48 53 56 55 60 64 64 58 65 61 57 48 Rach Gia 49 47 39 37 48 55 60 57 56 50 50 50 37 Phu Quoc 34 33 35 42 41 58 56 49 55 50 41 35 33 (Source: Kien Giang Hydrometeorology Center) Table 3.5: Characteristics of rain in Phu Quoc Month Highest rainfall per day Average monthly rainfall Average rainy days I II III mm 77.9 112.2 mm 32 28 date 6 4 IV V VI VII VIII IX X XI XII Year 103.2 127.1 109.6 126.8 196.5 327.1 188.4 181.2 136 105.4 327.1 66 154 260 365 390 474 458 355 145 52 277.9 12 19 21 22 24 23 21 13 6 177 7 (Source: Kien Giang Hydrometeorology Cent 17 Analysis of rainfall data from Phu Quoc stations for the period from 1985 to 2011 shows that total annual rainfall has decreased by an average of 19.8 mm /year (Nguyen Ngoc Tran 2013). Figure 3.2: Total annual rainfall in Phu Quoc station (1985 – 2011) (Source: Kien Giang Hydrometeorology Cente) Water level data from Phu Quoc station shows the maximum tide height, minimum tide height and the average trend line for the period (1988 - 2010); annual average tidal amplitude and the average trend line in the years (1988 2009) are shown in the image below: Figure 3.3: Hmax, Hmin in Phu Quoc island (Source: Kien Giang Hydrometeorology Center) 18 Figure 3.4: Tidal amplitude in Phu Quoc island (Source: Kien Giang Hydrometeorology Center) Tidal amplitude has the trend increased both on tidal and tidal foot. The maximum tide height, minimum tide height for the period (1988 – 2010) tend to increased. Based on the standards division of the rainy season and dry season Hydrometeorology Center (monthly rainfall exceeding 150 mm, surpassing the average evaporation month period, the fall in the rainy season) and in combination with the analysis of Duong Dong station rainfall data, rainfall regimes in Phu Quoc island can be divided into the following two seasons: rainy season lasts 7 months (May - November), coincided with the period of active southwest monsoon; 5 month long dry season (December- April years later), coinciding with the period of operation of the northeast monsoon. April rainfall average is 150 mm at Duong Dong station, but heavy rain and steady rainfall in the last 10 days of April, so April could be considered a transition month from dry season to the rainy season. The rainy season accounts for 81% of total rainfall leading to excess water during the rainy season, water shortages in the dry season. Moreover, due to the steep 19 topography, rain water should focus quickly generate large floods in the months VII-IX, often causing severe damage to infrastructure, land erosion and threaten people's lives (Nguyen Ngoc Tran 2013). d) Rivers Network The river and streams on the island of Phu Quoc with diverse characteristics, especially small rivers, estuaries flowing into different directions depending on terrain conditions. Surface water during rainy season is abounding in the inland. The density of spring is 0,42 km/km2 (largest density among islands in Vietnam). There are two main river systems in the. They occupy a total basin area about 25% of the total island area (NAWAPI 2010). These rivers have steep slopes, flood season caused major erosion. - Cua Can river: Derived from Chua mountain, flows from East to West. The river length is 29,75 km, the total length of the River in this basin is about 69km, the catchment area is 120km2. - Dong Duong river: Derived from Da Bac mountain, flow direction from east to west. The river length 21,5km, total length of the network of rivers and streams in this river around 63 km, the catchment area is 57 km2. - Cua Lap river connects with many small rivers derived from Ham Ninh mountain, flowing to the sea to the west, the river length is 11km, the total length of the river about 45km, the catchment area is 21 km2. - Tram river derived from Ham Ninh mountain, Ham Rong, flowing into the c North, river length is 9km, the total length of the rivers is about 22 km, catchment area is 41, 2 km2. - Suoi Lon river derived from Ham Ninh mountain, flows east - west, then enters the Dam river, flowing to the west - east, then to see; river length is 15km, the catchment area is 8km2. - Ca river: Dirived from Ham Ninh mountain, flowing into the East sea, river length is 5km, catchment area about 11km2. 20 There are also a number of other smaller Rivers are: Vung Bau River in the northwest of, Ham Ninh River in the Southeast, Dam river in the south and the Chanh river on the center island. The influence of natural conditions for the Island Development - Phu Quoc Island has steep terrain and complicated. Difficult mining, land used for agricultural purposes in many areas of upRiver rivers and Rivers. Steep topography is a major cause localized flooding on the Island, causing soil erosion. - Annual rainfall is relatively abundant on the island with the amount of 2902 mm/year (NAWAPI 2010). However, rainfall is not evenly distributed over the year. Rainfall during the rainy season accounts for 89%, in the dry season only 11% lead to water shortages in the dry season. - Every year in August, September heavy rains and lowland flooding, causing innundation, flooded from 1 to 2m. The flood prone areas at downRiver Cua Duong Dong, however Duong Dong downriver flood situation now has improved somewhat due to the reservoirs upriver. Flood damages situation in Phu Quoc, are not severe during the construction of hydraulic some coustruction system. - Droughts occur locally in Bai Thom and Ganh Dau commune. In coastal areas there are salt intrusion situations, affecting the farming activitis and lives of the people living there.