Assessment of livelihood vulnerability to climate change in Phu Hoa district, Phu Yen Province, Vietnam

This study aims to assess the livelihood vulnerability in Phu Hoa district, Phu Yen Province, which is located in Vietnam’s southern middle coastal areas. Climate change has strongly impacted coastal areas and threatened the living conditions there. Using the Livelihood Vulnerability Index (LVI), 200 local households were surveyed to determine the level of livelihood vulnerability in Phu Hoa district. In the results, LVI increased from 0 to 0.4. The values indicated that household characteristics are the least vulnerable of the choosing factors (0.114), followed in ascending order by water source (0.230), food (0.237), social network (0.238), health (0.271), livelihood strategies (0.370), natural disasters and climate change (0.399). The overall LVI in Phu Hoa district reached a moderate level of 0.270. It is expected that the study will serve as a reference document that provides administrators and the community with information to proactively adapt and develop policies and strategies to support and mitigate the effects of natural disasters.


Introduction
The principal consequences of climate change, such as sea level rise and global warming, pose substantial problems for humanity in the twenty-first century.The hazards associated with climate change make livelihoods and quality of life more vulnerable, particularly in rural and coastal communities where natural resources are the primary driver of socioeconomic activity.Moreover, because the manifestations and effects of climate change, such as storms, droughts, floods, landslides, and seawater intrusion, are becoming more unpredictable, there is a greater chance that infrastructure built to current standards will be unable to adapt to future change.As a result, it is vital to incorporate climate change factors into sector and field planning and development strategies.However, the integration faces significant obstacles, including a shortage of data and scientific support.Additionally, it calls for systematic and thorough research, particularly on vulnerability, to be considered in the relationship between exposure level, sensitivity level, and adaptability in the context of climate change, which is crucial in providing a foundation for formulating policies and strategies.Additionally, measuring the proper adaptation for each distinct circumstance lowers risks and promotes sustainable development [1].
Vietnam is one nation that has experienced particularly severe climate change effects [2].In addition, natural disasters have become more frequent and more severe recently as a result of climate change.Each locality will have different manifestations and levels of force.Some regions, for example, are heavily impacted by storms and floods, and others, where the saltwater intrusion penetrates deeper and deeper into the mainland, cause significant losses of people, property, and environmental resources as well as damage to infrastructure, economy, culture, and society.
The topographic structure of Phu Yen province on Vietnam's south-central coast is diverse.The entire eastern boundary of Phu Yen province is a seashore, stretching for approximately 189 kilometers.Its topography features a substantial slope area.Due to its location and unique topography, Phu Yen is sensitive to climate change and especially vulnerable to sea level rise, heavy rainfall, storms, and tropical depressions [3].The average annual temperature tends to change with a marked increase; within about 33 years , the temperature at Tuy Hoa station increased by about 0.9°C, and the total average annual rainfall increased by 1.21% (2012-2020).People have endured numerous unfavorable effects of climate change in the Phu Hoa district for a long time, including unpredictable weather, droughts, and floods that resulted in disease epidemics in livestock and poultry, directly impacting the local wet rice farming.Although agricultural output mostly depends on water supplies, it is also adversely affected by prolonged drought, rising temperatures, and decreased rainfall.These are just a few unfavorable effects directly affecting the residents' livelihoods, particularly farming and ranching [4].The vulnerability of the Phu Hoa community needs to be studied and evaluated so that managers, administrators, and the community can learn how to adapt and support policies proactively and how to rapidly lessen the effects of natural disasters.This critical issue must be addressed.

Theoretical foundations
A livelihood is sustainable if it can adapt to changes, recover from them, or develop capacities and resources for the future without harming the foundation of natural resources [5].In contrast, the term "livelihood vulnerability" is relatively vague and encompasses a wide range of topics, including the interaction between the catastrophe site and the social system and physical, economic, social, and resource expressions.According to the traditional idea, livelihood vulnerability is produced by two groups of factors: the degree of loss and resistance ability, and it frequently manifests itself through the structure of an economic, political, social, or environmental system.Studies and assessments of vulnerability related to the climate change element have been made in several publications by authors and organizations worldwide.The term "climate change vulnerability" refers to how vulnerable and incapable a system is to the harmful effects of climate change.
According to the IPCC (1997), vulnerability is the susceptibility of a natural or social system to long-term damage from climate change (IPCC, 1997).Climate change vulnerability is the degree to which a system is vulnerable and unable to withstand adverse impacts [6].
According to Abbs et al. [7], there are two methods for examining livelihood vulnerability: evaluating the possible effects of climate change on the system's components under various scenarios and evaluating social sensitivity, adaptive capability, and information on the implications of climate change.O'Brien et al. [8] argue that people's vulnerability to the effects of climate change is largely due to the socioeconomic and political contexts in which they live.Human vulnerability can be assessed in terms of various outcomes, such as food security or household income.The region's economic development is correlated to how community income or government policies affect people's livelihoods or food sources.
However, the study by Hahn et al. [9] laid the foundation for the livelihood vulnerability index (LVI).Hahn et al. combined the sustainable livelihoods approach with older methods to make a Livelihood Susceptibility Index (LVI) with multiple indicators to measure how sensitive and vulnerable people are to the different effects of climate change.Household characteristics, means of subsistence, social network, health, food, water source, natural hazards, and climate change are the LVI's seven key components.There are multiple sub-stats for each central element.
The Intergovernmental Panel on Climate Change (IPCC) [6] defines vulnerability to climate change as "the degree to which a natural or social system may be vulnerable or unable to cope with the adverse effects of climate change.The IPCC has specified vulnerability as a function of three factors, including the exposure of the system to the negative impacts of climate change (Exposure -E), the sensitivity of the system to climate changes (Sensitivity -S), and the adaptive capacity to climate change (AC).
Thus, the relationship of the vulnerability index with the component indexes can be briefly rewritten according to the mathematical relationship as V = f(E, S, AC).In place of calculating the LVI index, the LVI-IPCC index has been created by classifying the seven significant components above into three categories: Exposure, Sensitivity, and Capacity for Adaptation.Which: The exposure factor is an apt representation of the community's issues regarding the natural aspect.Climate change and natural disasters are the ways that this element manifests.Sensitivity is a term used to describe how strongly a system responds to climate change, whether positively or negatively.The components Food (F), Health (H), and Water (W) are used to measure community sensitivity.The ability to modify a system to lessen vulnerability to climate change, repair damage caused by climate change, or seize opportunities resulting from the positive effects of climate change is known as adaptation capability.Social Demographics (SDP), Livelihood Strategy (LS), and Social Network (SN) are three elements that together represent the community's ability for adaptation [9].

Research methods
Hahn et al. [9] state that the study modifies the leading causes of LVI and contributing factors for the region following prior research and local conditions.Diagram 1 depicts the vulnerability's primary components.

Evaluating the livelihood vulnerability index
Before determining the LVI, this method generates the indicators using primary data from home surveys.The socio-demographic profile (SDP), livelihood strategy (LS), social networks (SN), health (H), food (F), water (W), natural hazards, and climate change (NHCC) are the seven main components of the LVI.The LVI is derived using a weighted average of seven parts to ensure that each sub-factor contributes equally to the overall score.Because each sub-factor is measured by a different method, normalization is needed to get an index using the following formula: which Index   : the standardized index of sub-factors;   : the original value of the sub-factor (actual value) for the locality d (district/commune);   is the minimum value;   is the maximum value.
Once normalized, calculate the value of each main factor based on the average of sub-factors using the formula: which Md is one of 7 factors for locality d (district/commune); indexSdi displays sub-factors and n is the number of sub-factors in each main factor Once the values of the seven main components are determined, calculate the local livelihood vulnerability index (district/commune) according to the following method: which:   is the livelihood vulnerability of locality d (district/commune);   is determined by the number of sub-factors of the main factor.The index LVI ranges from 0 (lowest vulnerability level) to 1 (highest vulnerability level) [7].The LVI -IPCC index is calculated based on the combination of the principal elements according to Table 1 by the formula which:   is an IPPC contributor;   is the main factor for the locality (district/commune) recorded by parameter i;   is the weight of each main factor.
The factors of Exposure, Sensitivity, and Adaptive Capacity will be summed and calculated using the formula: LVI-IPCC = (E -AC) * S (5) In this study, the value of LVI-IPCC ranged from -1 (lowest lesion) to 1 (highest lesion) [9].Focusing on socio-demographic profile and livelihood parameters, samples were evenly dispersed throughout eight communes and one town.A semi-structured questionnaire was developed and directly interviewed households with agricultural and livestock farming activities to collect basic information about the family, as well as related livelihood activities, a livelihood budget, local government support, response options, and the application of the people's indigenous knowledge when facing climate changerelated difficulties.Thanks to the evenly distributed survey sample sizes, a more comprehensive understanding of how climate change affects livelihoods and people's capacity to adapt to its effects will be possible.In addition, local government offices and groups in Phu Hoa district and Phu Yen province were also questioned about the area's vulnerability to climate change.

Results and discussion
Through the results of surveys and interviews with households, combined with secondary data from relevant units, the values of the seven main factors of the LVI are calculated in Table 2. Regarding the livelihood strategy sub-indicator, most households depend on agriculture, which makes up a relatively high proportion of 56% of all households examined.However, climate change has significantly impacted farming and animal husbandry: the temperature increases and the irrigation needs of crops also increase in the area, as water resources that most depend on nature are limited, trees are severely lacking in water, and crop yields are significantly reduced.The total output of food crops compared to last year's period was 2.1%, of which rice decreased by 5.2%, maize decreased by 3.6%, and vegetable kinds decreased by 2.2%.In addition, increased temperature affects the adaptability of livestock, changing reproductive habits.Increased disease and disease transmission, reduced productivity, and herd numbers.
Additionally, 31% of all studied homes were impoverished households, with only one activity directly impacted by climate change.A significant portion (24%) of poor households also includes members who work away from home for at least three months to raise their family's income.As a result, they have inconsistent income, an insecure way of life, and little capacity for accumulation.A poor household lacks at least three indicators indicating the primary social service deficiency level with an average monthly income of 2 million VND or less (including employment, medical care, education, housing, drinking water, sanitation, and information).Regarding vulnerability variables, the local livelihood strategy index comes in second with 0.370.

Figure 3. The graph of the main components of the LVI index of Phu Hoa district
The sub-indices of social networks have a score of 0.238, placing them fourth in terms of vulnerability factors.It is noteworthy that a high percentage (68%) of people lack access to bank capital, and the remaining 20% do not receive any assistance from the government.Due to the absence of prerequisites such as poor or nearly poor households, it is impossible to borrow money for eradicating hunger and reducing poverty.As a result, people rely on local representatives and other organizations, such as the local Women's Union and Farmers' Association, to provide timely assistance in various ways.
Only 3% of families experience food shortages in the food sub-indicators at least once a year because they can cultivate their land and raise animals for their needs.However, 52.2% of the household's total monthly revenue was spent on average on indoor dining activities.The food index consequently rose to 0.237, placing it in fifth place.
Water resources indicators: The local water delivery system serves more than 70% of houses and has adequate groundwater reserves.Most people do not require water for domestic use or stockpile water for emergencies.Due to the drought, however, saline intrusion will impact groundwater, making prudent and efficient use of groundwater resources crucial.As a result, the water resource index fell to sixth place with a score of 0.230.
Few people suffer from chronic ailments, and the majority of homes are in close proximity to medical facilities for the health sub-indicators.However, a significant portion of the population -37% of all surveyed households -lacks health insurance.People continue to have limited access to health services and are not particularly concerned with health insurance.Typically, when they are ill, they purchase their medications.They will not seek medical attention until the illness worsens.The health score, which placed third among the vulnerability variables, was 0.271.Natural disasters and climate change have a lot of high-level sub-indicators.Natural disasters and climate change have a lot of high sub-indicators.For example, the South Central Coast has had several severe storms in recent years (the average frequency of occurrence is 10-12 times/year), particularly in Phu Yen province and the Phu Hoa district, severely damaging property and human life.So, the Index of Natural Hazards and Climate Change, at the top of the list of vulnerability variables, reached 0.399.Therefore, the residential community in Phu Hoa district's livelihood vulnerability index (LVI) reached 0.270.This number represents the average susceptibility.Natural hazards and climate change, livelihood strategy, health care, social network, food, water source, and household characteristics are the primary factors listed in descending order.As a result, households will suffer greatly when natural disasters cause major crop failures because they won't have any source of income to make up for the loss.Future consequences include less money, a more challenging life, and natural calamities.
Based on the IPCC's idea of vulnerability, the LVI-IPCC total vulnerability index looks at how climate change affects a community's way of life.It does this by combining seven important factors into three contributing variables.Hoa district has usually seen severe effects.However, according to an analysis of social network elements, family characteristics, and livelihood activities, the local adaptability is excellent (0.241).However, it is still insufficient to deal with the effects of natural disasters and climate change.Therefore, this data will serve as the foundation for decision-makers efforts to continue and advance current measures to combat climate change.

Conclusion
According to research findings, the LVI index for the Phu Hoa district indicates poor sensitivity to the impacts of climate change on livelihoods, (0.270).Despite being at the average threshold, there are two factors that require special consideration and attention.The first is the vulnerability index for climate change and natural hazards of 0.399, and the second number is the index for the livelihood strategy of 0.370.The LVI-IPCC index data also indicate the average vulnerability of Phu Hoa district (0.039).If the LVI indicates that the impact of disasters and livelihood strategies are the two most pressing issues, the LVI -IPCC shows that the vulnerability and responsiveness of the ward communities in Phu Hoa are comparable, with indices of 0.246 and 0.241, respectively.This result is similar to regions with similar geographical, topographical, and climatic characteristics in the central and south-central regions, such as Thua Thien Hue and Binh Thuan provinces [10,11].The majority of locals are aware of agricultural farming's extreme reliance on weather conditions.Additionally, the community has found it simpler to adapt to and mitigate the effects of climate change thanks to the assistance of local government bodies and influential groups.
Recommendations to improve the livelihoods index in order to support communities in adapting to climate change are proposed as follows: changing the varieties of plants and animals that are resistant to erratic rain and sun and have high heat capacity; changing husbandry methods; paying attention to livestock density, quality, and productivity; changing the purpose of land use for crops that do not give a high yield; diversifying industries; and creating jobs and stable incomes for people.

Figure 1 .
Figure 1.Location of the study area

Figure 2 .
Figure 2. Modeling the contribution of significant vulnerability elements to IPCC factors [9]The LVI -IPCC index is calculated based on the combination of the principal elements according to Table1by the formula There are 10,891 dwellings in the Phu Hoa district as a whole.The data is gathered from 200 families residing in the study region using Yamane's (1973) formula for calculating sample size and an error of 5-10%.

Table 2 .
LVI primary factors value

Table 3 .
LVI-IPCC index in Phu Hoa district