Livelihood vulnerability household fishermen household due to climate change in Lampung Province, Indonesia

Q = Total production (kg) TFC = Total fixed costs (IDR/season) TVC = Total variable cost (IDR/season) IDR = Indonesia Rupiah Furthermore, to calculate the household income of traditional capture fishermen in Bandar Lampung City, South Lampung Regency, and Tanggamus Regency, the following formula was used. Prt ¼ Pon fisheries þ Poff fisheries þ Pnon fisheries ð2Þ Description: Prt = Fishermen’s household income (IDR/year) Pon fisheries = Capture fisheries business income (IDR/year) Poff fisheries = Income from fishing hired labourers (IDR/year) Pnon fisheries = Business income excluded from the fisheries sector (IDR/year) The income vulnerability analysis of fisher households in this study uses the Livelihood Vulnerability Index (LVI). According to several researchers [33–36], the LVI is calculated by applying a balanced average approach in which each main component comprises several sub- components. However, each different sub-component contributes equally to the overall index. Analysis of the vulnerability index of fishing households uses the Livelihood Vulnerability Index (LVI). LVI measurements were carried out to see the value of fishermen’s household income vulnerability. Refer to the Intergovernmental Panel on Climate Changes, LVI mea- surements are divided into three categories including exposure, sensitivity, and adaptive capacity. Exposure consists of economic and ecological impact components. Adaptive capacity consists of components, namely natural capital, human capital, physical capital, financial capi-

tal and social capital. Sensitivity consists of two sub components, namely food and boat owner- ship. The main components, sub-components, and components measured in this study can be seen in Table 1. In this study the LVI was calculated by applying a weighted average approach (Hahn, et al. 2009) whereby each of the main indicators consists of a number of different sub-indicators, but each of the different sub-indicators contributes equally to the overall index. Therefore, the formula used to measure the livelihood vulnerability index is: Index Sd ¼ Sd Smin Smax Smi ð3Þ Description: Sd = Sub-component value Smin = Minimum value of the sub-component Smax = Maximum value of the sub-component Thenceforth, determine the value of the main component, namely by using the formula: Md ¼ Pn i¼1 index Sdi n ð4Þ Description: Md = Main component values Indeks Sd = Sub-component value n = The number of sub-components PLOS ONE Livelihood vulnerability household fishermen due to climate change in lampung province PLOS ONE | https://doi.org/10.1371/journal.pone.0315051 December 31, 2024 6 / 20