Factors influencing farming households’ climate change adaptation strategies in Central Vietnam

PLOS One | https://doi.org/10.1371/journal.pone.0328058 July 10, 2025 12 / 22 3.3 Challenges for climate change adaptation To better understand the constraints to adaptation implementation, farmers were asked to identify and rank key challenges that hinder the effective adoption of these strategies. This evaluation was conducted using a 5-point Likert scale ranging from 1 (“completely disagree”) to 5 (“strongly agree”). The mean scores of each statement were calculated and ranked accordingly to reflect the perceived severity of the challenges. The results of the ranking exercise highlighted “lack of water for irrigation” as the most critical constraint. This issue was consistently emphasized by respondents as a major barrier to sustaining agricultural production, particularly in the context of coastal Vietnam, where freshwater scarcity is exacerbated by climate-induced phenomena such as prolonged droughts, saltwater intrusion, and river salinization. Given the reliance of farming systems on water sources—rivers, rainfall, canals, and groundwater—any disruption to water availability significantly undermines productivity and food security. Although governmental organizations (GOs), non-governmental organizations (NGOs), and local civic groups have engaged in efforts to address water management issues, the challenges remain pervasive and unresolved in many areas. The second highest-ranked constraint was “lack of cultivable land.” With ongoing demographic expansion and rural-

urban transformation, increasing amounts of farmland are being converted to non-agricultural uses, such as housing development, industrial infrastructure, and public facilities. This trend of agricultural land loss poses a serious threat to cli- mate resilience, as it reduces the physical space available for adaptation-oriented diversification and sustainable farming practices. The third most frequently cited constraint was “lack of capital.” Financial limitations were reported by 48% of the respondents as a significant obstacle preventing the adoption of adaptation strategies. Limited access to credit and low savings rates reduce farmers’ ability to invest in climate-resilient technologies, improved seeds, irrigation systems, and other necessary inputs. In this context, access to microfinance, rural credit services, and public subsidies may play a criti- cal role in facilitating wider adaptation adoption. Other identified barriers included “lack of information” and “lack of technology,” which were noted by approximately 32% and 30% of the respondents, respectively. These constraints highlight the role of institutional support and information dissemination in climate adaptation processes. Without timely access to reliable climate forecasts, agricultural extension services, or demonstrations of new technologies, farmers are likely to rely on traditional practices that may no longer be sufficient under changing environmental conditions. In summary, the findings emphasize that adaptation to climate change among smallholder farmers in Central Vietnam

is constrained by a combination of physical, financial, and informational barriers. Addressing these barriers—particularly those related to irrigation water, land availability, capital resources, access to climate information, and agricultural technol- ogies—is essential for enhancing the adaptive capacity of rural communities. Doing so will contribute not only to the resil- ience of farming systems but also to the broader goals of sustainable agricultural development and rural poverty reduction in Vietnam (Fig 2). 3.4 Factors influencing households’ choice of climate change adaptation strategies To investigate the determinants influencing the adoption of climate change adaptation strategies among farming house- holds in the study area, a MNL model was employed. This model is particularly suitable for analyzing discrete choice data where the dependent variable represents the selection among multiple, unordered alternatives. In this study, the depen- dent variable was defined as the household’s choice of one of four main adaptation strategies: (1) vegetable production, (2) shrimp farming, (3) adoption of salt-tolerant rice varieties, and (4) lotus-fish integrated farming. Each of these strate- gies reflects a distinct approach to mitigating the adverse effects of climate variability and environmental stressors specific to the local agro-ecological context. For robustness of analysis and binary classification purposes, these four adaptation strategies were pooled, and an

index-based transformation was applied. Specifically, households that adopted adaptation strategies at a level above the