Results of the Multivariate Analysis of Variance (MANOVA)
The MANOVA results (
Table 4) demonstrate that flooding exerts a very strong and statistically significant multivariate impact on the livelihood system across all tests. Specifically, Pillai’s Trace, Wilks’ Lambda, and Hotelling’s Trace all report significance levels of
p = .000, confirming a clear and consistent overall multivariate effect of flooding on livelihood structures. The Partial Eta Squared values range from 0.127 to 0.155, indicating moderate to moderately strong effect sizes and suggesting that flooding simultaneously affects multiple forms of livelihood capital, including human, natural, physical, financial, and social capital.
The Roy’s Largest Root test further reveals an exceptionally strong dominant effect, with a value of 0.618, F (6, 107) = 11.025, p = 0.000, and a Partial Eta Squared of 0.382. This very large effect size indicates that flooding has a highly concentrated and intense impact along the principal dimension of the multivariate livelihood space, reflecting the abrupt, direct, and highly destructive nature of flood hazards. Such impacts generate simultaneous shocks across the five livelihood capitals, leading to profound disruptions in livelihood structures as well as ecosystem functioning.
The MANOVA results (
Table 5) demonstrate that drought exerts a statistically significant multivariate impact on the five livelihood capital dimensions, including human, natural, financial, physical, and social capital. All multivariate tests (Pillai’s Trace, Wilks’ Lambda, and Hotelling’s Trace) report
p values of .000, confirming a robust overall effect of drought on the livelihood capital system. The Partial Eta Squared values, ranging from 0.122 to 0.133, indicate moderate effect sizes, suggesting that drought generates cumulative and widespread pressures across multiple forms of livelihood capital rather than affecting a single dimension in isolation.
The Roy’s Largest Root statistic further reveals a highly concentrated dominant effect, with a value of 0.382, F (6, 107) = 6.815, p = .000, and a Partial Eta Squared of 0.276. This large effect size indicates that drought strongly affects a principal dimension of the livelihood capital system, reflecting the critical role of water scarcity in simultaneously undermining natural resources, constraining financial capacity, weakening physical assets, increasing stress on human capital, and eroding social support mechanisms. Together, these results highlight the structurally embedded and systemic nature of drought impacts on livelihood sustainability.
The analysis results (
Table 6) show that salinity intrusion exerts a very strong and statistically significant multivariate impact on the five livelihood capital systems, including natural capital, human capital, physical capital, financial capital, and social capital. Specifically, Pillai’s Trace, Wilks’ Lambda, and Hotelling’s Trace all reach significance at p = 0.000, confirming the presence of a comprehensive, pervasive, and severe overall effect of salinity intrusion on the livelihood structure. The Partial Eta Squared values range from 0.121 to 0.141, indicating moderate to moderately strong effect sizes and suggesting that salinity intrusion does not act in isolation but simultaneously degrades multiple forms of livelihood capital, particularly natural and physical capital, thereby generating indirect adverse consequences for financial and human capital.
The Roy’s Largest Root test further reveals a very strong dominant effect, with a value of 0.490, F (6, 107) = 8.741, p = .000, and a Partial Eta Squared of 0.329, indicating an extremely concentrated impact along a principal dimension of the multivariate livelihood space. This large effect size reflects the cumulative, persistent, and difficult to reverse nature of the salinization process, in which the degradation of natural capital plays a central role, undermining productive foundations, increasing livelihood risks, and constraining the long term adaptive capacity and resilience of households.
The MANOVA results (
Table 7) indicate that unseasonal rainfall exerts a statistically significant multivariate impact on the livelihood variable system across all tests. Specifically, Pillai’s Trace, Wilks’ Lambda, and Hotelling’s Trace yield significance levels ranging from
p = .002 to
p = .001, confirming the presence of an overall multivariate effect of unseasonal rainfall on livelihood structures. The Partial Eta Squared values range from 0.098 to 0.108, indicating small to moderate effect sizes and suggesting that unseasonal rainfall causes noticeable disruptions but does not exert a fully dominant influence across all livelihood capital components.
The Roy’s Largest Root test shows a highly significant result with F (6, 107) = 5.063, p = .000, and a Partial Eta Squared of 0.221, indicating the presence of a dominant impact dimension within the multivariate livelihood space. This relatively large effect size suggests that unseasonal rainfall strongly and selectively affects a specific livelihood dimension, reflecting the high sensitivity of ecosystems, agricultural production cycles, and season dependent livelihood strategies to abnormal climatic variability.
Table 8 shows that the interaction between flooding and drought produces the strongest statistically significant effect, with Pillai’s Trace = 0.422, F (25, 535) = 1.970,
p = .004, and partial
η2 = 0.084. The alternating cycle of floods and droughts fundamentally disrupts the natural resilience of ecosystems, leading to continuous environmental degradation. In addition, Roy’s Largest Root = 0.358 with a partial
η2 of 0.264 indicates a large effect size along the dominant dimension, providing strong evidence of a pronounced synergistic interaction effect.
The MANOVA results (
Table 9) indicate that the combined effects of unseasonal rainfall and salinity intrusion on the dependent variables are statistically significant at the 5% level across all multivariate tests. Specifically, Pillai’s Trace, Wilks’ Lambda, and Hotelling’s Trace report significance values of 0.034, 0.029, and 0.025, respectively, all below the 0.05 threshold, providing clear statistical evidence of an overall multivariate effect. The corresponding Partial Eta Squared values range from 0.079 to 0.084, indicating small to moderate effect sizes and suggesting that these combined climatic stressors exert a meaningful influence on the set of dependent variables.
In addition, the Roy’s Largest Root test yields a statistically significant result (Sig. = 0.001) with a Partial Eta Squared of 0.176, indicating the presence of a dominant effect dimension. This result suggests that unseasonal rainfall and salinity intrusion strongly affect at least one dependent variable or a subset of dependent variables, highlighting heterogeneity in the magnitude of impacts across variables.
The MANOVA results (
Table 10) indicate that the combined effects of drought and salinity intrusion on the dependent variables are not clearly significant at the 5% level for most multivariate tests. Specifically, Pillai’s Trace, Wilks’ Lambda, and Hotelling’s Trace yield significance values of 0.088, 0.079, and 0.071, respectively, all exceeding the 0.05 threshold, suggesting insufficient statistical evidence to confirm a significant overall effect. Nevertheless, the Partial Eta Squared values range from 0.108 to 0.116, indicating a moderate effect size and implying that practical effects may still be present despite the lack of strong statistical significance.
In contrast, the Roy’s Largest Root test shows a statistically significant result (Sig. = 0.001) with a Partial Eta Squared of 0.23, indicating that at least one dominant dimension of drought and salinity intrusion exerts a strong influence on a specific dependent variable or a subset of dependent variables. This result suggests heterogeneity in effects across variables and underscores the need for follow-up univariate ANOVA or post hoc analyses to identify the variables most strongly affected.
The divergence between Pillai’s Trace (
p = .088, non-significant) and Roy’s Largest Root (
p = .001, significant) reflects their fundamental difference: Pillai’s Trace evaluates effects across ALL dimensions, while Roy’s Largest Root examines only the FIRST dominant dimension (
Tabachnick and Fidell, 2019).The significant Roy’s Largest Root indicates that drought combined with salinity strongly affects one specific capital—natural capital—rather than all five capitals uniformly. Given the violation of homogeneity of covariance matrices (Box’s M,
p < .001), Pillai’s Trace is prioritized for conservative interpretation. Thus, this interaction is interpreted as having a targeted effect on natural capital rather than a systemic multivariate effect.
Following the multivariate analysis, the Tests of Between-Subjects Effects table was examined to assess both the individual and interaction effects of climate change variables on various livelihood capitals. The results are presented below.
Table 11 presents the multivariate test results examining the effects of both single and interactive climate change impacts on livelihood capitals. Overall, the findings indicate that different climate stressors exert heterogeneous and statistically significant influences across specific livelihood capital dimensions.
For single climate impacts, floods show statistically significant effects on natural, human, social, and physical capital (p < .05), while no significant association is observed with financial capital (p = .258). Unseasonal rainfall significantly affects natural capital (p = .001) and financial capital (p = .012), but does not exert statistically significant effects on human, social, or physical capital. Drought is found to significantly influence human, social, and physical capital (p < .05), whereas its effects on natural and financial capital remain statistically insignificant. Salinity intrusion demonstrates significant impacts on physical and financial capital (p < .01), while no significant effects are detected for natural, human, or social capital.
Regarding interactive climate impacts, the combined effects generally exhibit fewer statistically significant relationships compared to single stressors. The interaction between floods and unseasonal rainfall shows a significant effect only on social capital (p = .031). The combined impact of floods and drought significantly affects natural capital (p = .021) and financial capital (p = .004), highlighting compounding stress on both environmental and economic resources. Similarly, the interaction between floods and salinity intrusion significantly influences financial capital (p = .038). The interaction between unseasonal rainfall and drought does not yield any statistically significant effects across all livelihood capitals (p > .05). In contrast, unseasonal rainfall combined with salinity intrusion significantly affects human capital (p = .005), while the interaction between drought and salinity intrusion shows a significant association with natural capital (p = .012).
Taken together, these results suggest that single climate stressors tend to exert broader and more consistent impacts on livelihood capitals, whereas interactive effects are more selective and capital-specific. This pattern underscores the importance of disaggregating both individual and combined climate hazards when assessing livelihood vulnerability and designing targeted adaptation strategies. These findings must be interpreted cautiously given the SLF’s acknowledged limitations in capturing power relations and structural drivers beyond household-level capitals (e.g., upstream hydropower dams exacerbating drought and salinity in the Mekong Delta;
Smajgl et al., 2015). The stronger single-stressor effects compared to interactions may partly reflect the framework’s static view of capitals, potentially underestimating cumulative, long-term synergies from compounded hazards (e.g., repeated drought-salinity cycles leading to irreversible land degradation; recent 2024–2025 DSI events in VMD). Moreover, the sample’s focus on agricultural households with ≥ 5 years’ experience may bias toward more resilient groups, excluding landless or newly vulnerable populations often hit hardest by climate shocks (
IPCC, 2023). Despite these constraints, the MANOVA approach advances SLF applications by providing quantitative evidence of capital interdependencies, supporting more precise, capital-targeted policies.