3.1. Wilcoxon–Mann–Whitney Test
We first conducted an ordinary statistical analysis to determine whether migrants became happier after moving to Hulhumalé.
Figure 1 and
Table 3 show the respondents’ life satisfaction levels before and after their migration to Hulhumalé. Results show that many people are satisfied with their lives after migration. (Unless otherwise noted, the difference between the two groups presented in this paper was found to be significant by the Wilcoxon–Mann–Whitney test with a
p-value < 0.05.)
Table 4 shows different aspects of life in Hulhumalé that are the most or least valued by the residents. Residents generally value the environment of Hulhumalé, specifically its natural beauty and air and water quality. Transportation is also highly valued, as are sports facilities and parks. In contrast, the high costs of acquiring a residence and living in Hulhumalé were least appreciated by the residents, along with the lack of cultural activities, well-paying jobs, police protection, and public order.
The statistical significance between the two groups per attribute was then examined using the Wilcoxon–Mann–Whitney test. Respondents were divided into two groups according to age (c1), sex (c2), education (c3), place of origin (c5), income (c8 and c9), and intention to return to their place of origin (c11) (
Table 5). We then attempted to identify the demographic characteristics associated with higher life satisfaction among residents of Hulhumalé. To achieve this, we analyzed the responses regarding satisfaction after migration (x2). We assessed whether there were significant differences in responses to this question based on respondents’ attributes. As illustrated in
Table 6, migrants from Malé (Category 1 of attribute c5) exhibited significantly higher satisfaction with life in Hulhumalé compared to those from outside Malé (Category 2 of attribute c5). Additionally, our analysis revealed that migrants who opted to remain in Hulhumalé (Category 2 of attribute c11) reported greater life satisfaction compared to those intending to return to their place of origin or were undecided about returning (Category 1 of attribute c11).
We further determined the instances in which the answers to a particular question differed significantly by attribute (
Table 7). The following findings were obtained.
In terms of age (c1), the answers of Category 1 (20–29 years old) and Category 2 (more than 50 years old) respondents to questions x3, x4, x8, x12, x14, x15, x23, x29, and x32 significantly differed. Unsurprisingly, the younger generation is more concerned about convenience, particularly access to educational opportunities, employment possibilities, transportation, and services provided by government offices. In addition, interest in natural disasters varies by age, with younger generations being more concerned about the resilience of Hulhumalé to natural disasters. This was also the case with people’s connections before migration.
In terms of sex (c2), Category 1 (Male) and Category 2 (Female) responses to questions x3, x4, x19, x22, and x25 also differed considerably, suggesting that sex influences employment opportunities in Hulhumalé. Interestingly, concerns such as the preservation of local and traditional culture, beautiful and rich natural environments, and territorial integrity are evaluated differently by sex.
In terms of education level (c3), the responses of individuals from categories 1 (O’Level) and 2 (First degree and higher) to questions x13 and x27 were significantly different. This was a surprise to the authors, as we expected educational level to have an impact on other questions. This suggests that factors other than education have a greater impact on residents’ evaluations of their living environment in Hulhumalé.
In terms of pre-migration settlement (c5), the answers to questions x1, x2, x3, x4, x5, x6, x10, x11, x12, x13, x14, and x20 were significantly different for respondents from Malé (Category 1) and other cities (Category 2). Notably, for those who have migrated to Hulhumalé from areas other than Greater Malé, life in Hulhumalé is quite different (mostly positive) compared with their places of origin. This may be because of the better educational and employment opportunities offered in Hulhumalé, which are major factors in people’s decisions to move. However, for these people, the cost of living in Hulhumalé is a major constraint in their decision to move.
In terms of annual personal income before migration (c8), only responses to question x28 proved significantly different between Category 1 (less than Rf. 29,999) and Category 2 (more than Rf. 210,000) respondents. Wealthier people are more likely to enjoy the services provided by Hulhumalé, such as public facilities.
In terms of annual personal income after migration (c9), the answers to questions x9, x20, and x28 were significantly different between people who earn less than Rf. 29,999 (Category 1) and more than Rf. 210,000 (Category 2). These findings suggest that the higher-income bracket enjoys the facilities and favorable environment in Hulhumalé, whereas people with lower incomes miss the opportunity to enjoy services and public facilities provided in Hulhumalé.
In terms of respondents’ interest in returning to their original homes (c11), the answers to questions x1, x2, x3, x8, x9, x11, x20, x22, and x32 proved significantly different between Category 1 (yes or undecided) and Category 2 (no). The respondents’ intention to live permanently in Hulhumalé was reflected in the differences in their ratings of the living environment in Hulhumalé across a number of questions. Unsurprisingly, those who rated their living environment as high intended to continue living in Hulhumalé. This suggests that the proportion of people who wish to continue living in Hulhumalé can be increased by further improving public facilities and other services.
3.2. Permutation Feature Importance
To identify the factors influencing migration, we implemented two sequential procedures. Firstly, we applied the extreme gradient boosting algorithm to construct a model, with respondents’ satisfaction after the migration (question x2) as the objective variable and all other questions serving as explanatory variables. Subsequently, we utilized PFI within the calibrated model to pinpoint the explanatory variables contributing to the most significant factors.
PFI assesses the importance of independent variables by quantifying the reduction in model accuracy when the values of a specific independent variable are randomly rearranged. Notably, for the dependent variables, which were categorized using the Likert scaling method from 1 to 5, the estimation error was minimized to 0% when the model’s output was rounded to the nearest integer.
The outstanding factors that were identified are as follows:
x11—Clean new home
x23—Resilience to natural disasters
x9—Sports facilities and parks
x20—No air and water pollution
x25—Territorial integrity
These factors represent the five most significant independent variables, as evidenced by the magnitude of the model error rate. This finding indicates that current inhabitants highly value the factors related to their living conditions.
“Resilience to natural disasters” was the second-most influential explanatory variable. The respondents perceived the ordinary land of the Maldives, which consists of coral reefs, as vulnerable to natural disasters, and Hulhumalé, a modern city, as more vulnerable to natural disasters than coral reefs.
“Territorial integrity” was also found to be an important explanatory variable, suggesting that this issue, which in part should be affected by the expected sea level rise, is of interest to the residents of Hulhumalé.
3.4. Overall Implications
The vulnerability of atoll countries to the impacts of climate change, particularly sea level rise, presents an existential threat that cannot be ignored. The atoll nations of Kiribati, the Maldives, the Marshall Islands, and Tuvalu are at the forefront of this crisis, facing the prospect of uninhabitability within the coming decades if global sea levels continue to rise at the projected rates. This vulnerability arises from a combination of geographical characteristics, limited land area, economic dependence on the ocean, and heightened susceptibility to extreme weather events. Addressing this critical problem requires multifaceted strategies that consider the socioeconomic, environmental, and cultural dimensions of these affected countries.
Migration stands out as a potential solution for atoll nations grappling with the impact of sea level rise. The Maldives exemplifies this approach with the construction of Hulhumalé, an artificial island, offering a place for residents to seek higher ground. Hulhumalé serves as a model for addressing population congestion in the capital, Malé, while simultaneously responding to the threat of rising sea levels. The Maldivian government’s efforts to create economic opportunities and develop sustainable infrastructure demonstrate a proactive approach to the challenges posed by climate change. However, the survey revealed that many of the current residents of Hulhumalé did not move to the island because of its immunity to the effects of climate change. As Karabchuk et al. [
21] observed, there is a negative association between life satisfaction and the desire to emigrate in the existing literature. They also examined the role of human development as a moderator in this relationship. This suggests that higher levels of human development in Hulhumalé could encourage residents to stay in the Maldives.
The findings of the questionnaire survey conducted in Hulhumalé shed light on the factors influencing resident perceptions of life after migration. Residents’ satisfaction with their new lives, as evident from the survey results, underscores the importance of addressing concerns such as housing quality, environmental resilience, sports facilities and parks, and air and water quality. These factors play crucial roles in determining the success of migration-based adaptation strategies. The PFI analysis, as well as SEM analysis, highlights the significance of factors such as clean housing, resilience to natural disasters, sports facilities and parks, and unpolluted environments, indicating that residents’ well-being and comfort are central to their overall satisfaction.