1. Introduction
Climate change is responsible for catastrophic disasters such as droughts, storms, and floods that lead to human migration [
1]. Over the last 30 years, the frequency of disasters such as cyclones, storm surges, floods, and droughts increased threefold, which led to human migration at an alarming rate [
2]. It is predicted that, by 2050, between 250 million (which is one of every 45 people in the world) [
3] and one billion [
4] people will be forced to move permanently because of climatic disasters. Bangladesh is generally recognized as one of the most climate-vulnerable countries because of its vast low-lying areas [
5,
6,
7]. The country is frequently affected by climatic events such as cyclones, floods, droughts, and storm surges, which represent approximately two-fifths of those faced globally [
8,
9]. In fact, a severe cyclone hits Bangladesh every three years on average [
10,
11,
12]. Moreover, the coastal areas and the Bay of Bengal are located at the northern tip of the Indian Ocean, and are frequently hit by cyclonic storms, generating high tidal surges, floods, and storm surges, which lead to permanent or temporary human displacement [
6,
13,
14,
15,
16,
17]. It is forecasted that, by 2050, about 17% of coastal areas will be inundated [
16].
Furthermore, global warming and sea-surface temperature anomalies (SSTAs) are interlinked [
18]. Coastal people face enormous coastal erosion due to climate change, which may accelerate the destructive wind–wave interaction faced by coastal seashores, subjecting them to a higher sea surface temperature [
19]. It was observed that the sea-surface temperature (SST) increased over the last four decades in the northern Indian Ocean, as well as in the Bay of Bengal, which is one of the major factors leading to the formation of depressions and low-pressure systems in the area [
8,
16,
18,
20]. Furthermore, SST changes are responsible for various kinds of disasters; thus, climate change will increase the frequency of disasters in the future, especially in the Indian Ocean. Cyclone Aila in 2009 was one of the catastrophic events formed in the Indian Ocean. Furthermore, an increase in the number of disasters will destroy infrastructure, crop production, livelihoods, and the economy of the country [
12].
Cyclone Aila, a category-1 cyclonic storm, was the second tropical cyclone hit in 11 southwestern coastal districts in Bangladesh on 21 May 2009. Around 3,928,238 people and 948,621 households were affected by Cyclone Aila [
21]. It formed in the northern Indian Ocean, about 350 km offshore and became a severe cyclonic storm within four days. Cyclone Aila struck the coastal districts during the spring tide. The cyclone’s effects lasted 15 h (approximately) with wind speeds up to 120 km/h (75 mph) and tidal surges up to 6.5 m [
20]. Although the intensity of the cyclone was relatively low, it inundated 350,000 acres of cropland [
21]. About 1742 km of coastal polders (embankments) were washed away by the tidal surge from the cyclone, and saline water inundated large parts of the southern districts of Khulna and Satkhira (46% of croplands) for up to two years [
21,
22]. The full moon worsened the effects of the cyclone. It was also reported that Cyclone Aila damaged around 38,885 hectares of shrimp fields (ghers), as well as sweet fishponds [
20,
23]. Fully damaged also were 445 educational institutions, 2233 km of road, and 157 km of bridges/culverts [
24]. The cyclone struck at a time when people were trying to recover from the losses following Super Cyclone Sidr (Category 4), which battered the districts in 2007 (merely 18 months before). These two events illustrate both rapid and slow-onset climate events; however, the consequences of Cyclone Aila differed from those of Super Cyclone Sidr. While Aila was a Category 1 cyclone, the losses and damages it caused were widespread; in fact, the recovery after Sidr was much more rapid than that after Aila. The death toll from Cyclone Aila was 190 people, which was comparatively much lower than other major disasters that occurred in Bangladesh. However, the recovery from Cyclone Aila remained a challenge because the coastal people could not fully recover from the effects of Cyclone Sidr (2007) [
21]. Almost two years after Aila (in 2011), many parts of Aila-affected areas remained underwater, where the land was unproductive and trees died due to saline intrusion in the soil, and people faced severe water and food shortage, as well as unemployment.
Figure 1 provides a map of Cyclone Aila-affected areas.
The coastal people were mostly dependent on natural resources for their livelihood. The two major occupations of the coastal people, farming and fishing, were severely affected by Cyclone Aila [
21]. Post Aila, prolonged waterlogging resulted in the increase in salinity in both water and soil [
12,
22,
25]. Due to prolonged waterlogging, about 90% of the livelihood options of southwestern coastal communities were damaged [
26]. It is a fact that the consequences of a disaster are not the same in the affected households even those from the same community. In general, vulnerable poor people have limited abilities in terms of socioeconomic condition, social network, and access to information, education and technology to adapt themselves to a severe situation, forcing them to migrate abruptly. In contrast, people in a comparatively better position in terms of human and social capital, migrated in a planned way, while relatively poor women and dependent members were trapped and stayed in affected areas [
12,
27].
Nevertheless, the consequence of cyclone Aila was much different from other cyclones as Aila was a Category 1 type, cyclonic storm formed in the Indian Ocean, with a slow onset but long-term consequences. For instance, it induced the migration of around two million people [
20]. Another main difference between cyclones Aila with other cycloneis that it led to three other extreme events or climatic events, flood, storm surge, salinity, and waterlogging, viewed as new forms of calamities in the southern coastal districts [
28]. Although Cyclone Aila was a slow onset event that did not cause a significant loss of life or property, its impact was prolonged. It reduced land productivity, so households required external assistance to cope with loss of incomes. As Cyclone Aila continued to directly threaten the source of income of the coastal communities several years after it struck, many people migrated to reduce their hardship; in particular, male members of the affected households moved out to look for income opportunities [
29,
30].
The shock resulting from climatic events also affected the socio-economic conditions of coastal communities that were dependent on natural resources in various ways such as a loss of assets and livelihood options, reduced income, food shortage, and water scarcity [
16]. Disaster preparedness response strategies such as an early warning system and the construction of a cyclone shelter reduced the death tolls in years, but the impacts on the socio-economic conditions of the affected people remained substantial. Cyclone Aila also adversely affected the socio-economic conditions of the coastal communities in terms of assets, incomes, livelihood options, and food consumption. However, though many research studies have been carried out with regard to the impact of Cyclone Aila on the socio-economic conditions of affected communities and the factors of climate-induced migration [
2,
12,
16,
20,
25,
31,
32], comparative analyses on the socio-economic conditions of migrant and non-migrant households were neither carried out nor was there an analysis performed on the households’ strategy in dealing with similar climatic events such as migration or shifting livelihood options. Therefore, understanding the coastal people’s behavior toward coping with Cyclone Aila is necessary in order to deal appropriately with other climatic events in the future. This research, therefore, is aimed to assess to assess the impact of a climatic event i.e., Cyclone Aila, on the socio-economic conditions of migrant and non-migrant households in the southwestern coastal areas of Bangladesh. Thus, lessons from the Cyclone Aila can be applied to deal with similar future disasters.
4. Concluding Remarks
This paper focused on the impacts of the cyclone Aila in 2009 on the socio-economic conditions of migrant and non-migrant households in the southern part of the coastal areas of Bangladesh. The research was conducted in Koyra sub-district in Khulna and in Shymnagar in Satkhira district. The devastation of the cyclone had considerably affected the coastal communities, economically and socially. Furthermore, some people decided to migrate to look for alternative solutions to their problems as a result of the cyclone, while some stayed behind. The unit of analysis was migrant and non-migrant households. A comparative analysis on the socioeconomic conditions post Aila between migrant and non-migrant households.
Results from the study revealed that the cyclone adversely people’s income, occupation, housing, food consumption, and croplands. Although the affected communities received external assistance and adopted various responsive strategies to recover their losses, the strategies may not be effective in the long term [
43]. Evidence showed that the short-term strategies and insufficient external assistance failed to reduce the hardships of the cyclone-affected households, which induced out-migration [
19,
47].
As discussed in the previous sections, the findings revealed that during the cyclone, the severe storm and prolonged water logging resulted in increased salinity in both water and soil, which had a considerable impact on agriculture and fishing or aquaculture; shrimp farming [
10,
39]. Therefore, agricultural land became unproductive, and the enormous crop failure and reduced crop production threatened their livelihood opportunities, which forced some households to diversify their sources of income [
22]. Moreover, the cyclone devastated the farmers just before harvesting, leaving them with massive financial losses inducing migration. From the survey, it was found that the number of small landholders in migrant households decreased, while functionally landless and marginal farmers significantly rose. The FGDs participants argued that migrant households with farmland holders sold or leased out their lands before leaving and became medium and small landholders. On the other hand, the polders that protected shrimp farms have collapsed due to the high pressure of tide; thus, waterlogging and salinity affected the shrimp farms drastically. Moreover, the lingering reconstruction of the embankment also increased soil salinity two years after Aila; thus, the recovery of shrimp farms was impossible for some farmers [
56], which may have influenced them to diversify from farm to non-farm or off-farm activities, which also triggered migration.
The findings of this paper also revealed that affected households took loans from informal and formal institutions; however, the repayment status of loans among migrant households was statistically significantly higher than that of non-migrant households. The outcome also showed that the average monthly income of migrant households was higher than that of non-migrant households. Based on these findings, it can be said that migration is a better strategy in terms of increasing income or reducing liability due to loans. Furthermore, the number of houses (Kacha houses) reduced migrant households while semi-pucca and wooden houses increased, showing that a higher income also impacts a household’s housing conditions.
According to the field survey, tube wells and ponds were the major sources of water for the households. Post cyclone Aila high tidal surges contaminated soil and water by salinity. Therefore, rainwater harvesting becomes another option for the affected households. Moreover, post-Aila food insecurity increased affected the food consumption pattern of coastal people. The crisis became so severe that affected people were forced starvation two or three times a day during Aila. Findings show post-Aila food intake among migrant households was significantly higher than non-migrant households. This was clear evidence that shifting occupation through migration had an enormous impact on food consumption patterns.
The outcome of this research reveals that migrating households were better equipped to recover from their losses and their socio-economic conditions in terms of income, housing, food consumption, and repayment of the loan than non-migrant households. Considering these aspects, it can be argued that migration or shifting livelihood options could be a better strategy for affected households dealing with climatic events (for example cyclone Aila). Thus, the experiences from the cyclone Aila can be helpful for coastal people for preparing the vulnerable population for future climatic events like Aila.
Using the logistic regression model (
Appendix A), the results show that factors like household land ownership after Aila, change in occupation, food consumption pattern, age of migrant, educational attainment of migrant, economically active member, type of house, and debt were significantly associated with migration.
These findings of this research could be useful considering the limitation i.e., health (physical, mental, social, and psychological), gender role, culture, marriage, family reunion, and education, which did not cover. During the survey, only the households that experienced internal migration were considered although international migration also occurred post-Aila because the time, the cost for internal and international migration was different.
Furthermore, the outcome of this research could be a contribution to a growing body of knowledge in an area where there are evident gaps. It could give direction for policymakers, researchers to understand the impacts of climatic events (i.e., cyclone Aila) and how migration affects households. The study could be useful to develop and refine policies to recover from a similar kind of climatic events in the future.