Evidence against disaster-induced migration: the 2004 tornado in north-central Bangladesh

Resilience as Mediator in Relation to Parental Attachment and Posttraumatic Stress Disorder in Adolescents Following the Yancheng Tornado

Resilience and secure parental attachment have been proven as important factors to alleviate the posttraumatic stress disorder (PTSD). However, the effects of the two factors on PTSD and the mechanisms of its effect at different time points in the aftermath of trauma are still unclear. This study explores the relationship among parental attachment, resilience, and development of PTSD symptoms in adolescents from a longitudinal perspective following the Yancheng Tornado. Using cluster sampling method, a total of 351 Chinese adolescents, survivors of a severe tornado, were tested on their PTSD, parental attachment and resilience at 12-months and 18-months after experiencing the natural disaster. The results showed that our proposed model fit the data well: χ2/df = 3.197, CFI = 0.967, TLI = 0.950, RMSEA = 0.079. It revealed that the resilience at 18-months partially mediated the relationship between parental attachment at 12-months and PTSD at 18-months. Research results showed that parental attachment and resilience are key resources for coping with trauma.

Air pollution and migration

This paper investigates the impact of air pollution on China’s internal migration using the Migrant Population Dynamic Monitoring Survey and Air Quality Index (AQI) data in 2014. Binary response models suggest that, on average, the probability of the willingness to leave will grow by approximately 0.1 if the average value of AQI is increased by 100 points. The migration effect of sever air pollution still holds using two-stage least squares estimation. In particular, compared to inter-province and intra-city within the same province, interviewees are more willingness to leave in intra-county with the same city. Besides, individuals from the cities in central and western regions, the listed key environmental protection (KEP) cities and cities not listed as resource-based (RB) cities have stronger willingness to leave than those from the cities in eastern region, Non-KEP cities and RB cities. Our results are robust to alternative measures of air pollution and models specification.

A Deep Gravity model for mobility flows generation

The movements of individuals within and among cities influence critical aspects of our society, such as well-being, the spreading of epidemics, and the quality of the environment. When information about mobility flows is not available for a particular region of interest, we must rely on mathematical models to generate them. In this work, we propose Deep Gravity, an effective model to generate flow probabilities that exploits many features (e.g., land use, road network, transport, food, health facilities) extracted from voluntary geographic data, and uses deep neural networks to discover non-linear relationships between those features and mobility flows. Our experiments, conducted on mobility flows in England, Italy, and New York State, show that Deep Gravity achieves a significant increase in performance, especially in densely populated regions of interest, with respect to the classic gravity model and models that do not use deep neural networks or geographic data. Deep Gravity has good generalization capability, generating realistic flows also for geographic areas for which there is no data availability for training. Finally, we show how flows generated by Deep Gravity may be explained in terms of the geographic features and highlight crucial differences among the three considered countries interpreting the model's prediction with explainable AI techniques.

Exploring Connections—Environmental Change, Food Security and Violence as Drivers of Migration—A Critical Review of Research

Migration, whether triggered by single events, such as violent conflict, or by long term pressures related to environmental change or food insecurity is altering sustainable development in societies. Although there is a large amount of literature, there is a gap for consolidating frameworks of migration-related to the interaction and correlation between drivers. We review scientific papers and research reports about three categories of drivers: Environmental Change (EC), Food Security (FS), and Violent Conflict (VC). First, we organize the literature to understand the explanations of the three drivers on migration individually, as well as the interactions among each other. Secondly, we analyse the literature produced regarding Colombia, Myanmar, and Tanzania; countries with different combinations of the driving factors for migration. Although we find that many correlations are explained in the literature, migration is mostly driven by structural vulnerabilities and unsustainable development paths in places that have a low resilience capacity to cope with risk. For example, food insecurity, as a product of environmental changes (droughts and floods), is seen as a mediating factor detonating violent conflict and migration in vulnerable populations. The paper contributes to the literature about multi-driven migration, presenting an overview of the way in which different driver combinations trigger migration. This is important for determining the best governance mechanisms and policy responses that tackle forced migration and improve the resilience of vulnerable communities as well as sustainable development.

Imaginary Numbers of Climate Change Migrants?

Within the extensive scientific and policy discussions about climate change migrants, detailed analyses continue to highlight the lack of evidence thus far for climate change directly causing migration. To understand better how climate change might or might not lead to migration, this paper explores possibilities for developing a robust, repeatable, and verifiable method to count or calculate the number of people migrating or not migrating due to climate change. The discussion starts by examining definitions of “climate change” and “migration”, then looking at how to determine numbers of climate change migrants based on those definitions. These points lead to descriptions of the subjectivity and arbitrariness of the decisions needed for counting or calculating climate change migrants and non-migrants. While the scientific study of working out numbers of climate change migrants and non-migrants is challenging and interesting, especially due to its complexity, changing baselines alongside legitimate concerns about necessary assumptions lead to questions regarding the usefulness of the calculations for policy and action. Ultimately, labelling, counting, and calculating climate change migrants and non-migrants depend on political choices, so any numbers reached might not be scientifically robust. Improved understanding of people’s motivations for migrating and not migrating under different circumstances, including under climate change and perceptions thereof, would be preferable to a starting point assuming that climate change inevitably causes migration.

Looking forward: Disasters at 40

This paper reflects on contemporary studies of and responses to disasters, highlighting the importance of historical, spatial, and intersectional modes of analysis, and draws on the author's ongoing research on Southern-led and local community responses to displacement in the Middle East. Acknowledging the plurality of 'international communities of response', it begins by critiquing the depiction of selected responses to disasters as 'positive' 'paradigm shifts', including in reference to the 'localisation of aid, and the United Nations' Regional Refugee and Resilience Plan for Syria. Next it turns to three key themes that are central to disasters studies: migration; forced displacement; and Southern-led responses to disasters. Among other things, the paper argues that exploring the principles and modalities of South-South cooperation, rather than promoting the incorporation of Southern actors into the 'international humanitarian system' via the localisation agenda, presents a critical opportunity for studies of and responses to disasters.

The UCL-Lancet Commission on Migration and Health: the health of a world on the move

With one billion people on the move or having moved in 2018, migration is a global reality, which has also become a political lightning rod. Although estimates indicate that the majority of global migration occurs within low-income and middle-income countries (LMICs), the most prominent dialogue focuses almost exclusively on migration from LMICs to high-income countries (HICs). Nowadays, populist discourse demonises the very same individuals who uphold economies, bolster social services, and contribute to health services in both origin and destination locations. Those in positions of political and economic power continue to restrict or publicly condemn migration to promote their own interests. Meanwhile nationalist movements assert so-called cultural sovereignty by delineating an us versus them rhetoric, creating a moral emergency.

In response to these issues, the UCL-Lancet Commission on Migration and Health was convened to articulate evidence-based approaches to inform public discourse and policy. The Commission undertook analyses and consulted widely, with diverse international evidence and expertise spanning sociology, politics, public health science, law, humanitarianism, and anthropology. The result of this work is a report that aims to be a call to action for civil society, health leaders, academics, and policy makers to maximise the benefits and reduce the costs of migration on health locally and globally. The outputs of our work relate to five overarching goals that we thread throughout the report.

First, we provide the latest evidence on migration and health outcomes. This evidence challenges common myths and highlights the diversity, dynamics, and benefits of modern migration and how it relates to population and individual health. Migrants generally contribute more to the wealth of host societies than they cost. Our Article shows that international migrants in HICs have, on average, lower mortality than the host country population. However, increased morbidity was found for some conditions and among certain subgroups of migrants, (eg, increased rates of mental illness in victims of trafficking and people fleeing conflict) and in populations left behind in the location of origin. Currently, in 2018, the full range of migrants’ health needs are difficult to assess because of poor quality data. We know very little, for example, about the health of undocumented migrants, people with disabilities, or lesbian, gay, bisexual, transsexual, or intersex (LGBTI) individuals who migrate or who are unable to move.

Second, we examine multisector determinants of health and consider the implication of the current sector-siloed approaches. The health of people who migrate depends greatly on structural and political factors that determine the impetus for migration, the conditions of their journey, and their destination. Discrimination, gender inequalities, and exclusion from health and social services repeatedly emerge as negative health influences for migrants that require cross-sector responses.

Third, we critically review key challenges to healthy migration. Population mobility provides economic, social, and cultural dividends for those who migrate and their host communities. Furthermore, the right to the highest attainable standard of health, regardless of location or migration status, is enshrined in numerous human rights instruments. However, national sovereignty concerns overshadow these benefits and legal norms. Attention to migration focuses largely on security concerns. When there is conjoining of the words health and migration, it is either focused on small subsets of society and policy, or negatively construed. International agreements, such as the UN Global Compact for Migration and the UN Global Compact on Refugees, represent an opportunity to ensure that international solidarity, unity of intent, and our shared humanity triumphs over nationalist and exclusionary policies, leading to concrete actions to protect the health of migrants.

Fourth, we examine equity in access to health and health services and offer evidence-based solutions to improve the health of migrants. Migrants should be explicitly included in universal health coverage commitments. Ultimately, the cost of failing to be health-inclusive could be more expensive to national economies, health security, and global health than the modest investments required.

Finally, we look ahead to outline how our evidence can contribute to synergistic and equitable health, social, and economic policies, and feasible strategies to inform and inspire action by migrants, policy makers, and civil society. We conclude that migration should be treated as a central feature of 21st century health and development. Commitments to the health of migrating populations should be considered across all Sustainable Development Goals (SDGs) and in the implementation of the Global Compact for Migration and Global Compact on Refugees. This Commission offers recommendations that view population mobility as an asset to global health by showing the meaning and reality of good health for all. We present four key messages that provide a focus for future action.

Gravity and scaling laws of city to city migration

Models of human migration provide powerful tools to forecast the flow of migrants, measure the impact of a policy, determine the cost of physical and political frictions and more. Here, we analyse the migration of individuals from and to cities in the US, finding that city to city migration follows scaling laws, so that the city size is a significant factor in determining whether, or not, an individual decides to migrate and the city size of both the origin and destination play key roles in the selection of the destination. We observe that individuals from small cities tend to migrate more frequently, tending to move to similar-sized cities, whereas individuals from large cities do not migrate so often, but when they do, they tend to move to other large cities. Building upon these findings we develop a scaling model which describes internal migration as a two-step decision process, demonstrating that it can partially explain migration fluxes based solely on city size. We then consider the impact of distance and construct a gravity-scaling model by combining the observed scaling patterns with the gravity law of migration. Results show that the scaling laws are a significant feature of human migration and that the inclusion of scaling can overcome the limits of the gravity and the radiation models of human migration.

Disruption, not displacement: Environmental variability and temporary migration in Bangladesh

Mass migration is one of the most concerning potential outcomes of global climate change. Recent research into environmentally induced migration suggests that relationship is much more complicated than originally posited by the 'environmental refugee' hypothesis. Climate change is likely to increase migration in some cases and reduce it in others, and these movements will more often be temporary and short term than permanent and long term. However, few large-sample studies have examined the evolution of temporary migration under changing environmental conditions. To address this gap, we measure the extent to which temperature, precipitation, and flooding can predict temporary migration in Matlab, Bangladesh. Our analysis incorporates high-frequency demographic surveillance data, a discrete time event history approach, and a range of sociodemographic and contextual controls. This approach reveals that migration declines immediately after flooding but quickly returns to normal. In contrast, optimal precipitation and high temperatures have sustained positive effects on temporary migration that persist over one to two year periods. Building on previous studies of long-term migration, these results challenge the common assumption that flooding, precipitation extremes and high temperatures will consistently increase temporary migration. Instead, our results are consistent with a livelihoods interpretation of environmental migration in which households draw on a range of strategies to cope with environmental variability.

Cyclone Aila, livelihood stress, and migration: empirical evidence from coastal Bangladesh

This paper investigates why households migrated as a unit to Khulna City from the affected Upazilas of Dacope and Koyra in Khulna District, Bangladesh, following Cyclone Aila on 25 May 2009. The study reveals that households migrated primarily because of the livelihood stress that resulted from the failure to derive a secure income like before the event from the impacted areas-other push and pull factors also played a part in their migration decision. Despite all of the Aila-induced losses and problems, all households wanted to avoid migration, but they were unable to do so for this principal reason. The findings also demonstrate that, if livelihoods cannot be restored, some form of widespread migration is inevitable after a disaster such as this one. In addition, they show that migration has the potential to serve as a key adaptive response to environmental events, as evidenced by the improved economic conditions of a substantial number of the migrated households.

Opportunities and Challenges for Investigating the Environment-Migration Nexus

Environmental change is an acknowledged factor influencing human migration. Analytical research regarding the relationship between the environment and human migration has increased in recent years yet still faces numerous hurdles, partly due to limited availability of suitable data. We review available data and methodologies for investigating the environment-migration nexus, identifying data inconsistencies resulting from the combination of different sources and illustrating the underlying reasons for them. We discuss a number of methods for investigating the environment-migration relationship, including frameworks and concepts; surveys; empirical, quantitative methods; and simulation approaches. Based on this overview, we offer recommendations for improved analyses of the environment-migration nexus including reporting data inconsistencies and uncertainties, combining approaches and data sources, and developing multiple-study approaches.

Measuring the Environmental Dimensions of Human Migration: The Demographer's Toolkit

In recent years, the empirical literature linking environmental factors and human migration has grown rapidly and gained increasing visibility among scholars and the policy community. Still, this body of research uses a wide range of methodological approaches for assessing environment-migration relationships. Without comparable data and measures across a range of contexts, it is impossible to make generalizations that would facilitate the development of future migration scenarios. Demographic researchers have a large methodological toolkit for measuring migration as well as modeling its drivers. This toolkit includes population censuses, household surveys, survival analysis and multi-level modeling. This paper's purpose is to introduce climate change researchers to demographic data and methods and to review exemplary studies of the environmental dimensions of human migration. Our intention is to foster interdisciplinary understanding and scholarship, and to promote high quality research on environment and migration that will lead toward broader knowledge of this association.

Studying Displacement After a Disaster Using Large Scale Survey Methods: Sumatra After the 2004 Tsunami

Understanding of human vulnerability to environmental change has advanced in recent years, but measuring vulnerability and interpreting mobility across many sites differentially affected by change remains a significant challenge. Drawing on longitudinal data collected on the same respondents who were living in coastal areas of Indonesia before the 2004 Indian Ocean tsunami and were re-interviewed after the tsunami, this paper illustrates how the combination of population-based survey methods, satellite imagery and multivariate statistical analyses has the potential to provide new insights into vulnerability, mobility and impacts of major disasters on population well-being. The data are used to map and analyze vulnerability to post-tsunami displacement across the provinces of Aceh and North Sumatra and to compare patterns of migration after the tsunami between damaged areas and areas not directly affected by the tsunami. The comparison reveals that migration after a disaster is less selective overall than migration in other contexts. Gender and age, for example, are strong predictors of moving from undamaged areas but are not related to displacement in areas experiencing damage. In our analyses traditional predictors of vulnerability do not always operate in expected directions. Low levels of socioeconomic status and education were not predictive of moving after the tsunami, although for those who did move, they were predictive of displacement to a camp rather than a private home. This survey-based approach, though not without difficulties, is broadly applicable to many topics in human-environment research, and potentially opens the door to rigorous testing of new hypotheses in this literature.

Natural disasters and population mobility in Bangladesh

The consequences of environmental change for human migration have gained increasing attention in the context of climate change and recent large-scale natural disasters, but as yet relatively few large-scale and quantitative studies have addressed this issue. We investigate the consequences of climate-related natural disasters for long-term population mobility in rural Bangladesh, a region particularly vulnerable to environmental change, using longitudinal survey data from 1,700 households spanning a 15-y period. Multivariate event history models are used to estimate the effects of flooding and crop failures on local population mobility and long-distance migration while controlling for a large set of potential confounders at various scales. The results indicate that flooding has modest effects on mobility that are most visible at moderate intensities and for women and the poor. However, crop failures unrelated to flooding have strong effects on mobility in which households that are not directly affected but live in severely affected areas are the most likely to move. These results point toward an alternate paradigm of disaster-induced mobility that recognizes the significant barriers to migration for vulnerable households as well their substantial local adaptive capacity.

Epidemiology of tornado destruction in rural northern Bangladesh: risk factors for death and injury

The epidemiology of tornado-related disasters in the developing world is poorly understood. An August 2005 post-tornado cohort study in rural Bangladesh identified elevated levels of death and injury among the elderly (≥ 60 years of age) (adjusted odds ratio (AOR) = 8.9 (95 per cent confidence interval (CI): 3.9-20.2) and AOR = 1.6 (95 per cent CI: 1.4-1.8), respectively), as compared to 15-24 year-olds, and among those outdoors versus indoors during the tornado (AOR = 10.4 (95 per cent CI: 5.5-19.9) and AOR = 6.6 (95 per cent CI: 5.8-7.5), respectively). Females were 1.24 times (95 per cent CI: 1.15-1.33) more likely to be injured than males. Elevated risk of injury was significantly associated with structural damage to the house and tin construction materials. Seeking treatment was protective against death among the injured, odds ratio = 0.08 (95 per cent CI: 0.03-0.21). Further research is needed to develop injury prevention strategies and to address disparities in risk between age groups and between men and women.

Katrina in Historical Context: Environment and Migration in the U.S

The massive publicity surrounding the exodus of residents from New Orleans spurred by Hurricane Katrina has encouraged interest in the ways that past migration in the U.S. has been shaped by environmental factors. So has Timothy Egan's exciting book, The Worst Hard Time: The Untold Story of those who survived the Great American Dust Bowl. This paper places those dramatic stories into a much less exciting context, demonstrating that the kinds of environmental factors exemplified by Katrina and the Dust Bowl are dwarfed in importance and frequency by the other ways that environment has both impeded and assisted the forces of migration. We accomplish this goal by enumerating four types of environmental influence on migration in the U.S.: 1) environmental calamities, including floods, hurricanes, earthquakes, and tornadoes, 2) environmental hardships and their obverse, short-term environmental benefits, including both drought and short periods of favorable weather, 3) environmental amenities, including warmth, sun, and proximity to water or mountains, and 4) environmental barriers and their management, including heat, air conditioning, flood control, drainage, and irrigation. In U.S. history, all four of these have driven migration flows in one direction or another. Placing Katrina into this historical context is an important task, both because the environmental calamities of which Katrina is an example are relatively rare and have not had a wide impact, and because focusing on them defers interest from the other kinds of environmental impacts, whose effect on migration may have been stronger and more persistent, though less dramatic.