Climate change impacts and adaptations on health of Internally Displaced People (IDP): An exploratory study on coastal areas of Bangladesh

Multi-order analytical solving computation of rainstorm causal decomposition during typhoons using a designed key-lock quasi-Newton optimizing derivation

To precisely identify multi-dimensional spatiotemporal rain-making parameters, generate an approximate Hessian matrix, and solve the nonlinear ill-posed problem, this study uses composite logical tangent hyperbolic functions to construct the rain-generating simulation model as nonlinear algebraic equations with designed key-lock quasi-Newton optimization for deriving multi-order objective functional derivatives for rainstorm causal decomposition into advanced functional, analytical solution (lock) and Newton's conditional constraints. Specifically, the rank-two approximate structure of the Levenberg-Marquardt and Broyden-Fletcher-Goldfarb-Shanno quasi-Newton algorithms are modified as the symmetric rank-four structure to efficiently calculate a positive definite stable Hessian and solve the constrained nonlinear rain-making threshold. The model projects various rain-making factors into multi-rank loading scores, characterizing rain-generating mechanisms and causal components as associated DNAs. To accelerate/modify directional convergence, avoid local minimum, and detect global optimum, the devised vectorized limited switchable step sizes are optimized using advanced double-bracketing approaches combined with candidate parameters' correction vectors (key) and referenced step-size distributions solved by Newton's constrained analytical solution to reduce heterogeneous differences and eliminate the conventional overestimated Hessian. The identified rain-making DNAs reveal that typhoons with similar DNAs move in similar directions. Specifically, rain-making DNAs in Taipei Category 1 were correlated with wind force/direction and cloud height along PCs 1, 3, 4, and 7, and those in Category 2 were correlated with cloud-cover distribution along PCs 1, 2, and 5. The identified rain-making thresholds of typhoons with constant direction/structure showed a weaker steady state, whereas the unsteady rest produced multi-peak rainfall hydrographs. Rain evolution analysis reveals that cloudy rainbands, carried by the wind field, move along the Tamsui River valley when traveling between northeast and south-southeast of Taipei; converge with gradient and geostrophic winds when traveling between east-northeast and southwest; merge with southwest monsoon when traveling between west-southwest and northeast of Kaohsiung.

Evaluation of daily average temperature trends in Kerala, India, using MERRA-2 reanalysis data: a climate change perspective

Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) data for a period of 40 years (1980-2019) was used to detect the trend characteristics of daily average temperature in the state of Kerala, India. Data extracted from a total of fifty locations in the state were statistically processed using Mann-Kendall (MK) and Spearman's Rho (SR) tests to detect the trend, Pettitt test to identify the single change point, and Theil-Sen's method for the calculation of the rate of change. The MERRA-2 product is validated for the study region according to statistical indicators. The daily average temperature in the state during the period of study varies between 16.56 and 32.64 °C. The spatial pattern of daily average maximum temperature shows higher temperature domains in the central and southern parts of the state. Trend characteristics of daily average temperature assessed through MK and SR tests show a significant increasing trend in all stations, with maximum values in stations located in the northern part of the state. Change point detected through the Pettitt test divided the sampling stations into three groups based on the change in daily average temperature characteristics in the years 2002 (north zone), 2009 (south zone), and 2012 (central zone), indicating nonunique spatial variability in temperature characteristics in the state. The rate of change in the daily average temperature assessed indicates an increase at the rate of an average of 0.013 °C.year^-1. During the whole study period, the daily average temperature showed an overall increase of 0.54 °C, and for the 100-year futuristic prediction, the daily average temperature in the state shows an average increase of 1.35 °C. Among the stations, a higher rate of increase in daily average temperature is shown by stations located in the eastern part of the Pathanamthitta, Idukki, and Kollam districts. Though the rise in daily average temperature is not much higher, its spatial characteristics require more attention because, in recent times, the study area has faced repeated, severe, and long drought conditions along with sunburn incidents. As an agrarian state, a change in the temperature domain will adversely affect the overall agricultural production and will evoke not only a food crisis but also economic as well as water resources issues. The result obtained can be used as holistic basic information for understanding the impending effect of climate change in the state to frame better mitigation as well as management strategies.

Analysis of the livelihood and health of internally displaced persons due to riverbank erosion in Bangladesh

Bangladesh is particularly vulnerable to natural calamities such as flooding, cyclones, droughts, and severe riverbank erosion as a deltaic country. Riverbank erosion brings about terrible consequences such as loss of land, human displacement, social isolation, and physical and mental well-being problems. The study used a mixed-method research approach and a multi-method data collection procedure to analyse the impact of riverbank erosion on livelihood and health. Households of Internally Displaced Persons (IDPs) due to riverbank erosion in Bangladesh's Lakshmipur district were surveyed using a structured questionnaire and an unstructured interview schedule to collect quantitative and qualitative data. Thematic content analysis, and descriptive statistics were applied to identify how riverbank erosion is inextricably linked to the IDPs' socio-economic conditions and well-being vulnerability. The findings show that riverbank erosion is responsible for the IDPs' livelihood uncertainty and substantial health concerns. Uncertainty about livelihood gives rise to socio-economic instability, poverty, diseases, and medical expenses. On top of that, the displaced people faced several difficulties, including no land ownership, living in substandard housing, no access to power, use of unhygienic toilets, social isolation, and anxiety. The research also finds inadequate government or non-governmental master plans for IDPs to overcome miserable conditions. The study results will help policymakers in Bangladesh and elsewhere to better understand the needs of vulnerable riverine communities and to design and implement policies and programmes to improve those communities' capacity to withstand shocks and recover quickly.

Exploring the temporal patterns and crisis-related risk factors for population displacement in Somalia (2016-2018)

Introduction

Over the past 30 years, south-central Somalia, Puntland (north-east) and Somaliland (north-west) have experienced recurring drought- and conflict-related crises. By the end of 2018, the number of internally displaced persons (IDPs) in the region had reached 2.6 million; most were displaced to larger towns under government control, where humanitarian assistance was more accessible. Understanding the drivers of crisis-related displacement can provide insight into how responses can best manage and respond to displacement to prevent downstream morbidity and mortality. We aimed to explore the temporal patterns and crisis-related risk factors for population displacement in Somalia from 2016 to 2018, a period of severe drought.

Methods

We conducted an ecological study of secondary panel data stratified by district and month. The study population included all people in the region from 2016 to 2018. The outcome was defined as the number of new out-migrating internally displaced persons (IDPs) per district-month. Exposure variables included armed conflict, rainfall, food insecurity and food security services. Lags at one, two and three months were generated to explore possible delayed effects. All univariate and multivariate analyses were conducted using negative binomial regression models with mixed effects incorporating the district as a random effect.

Results

From 2016 to 2018, the proportion of IDPs increased from 9% to 25% in Somalia, Puntland and Somaliland. We observed strong associations between IDP out-migration rate and failed rains at a three-month lag, food insecurity at a one-month lag, and the presence of therapeutic food services with no lag. IDP out-migration rate was not associated with armed conflict intensity, and cash- and rations-based food security services.

Discussion

This study identified temporal, and socially and biologically plausible associations between key crisis-related risk factors and displacement in Somalia. The findings suggest a sequence of events spanning a few months, where failed rains and consequent food insecurity likely prompted early population out-migration to larger urban centers where humanitarian services were more accessible. The presence of therapeutics-based food security services could represent a more general correlate of crisis severity and the decision to migrate.

A systematic review of the health of internal migrants in Bangladesh

Internal migrants are more disadvantaged than non-migrants in terms of their health. However, the extent of this difference is unclear. Following the PRISMA guideline, we conducted a systematic review to explore the existing evidence on the health of internal migrants of Bangladesh. We searched Pubmed, Web of Science and Google Scholar to identify peer-reviewed literature on health related issues of the internal migrant population and identified 29 papers for inclusion. Included studies reported health issues or risk factors relating to water, sanitisation and hygiene access and practice, risky sexual behaviour and sexually transmitted infection, mental health status, occupational health status, general healthcare availability, healthcare service utilisation and healthcare seeking behaviour. This systematic review reveals that research on health issues of internal migrants of Bangladesh is limited for common communicable and noncommunicable diseases like waterborne and skin disease, tuberculosis, hypertension and diabetes. Further, despite that many of these migrants are labourers, occupational health related issues like work place accidents, musculoskeletal disorders are insufficiently explored. Barriers to healthcare accessibility in this population are poor socioeconomic status, illiteracy and low general health knowledge. For improved development and implementation of health policies targeting this important population, future studies should focus on understudied diseases and disease prevalence and be designed to elicit from the perspectives of internal migrants, their key health needs around risk factors and health services accessibility.