Bangladesh is among the most climate-vulnerable nations globally, facing compounding risks from rising temperatures, shifting precipitation patterns, and intensifying extreme events. This study assesses projected changes in precipitation, maximum temperature (Tmax), and minimum temperature (Tmin) over Bangladesh under two emission pathways — SSP2-4.5 and SSP5-8.5 — and two Solar Radiation Management (SRM) scenarios — G6Solar and G6Sulfur — using bias-corrected CMIP6 multi-model ensemble data for the period 2070–2099. Bias correction using the Quantile Delta Mapping method substantially improved model performance, with Nash-Sutcliffe Efficiency rising from −0.28 to 0.97 for precipitation and from −0.11 to 0.99 for temperature. Relative to the historical baseline (1985–2014), annual Tmax increases by 1.27°C under SSP2-4.5 and 2.36°C under SSP5-8.5, while Tmin increases by 1.71°C and 3.02°C, respectively. SRM scenarios substantially moderate warming, with Tmax increases of 1.33°C (G6Solar) and 1.45°C (G6Sulfur), and Tmin increases of 1.90°C (G6Solar) and 1.95°C (G6Sulfur). Warming is strongest in winter and weakest during the monsoon across all scenarios. Annual precipitation increases across all scenarios relative to historical levels, with the largest rise under SSP5-8.5; however, G6Solar produces 2.5% less precipitation than SSP2-4.5, raising concerns about seasonal drought risk, particularly during pre-monsoon and post-monsoon periods. Spatially, the southeastern and coastal regions experience the greatest increases in both temperature and precipitation, while northern Bangladesh shows comparatively smaller changes. Trend analysis using the Modified Mann-Kendall test reveals significant increasing temperature trends in all scenarios, strongest under SSP5-8.5 (Tmin: 0.47°C decade−1; Tmax: 0.38°C decade−1). The SRM scenarios partially offset high-emission warming but introduce precipitation uncertainties, underscoring that geoengineering should complement, not replace, greenhouse gas mitigation.

The Sundarbans, the world's biggest mangrove forest and swamp, is notable for its biodiversity, ecology, and local economy. However, the ecosystem's distinct structure is increasingly vulnerable to both natural disasters, particularly cyclones, and pressurized human activity. The purpose of this study was to evaluate changes in land use and land cover (LULC) before and after Cyclone Remal (May 2024) in the Sundarbans region of Bangladesh, utilizing the Sentinel 2 imageries in the Google Earth Engine (GEE) platform. Here, the Normalized Difference Vegetation Index (NDVI) and supervised classification techniques have been used to assess the changes in landcover pattern, including the waterlogging, vegetation loss, and built-up areas, following the disaster. Here, an increase in water bodies (1.4%) and healthy vegetation (29.41%), where a decrease in built-up (0.17%), mudflat (1.83%), and less healthy vegetation (28.82%) have been observed, which crucially impacts the residents of the Sundarbans. Therefore, this study urges the utilization of satellite remote sensing-based management techniques to address the ecological and socioeconomic impacts that result from extreme weather events, such as cyclones.

The changes in the Land Use Land Cover (LULC), particularly the industrialization and urbanization, significantly impact the Land Surface Temperature (LST). Therefore, this study investigates the impact of urban expansion on LST in an industrial zone of Gazipur, Bangladesh, and analyzes the relationship between LULC changes and land surface emissivity over the period of 1995 to 2024, utilizing the satellite imageries and Machine Learning (ML)-based remote sensing techniques in Google Earth Engine (GEE). The study’s results revealed significant urbanization, accompanied by a sharp increase in land surface temperature. The built-up area increased more than fourfold (4.4-fold), expanding from 60.46 km² (3.33

Extreme precipitation events increasingly threaten populations and food security across South Asia. Whilst prior research has examined climate change impacts on rainfall patterns, the exposure of populations and cropland to these extremes remains understudied. This study assesses future exposure to extreme precipitation using CMIP6 projections under three Shared Socioeconomic Pathways (SSPs): SSP1-2.6, SSP2-4.5 and SSP5-8.5, for 2021-2060 and 2061-2100, relative to the 1975-2014 baseline. We analyse changes in four key precipitation indices: consecutive wet days (CWD), maximum five-day precipitation (Rx5day), days with precipitation >= 20 mm (R20mm) and total wet-day precipitation (PRCPTOT). Results indicate a significant increase in heavy rainfall and prolonged wet periods, particularly under SSP5-8.5. Compared to the baseline, R20mm is projected to increase by 59.25%, Rx5day by 44.06%, CWD by 9.15% and PRCPTOT by 28.65%. Western India and Pakistan are expected to experience the most pronounced changes, whilst the IGP-including Bangladesh and eastern India-faces the highest exposure due to dense populations and extensive croplands. Population exposure to R20mm is projected to rise by 91.7% under SSP5-8.5 and 103.60% under SSP1-2.6, whilst cropland exposure to Rx5day could increase by 44.44% and 7.12% respectively. These findings underscore the urgent need for targeted adaptation strategies, including improved water management, flood protection and climate-resilient agriculture, to mitigate the escalating risks of extreme precipitation in South Asia.

Urban heat islands (UHIs) are urbanized regions with elevated temperatures compared to their surrounding environments. Dhaka, burdened by a dense population, haphazard urbanization, and intense vehicular activity within limited land space, has emerged as one of the most polluted and conducive environments for UHIs. This investigation aimed to pinpoint UHI hotspots during summer and winter while exploring the relationship between land use patterns and UHI formation. Dhaka City was scrutinized and divided into Dhaka North City Corporation (DNCC) and Dhaka South City Corporation (DSCC). This research utilized spatial data from 2015 to 2022 for April–May and December–January to analyze land surface temperature (LST) employing RS-GIS software, specifically “QGIS 3.22.16”. Landsat 8 Level 2 data facilitated the generation of LST maps, while Sentinel 2 imagery aided in land use classification within UHI zones. The findings revealed UHI coverage of 61.784 km2 in summer and 75.168 km2 in winter, accounting for 20.6

A hydrogeochemical study of groundwater in the aquifer system of the southeastern coastal area of Bangladesh was carried out to investigate the processes of groundwater hydrogeochemistry as well as the suitability of groundwater for drinking purposes. Water samples from tube wells (depths 6.5–165 m) were collected and examined for several water quality parameters to describe the hydrogeochemical characteristics. Most of the water samples were found to be fresh and soft water with few numbers of hard and brackish water. The overall sequence of cation and anion throughout the study area is Ca2+> Na+> Mg2+> K+ and HCO3− > CO3− > NO3− > SO42-> Cl−, respectively. Maximum water quality parameters satisfy the drinking water quality standard proposed by WHO. The piper diagram suggests that Ca2+-Mg2+-HCO3− (80%) and Ca2+-Na+-HCO3− (20%) facies are the predominant water types. Gibb's plot implies a rock-dominant inheritance that regulates the groundwater chemistry. The most significant hydrogeochemical processes in the study area are carbonate weathering. Correlation analysis recommends that TDS, EC, Na+, Ca2+, Cl−, and SO42− are strongly correlated with each other, indicating their contribution to water mineralization. The principal component analysis (PCA) and cluster analysis show that weathering and leaching of parent rocks are the leading environmental sources that influence the groundwater hydrochemistry.

The present work aims at assessing vegetation patterns and of the recovery process over the long term (2006 to 2025) in the Sundarbans mangroves based on the NDVI and SAVI. Landsat 5 TM and Landsat 8 OLI surface reflectance images were processed in Google Earth Engine to derive seasonal composites for the dry season (December-February). A supervised classification method was used to delineate five land-cover classes, namely water bodies, bare soil, sparse, intermediate, and dense vegetation. Accuracy assessment was carried out by visual interpretation of the sample points by using Google Earth Pro where overall accuracy was in the 88-93% over the entire study period. In 2006, dense vegetation was the most dominant (similar to 68%) and sparse and intermediate other categories had low frequency and water bodies covered 21% of plots. For post-Sidr in 2008, nearly all plants showed more severe damage (76-79%). Post-Aila (2010) data suggested continuous intermediate (46%) and sparse (25%) vegetation cover but with negligible closed canopy. During 2015, the dense vegetation recovered to 60%, and dynamic changes among dense, intermediate, and sparse vegetation areas emerged, and the area of dense vegetation was up to 67% in 2025 indicating that the long-term restoration exhibits space heterogeneity. NDVI was effective for monitoring the overall trend of large scale canopy, while SAVI was able to capture very small scale regeneration and understory growth. The findings show the impressive resilience of the Sundarbans and the significance of such key ecological processes as canopy recovery and succession, and the need for more adaptive management to improve mangrove resilience in cyclone-prone coastal areas.

Endoscopic transnasal repair of CSF rhinorrhoea is gaining popularity around the world because of its tremendous success rate but it depends on defect site, size, technique of repair, experiences of surgeon and also patient's profile. Aim of this study was to analysis of surgical outcome of endoscopic transnasal repair of CSF rhinorrhoea. A retrospective study carried out in the department of ENT and Head neck surgery at Bangabandhu Sheikh Mujib Medical University (BSMMU) from January 2018 to December 2019. Of the total of 24 patients 16(66.0%) were female and 8(33.0%) males. The commonest site of the leak was in the cribriform plate in 18(75.3%) followed by 5(20.8%) in the fovea ethmoidalis, and 1(4.0%) in the sphenoid sinus, the overall success rate of this series with first surgical procedure was 95.83% and 100.0% with a second procedure. Meticulous pre-operative evaluation, proper identification of leakage site, choice of graft materials and surgical technique are keys to attaining excellent results.

This study investigates the ecological impacts of urban expansion in Savar Upazila, adjacent to Dhaka City, from 2011 to 2022. Utilizing Landsat (Level 2) imagery and the Time-weighted Dynamic Time Warping (TWDTW) classification method, the research assesses urban sprawl with high accuracy (98.87%, 96.01%, and 96.53% for 2011, 2015, and 2022, respectively). Urban expansion was predominantly through extension, with a 9.19% increase in urban areas. The study also calculates Urban Hotspot Zones (UHs) and the Urban Thermal Field Variance Index (UTFVI) from Land Surface Temperature (LST) data, highlighting the growth of urban hotspots. The Partial Least Squares Regression (PLSR) reveals that development type affects the Urban Heat Island effect and extension is the most determining factor for ecological change. A local level analysis reveals that nearly all unions, except Shimulia and Pathalia, experienced a rise in areas with adverse ecological conditions, with Tetulihora, Amin Bazar, Ashulia, and nearby areas facing the most significant ecological deterioration due to urbanization (∼50%). The findings underscore a considerable decline in the region's ecological health due to urban expansion, urging policymakers to integrate stable ecological zones into urban planning for sustainable development.

In this review, we thoroughly analyze the state of global rivers, focusing on their physical and ecological characteristics as well as management strategies. The review results have helped us generate four recommendations. Firstly, rivers should be managed under a legally binding global accord at the basin level. Secondly, challenges related to river pollution and inappropriate project implementation can be mitigated by adopting newly defined strategic environmental assessments and the United Nations System of Environmental Economic Accounting. Thirdly, we need data from the latest scientific sources, such as geospatial sources, to better understand rivers at different scales as composite systems. The last recommendation calls for taking into account climate change concerns in river management approaches. We also outline a proposition for developing a river monitoring and assessment program in order to perform comprehensive and planet-wide river assessment. The article elaborates on the strategies for achieving these recommendations.

Identification of potential flood risk areas is crucial to reduce flood damage for the frequently flooded and low-lying South Asian developing countries. The present study has prepared district-level (District: second administrative unit of the country) flood risk map for the flood-prone Rangpur Division (Division: first administrative unit) of Bangladesh using the multi-criteria decision analysis along with the application of analytical hierarchy process (AHP) method. Eight physical factors such as elevation, slope, distance from river, drainage density, land cover, rainfall, height above nearest drainage (HAND), and topographic wetness index (TWI), and six social factors such as population density, dependent population, disabled population, female population, agriculture dependent population, and literacy have been assessed to create a final risk map. The flood risk map is divided into five risk zones: very low, low, moderate, high, and very high. Integration of the social factors along with the physical factors reflects the insight of the vulnerability and increases the authenticity of the generated risk map. This study found that 62.46% area of the Rangpur Division resides under the moderate to very high-risk zone of flooding. Using ROC (receiver operating characteristic)-AUC (area under the curve) curve, the risk map is validated with a score of 0.83 from the flood inventory map of 2020 generated from the Sentinel 1 image. This risk map will guide policymakers to easily identify the vulnerable area for flood hazards and suitable areas for development activities necessary to attain sustainable development.

Water is an essential resource for life and livelihood for human beings whose allocation, allotment, and management stay behind the great anxiety being improvement reflection and practices for quite a long time. Bangladesh, a water-copious nation with low per capital water availability, is now a highly exposed country because of climate change and salinity intrusion, becoming the primary concern for freshwater scarcity in the coastal area. Water salinity is rising significantly because of the intrusion of salinity from the sea, declination of upstream water flow because of the flawed system of polders and embankments, coastal aquaculture and salt farming with the salty water, and increasing level of sea because of melting of polar ice caps, depletion of groundwater and frequent natural disasters. This chapter focuses on water management–related policies and strategies of Bangladesh, including administrative bodies for water management in coastal areas. Besides, the authors focus on the water-related crisis for coastal communities and the resilience capabilities of coastal communities in response to salinity intrusion in the country’s cropland and groundwater level. The authors suggested that integrated coordination is urgently necessary between individual, coastal community, and institutional levels to solve the drinking water crisis, and a community-focused approach of water management could be the principal accessible position for building inroads in the direction of transforming the practicing of climate-resilient agricultural production technologies in the coastal areas of Bangladesh.

Food safety and security have now been regarded as a significant emerging area within the food supply chain leading to scientific and public health concerns in the global world. The poultry sector is a substantial threat to heavy metal intoxication for Bangladeshi people due to contaminated drinking water and feed sources, as well as the poultry sector’s surrounding environment and soil. This study was carried out to ascertain the residual concentrations of heavy metals (Pb, Cd) and trace elements (Cr, Fe, Cu, and Zn) in various edible chicken body parts (breast, liver, gizzard, heart, kidney, and brain) to observe the quality of the consumed chickens and to assess public health risk. Atomic absorption spectrometry (AAS) was used to check the content of toxic heavy metals and trace elements in 108 samples of 18 broiler chickens collected from six different locations of Dhaka North City Corporation markets in Bangladesh. The measured concentrations (mg/kg fresh weight) ranged from 0.33±0.2 to 4.6±0.4, 0.004±0.0 to 0.125±0.2, 0.006±0.0 to 0.94±0.4, 4.05±4.2 to 92.31±48.8, 0.67±0.006 to 4.15±2.7, and 4.45±0.62 to 23.75±4.3, for Pb, Cd, Cr, Fe, Cu, and Zn respectively. Except for Pb and Cu most of the investigated heavy metals and trace element levels in chickens were lower than the maximum allowable concentration (MAC) set by FAO/WHO and other regulatory agencies., The estimated level of Pb was nearly six times higher in the chicken brain. The estimated daily intake (EDI) values for all the studied metals were below the preliminary tolerated daily intake (PTDI). The target hazard quotient (THQ) values of the broiler chicken meat samples varied for adults and children, and the range was found to be 0.037–0.073 for Pb, 0.007–0.01 for Cd, 0.0–0.08 for Cr, 0.002–0.004 for Fe, for 0.00–0.002 Cu, and 0.004–0.008 for Zn, not exceeding the maximum level of 1 according to USEPA. The calculated THQ and total target hazard quotient (TTHQ) values were measured at less than one, suggesting that the consumption of chicken meat has no carcinogenic danger to its consumers. The Target carcinogenic risks (TCRs) of Pb, Cd, Cr, and Cu were within acceptable limits. The TCR values for children were, to some extent, higher than that of adults, which proposes that regular monitoring of both harmful and essential elements in chicken samples is necessary to determine whether or not any possible health risk to consumers exists. In terms of health, this study demonstrated that consumers are chronically exposed to elemental contamination with carcinogenic and non-carcinogenic effects.

On-site 222Rn concentration at three different soil depths was measured at the south-eastern coastal area of Bangladesh to evaluate the annual effective dose received by the inhabitants of the study area. The range of radon concentration stretches out within 132–66,800 Bq m−3. The average annual effective dose from radon concentration is 0.13 mSv y−1 which stands below the worldwide annual average dose of 1.26 mSv y−1. In addition, 238U, 232Th and 40K content along with natural gamma dose rates in soil were evaluated. The estimated average gamma dose rate was 319 nGy h−1 and was found to have a better relationship to soil gas radon. Noticeable amount of radon and natural radionuclides have to be considered from the radiological perspective.

Climate change is one of the biggest threats for the new millennium, and Bangladesh is considered as "Poster Child" as an impact on climate change in the world. The main focus of this study is to investigate the changing pattern of climate parameters, particularly temperature, rainfall, humidity, cloud coverage, and wind speed in two coastal islands of the southeastern coast of Bangladesh from 1977 to 2017. The linear regression model described that the temperature in Kutubdia and Sandwip islands was 0.0298 and 0.0444 times increased from 1977 to 2017. Besides, rainfall patterns in Kutubdia decreased by 0.4083, and Sandwip Islands increased by 0.875 every year from its previous counterpart. The humidity level also increased due to the rise of temperature and water availability for evaporation from irrigation. Moreover, significant changes in wind speed and the cloud coverage rate in the Island areas increased with the increasing value of temperature and humidity. It also means the rainfall rate increases with cloud cover in the sky. However, the study found decreasing rates of bright sunshine in the Island areas. The declining rate of sunshine is very high and is a matter of great concern for the agriculture and health sectors in particular areas. Therefore, the community's concept of climate parameters, association, and extremes is well apparent. Identify poor land use planning as the primary anthropogenic driver of the change, and they advocated boosting the capacity of linked fields that are in danger owing to climate change. To conclude, the coastal inhabitants recommended that taking preparedness would be easier if the information transmitted through quicker and reliable sources such as news broadcasts, phone messages, or the internet.

Climate change has become the biggest risk to the nutritional and food security of the planet worldwide. Rising temperatures, uneven rainfall, cyclones and droughts are unfavourably impacting agricultural production, which, in turn, is creating an elevated vulnerability to the livelihood of Bangladesh’s huge population. Bangladesh is an agrarian country and almost half of the population depends on agriculture activities as a profession. But the agriculture sector of the country is experiencing adverse impacts at various levels and ways because of climate change-induced natural hazards. The present study was done to explore the salinity intrusion problem, soil fertility and rice production in the study areas. Besides, the authors also discover some indigenous knowledge-based adaptation and coping practices of the farmers for reducing the impact of climate change in the study areas. The study disclosed that salinity intrusion into the surface water recorded at high values everywhere and the quality of the sediments was alarming. According to the experiences of the farmers, knowledge and resources, they looked for adaptation strategies to cope with the changing climatic situation. The study will help to demonstrate adaptation practices by the farmers for reducing the salinity level of the agriculture field which will be effective in the vulnerable areas of other parts of the country and worldwide while the area was affected by the salinisation problem.

Groundwater provides the largest source of usable water storage in Bangladesh. Groundwater samples have been analyzed for Fe, Mn, Zn, Ni, Cr, Cu, Cd, Pb, and Co using atomic absorption spectrophotometer to evaluate the heavy metal distribution and contamination level at the southeastern coastal area of Bangladesh. Heavy metals in water samples are in the range of Fe (490–4710 µg/L), Mn (13–1970 µg/L), Zn (70–550 µg/L), Ni (42–255 µg/L), Cr (25–133 µg/L), Cu (34–95 µg/L), Cd (7–26 µg/L), Pb (0–20 µg/L), and Co (43–141 µg/L). The mean concentration of Cr, Cd, Fe, Mn, and Ni exceeded the Bangladesh standards for drinking water. Application of Pearson correlation, principal component analysis (PCA), cluster analysis (CA) and hierarchical cluster analysis (HCA) indicate that groundwater of the study area are influenced by both geogenic and anthropogenic sources of the heavy metals. Heavy metal evaluation index (HEI), degree of contamination (Cd) and heavy metal pollution index (HPI) are employed to evaluate the overall pollution level of groundwater estimating 40, 27 and 60% of samples respectively and exhibit the medium degree of pollution.