Anik Hossain

Chalan Beel, Bangladesh’s largest inland wetland, is experiencing rapid ecological degradation under rising anthropogenic pressure. This study examines spatiotemporal land use/land cover (LULC) change and associated landscape ecological risk from 2000 to 2023 using multispectral satellite imagery for 2000, 2010, and 2023. After preprocessing, images were classified in ENVI 5.3 into five classes: deep water, shallow water, agricultural land, settlement–vegetation mix, and vegetation. LULC transitions were quantified for 2000–2010, 2010–2023, and 2000–2023 using Change Detection Statistics and the Thematic Change Workflow. Landscape ecological risk was then evaluated in Fragstats 4.2 using an ecological risk index and categorized from lowest to highest. Results show substantial LULC change over the study period: around 40% of vegetation cover was converted to settlement–vegetation mixed areas (indicative of rural settlement expansion), 22.88% of deep water shifted to shallow water, and 31.83% of shallow water converted to agricultural land; agricultural land also showed a 28.76% conversion to rural settlements. During 2000–2010, major transitions included vegetation to rural settlements (41.63%), agricultural land to rural settlements (28.78%), and deep water to shallow water (23.76%). From 2010–2023, key changes were deep water to shallow water (31.67%) and shallow water to agricultural land (28.29%). Ecological risk varied over time, and by 2023 more than half of the area fell into the middle-to-high risk classes. High-risk zones are concentrated in the southeast and northwest, whereas low-risk zones are mainly in the central and northern parts, indicating an overall increase in ecological risk.

Urbanization, land use change, and Urban Heat Island (UHI) effects are critical for sustainable planning in rapidly growing coastal cities. Rapid urban expansion in Bangladesh has significantly altered land cover patterns, intensifying environmental and thermal stress in both urban and coastal regions. This study examines the spatiotemporal dynamics of Land Use/Land Cover (LULC) and UHI in Khulna City Corporation (KCC), southwestern Bangladesh, from 1994 to 2024, with projections to 2044, using integrated geospatial and socio-perceptual approaches. Landsat TM, ETM+, and OLI/TIRS imagery were analyzed using Maximum Likelihood Classification, Land Surface Temperature (LST) retrieval, and spatial statistics including Moran’s I and Getis-Ord Gi* hotspot analysis. Future LULC and UHI patterns were projected using a CA–Markov chain model. In addition, a structured survey of 150 residents was conducted to assess thermal perception, health impacts, and adaptive responses. Results show substantial urban expansion, with built-up areas increasing from 21% in 1994 to 47% in 2024 and projected to reach 52% by 2044, accompanied by a marked decline in agricultural and vegetated land. Mean LST increased from 19.95°C to 33.06°C over the study period, with strong and very strong UHI zones expanding more than fourfold. Hotspot analysis identified persistent high-temperature zones in central and southern wards of the city. Survey findings indicate that 96% of respondents experienced thermal discomfort, while 61.7% reported heat-related health impacts. These findings indicate that uncontrolled urban expansion is the primary driver of increasing thermal stress in Khulna. The study highlights the need for integrated urban greening, reflective materials, and climate-sensitive urban planning to enhance resilience and urban livability.

Physicochemical and bacterial contamination pose a significant threat to drinking water quality in Bangladesh, requiring comprehensive analysis. This study investigates the physicochemical and metagenomic quality of drinking water from one of four water treatment plants (WTPs) in Kushtia Municipality, Bangladesh. Water samples (n = 3) from untreated, treated, and supplied water were collected between March 1 and 7, 2025. Thirteen physicochemical parameters were analyzed using traditional methods, while bacterial load was assessed using Plate Count Agar. Microbial diversity was analyzed through metagenomic sequencing of DNA extracted using the DNeasy PowerWater Kit, targeting the 16S rRNA gene (V3-V4 region) on the Illumina MiSeq platform. Alpha and beta diversity were evaluated with Chao1, Shannon, and Simpson indices, and taxonomic and pathway analysis were performed on the Kaiju and Nephele platforms. Water quality was assessed using treatment efficiency metrics, the Water Quality Index (WQI), and the Nemerow Pollution Index (NPI). Results reveal that only three of the physicochemical parameters meet the water quality standards of Bangladesh. The WTP's cumulative efficiency metric was found to be 30.76%. The WQI indicated that all water samples were unfit for drinking. The NPI showed that eight out of thirteen physicochemical parameters significantly contribute to poor water quality. Microbial evaluations revealed high bacterial levels in untreated and supplied water samples. Alpha diversity analysis, using Shannon and Simpson indices, showed no significant differences in bacterial abundance across water types. Beta diversity analysis indicated minimal dissimilarity. Functional profiling suggested the presence of antibiotic resistance–associated pathways, with predicted beta-lactam resistance representing 24.1% in treated water and 25.0% in supplied water. The dominant phyla include Proteobacteria (38% in untreated, 39% in treated, and 42% in supplied). About 75%, 83%, and 67% of the identified bacterial species were found to be pathogenic, antibiotic-resistant, and biofilm-forming, respectively, while 58% were classified as opportunistic pathogens. These results underscore the need for improved water treatment practices and more robust monitoring systems to ensure the population can access safe drinking water.

Pipeline water supply, a primary source in urban areas, delivers treated water from water treatment plants (WTPs) directly to consumers. This study comprehensively evaluates water quality in Kushtia Municipality, Bangladesh, focusing on untreated water, treated water, and freely available public water point (PWP) samples. Twelve water samples were collected from March 1 to 7, 2024, and analyzed for physicochemical and microbiological parameters using standard methods. The treatment efficiency, water quality index (WQI), Nemerow pollution index (NPI), and hazard quotient were calculated based on the analytical measurements. Findings indicate that, among the 12 assessed parameters, only three comply with Bangladesh’s water quality standards. The mean cumulative efficiency shows that WTP 2 exhibits the highest treatment efficiency (30.76%), whereas WTP 1 has the lowest (12.34%). While WQI scores classify all treated and PWP samples as “unfit” for consumption, treated water demonstrates comparatively better quality than PWPs. The NPI analysis identifies the primary contributing pollutants in the following order: Biochemical oxygen demand>hardness>alkalinity>iron>temperature>electrical conductivity. The health risk assessment reveals no significant risk of iron ingestion or dermal exposure for adults and children. However, long-term ingestion of arsenic-contaminated water presents a moderate health risk for both groups, while dermal contact poses no risk.

Internal migration is a process of relocation within a country by a person primarily to find a better prospect, education, or in response to natural calamities. Researching internal migration must be given attention to comprehend demographic movements and how they affect places where migration takes place and where it is received. This study sheds light on the very complicated relationship between internal migration and environmental effects. This paper lays out the systematic literature reviews by descriptively analyzing the causes of internal migration: economic opportunity, social bonds, and the environment. This paper explores the effect of internal migration on the environment, including the positive aspects (e.g. knowledge transfer, investment in green technology) and the negative ones (urban sprawl, increased consumption). The study of footprints and fingerprints and their effects on environmentalism is complex and at the same time contradictory. This study also focuses on policy responses and mitigation options, stating that there is a need for a holistic strategy that will meet the special demands of internal migrants and help them to be integrated into society. It will also promote sustainable development. The study makes valuable recommendations for drawing up sustainable development strategies that consider the link between internal migration and environmental well-being.

Salinity intrusion is one of the major problems in coastal regions in Bangladesh which affects crop production and livelihood. This study examines the impact of salinity intrusion from the Pasur River on soil quality and agricultural productivity in the coastal region of Bangladesh. For this study, both water and soil collections and field surveys were carried out in seven unions that are directly impacted by the river in Dacope and Mongla Upazilas. Physicochemical analyses of water and soil samples revealed significant variations in salinity levels, with higher concentrations observed in southern regions’ spatial distribution. A strong positive relationship between water and soil salinity indicates a direct influence of river salinity on soil quality from the Pearson correlation analysis. Survey data from 240 respondents, predominantly farmers, corroborated these results, with widespread recognition of salinity’s detrimental effects on crop yields, especially rice. So, smaller farms focus on vegetables, medium on rice, and larger ones on high-value crops like watermelon. Mitigation strategies such as freshwater irrigation, drainage systems, and salt-tolerant crop cultivation were identified as potential remedies. Additionally, experts suggested implementing sluice gates to control saltwater intrusion from tributary rivers like Chila Khal. These results emphasize the immediate requirement for proactive actions to reduce the negative effects of salt-induced soil degradation and ensure sustainable agricultural practices in the vulnerable region.

Water and vegetation are the two most important land cover features of any natural setting. The Jhenaidah District of Bangladesh is known for its remarkable physical geography, featuring diversified vegetation cover and numerous oxbow lakes. Due to several anthropogenic causes, this majestic land cover is degrading rapidly. This study examines the study area's spatiotemporal water and vegetation cover change from 1990 to 2020. Freeware Satellite imageries from the USGS data archive were used as the main secondary data source, ensuring consistency by collecting dry season images. In addition, open discussions with the residents provided valuable insights into the situation. Remote sensing (RS) based Soil Adjusted Vegetation Index (SAVI) was used to detect the water and vegetation cover from the preprocessed satellite imageries. Furthermore, the water and vegetation cover were classified based on a scheme developed by field observation and discussion with the residents. The analysis reveals an overall 84.47% decline in dense vegetation, 63.01% decline in deep water cover, 185.69% increase in shallow water cover, and 16.08% increase in agricultural lands within the mentioned time frame. Almost all the upazila of Jhenauidah district experience the criticality of the land cover change. Among the upazila, Shailkupa faced an unprecedented decline in deep water (95.29%), and Kaliganj faced a heavy decrease in forested vegetation (92.40%). In contrast, shallow water expanded significantly in Sadar Upazila (251.37%), and agricultural land experienced the most increasing trend (32.70%) in Shailakupa Upazila. JEL Classification Codes: C21, Q24, Q25.