Urban expansion, driven by rapid population growth, has increasingly encroached upon agricultural land and contributed to the degradation of ecological systems. In this study, the spatiotemporal dynamics of urban growth in Narayanganj District, Bangladesh, were assessed over a 20-year period (2003–2023) using integrated Geographic Information System (GIS) and remote sensing techniques. Land Use and Land Cover (LULC) changes were quantified, and their ecological consequences were evaluated through vegetation indices including the Normalized Difference Vegetation Index (NDVI) and the Soil-Adjusted Vegetation Index (SAVI), alongside the Normalized Difference Built-up Index (NDBI). An LULC classification revealed a net increase of 5.61% in built-up areas, accompanied by reductions of 7.61% and 1.61% in barren land and agricultural land, respectively. The spatial pattern of urban expansion was found to be uneven, with pronounced growth observed from the northern to north-northwestern sectors of the district. A two-phase conversion analysis indicated that 15.68% of agricultural land was transformed into urban areas between 2003 and 2013, followed by a slightly lower conversion rate of 14.74% from 2013 to 2023. Notably, a statistically significant inverse correlation was detected between NDBI and both NDVI and SAVI, suggesting a measurable decline in vegetation health associated with urban intensification. These findings provide empirical and geographically grounded evidence of the adverse ecological impacts of urbanization in a peri-urban context. The integration of multi-temporal satellite images with vegetation and built-up indices enabled a comprehensive evaluation of land transformation processes and their environmental implications. The insights gained from this research may inform sustainable land use planning, urban policy formulation, and conservation strategies aimed at mitigating the loss of agricultural land and safeguarding vegetation health in rapidly urbanizing regions.

The spatiotemporal dynamics of urban expansion and its impact on forest fragmentation within Dhaka City Corporation (DCC), a rapidly urbanizing megacity in South Asia, were critically investigated in this study. While prior research has predominantly focused on broad land-use changes and general vegetation loss, detailed analysis of forest fragmentation and its direct correlation with urban expansion intensity remains limited. This gap was addressed by integrating high-resolution Landsat satellite imagery from 2016, 2020, and 2024 with advanced landscape metrics and urban expansion indices, enabling a comprehensive and replicable assessment of urban-driven ecological disruption. Land use and land cover (LULC) classifications were generated through supervised classification in Google Earth Engine. Urban growth was quantified using the Urban Expansion Intensity Index (UEII) and the Annual Urban Expansion Rate (AUER), while forest fragmentation was evaluated via patch density, edge density, and a comprehensive fragmentation index derived from FRAGSTATS. Results indicated a marked intensification of urban expansion, with the urban area increasing from 133 km² in 2016 to 139 km² in 2024. This growth was accompanied by a rise in UEII from 0.67% to 1.35% and in AUER from 0.37% to 0.73%. Concurrently, forest ecosystems experienced significant fragmentation, as evidenced by an increase in the fragmentation index from 33 to 80 and edge density from 4 to 9 per km², indicating a progressive decline in forest continuity and heightened ecological vulnerability. Pearson correlation analysis revealed strong positive relationships between urban expansion and both edge density (r = 0.953) and the fragmentation index (r = 0.922), confirming the direct influence of urban sprawl on forest disintegration. These findings underscore the urgent need for ecologically informed urban planning. By providing a replicable methodological framework for quantifying urbanization-driven ecological disruption, this study contributes to the broader discourse on sustainable urban development and forest conservation in rapidly transforming urban landscapes.

Groundwater in the Sudda Vagu basin, located in the Bhainsa region of Nirmal District, Telangana, serves as a critical source of water for both drinking and irrigation. To evaluate its quality and suitability, 25 groundwater samples were systematically collected during the pre-monsoon (May 2022) and post-monsoon (November 2022) periods and analyzed for major cations and anions. The concentrations of sodium (Na⁺), potassium (K⁺), carbonate (CO₃²⁻), bicarbonate (HCO₃⁻), and sulfate (SO₄²⁻) were found to remain within the permissible limits recommended by the Bureau of Indian Standards (BIS), whereas elevated levels of calcium (Ca²⁺), magnesium (Mg²⁺), chloride (Cl⁻), nitrate (NO₃⁻), and fluoride (F⁻) were detected in several samples, exceeding the prescribed thresholds. The pH of the groundwater ranged from 6.5 to 8.5, indicating alkaline conditions, and was deemed generally acceptable for drinking based on BIS guidelines. Hydrochemical facies classification using the Piper trilinear diagram revealed the predominance of Ca²⁺-HCO₃⁻, Na⁺-Cl⁻, and mixed water types. Irrigation suitability was further assessed through indicators including the Sodium Adsorption Ratio (SAR), Kelly Ratio (KR), and Residual Sodium Carbonate (RSC), along with the Wilcox diagram. Pre-monsoon evaluation indicated that 12 samples were categorized under the S1C2 class (low sodium hazard–medium salinity hazard), while 13 samples were assigned to the S1C3 class (low sodium hazard–high salinity hazard). Post-monsoon analysis revealed that four samples remained in S1C2, whereas 21 shifted into S1C3. The findings indicate that the majority of samples are suitable for drinking and irrigation. Continuous monitoring and the implementation of sustainable groundwater management strategies are therefore essential to ensure water security in this region.